In a big emergency they might land there (edit -- probably only considered for low-inclination flights, which are now concluded), but the execute packages for 125 noted that Banjul was "politically not recommended."Banjul, also no longer used, is Yundum International Airport. NASA built a dedicated building at each of those locations.
STS-125 was told "negative Moron, select Banjul." Wouldn't that imply it's still used?
Is Groom Lake a possible landing location of the Space Shuttle?
What are the tanks I've circled? Nitrogen or Helium? I assume they are gaseous tanks? What function do the contents serve? Thanks.
I have some questions about some aspects of the Space Shuttle's ascent procedures:
1. When had the OMS assist burn during ascent (on Direct Insertion) been introduced for the first time?
2. Which missions used the OMS assist burn during ascent? Is there a list available somewhere?
3. To me, it seems like all ISS missions used it, is that correct? What about other missions (e.g. Mir missions and others)? On the Ascent checklists that are available on the web, I noticed that the Hubble missions did not have an OMS assist burn, as well as STS-400.
4. What are the reasons that determine, if an OMS assist is needed during ascent? Is it only the ET reentry footprint on certain inclinations? Does it also depend on the total weight of the orbiter (incl. payload)? Other factors?
5. When had the Roll to Heads Up been introduced for the first time?
6. Which missions had performed the Roll to Heads Up? Is there a list available?
7. I have read that the reason for the introduction of Roll to Heads Up was, to establish the comm link with a TDRS satellite during ascent, which in turn made a tracking station on the Bermudas obsolete. So, I assume that after a certain point in the history of the Shuttle program all missions performed the Roll to Heads Up. Is this correct?
I have some questions about some aspects of the Space Shuttle's ascent procedures:
1. When had the OMS assist burn during ascent (on Direct Insertion) been introduced for the first time?
2. Which missions used the OMS assist burn during ascent? Is there a list available somewhere?
3. To me, it seems like all ISS missions used it, is that correct? What about other missions (e.g. Mir missions and others)? On the Ascent checklists that are available on the web, I noticed that the Hubble missions did not have an OMS assist burn, as well as STS-400.
4. What are the reasons that determine, if an OMS assist is needed during ascent? Is it only the ET reentry footprint on certain inclinations? Does it also depend on the total weight of the orbiter (incl. payload)? Other factors?
5. When had the Roll to Heads Up been introduced for the first time?
6. Which missions had performed the Roll to Heads Up? Is there a list available?
7. I have read that the reason for the introduction of Roll to Heads Up was, to establish the comm link with a TDRS satellite during ascent, which in turn made a tracking station on the Bermudas obsolete. So, I assume that after a certain point in the history of the Shuttle program all missions performed the Roll to Heads Up. Is this correct?
ok i dont understand. by "range" im assuming NASA means the entire sky right? maybe a certain radius of it anyway? since the sky is all open and just "there" I dont get what this conflict is about? so what if numerous ships have a launch schedule close together, launch one, say at 10am, then launch another at 1030am---so what? why does the range only allow a certain vessel at a time to only launch at a certain period? the sky is the sky. Once something launches and clears, why cant another go right after it? even a day later, why is it still closed off?
ok i dont understand. by "range" im assuming NASA means the entire sky right?
OMS Assist capability was implemented with the OI-26 software, I will have to check which flight did it first. From a quick search it looks like it was STS-90 but I seem to remember being in the simulator with John Young (yes name dropping) the night before STS-92 because of cg concerns he had with the OMS assist and subsequent aborts - I thought that was the first flight but I will have to double check I just don't remember but wiki is saying STS-90. STS-90 might have tested the concept prior to an actual heavy station mission.
Mark Kirkman
P.S.
Yep, I checked my notes and it was indeed a test objective on STS-90 which was the neurolab flight and not a station mission.
Do the tanks HAVE to be full on launch?
Secondly, watch this video, if you would be so kind :)
http://www.youtube.com/watch?v=_vLl3K8yzOk
While "boundary" is self explanatory as an abort boundary, can anyone tell me what the crew mean when they mention "window"
Posting from Part 4:
While "boundary" is self explanatory as an abort boundary, can anyone tell me what the crew mean when they mention "window"
ok i dont understand. by "range" im assuming NASA means the entire sky right? maybe a certain radius of it anyway? since the sky is all open and just "there" I dont get what this conflict is about? so what if numerous ships have a launch schedule close together, launch one, say at 10am, then launch another at 1030am---so what? why does the range only allow a certain vessel at a time to only launch at a certain period? the sky is the sky. Once something launches and clears, why cant another go right after it? even a day later, why is it still closed off?
Could be because that gain would be smaller than increased gravity losses of a heavier orbiter earlier in the ascent.
Hi folks:
I am using a Quote from Jorge near the bottom of page one.
"OMS assist is performed if 1) the OMS prop required for the mission itself does not require full tanks and 2) the mission could benefit from the additional payload capacity gained by filling the OMS tanks full and burning the difference as OMS assist (IIRC it's roughly 200 lb payload for 4000 lb OMS prop). CG location is a secondary consideration on the amount"
I thought OMS assist was used if payload was -TOO heavy-
I still don't really understand why they don't just not fill the amount of OMS that they'd burn off on the ascent anyway.
Am I missing something?
I guess what I'm wondering is what gives the greater benefit, loading those OMS tanks with fuel and then burning them, or not filling the amount that would be burned.
I assume from your answer that it's the former.
Sorry if I steped on Jorge's answers earlier but they weren't visible when I typed mine.
As for RTHU, after STS-87 I think ALL flights performed the roll because it was implemented based on the performance enhancement certifications. Flight Procedures Handbook states it is REQUIRED for low inclination flights for that reason alone. FPH also states that roll costs about 35 lbs in performance.
I have the STS-97 checklist Jorge referred to in my files so I can look that up to confirm.
Mark Kirkman
The Program Office has recently approved a change in design to remove the Roll-to-Heads-Up from the ascent profile as a performance enhancement of ~50 to 100 lbs. The Flight Design community deems this change as undesirable to STS-97 because it requires a change to ascent design procedures and internal software verification tools before implementation. The time required to incorporate these changes may not be adequate to ensure all procedures and off-line software tools are implemented properly. However, ADFD management felt that the risk to implement the No RTHU on this flight was acceptable when weighted against the very low APM and future APM threats. The ADFD flight team will work to mitigate any risks due to this change by aggressively communicating details through the design community and carefully implementing any changes associated with a No RTHU maneuver. As a result, the SSP directed Flight Design not to perform the Roll-To-Heads-Up maneuver for STS-97 Flight Cycle in order to realize the APM gain. The STS-97 CDR asked if the Engineering Cycle load could be updated to include this change in training. This is being investigated and will be updated is possible.
So at one point no-RTHU was the baseline for STS-97. If STS-97 did fly RTHU, it must have been restored after the FLT cycle.FWIW, it's hardly definitive, but I don't hear any mention of a roll to heads up in the public broadcast of STS-97. On STS-98, Ken Cockrell added "and we're rollin'" when acknowledging the 'Press to MECO' call...
I guess what I'm wondering is what gives the greater benefit, loading those OMS tanks with fuel and then burning them, or not filling the amount that would be burned.
I assume from your answer that it's the former.
That is correct, and that is why OMS assist is done.
IIRC, the OMS tanks have to be filled completely (or as close to full as possible) because there is no sensor gage to tell you how much prop is in them. They have to fill OMS tanks completely to know with a high degree of certainty how much prop is in them at launch. Then, you burn what you don't need for the miss during ascent -- OMS assists -- and use calculations once on orbit to approximate how much OMS prop is left in the tanks after each firing of the OMS engines.The OMS/RCS load may work this way, too, but you may be thinking of Steve Payne answering a question during a recent countdown briefing about PRSD offload and why it takes an extra shift or half-shift to do that. (His answer sounds similar to what you're describing.)
Am I remember incorrectly?
IIRC, the OMS tanks have to be filled completely (or as close to full as possible) because there is no sensor gage to tell you how much prop is in them. They have to fill OMS tanks completely to know with a high degree of certainty how much prop is in them at launch. Then, you burn what you don't need for the miss during ascent -- OMS assists -- and use calculations once on orbit to approximate how much OMS prop is left in the tanks after each firing of the OMS engines.
Am I remember incorrectly?
With regard to OMS assist, I thought I read some where that the OMS engine could only work in the vaccum(spel) of space, or am I getting RCS thusters and OMS engine mixed up?
I guess what I'm wondering is what gives the greater benefit, loading those OMS tanks with fuel and then burning them, or not filling the amount that would be burned.
I assume from your answer that it's the former.
That is correct, and that is why OMS assist is done.
IIRC, the OMS tanks have to be filled completely (or as close to full as possible) because there is no sensor gage to tell you how much prop is in them. They have to fill OMS tanks completely to know with a high degree of certainty how much prop is in them at launch. Then, you burn what you don't need for the miss during ascent -- OMS assists -- and use calculations once on orbit to approximate how much OMS prop is left in the tanks after each firing of the OMS engines.
Am I remember incorrectly?
They're all helium, no? The Air Liquide GN2 line is kept at 6-7 ksi. No real need for a plenum.
It's been a while since I was out there, but my foggy memory is that the tanks contain, not just helium, but also nitrogen and breathing air (for SCAPE operations and possibly crew cabin supply). But I could be wrong (happened once or twice before)......
Banjul, also no longer used, is Yundum International Airport. NASA built a dedicated building at each of those locations.
STS-125 was told "negative Moron, select Banjul." Wouldn't that imply it's still used?
Can the shuttle launch in rain (not thunderstorms)?No. Flight through precip is a violation of weather rules. (In fact, they won't even ferry an orbiter through rain if they can avoid it.)
Can the shuttle launch in rain (not thunderstorms)? And does it go through mach 5 before 60,000 ft or above it?
Can the shuttle launch in rain (not thunderstorms)? And does it go through mach 5 before 60,000 ft or above it?
Can the shuttle launch in rain (not thunderstorms)? And does it go through mach 5 before 60,000 ft or above it?
rain on tiles is like water on sugar cubes
I wasn't sure about rain during launch, due to the weatherproofing on the tiles. Thanks gentlemen.
Hi folks:
I am sitting sitting here in Vancouver, Canada watching launch prep for STS-127 -hope she goes- and some questions came to mind.
1) How do they chill the lines for tanking (I didn't think you could put anything in the lines prior to tanking as they go to the LH2, LOX tanks)?
2) Why does the GUPC vent line come off at ignition and not when the "beanie cap" comes off as I assume both tanks need to be repressurized?
3) What is the difference between fast fill and slow fill?
4) Why are the LH2 tank and LOX tank filled at different times?
I kept reading about the shuttle not flying till the leak was found, and after a "Thermal Blackout Period" What is this blackout period ?
Thanks
Duane
I kept reading about the shuttle not flying till the leak was found, and after a "Thermal Blackout Period" What is this blackout period ?
Thanks
Duane
Thanks Jim for the info. I'll go dig there also. Actually did a little digging and found the video clip of the news conf where "beta cutoff" was used. Did some digging, and found it explained on alternate news sites. Just not the lousy mainstream media for the masses sites.I kept reading about the shuttle not flying till the leak was found, and after a "Thermal Blackout Period" What is this blackout period ?
Thanks
Duane
Seach shuttle Q&A thread 4, it has been answered multiple times
It's called the "beta angle cutout" and here is a link that provides some good information. Google is your friend.
http://sci.tech-archive.net/Archive/sci.space.shuttle/2006-08/msg00226.html
OMS Assist capability was implemented with the OI-26 software, I will have to check which flight did it first. From a quick search it looks like it was STS-90 but I seem to remember being in the simulator with John Young (yes name dropping) the night before STS-92 because of cg concerns he had with the OMS assist and subsequent aborts - I thought that was the first flight but I will have to double check I just don't remember but wiki is saying STS-90. STS-90 might have tested the concept prior to an actual heavy station mission.
Mark Kirkman
P.S.
Yep, I checked my notes and it was indeed a test objective on STS-90 which was the neurolab flight and not a station mission.
What is the mechanical component that allows the shuttle, ET and SRB's to complete the "roll over" technique during launch. I would assume that it is the elevon/ailerons or tail of the orbiter.
I have researched this question (curious myself):Going through some old threads and wanted to add some additional trivia.
#1 STS-1 (102) days on Pad
#2 STS-122 (89) days on Pad (Eco Sensor issue)
#3 STS-127 (85) days (if launched on 7/11)
Note: STS-35 had (109) "non-continuous" days split between Pad-A/B but briefly rolled back to VAB (hydrogen leaks).
It's called the "beta angle cutout" and here is a link that provides some good information. Google is your friend.
http://sci.tech-archive.net/Archive/sci.space.shuttle/2006-08/msg00226.html
Among Space Shuttle flight controllers, beta angle cutouts are also known as "a good time to schedule a vacation." Otherwise, as Murphy dictates, the next launch will invariably slip into the long awaited trip for which you purchased non-refundable tickets! ;)
It's called the "beta angle cutout" and here is a link that provides some good information. Google is your friend.
http://sci.tech-archive.net/Archive/sci.space.shuttle/2006-08/msg00226.html
Among Space Shuttle flight controllers, beta angle cutouts are also known as "a good time to schedule a vacation." Otherwise, as Murphy dictates, the next launch will invariably slip into the long awaited trip for which you purchased non-refundable tickets! ;)
Hey... that's me for any launch in July!!!!!!! Non-refundable tickets... vacation... and now a potential Shuttle launch!
Hi guys, a question about DPS :
The DPS seems to allow switching between some of the major modes (OPS 201 and 202 for example), but apparently it seems impossible to revert back from some modes to the previous one. For example it seems impossible (if you have a look at the DPS dictionnary for instance) to revert back to OPS 303 once OPS 304 was entered.
So three questions in one :
1) is it possible to go back from OPS 304 to OPS 303 for example (and all the other similar configurations) ?
2) if yes how ?
3) if no : how would they do if someone entered OPS 304 too early by mistake ?
Thanks in advance
Nephi
Hi guys, a question about DPS :
The DPS seems to allow switching between some of the major modes (OPS 201 and 202 for example), but apparently it seems impossible to revert back from some modes to the previous one. For example it seems impossible (if you have a look at the DPS dictionnary for instance) to revert back to OPS 303 once OPS 304 was entered.
So three questions in one :
1) is it possible to go back from OPS 304 to OPS 303 for example (and all the other similar configurations) ?
2) if yes how ?
3) if no : how would they do if someone entered OPS 304 too early by mistake ?
Thanks in advance
Nephi
Yes, some OPS are a oneway street. I have been out the training business for a while, so don't trust what I say 100%.
On going to 304 by mistake, I am assuming you haven't done the deorbit burn yet. I think you could somehow take your time and if nothing else go back to OPS 2. BFS engage could be an option if it didn't also go over. I don't remember if BFS does what is called a DK listen to the command to PASS to go the 304, or if the crew has to take if over separately.
Please forgive me if this is all lies. Even in my prime, I wasn't a DPS instructor. But I used to know this stuff pretty good as a control/prop instructor.
I do know going in and out of the OPS 2 mode to do an orbit burn is two way. I can't remember the number of the modes. I think it is 201 and 202.
Danny Deger
Where did you get a DPS dictionary. Make sure it is on L2. I bet Chris would trade you some L2 time for a DPS dictionary if he doesn't already have on.
Where did you get a DPS dictionary. Make sure it is on L2. I bet Chris would trade you some L2 time for a DPS dictionary if he doesn't already have on.
As for OPS 201 <-> OPS 202 this is indeed two-way. 201 is for burns, 202 is for payload bay doors.
In PASS, GNC OPS 2 and SM OPS 2 are different memory configs (i.e. they can't run on the same GPC at the same time). Typically during orbit ops GPCs 1, 2, and 3 are loaded with PASS GNC OPS 2 and GPC 4 is loaded with PASS SM OPS 2. GPC 5 is loaded with BFS, but the BFS does not have OPS 2, of course...
As for OPS 201 <-> OPS 202 this is indeed two-way. 201 is for burns, 202 is for payload bay doors.
Not quite. You're describing two different major functions. Burns fall under the GNC major function (and it's 202, not 201), and PL bay doors fall under the SM major function.
GNC OPS 201 - orbit coast
GNC OPS 202 - orbit burns
SM OPS 201 - normal orbit ops
SM OPS 202 - PL bay doors
You can transition both ways (201<->202) *within* a major function, but not *across* major functions.
In PASS, GNC OPS 2 and SM OPS 2 are different memory configs (i.e. they can't run on the same GPC at the same time). Typically during orbit ops GPCs 1, 2, and 3 are loaded with PASS GNC OPS 2 and GPC 4 is loaded with PASS SM OPS 2. GPC 5 is loaded with BFS, but the BFS does not have OPS 2, of course...
snip
That's a horrendously bad schoolboy error on my part, thanks for making me look stupid :)
The annoying thing is that I pride myself on getting stuff like that right, and I've played a lot of SSM2007 lately :p
Maybe that's a good idea for a thread. Most embarrassing moment in training. Or just a general "funny things that happened to me in the spaceflight business" thread.
snip
@Danny : if you are in OPS 303 and get to 304 it means that on the contrary, the deorbit burn has indeed been done (OPS 302 normally). So I'm not sure if you could get back to OPS 2 anyhow ?!
The problem is that there seems to be only a one way arrow from 303 to 304 on the DPS dictionnary OPS synthesis.
The problem is that OPS 303 is used to dump a few things (among other activities) and that you cannot do it from OPS 304 (entry traj). So if you went to 304 before dumping the right stuff, how do you get back to doing it before entry interface ? Hence my question about going back from 304 to 303 :) I believe that there should be a procedure somewhere.
snip
Danny, I definately see your point about time. That was my point, really. You COULD do it by manually loading it in, but there wouldn't be enough time to do it.
And I'm pretty sure Nephi's not trying to use the Dictionary as a training manual. It already is a headbender as it is! :)
Also, re your last paragraph. Shame I'm in the UK... maybe some other nice soul wants to ring up and find us a new document for L2...
PS, we're playing Space Shuttle Mission 2007 but it's by no means a complete copy of the STS system. The DPS is very cut down in places.
Essentially, the situation (to simplify your words) is this:
If there's a one way arrow between modes, you cant go backwards because the system won't let you (ILLEGAL ENTRY?), so by my reckoning the only way would be to manually load into memory the program you want. Which, I understand, is time consuming.
As for your point about not being able to go back to OPS 2 because the deorbit burn was already done, I'm sure it could be done manually, there'd just be little use for OPS 2 at that point.
Can someone help me out here, I'm wondering how badly I'm understanding this. DPS is a little sketchy for me so this is a learning curve.
I get the sense that neglecting a necessary dump before deorbit burn would be considered a contingency situation, and the solution may be manual intervention rather than jumping backwards in software routines.
I don't know specifically what kinds of dumps are in question. I know that the potable water system can be dumped through the flash evaporator system down to 100,000 ft altitude during reentry by switching the freon loop radiator out temp to hi.
Other fluids might also be dumped in a contingency situation by manually operating valves via switch and breaker panels. This might be more practical in a time-critical emergency than changing OPS modes.
Here are a couple of the astronaut training workbooks for the space shuttle's data processing system (DPS) - I don't have the more recent versions in an electronic format, however, for all practical purposes these are still valid - at least for the purposes of this most recent discussion.
These were current when I was there and since they have been circulated on the internet in the past I have no problem posting them in this public thread.
Mark Kirkman
According to the crew interface workbook, the PASS can only drive three CRTs. If the BFS is taken offline during on-orbit operations then what does the fourth CRT display? Just a cross as it has been deassigned? Or powered off?
Question re: STS-91. According to the mission press kit, the SPACEHAB carried "Cosmonaut Return Packages" up to Mir. Does anyone know what these packages specifically contained? Thanks!
Standard ops is for CRT3 to be powered down on orbit. Some CDRs like to deassign CRT4 and bring up CRT3 for OMS burns.
Standard ops is for CRT3 to be powered down on orbit. Some CDRs like to deassign CRT4 and bring up CRT3 for OMS burns.
Displaying what? Pages for monitoring the OMS/RCS/Whatever?
Here are a couple of the astronaut training workbooks for the space shuttle's data processing system (DPS) - I don't have the more recent versions in an electronic format, however, for all practical purposes these are still valid - at least for the purposes of this most recent discussion.
These were current when I was there and since they have been circulated on the internet in the past I have no problem posting them in this public thread.
Mark Kirkman
Thanks Mark,
Can you grab a scanned copy of the Entry Guidance Workbook? I know this crowd will like it. It is written in plain English with lots of humor.
Danny Deger
I don't have that in an electronic format but it is good workbook and I see no reason it can't be posted - so give me some time (about a week or so since I will be on the road) and I will scan it.
Hmmm, I wonder who wrote the version I have - it says some clown named Danny prepared it - doesn't ring a bell. ;)
Mark Kirkman
Question re: STS-91. According to the mission press kit, the SPACEHAB carried "Cosmonaut Return Packages" up to Mir. Does anyone know what these packages specifically contained? Thanks!
I would have packed them onboard the SPACEHAB module. I don't quite remember Return Packages.
We did fly "Cosmonaut Family Packages" and "Cosmonaut Psychological Support Packages.
All were sealed in semi opaque bags. The family packages is self describing and the other had "magazines" in it and liquid containers.
Edit: Now I remember, Return packages weren't launched on board, they came back on the flight and were like the shuttle official flight kit/crew personal preference kit (trinkets/memorabilia).
snip
I don't have that in an electronic format but it is good workbook and I see no reason it can't be posted - so give me some time (about a week or so since I will be on the road) and I will scan it.
Hmmm, I wonder who wrote the version I have - it says some clown named Danny prepared it - doesn't ring a bell. ;)
Mark Kirkman
snip
I don't have that in an electronic format but it is good workbook and I see no reason it can't be posted - so give me some time (about a week or so since I will be on the road) and I will scan it.
Hmmm, I wonder who wrote the version I have - it says some clown named Danny prepared it - doesn't ring a bell. ;)
Mark Kirkman
Don't give me any flak on that book. The astronauts gave me a Silver Snoopy for it. I think they were trying to send a signal that they would like the other books to not be good cures for insomnia when read for more than 10 minutes :-\
I had to get my branch chief to call the editors to let my "inappropriate" writing style into the book.
Danny Deger
Because the vehicle has to pass by you to hear the boom. When the shuttle was going to launch from VAFB, it would have passed over the Channel Islands and a boom would have heard. Since the islands were the home of many pinnipeds (seals), there was concern that during the breeding season, a boom would have made the mothers rush for the water causing the pups to be crushed.
Because the vehicle has to pass by you to hear the boom. When the shuttle was going to launch from VAFB, it would have passed over the Channel Islands and a boom would have heard. Since the islands were the home of many pinnipeds (seals), there was concern that during the breeding season, a boom would have made the mothers rush for the water causing the pups to be crushed.
Did they have the same concerns about thunderstorms?
I believe they are rare out there, also most thunderstorm build up and not have an "out of the blue" boom
During NASA TV broadcasts of shuttle launches there is a periodic hissing sound that can be heard before liftoff. These sounds seem to pulse in a regular rhythmic pattern. Can someone explain what the cause of these sounds are?
Because the vehicle has to pass by you to hear the boom. When the shuttle was going to launch from VAFB, it would have passed over the Channel Islands and a boom would have heard. Since the islands were the home of many pinnipeds (seals), there was concern that during the breeding season, a boom would have made the mothers rush for the water causing the pups to be crushed.
Did they have the same concerns about thunderstorms?
I believe they are rare out there, also most thunderstorm build up and not have an "out of the blue" boom
Essentially, the situation (to simplify your words) is this:
If there's a one way arrow between modes, you cant go backwards because the system won't let you (ILLEGAL ENTRY?), so by my reckoning the only way would be to manually load into memory the program you want. Which, I understand, is time consuming.
As for your point about not being able to go back to OPS 2 because the deorbit burn was already done, I'm sure it could be done manually, there'd just be little use for OPS 2 at that point.
Can someone help me out here, I'm wondering how badly I'm understanding this. DPS is a little sketchy for me so this is a learning curve.
You can get just about anywhere from OPS 0, but OPS 000 PRO is not a legal transition from 304.
However, you can force a GPC to OPS 0 by taking the GPC MODE switch to STBY and back to RUN.
So... you take GPCs 1-4 to STBY, then back to RUN, one at a time. Once you have done this, you will have a GPC common set in OPS 0. The vehicle will not be controllable at this point! Check memory config 3 (ITEM 1+3), should be fine since you used it earlier to transition to OPS 3 the first time around, then invoke the NBAT with OPS 301 PRO. Now the vehicle is under control again.
May need to clean up the BFS afterward. I never certified DPS so not my specialty.
During NASA TV broadcasts of shuttle launches there is a periodic hissing sound that can be heard before liftoff. These sounds seem to pulse in a regular rhythmic pattern. Can someone explain what the cause of these sounds are?
Because the vehicle has to pass by you to hear the boom. When the shuttle was going to launch from VAFB, it would have passed over the Channel Islands and a boom would have heard. Since the islands were the home of many pinnipeds (seals), there was concern that during the breeding season, a boom would have made the mothers rush for the water causing the pups to be crushed.
1. Have there been issues in the past with power reactant loading?
2. Does the orbiter have a dedicated GH2 vent umbilical for PRSD?
3. Is the same pad storage/pumping infrastructure used for ET and PRSD?
4. Why does power reactant loading take place 48 hours before launch?
5. Are there separate teams of "pad rats" for ET and PRSD cryo ops?
You can get just about anywhere from OPS 0, but OPS 000 PRO is not a legal transition from 304.
However, you can force a GPC to OPS 0 by taking the GPC MODE switch to STBY and back to RUN.
So... you take GPCs 1-4 to STBY, then back to RUN, one at a time. Once you have done this, you will have a GPC common set in OPS 0. The vehicle will not be controllable at this point! Check memory config 3 (ITEM 1+3), should be fine since you used it earlier to transition to OPS 3 the first time around, then invoke the NBAT with OPS 301 PRO. Now the vehicle is under control again.
May need to clean up the BFS afterward. I never certified DPS so not my specialty.
Tried this in the NGSMS this morning... worked. In the middle, I did get paranoid about losing PASS CRT interface and worked around it by taking the CRT1 major function switch to PL, then using one of the remaining PASS GPCs to hard-assign GPC1 to CRT1. (Then of course I had to remember to take CRT1 back to GNC before doing the OPS 301 PRO). As expected, the BFS went standalone when the PASS set went away. Probably broke every one of the "good DPS habits" in the process, but I did get back to 301.
7:47:20 PM...T+07:47...LAST 1E PRE-MECO TAL ZARAGOZA ([email protected]%)......15,342
7:47:25 PM...T+07:52...23K...........................................15,683
7:47:25 PM...T+07:52...LAST 3E PRE-MECO TAL ZARAGOZA (67%)...........15,683
On Bill Harwood's ascent timeline, what does the 23K line mean?Quote7:47:20 PM...T+07:47...LAST 1E PRE-MECO TAL ZARAGOZA ([email protected]%)......15,342
7:47:25 PM...T+07:52...23K...........................................15,683
7:47:25 PM...T+07:52...LAST 3E PRE-MECO TAL ZARAGOZA (67%)...........15,683
You can get just about anywhere from OPS 0, but OPS 000 PRO is not a legal transition from 304.
However, you can force a GPC to OPS 0 by taking the GPC MODE switch to STBY and back to RUN.
So... you take GPCs 1-4 to STBY, then back to RUN, one at a time. Once you have done this, you will have a GPC common set in OPS 0. The vehicle will not be controllable at this point! Check memory config 3 (ITEM 1+3), should be fine since you used it earlier to transition to OPS 3 the first time around, then invoke the NBAT with OPS 301 PRO. Now the vehicle is under control again.
May need to clean up the BFS afterward. I never certified DPS so not my specialty.
Tried this in the NGSMS this morning... worked. In the middle, I did get paranoid about losing PASS CRT interface and worked around it by taking the CRT1 major function switch to PL, then using one of the remaining PASS GPCs to hard-assign GPC1 to CRT1. (Then of course I had to remember to take CRT1 back to GNC before doing the OPS 301 PRO). As expected, the BFS went standalone when the PASS set went away. Probably broke every one of the "good DPS habits" in the process, but I did get back to 301.
Thanks for trying this, I hope you didn't spend too much time off the back of someone's forum query.
Why would you lose the interface?
And what would taking the major function switch to PL do to resolve that? After reading the workbook I saw that taking the switch to PL keeps it in the current major function, but switches to SPEC 0 (I think?) - was that just so you could work on GPC MEMORY?
From what I've seen you guys say and from what I've seen in online documentation, the Shuttle flight software UI is very, very primitive. This is perfectly understandable given its age, but I was wondering: is it considered to be difficult to upgrade the flight software or is it just something you wouldn't want to do given the amount of work needed for validation and verification and given that it would mean throwing away the flight record?I think it's a matter of if it ain't broke... Reliability and the least amount of question marks has always been the priority in software used in human spaceflight. Besides, even if there was a will to upgrade already working software, probably wasn't much of a budget for it.
From what I've seen you guys say and from what I've seen in online documentation, the Shuttle flight software UI is very, very primitive. This is perfectly understandable given its age, but I was wondering: is it considered to be difficult to upgrade the flight software or is it just something you wouldn't want to do given the amount of work needed for validation and verification and given that it would mean throwing away the flight record?I think it's a matter of if it ain't broke... Reliability and the least amount of question marks has always been the priority in software used in human spaceflight. Besides, even if there was a will to upgrade already working software, probably wasn't much of a budget for it.
I believe for docking, the crew heavily relies on laptops. Do any of these actually interface directly with on board shuttle systems?
Or is the crew just acting as the end of the guidance loop and manually maneuvering the orbiter in response to what they see on the laptops?
I wonder what the software on Orion will look like. Will it be a purpose built language or an "off the shelf" commercial language? Significant parts of the Mars Rover use C++ IIRC.
From what I've seen you guys say and from what I've seen in online documentation, the Shuttle flight software UI is very, very primitive. This is perfectly understandable given its age, but I was wondering: is it considered to be difficult to upgrade the flight software or is it just something you wouldn't want to do given the amount of work needed for validation and verification and given that it would mean throwing away the flight record? Have you ever had the opportunity to look at the source code? What does it look like?
QuoteWhy would you lose the interface?
When you take a GPC driving a CRT to STBY, you get the Big X/Poll fail on that CRT and you can no longer type to it. After I'd done that to GPCs 1 and 2, I started getting paranoid about what would happen after I took GPCs 3 and 4 down.QuoteAnd what would taking the major function switch to PL do to resolve that? After reading the workbook I saw that taking the switch to PL keeps it in the current major function, but switches to SPEC 0 (I think?) - was that just so you could work on GPC MEMORY?
Because I vaguely recalled (again, not a DPS specialist) that PL is how you signal that you want to type to an OPS 0 GPC. That didn't get rid of the Big X/Poll fail, but the hard-assign did.
QuoteWhy would you lose the interface?
When you take a GPC driving a CRT to STBY, you get the Big X/Poll fail on that CRT and you can no longer type to it. After I'd done that to GPCs 1 and 2, I started getting paranoid about what would happen after I took GPCs 3 and 4 down.QuoteAnd what would taking the major function switch to PL do to resolve that? After reading the workbook I saw that taking the switch to PL keeps it in the current major function, but switches to SPEC 0 (I think?) - was that just so you could work on GPC MEMORY?
Because I vaguely recalled (again, not a DPS specialist) that PL is how you signal that you want to type to an OPS 0 GPC. That didn't get rid of the Big X/Poll fail, but the hard-assign did.
I presume you did this on CRT3 by switching one of the keypads over to it?
This may have been asked before, but how long can they leave the external tank full?
Hi folks,
Are there any photos of the OMBUU as I would like to know what it is, and what it does?
thanks
Carl
Thanks for the quick response Jim, but it seems to be in L2 which I am not a member of.
Thanks
Oxford750
I have a question: what are SRB water baggies? Chris mentioned them this morning, but google wasn't doing it for me. Sound suppression?
2) I was reading NASA Facts on launch Complex 39. pads A & B, and noticed that in one photo of "the stack" at the pad, you could see the flame trench, and I remembered once that someone told me, there is a metal inverted "v" in the trench that deflects flames from the SRB's one way, and flames from the SSME's the other. That is why the "steam" from the SSME's goes one way and the smoke from the SRB's goes the other way
My question is: why is that deflector there?
Hi folks,
Here to ask more questions.
1) Does anyone know how "dirty" the "white room" gets after a launch?
3) How are some valves recycled? ie: ET/GUCP valve. My understanding is either a valve is open or closed and if there is a leak around it, it won't change the situation till you tighten the valve physicaly(spel) and/or replace it.
Thanks
Oxford750
OK this one is off the wall, saw it on the NasaKSC Facebook.
Would VAFB launches to ISS been feasible?
OK this one is off the wall, saw it on the NasaKSC Facebook.
Would VAFB launches to ISS been feasible?
No,The shuttle can't get to 51.8 degrees from there
I somewhat understand that NASA has to calculate the launch time based on where the ISS is in orbit to determine launch time, but, why is this window so critical?
What sort of an impact would launching 30 or so minutes before a given launch time, such as STS-127's 7:13 time this past Sunday. If they could have launched 30 minutes earlier, the weather might have been a GO for launch.
Would the shuttle not have been able to catch up with the station properly if launched a few minutes before or after the given window?
Thanks.
When the White Room is disassembled, how much of a gap is it between the orbiter hatch opening and the white room floor? If the astronauts had to get out quickly, wouldn't that pose a safety risk in itself, considering the White room personnel have to be harnessed after disassembling the White Room?
When the White Room is disassembled, how much of a gap is it between the orbiter hatch opening and the white room floor? If the astronauts had to get out quickly, wouldn't that pose a safety risk in itself, considering the White room personnel have to be harnessed after disassembling the White Room?
I know there's an "egress pole" designed to guide escaping crew clear of the wing leading edge when bailing out in flight. I think it's deployed as a part of the pyrotechnic sequence that blows the hatch. I wonder if that also plays a role in helping the crew escape a pad emergency?
OK this one is off the wall, saw it on the NasaKSC Facebook.
Would VAFB launches to ISS been feasible?
No,The shuttle can't get to 51.8 degrees from there
The shuttle can't get there, but some LVs can access that orbit from VAFB.
Reguarding the tyvek covers, are they disposed of as the shuttle reaches orbit, or what happens to them during a launch?
Hi folks:First image: The GOX Vent Hood maintenance access platform.
What are the objects I have circled, in these pictures?
Reguarding the tyvek covers, are they disposed of as the shuttle reaches orbit, or what happens to them during a launch?
fall off or burn off.
Reguarding the tyvek covers, are they disposed of as the shuttle reaches orbit, or what happens to them during a launch?
fall off or burn off.
Thanks for the answer! As a follow up question, has there ever been a case where one of the covers did not come off???
Also what are they made out of, lightweight material of some type I'd imagine and how are they attatched?? (sorry for the boat load of questions)
How accurately is the Shuttle launch mass known and how is it determined?
What limits the accuracy of this figure? Maybe ice build up or... ?
I think I know where he might be coming from.
On a 24 hour turnaround, it seems like they get the tank drained and then fill it again just a few hours later. Why not keep the External Tank fueled and just keep it in stable replenish for the next attempt the next day?
How accurately is the Shuttle launch mass known and how is it determined?
What limits the accuracy of this figure? Maybe ice build up or... ?
The orbiter is weighed. Not all the other components are (like SRB's). But pieces parts are weighed. The amount of propellants in the ET is known. Knowing the weight of the whole stack within .1% (not saying that this is the accuracy) means that they could be off by 6000 lbs. Most of this is going to be in the SRB's so it doesn't affect payload to orbit by that much (around 12 to 1 ratio or so)
Analyst pointed me to STS-94, which launched with a 90% forecast going into tanking -- even with a 2 hour, 30 minute launch window; reference:Point taken -- especially in the summer time -- but can't think of a launch with a 90% WX violation forecast going into tanking. I believe they have tanked with that forecast and scrubbed. And they have launched with a 70% chance of violation going in (I believe STS-116 was the most recent example). Not sure about launches with a 80% chance of violation at tanking.Is there a certain percentage of "no-go" for weather where they do not even try to launch? Because Tuesday there was a 60% change no-go. With the open Tyvek cover in mind, wouldn't it have been wiser to immediatly put the launch to Wednesday and repair the tyvek cover on Tuesday? I'm a newbie, so just kick me if I'm wrong.
No percentage. Have you ever been to Florida? Weather changes often by the minute there. They have launched on 90% no-go days before.
Analyst
Is this black marking permanent or is the same SRB sometimes used as the left SRB and sometimes as the right SRB? Are they symmetrical or are they mirror images?
According to Google Earth which I've found to be surprisingly accurate in the past:
N end: 28°37'57.95"N 80°42'21.94"W
S end: 28°35'49.26"N 80°40'57.81"W
Here' s the audio stream link:
http://www.nasa.gov/178952main_Mission_Audio_UP.asx (http://www.nasa.gov/178952main_Mission_Audio_UP.asx)
Here's the media channel link:
http://www.nasa.gov/145590main_Digital_Media.asx (http://www.nasa.gov/145590main_Digital_Media.asx)
Here's the public channel link:
http://www.nasa.gov/qtl/151335main_NASA_TV_QT.qtl (http://www.nasa.gov/qtl/151335main_NASA_TV_QT.qtl)
Hopefully, one of these will work for you. The audio quality seems to be best on the media channel.
Does anyone know of a link for NASA TV or at least the audio that streams on an iPhone (I'm not even sure if the iPhone is capable of streaming media, but it's all I have today)?
If by chance you can give exacts for VAB / 39A / 39B it'd be appreciated.
Thanks much! The Rwy33 side was fine but the northwest end was angled too far to the north on the numbers I had.
If by chance you can give exacts for VAB / 39A / 39B it'd be appreciated.
- Rob
Did I see the left SSME twitch pretty hard during APU prestart/start?Saw that, too, but have seen it on other counts.
Second question, the huge clamps that clamp onto the wings, holding the craft in place on the pad...how do those not damage the wings? I assume a lot of force must be used to do the work needed.Those aren't clamps and they don't touch the wings. They are tail service masts and are only connected to the orbiter via a plate on each side of the aft fuselage, through which electrical and fluid connections are made (they are called T-0 umbilicals because they separate from the vehicle at liftoff). The vehicle is only held to the pad by the four bolts in each SRB aft skirt (for a total of eight).
These surely have been asked before, but...
A few seconds after liftoff, the shuttle rolls to a position where it is basically hanging underneath the external tanks, why?
Second question, the huge clamps that clamp onto the wings, holding the craft in place on the pad...how do those not damage the wings?
I calculate that space shuttle needs to break the sound barrier from lift of to sound barrier=10.7sec. Is this correct or does anyone have some other data about this. I really wanna know how much time does it take that space shuttle breaks the sound barrier.
Out of curiosity, I was reading a report on L2 about the fuel cell and was wondering what type of redundancies the orbiter has for a Fuel Cell loss. Would it have any impact on mission and if so what would that be? Thanks in advance.
Mike Moses with Candrea Thomas:
Water cycled through the fuel cell, then we can transfer for drinking water (which we do). If we don't drain the water, it'll build up, of course. Too much water would let the electrolyte compound into the fuel cell. It would end up drying out the fuel cell. Worst case would be the fuel cell getting way too hot, way too fast. We monitor the temps, the trend on the past few launch attempts have been that the temps are creeping up a bit. We can't monitor the KOH (electrolyte compound) on orbit, but we can on ground. When we run the SSPTS system, it takes off a lot of the load from the fuel cells. That means, we don't dry the fuel cells out enough, and the temps increase. If we can't, then we can't take as much power from the SSPTS, then we lose some mission durations. Preliminary calculations show a normal mission, not anything currently big enough to knock off mission duration. We'll ask JSC again today just to check.
Why does the SRB on the left have a black ribbon around the top? Is it to indicate which SRB (left or right side) it is?
Would they just immediately deorbit and land/egress wherever they ended up? Any links to documents about this would be greatly appreciated
Copied this from the Launch/FD1 thread because it is an excellent explanation of "Why (power-wise) can't the shuttle stay docked forever with the SSPTS on?"
I can think of a bunch of potential reasons, but why can't the fuel cells be shut down while the orbiter is docked to the ISS?
What exactly is the "big loop?" Is it merely joining together A/G1 and S/G1? Or is there something more complex involved?
Sorry if covered, but unable to find anything through searching...
Approximately during which time window of the total ascent is foam debris considered a potential threat to the vehicle?
Is there any documentation regarding the deployment of the Centaur or PAM assisted payloads from the Shuttle?
In particular I'm trying to find out what sort of range those payloads had to have from the Orbiter before the engines were ever ignited.
Ross.
http://forum.nasaspaceflight.com/index.php?topic=10600.msg331064#msg331064
http://forum.nasaspaceflight.com/index.php?topic=10600.msg331064#msg331064
Okay, this really does not answer my question. I'm asking exactly _how_ the shuttle is mated to the ET.
Thanks!
and mentioned the ISS being "200 ft above the ocean"
Does anyone know who the female PAO is that sort of sounds like a southern cheerleader? She covered the mission after the -127 launch, and mentioned the ISS being "200 ft above the ocean" so I was curious who she was. For that matter any of the PAO's aside from Mr. Diller. Thanks.Brandi Dean. She's the Shuttle
http://forum.nasaspaceflight.com/index.php?topic=10600.msg331064#msg331064
Okay, this really does not answer my question. I'm asking exactly _how_ the shuttle is mated to the ET.
Thanks!
The bipod at the front doesn't take the weight or thrust load, the aft struts do. They're all connected with explosive bolts.
EDIT: specifics: http://forum.nasaspaceflight.com/index.php?topic=625.msg9752#msg9752
Are these explosive bolts attached from inside the shuttle? If so, how do they gain access to this area?
Does anyone know who the female PAO is that sort of sounds like a southern cheerleader? She covered the mission after the -127 launch, and mentioned the ISS being "200 ft above the ocean" so I was curious who she was. For that matter any of the PAO's aside from Mr. Diller. Thanks.Brandi Dean. She's the Shuttle Orbit 2 PAO for this mission:
http://www.cbsnews.com/network/news/space/127/127personnel.html
is that real, or is that supposed to be a gag? what is it referring to?
looking at old landing video (sts-2, 41-d, etc, etc)....why does the shuttle appear to no longer use the RCS above mach 1. it always left contrails in the sky as quick puffs of white smoke.....i never see them anymore....has something changed?
thanks!
I believe those were OMS pulses and I further believe it was used to help the T-38's visually acquire the shuttle.
Thanks for the answers to my earlier questions. I do have a couple of others.
How are the liquid hydrogen and oxygen generated for the shuttle?
How are the gases generated and then subsequently cooled to cryogenic temperatures?
Are they generated on site or transported in?
Can someone email me some shuttle first stage trajectory data?
2) why it can't dock while a Shuttle is present?
Very stupid (non) reason. (I talk about the reason, not about your answer.)
Analyst
Very stupid (non) reason. (I talk about the reason, not about your answer.)
Analyst
1) And post launch tile inspections are ...........
2) Rules like this are made when you are risk adverse.
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
Why doesn't the shuttle bring up a free flying camera and/or imax to film the station/shuttle stack? The pictures would be phenomenal. Bring one up & leave it attached to the truss for servicing by arm or EVA.
Very stupid (non) reason. (I talk about the reason, not about your answer.)
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
3) Yes, the whole ISS is at risk and this is o.k., but not for Shuttle. Inconsistent. Shouldn't we stop all docking operations with ISS (Progress and all other vehicles)? Would be safer.
IMAX camera only holds 7 mins of filmIIRC, the STS-125 crew only shot 4 "reels" (28 min.) of Hubble. If I had to guess, I'd say another IMAX will be going up before shuttle retirement to capture the completed station during the traditional post-docking 'flyaround'. I sure hope so.
Very stupid (non) reason. (I talk about the reason, not about your answer.)
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
3) Yes, the whole ISS is at risk and this is o.k., but not for Shuttle. Inconsistent. Shouldn't we stop all docking operations with ISS (Progress and all other vehicles)? Would be safer.
No, it's perfectly consistent. Shuttle is more fault-tolerant and has a human crew controlling it, so its approach is safer than Progress. Period.
Because one hit MIR
Very stupid (non) reason. (I talk about the reason, not about your answer.)
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
3) Yes, the whole ISS is at risk and this is o.k., but not for Shuttle. Inconsistent. Shouldn't we stop all docking operations with ISS (Progress and all other vehicles)? Would be safer.
No, it's perfectly consistent. Shuttle is more fault-tolerant and has a human crew controlling it, so its approach is safer than Progress. Period.
No. You completely misunderstood. This has nothing to do with a Shuttle docking. This is about Progress being allowed to dock with ISS only when a Shuttle is not present.
So Progress is is safe enough (redundancy etc.) to dock with ISS, worth tens of billions of dollars, with 6 folks on board. But it is not safe enough to dock when a Shuttle is present at the very same ISS. This is inconsistent. Eighter it is safe enough in both situation or in none. Period. Period.
Very stupid (non) reason. (I talk about the reason, not about your answer.)
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
3) Yes, the whole ISS is at risk and this is o.k., but not for Shuttle. Inconsistent. Shouldn't we stop all docking operations with ISS (Progress and all other vehicles)? Would be safer.
No, it's perfectly consistent. Shuttle is more fault-tolerant and has a human crew controlling it, so its approach is safer than Progress. Period.
No. You completely misunderstood. This has nothing to do with a Shuttle docking. This is about Progress being allowed to dock with ISS only when a Shuttle is not present.
So Progress is is safe enough (redundancy etc.) to dock with ISS, worth tens of billions of dollars, with 6 folks on board. But it is not safe enough to dock when a Shuttle is present at the very same ISS. This is inconsistent. Eighter it is safe enough in both situation or in none. Period. Period.
Incorrect, Analyst. I have explained this before. The auto-abort function in Kurs is designed to protect the station. It does not and cannot account for the presence of a docked shuttle.
Very stupid (non) reason. (I talk about the reason, not about your answer.)
3) Progress have had other instances of control problems. But then again, the whole ISS is at risk
3) Yes, the whole ISS is at risk and this is o.k., but not for Shuttle. Inconsistent. Shouldn't we stop all docking operations with ISS (Progress and all other vehicles)? Would be safer.
No, it's perfectly consistent. Shuttle is more fault-tolerant and has a human crew controlling it, so its approach is safer than Progress. Period.
No. You completely misunderstood. This has nothing to do with a Shuttle docking. This is about Progress being allowed to dock with ISS only when a Shuttle is not present.
So Progress is is safe enough (redundancy etc.) to dock with ISS, worth tens of billions of dollars, with 6 folks on board. But it is not safe enough to dock when a Shuttle is present at the very same ISS. This is inconsistent. Eighter it is safe enough in both situation or in none. Period. Period.
Incorrect, Analyst. I have explained this before. The auto-abort function in Kurs is designed to protect the station. It does not and cannot account for the presence of a docked shuttle.
Sounds like an excuse to me.
This system can abort safely from the ever growing station (100m by 70m or so), but can't when the station is yet a little bigger because of a present Shuttle? Or to put it differently: Progress would barely miss PMA-2, or a solar array, but hit the Shuttle if present?
Wouldn't it be much easier if this system assumes the station is a little bigger? Would ease operations.
Edit: Can someone point me to the SODB? I know it is on L2 somewhere, but "search" doesn't find it.
On a similar line - what happened to Aercam (Sprint).
Don't think this has been answered yet so here is my question.
Challenger had the major malfunction during its launch. I heard that it was "Blown Up" to keep the debris farther away from the audience or something. Is that true or was the entire explosion just from the O-Ring seal problem?
Thanks
Don't think this has been answered yet so here is my question.
Challenger had the major malfunction during its launch. I heard that it was "Blown Up" to keep the debris farther away from the audience or something. Is that true or was the entire explosion just from the O-Ring seal problem?
Thanks
Hi folks:
Why is an astronaut always on capcom, I mean they all speak english don't they?
No explosion whatsoever. What looks like an explosion cloud is nothing other than burning gases from the destroyed ET.Don't think this has been answered yet so here is my question.
Challenger had the major malfunction during its launch. I heard that it was "Blown Up" to keep the debris farther away from the audience or something. Is that true or was the entire explosion just from the O-Ring seal problem?
Thanks
The explosion was just from the O-ring seal problem. The SRBs were destroyed almost 40 seconds later by RSO.
No explosion whatsoever. What looks like an explosion cloud is nothing other than burning gases from the destroyed ET.Don't think this has been answered yet so here is my question.
Challenger had the major malfunction during its launch. I heard that it was "Blown Up" to keep the debris farther away from the audience or something. Is that true or was the entire explosion just from the O-Ring seal problem?
Thanks
The explosion was just from the O-ring seal problem. The SRBs were destroyed almost 40 seconds later by RSO.
No shock waves or any other effects associated with an explosion was present.
Is a shockwave impossible with LOX/LH2 or did it just not happen in the case of Challenger? I was under the impression that the old hypergolic launchers didn't need escape rockets because they couldn't detonate because the propellant couldn't mix properly and would only burn at the two dimensional interface.
That's one of the reasons why it's hard to predict what a total destructive power of a catastrophic vehicle explosion would be.
1)What is METOX?
2) why were two coverings taken off parts of pieces, then jettisoned into space? Where they dropped? I mean they could have been brought in and put with the other "space junk.
Why is an astronaut always on capcom, I mean they all speak english don't they?
Tests have shown hydrogen can give you a blast because it can mix then go off.
Why is an astronaut always on capcom, I mean they all speak english don't they?
Not sure who you mean by "they", but astronauts are uniquely qualified to serve as the communications liaison between the on-orbit crew and the flight control team. They're not just reading a script. During shuttle missions, they are often members of the back-up crew, so they will be familiar with all aspects of the mission.
Tests have shown hydrogen can give you a blast because it can mix then go off.
in about 90% of the jobs that we do one of the first steps we do before we open the system is to verify that the system is at less than 1% H2 and less than 1% O2. Then while the system is open it is purged with GN2/GHe to prevent air intrusion. The reason is to prevent what is called an "in-line detonation" which can, if severe enough, damage or destroy equipment. I've seen photos of one such detonation that occured in a vent line at Stennis. Every 90 degree turn in the line was split or blown out from the shockwave traveling through the line, since the shockwave resists sharp turns. Earlier this year we actually had a detonation for the first time that anyone could remember. We were between waves during tankers and got shut down for weather. It was an extremely windy day (at least 30 knot sustained winds) with a hot (H2 rich) vent line since we vent to the flare stack during tankers. We were in the shop and kept hearing this weird noise that sounded like something hitting the side of the shop, about every 15 mins or so, but couldn't figure out what it was. What was happening was that due to the low pressure in the line from no flow the wind was blowing out the flame and actually blowing air back into the line. It would mix, then the pressure would finally build enough to push the mixture out of the line, where it would ignite when it hit the propane igniters. We finally got the all clear to continue so we went back out and continued tanker offload. When tankers were done flow slowed again, but with an enriched line the wind blew it out again. This time when it lit it sounded like a bomb going off. It actually knocked all of the frost off the line all the way back to the storage area. Definately got our attention. There was alot of leak checking and inspections after that to make sure nothing was damaged.
1)What is METOX?
Metal Oxide == refers to the technology used for recyclable CO2 scrubbing canisters. The crew bakes them in a special oven to release the CO2 to the station's atmosphere, which is then removed by one of the central scrubbers.Quote2) why were two coverings taken off parts of pieces, then jettisoned into space? Where they dropped? I mean they could have been brought in and put with the other "space junk.
This question came up in one of the briefings. Those that weren't needed were thrown overboard to save the time/hassle of trying to wiggle them into a storage bag. Because of their low mass, they will reenter in a matter of days, IIRC, rather than becoming a long-term debris risk.
Why is an astronaut always on capcom, I mean they all speak english don't they?
Not sure who you mean by "they", but astronauts are uniquely qualified to serve as the communications liaison between the on-orbit crew and the flight control team. They're not just reading a script. During shuttle missions, they are often members of the back-up crew, so they will be familiar with all aspects of the mission.
It is my observation that capcoms during shuttle missions are always astronauts while ISS stage operations sometimes have non-astronaut capcoms. That's probably just a function of the large number of hours during stage operations.
Why is an astronaut always on capcom, I mean they all speak english don't they?
Not sure who you mean by "they", but astronauts are uniquely qualified to serve as the communications liaison between the on-orbit crew and the flight control team. They're not just reading a script. During shuttle missions, they are often members of the back-up crew, so they will be familiar with all aspects of the mission.
It is my observation that capcoms during shuttle missions are always astronauts while ISS stage operations sometimes have non-astronaut capcoms. That's probably just a function of the large number of hours during stage operations.
Thanks again ginahoy.
I just thought that "anybody" at mission control in Houston that works on the specific mission (i.e. STS-127) can speak to the astronauts as most of MCC-H know the mission "like the back of tere hand",but you had good answer to things I never thought of.
snip
Flight controllers are trained as specialists. Astronauts are generalists. A flight controller will not necessarily have any training in systems outside their particular console position. They know their systems like the backs of their hands, and they know how their system fits into the big picture of the mission, but that does not grant them particular insight into other systems nor to communicate those insights to the crew.
As for question 2: Am I to assume then that something that is bigger and has a higher mass will stay in orbit longer?
As for question 2: Am I to assume then that something that is bigger and has a higher mass will stay in orbit longer?
Lightweight objects loose energy quicker due to atmospheric drag. Remember, there's enough atmosphere still present at 220 miles to cause the space station to require periodic reboost.
As for question 2: Am I to assume then that something that is bigger and has a higher mass will stay in orbit longer?
Lightweight objects loose energy quicker due to atmospheric drag. Remember, there's enough atmosphere still present at 220 miles to cause the space station to require periodic reboost.
So are you saying that two idenical cases in orbit, -one lighter than the other-, that the lighter one will fall faster.
OR
something that is round and flat (ie a cover or blanket) will fall faster because of its shape?
Oxford750
Why is thr ISS "red".
Oxford750
And some people think we will be putting this stuff in cars at gas stations someday. I think not.
Danny Deger
A quick question on astronaut training:
When using the Shuttle Mission Simulator, does the crew periodically wear their ACES suits?
Ok, apologies for this but I HAVE looked (as much as I will at bed time :) ) , but when was STS-134 announced??? I thought the schedule went to STS-133 but the NASA site is showing an additional flight for launch on Sept 16th. Cant believe I'm the 1st to see this but can not see a thread?????
I have two shuttle-related questions:
1) To what extent if any was the orbiter weight constrained by the 747 ferry requirement when the sts was being designed?
2) In an emergency, could an astronaut make a brief spacewalk in the current ACES, being that it's a full-pressure suit?
How does the orbiter's onboard flight simulator work? For example, when they practice entry and landing before deorbit, do they throw switches on the flight deck control panels? How is the simulation environment isolated from the flight environment? Is it just a GPC video game that temporarily takes over the rotational hand controller?
And some people think we will be putting this stuff in cars at gas stations someday. I think not.
Danny Deger
Well, I wouldn't necessarily say that. I'm one all for a hydrogen society. It will just take a learning and education process like it was for gasoline way back when. We will develop processes and safety guidelines, develop new specialized hardware and safety equipment. I'm sure there will be accidents and we will learn from them. It's just that, here, we work for a government entity that has it's own safety regulations, industry-wide safety regulations, and we are dealing with a much, much larger amount of commodity that most of the public will ever have to at one time.
Is there an article (for the layman like me) that explains in which direction each thruster fires, and which way it would make the shuttle move?
I know what the OMS engines do, but what about the others?
If one OMS engine failed for any reason, would firing just one for a "longer" period be enough or would that induce a yaw as the other one can't compensate?
Thanks
Oxford750
Here's a question before it gets busy:I'm not sure that's ever been documented, even as far back as the Enterprise landing tests (where they exited via a mostly regular airline mobile stairway).
Are there any photos online of the egress process? Since the hatch opens on the left side when the orbiter is on the pad, I presume that it opens downward on the runway. There must be some interesting hardware to accommodate that...
1. If one OMS engine failed for any reason, would firing just one for a "longer" period be enough or
2. would that induce a yaw as the other one can't compensate?
Here's a question before it gets busy:I'm not sure that's ever been documented, even as far back as the Enterprise landing tests (where they exited via a mostly regular airline mobile stairway).
Are there any photos online of the egress process? Since the hatch opens on the left side when the orbiter is on the pad, I presume that it opens downward on the runway. There must be some interesting hardware to accommodate that...
From STS-1-on, the hatch area has been covered and I can't recall ever seeing any pics of the hatch being opened. or of any crew exiting after a mission.
Is there an article (for the layman like me) that explains in which direction each thruster fires, and which way it would make the shuttle move?
I know what the OMS engines do, but what about the others?
If one OMS engine failed for any reason, would firing just one for a "longer" period be enough or would that induce a yaw as the other one can't compensate?
Thanks
Oxford750
Would love to hear the rest of that story, Danny. So you were advocating the use of prebank as a nominal procedure? What happens then if you underburn? :)
That document you linked is from the SCOM, the full version of which is on L2.
Has there ever been a shuttle landing at KSC while a shuttle rollout was in progress?
Is there an article (for the layman like me) that explains in which direction each thruster fires, and which way it would make the shuttle move?
I know what the OMS engines do, but what about the others?
If one OMS engine failed for any reason, would firing just one for a "longer" period be enough or would that induce a yaw as the other one can't compensate?
Thanks
Oxford750
Attaching a diagram from the Shuttle Crew Operations Manual which should explain things.
Would't the body flap negate the momentum of the plumes of thrusters: R4D,R2D,R3d,L4D,L2D,L3D or can the body flap move down 90 degrees, or is it there just to protect the engines
You are the expert on this stuff, so you give me a ray of hope. Is the goal liquid or compressed gas. I understand there some prototype stations working today.
But, I don't recall there ever being that big of an issue in handling gasoline into cars. Heck, we don't even ground our cars like we do planes. It takes about 5 seconds to teach someone to gas up a car. If there is a big spill (which there are), it doesn't quickly boil into an explosive cloud. Detonating a cloud is really, really bad. Probably a gallon turning into vapor will level a whole gas station when it goes off.
I can't imagine my ex ever gassing up her car with liquid hydrogen :o
In my opinion, even liquid propane is something that shouldn't be taken lightly.
Danny Deger
Thanks for the write up, Danny. What was your plan for any underburn, then? If an engine quits before the targets are met, then you can't prebank anymore.
You are the expert on this stuff, so you give me a ray of hope. Is the goal liquid or compressed gas. I understand there some prototype stations working today.
But, I don't recall there ever being that big of an issue in handling gasoline into cars. Heck, we don't even ground our cars like we do planes. It takes about 5 seconds to teach someone to gas up a car. If there is a big spill (which there are), it doesn't quickly boil into an explosive cloud. Detonating a cloud is really, really bad. Probably a gallon turning into vapor will level a whole gas station when it goes off.
I can't imagine my ex ever gassing up her car with liquid hydrogen :o
In my opinion, even liquid propane is something that shouldn't be taken lightly.
Danny Deger
Most of the concepts I've seen deal with compressed gas. Would probably be similar to gassing a vehicle with propane or LNG nowadays.
One other thing to keep in mind is that hydrogen dissipates much faster than gasoline does. The liquid boils so fast you would probably never see it, just vapor. The biggest concern is if it is in an enclosed space or covered area, so it accumilates more and won't disperse as quickly. Then you may have quite a safety hazard. But for the most part, most experts say that hydrogen is overall safer than gasoline. Biggest concern is the large flammability range (4-74%).
BTW, if anyone is interested, there's a website I've found to be very informative on hydrogen and related topics (hydrogen cars, etc.)
http://www.hydrogenassociation.org
Thanks for the write up, Danny. What was your plan for any underburn, then? If an engine quits before the targets are met, then you can't prebank anymore.
I'm not sure I completely understand your question's context, by definition the enigne quiting early would result in an underburn. Which engine are you talking about - an OMS engine? In that case you down-mode to other options such as RCS Completeion, Recovery Pre-bank & Landing Site Redesignation(for ex: can't make KSC then maybe redes to Gander or Shannon).
Entry Flight Procedures Handbook explains much of this in section 4. Chris has a semi current version although it is not accurate about the KSC re-des options since those procedures are relatively new.
Mark Kirkman
snip
Thanks Mark, but you're misunderstanding me. Danny was advocating a nominal entry with a prebank. Ergo, less fuel required for the deorbit burn, I guess. But then, if you're targetting for that, and then the engines quit, you're already planning to prebank, so you might not be able to prebank anymore (if you were targetting for a 90deg prebank, for instance).
2) It would be ferried with quite a few stops on the way. An orbiter has been carried to and from Europe before.That was Enterprise(OV-101). I believe she was a fair bit lighter than an operational OV would be for a TAL abort ferry.
1) I saw a pic of the SLF and noticed for the first time there is a canal around the runway (broken up by a few roads/access points).
Is that to try to limit wildlife other than alligators from easily accessing the SLF or does it serve some other purpose?
You are the expert on this stuff, so you give me a ray of hope. Is the goal liquid or compressed gas. I understand there some prototype stations working today.
My guess is compressed gas hydrogen cars will not have enough range to be viable. I will look at the link.
If only one engine fails, could you use RCS and the remaining engine simultaneously?
You'd have to reorientate to an attitude that would account for the difference in thrust level. Which would probably then be hideously unefficient. Most likely they'd kill the other engine and complete the entire burn in RCS, I guess?
You'd have to reorientate to an attitude that would account for the difference in thrust level. Which would probably then be hideously unefficient. Most likely they'd kill the other engine and complete the entire burn in RCS, I guess?
Nope, as long as you have a single engine, you will continue to use it. It is more efficient than downmoding to RCS.
You'd have to reorientate to an attitude that would account for the difference in thrust level. Which would probably then be hideously unefficient. Most likely they'd kill the other engine and complete the entire burn in RCS, I guess?
Nope, as long as you have a single engine, you will continue to use it. It is more efficient than downmoding to RCS.
So if a single engine on one side is still firing, the RCS will fire to keep the attitude where it's needed?
Is there any plan for the centrifugal module going up to the ISS if the shuttle is extended? Wasn't it completed, just waiting for a ride? I seem to remember reading something like that, but now I can't remember.
Is there any plan for the centrifugal module going up to the ISS if the shuttle is extended? Wasn't it completed, just waiting for a ride? I seem to remember reading something like that, but now I can't remember.
what are nasa's plans on figuring out microgravity effects on biological creatures prior to moon/mars/neo missions, if they threw away the "artificial gravity" maker?
just a quickie whilst its on my mind but where do the sound suppression system's water tanks get their water supply from? is it sea water thats treated at a plant in KSC?
Hereis a question I have often wondered since they started showing SRB camera footage of SRB Seperation.
I notice that the underside of the ET (Very bottom) always seems burnt black looking and even sometimes as if its glowing, Does the heat from the Shuttles Main Engines darken this area or is this marks left from the SRB's during liftoff or more from when they jettison away?
Hereis a question I have often wondered since they started showing SRB camera footage of SRB Seperation.
I notice that the underside of the ET (Very bottom) always seems burnt black looking and even sometimes as if its glowing, Does the heat from the Shuttles Main Engines darken this area or is this marks left from the SRB's during liftoff or more from when they jettison away?
The scorching is caused by plume recirculation from both the SRBs and the SSMEs.
Gotcha, so is the tank coated there with something to keep the heat from blowingt hrough the tank and or heating the fuel inside?
LOL, I know that, But I was wondering if its coated extra there or something so the heat doesnt scortch through
Hey I have a question about the OBSS Inspection. As far as I know the OBSS inspection does not inspect the belly. It only inspects the RCC and nose and the OMS pods. Am I mistaken. The OBSS video on L2 shows only that but there is a diagram i saw from somebody that showed them scanning like the whole belly. Is there a video like the one on L2 that I can show somebody on the SSM forum. Thanks :)
Here is the pic.
Please forgive me if this has been asked before, but what is the protocol for flying the shuttle flags? Are the flags flown only when the shuttle is on orbit, or once the stack is rolled out?
IF there is a roll back, what happens to the payload, taken out of the shuttle of course
1. but does the canister come back out to get it, or
2. does it sit at the RSS (hopefully not during hurricane season)?
3. If so, doesn't this pose a higher risk of getting the payload "dirty" (not sure if contamination is the correct term)?
4. Second question, I googled the payload room at the RSS and I noticed in pictures everyone is in full protective garb but THEY AREN'T wearing gloves!!! Why???? (I would post pictures but I'm at work atm and they frown upon us saving pictures)
Thanks for the answers Jim... if you don't mind a few more silly questions; how do they determine which option to do? You mentioned it depends on a lot of factors, is the type of payload one of them?I think optical means like equipment for Hubble or anything for a telescope or maybe even a satellite. Hubble payload always goes under extreme clean room.
Also could you explain what you mean by optical, I'm not to sure how it is used in context with the space shuttle, but when I hear it I think lens type sensitivity.
Thanks for the answers Jim... if you don't mind a few more silly questions; how do they determine which option to do? You mentioned it depends on a lot of factors, is the type of payload one of them?
Also could you explain what you mean by optical, I'm not to sure how it is used in context with the space shuttle, but when I hear it I think lens type sensitivity.
Thanks Chris. That is actually exactly what I thought. What it is is on SSM-2007 it has you put the end of the arm under the belly for a short inspection.(Full inspection not yet here) and I was telling them on the forum that I didn't think it was right.So I was actually correct because I f I understand you than all flights carrying the OBSS except for STS-125 don't scan the under belly. Let me know Thanks!
Please forgive me if this has been asked before, but what is the protocol for flying the shuttle flags? Are the flags flown only when the shuttle is on orbit, or once the stack is rolled out?
Are you taking about these flags?
If so, then they are flown when the specific vehicle they represent is at the pad or on orbit.
Please forgive me if this has been asked before, but what is the protocol for flying the shuttle flags? Are the flags flown only when the shuttle is on orbit, or once the stack is rolled out?
Are you taking about these flags?
If so, then they are flown when the specific vehicle they represent is at the pad or on orbit.
Yes, Chris, those are the flags. I have small versions for my office, and I have been displaying the appropriate flag while the vehicle was on orbit. Then I realized they might also be flown while the vehicle is at the pad, and I didn't want to be incorrect in my use of the flags. I'll need to put out my Discovery flag when I get into the office on Monday. ;D Thanks!
Yes, Chris, those are the flags. I have small versions for my office, and I have been displaying the appropriate flag while the vehicle was on orbit. Then I realized they might also be flown while the vehicle is at the pad, and I didn't want to be incorrect in my use of the flags. I'll need to put out my Discovery flag when I get into the office on Monday. ;D Thanks!
Where can you get the small versions or any version?
Thanks
Ben
are they some kind of pyrotechnic device?
oh ok do they need to be replaced then between firings?, seems like that could be a problem if theres an RSLS abort or something like thatThey have to replaced if fired. I believe that was the main driver behind the 48 hr scrub turnaround between the first and second launch attempts of STS-93 in July 1999.
oh ok do they need to be replaced then between firings?, seems like that could be a problem if theres an RSLS abort or something like that
Ive looked and had no luck googling this but what design are the ROFI sparklers that are used for the shuttle....
They are nothing but fountain sparklers. No big deal.
Ive looked and had no luck googling this but what design are the ROFI sparklers that are used for the shuttle....
I've looked too, and found nothing. Would love to see some closeup photos of the actual hardware, not just while it is firing.
Ive looked and had no luck googling this but what design are the ROFI sparklers that are used for the shuttle....
I've looked too, and found nothing. Would love to see some closeup photos of the actual hardware, not just while it is firing.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890003237_1989003237.pdf has some info.
Are there any photos from UNDER the MLP while the stack is on the pad looking UP into the SRB nozzle? Shine a spotlight up into the booster core. I am presuming you could see the center hole all the way up to the top of the booster, right?
1. secondly, and bound to have been asked before but why is the GLS console behind a glass screen (I my have this wrong and its a different console but why are the two glass screens there atall?)
2. From what I understand the GLS operator has to manually "activate" the RSLS/Auto sequencer, is this just a case of pressing a button or is it more involved than that, same question goes about issuing a cutoff command,
3. Also is it true that this is the last time a human being has do something in order for the shuttle to put itself in orbit? (assuming everything works as planned)
I would attach a picture however i cant find one to hand of firing room 4, but they are the two "greenhouse" type things at either corner of the room which seem to be sealed off from the rest of the room
How many successive scrubs can the system handle?
Are these driven by the ET fill/drain cycles (limited number?) or something else?
Is there a time constraint as well - as in the system can't stand on the pad for more than x-number of days? If so, what drives that? (not launch window related)
How many successive scrubs can the system handle?
Are these driven by the ET fill/drain cycles (limited number?) or something else?
To me a more important question is this: Why is the Russian program so inflexible regarding launch dates?
It seems to me that Soyuz or Progress launches are set in stone by GOD and Shuttle with all of its weather related and other challenges always has to stand down to let Soyuz or Progress "play thru". Why can't Progress or Soyuz slip their launch a few days to let Shuttle "play thru"?
Heck, we even seriously contemplate shortening Shuttle missions so they can undock in time for a Progress or Soyuz launch. Why does this make sense? Slip the Russian launch a couple of days and we don't have to do this.
What am I missing here?
How many successive scrubs can the system handle?
Are these driven by the ET fill/drain cycles (limited number?) or something else?
2 when the ET is filled for both launch crew rest and MPS inspections.
Wow I just found out today that there had been launch aborts after Main Engine ignition. I was pretty amazed. I never hear about today.
Why were they having so many problems with the Main Engines cutting off?
Wow I just found out today that there had been launch aborts after Main Engine ignition. I was pretty amazed. I never hear about today.
Why were they having so many problems with the Main Engines cutting off?
Valves that weren't responding according to plans
When does an SRM become an SRB?Something else. SRM refers to the motor components only. SRB is the whole deal, both motor components and the non-motor components.
Is it a function of overall thrust percentage or a function of size of the unit... or something else?
What would happen if the shuttle did not throttle down for MaxQ? LOV/C, or survivable, but part of the launch profile to ensure against problems?
What would happen if the shuttle did not throttle down for MaxQ? LOV/C, or survivable, but part of the launch profile to ensure against problems?
Thanks, Dave
What confused the nomenclature- to me anyway- is that the 'little guys' on Deltas & Atlases are typically referred to as SRM's; while the larger stacks on Shuttle & the big Titans (until phase out) were always called SRB's.
When does an SRM become an SRB?
Is it a function of overall thrust percentage or a function of size of the unit... or something else?
The nomenclature for the shuttle is as the following:
The SRM is component that ATK produces, the motor with the nozzle. It becomes a SRM when the aft skirt, IEA, aft attach hardware, forward attachment, recovery systems, jettison motors and nose cone are added
I have a headache now ...
Thanks Jorge, Jim. Curveball question that seems better placed here than another thread, is John Shannon NASA or USA?NASA. He's a former Flight Director and the FDs have always been NASA employees and not contractor engineers. So Leroy Cain is NASA as well.
Thanks Jorge, Jim. Curveball question that seems better placed here than another thread, is John Shannon NASA or USA?NASA. He's a former Flight Director and the FDs have always been NASA employees and not contractor engineers. So Leroy Cain is NASA as well.
what's the ascent witch list performed at T-11H & hold???
This is an odd one but does anyone know where I can find a diagram of the first few orbits of an ISS flight after launch?
I have a few people on another forum asking about it, people wanted to try snagging the UHF comms with their scanners.
If the Apollo program could transmit live TV via S-band, why can't the Shuttle? When Ku is unavailable, the Shuttle is limited to sequential stills. If Apollo could send TV via S-band, what changed that the Shuttle cannot?
Why are built in holds of known durations added to the countdown? Why not simply have a countdown of longer duration that includes the holds without stopping the clock?
Why are built in holds of known durations added to the countdown? Why not simply have a countdown of longer duration that includes the holds without stopping the clock?
Why are built in holds of known durations added to the countdown? Why not simply have a countdown of longer duration that includes the holds without stopping the clock?
Is there a place to look at time to launch assuming the holds all go as planned? If NASA doesn't have one, it would be trivial to build and add to nasa.gov.
Danny Deger
Is this what you're looking for?
9:41 pm Countdown resumes at the T-3 hour mark
12:21 am Countdown enters a 10-minute hold at the T-20 minute mark
12:31 am Countdown resumes at the T-20 minute mark
12:42 am Countdown enters an ~45-min. hold at the T-9 minute mark
1:27:05 am Countdown resumes at the T-9 minute mark
Is this what you're looking for?
9:41 pm Countdown resumes at the T-3 hour mark
12:21 am Countdown enters a 10-minute hold at the T-20 minute mark
12:31 am Countdown resumes at the T-20 minute mark
12:42 am Countdown enters an ~45-min. hold at the T-9 minute mark
1:27:05 am Countdown resumes at the T-9 minute mark
Yes, thank you. 10 minute hold at T minus 20, 45 minutes at T-9. How about the T minus 3 hour hold? How long is it?
Danny
During tanking/replenish is the LO2 pumped through the SSMEs and then into the tank or is it sent straight up into the tank with a "trickle" sent through the engines, if its option 2 what percentage of the total flow is sent to the engines?
then there should be alternative methods of monitoring the valve position.
What does the scrub scenario look like if one of the LH2 fill/drain valves were to get stuck in the closed position? Wait a week for boiloff via flarestack?
I notice on another thread that after boiloff they have inerted the tank with helium. Is there a reason for using helium for this rather than (say) nitrogen? Is it a concern that the tank is too cold for nitrogen?
Is it due to the volatility of the liquid hydrogen? Or would it waste too much fuel via boil-off?
What does the scrub scenario look like if one of the LH2 fill/drain valves were to get stuck in the closed position? Wait a week for boiloff via flarestack?
There's an 8-1/2 minute rapid-drain procedure - but it's likely a one-shot deal :o
LH2 and LOX are loaded through the T0 umbilicals into the aft of the Orbiter, then up through the porpellant lines and into the respective tanks of the ET.
LH2 and LOX are loaded through the T0 umbilicals into the aft of the Orbiter, then up through the porpellant lines and into the respective tanks of the ET.
Are the T0 umbilicals those grey things that stand up from the MLP behind the wings?
If not, where are they located?
What does the scrub scenario look like if one of the LH2 fill/drain valves were to get stuck in the closed position? Wait a week for boiloff via flarestack?
There's an 8-1/2 minute rapid-drain procedure - but it's likely a one-shot deal :o
This "8-1/2 minute rapid drain sounds like a "launch" without lighting the SRB's. But, that is not even a consideration right? Wouldn't that require replacement of the SSME's?
I've read that the aft skirts of the SRBs support the entire weight of the shuttle on the pad. However, it seems like they would be offset by quite a bit from the CG of the entire stack, considering that there's an orbiter hanging off one side and not the other. Is there any other structure providing a lateral force to keep the stack from tipping over? Or are the hold-down posts on the skirts enough to keep the stack securely upright?
I've read that the aft skirts of the SRBs support the entire weight of the shuttle on the pad. However, it seems like they would be offset by quite a bit from the CG of the entire stack, considering that there's an orbiter hanging off one side and not the other. Is there any other structure providing a lateral force to keep the stack from tipping over? Or are the hold-down posts on the skirts enough to keep the stack securely upright?
You need to realize that the orbiter only weighs on the order of 1/10th as much as two fueled SRBs, so the CG isn't offset all that much. The moment it applies is the same regardless of the SRB mass of course, but even that moment isn't all that much - around 100 metric tons times something in range of high single-digit meters. That's nothing for a large steel tube to take in bending (much less two of them) and the 8 bolts Jim mentioned are large and widely spaced from each other.
You need to realize that the orbiter only weighs on the order of 1/10th as much as two fueled SRBs, so the CG isn't offset all that much. The moment it applies is the same regardless of the SRB mass of course, but even that moment isn't all that much - around 100 metric tons times something in range of high single-digit meters. That's nothing for a large steel tube to take in bending (much less two of them) and the 8 bolts Jim mentioned are large and widely spaced from each other.
Thanks (& to Jim too). The weight difference had occurred to me but I didn't know it was quite that much.
Does anyone know the difference in q between a high q and low q profile? I also need to know how much performance gain there is.
Danny Deger
Hypothetically,
If a foam strike occurs while climbing to orbit, and severe damage is very obvious (i.e. can be seen to anyone looking at the camera mounted on the ET that is usually shown on the public channel), could they do an RTLS abort based on that?
(not that I hope this ever occurs)
Hypothetically,Also asked and answered here before...start with this and read down:
If a foam strike occurs while climbing to orbit, and severe damage is very obvious (i.e. can be seen to anyone looking at the camera mounted on the ET that is usually shown on the public channel), could they do an RTLS abort based on that?
(not that I hope this ever occurs)
Thanks :)
On that note, what does qualify for an RTLS abort? Engine or two going down I would assume, but is there anything else?
A dual engine failure early in ascent is probably more a contingency abort case than RTLS -- if Mark's nearby, you can ask him. :)Thanks :)RTLS is any system error (single engine or dual engine failure or severe cabin leak, etc....) that prevents you from either safely reaching orbit or safely executing a TAL before the moment of Negative Return (approximately T+4 mins) -- at which point the Shuttle vehicle has passed too far downrange and gained too much forward moment to safely return to KSC.
On that note, what does qualify for an RTLS abort? Engine or two going down I would assume, but is there anything else?
1. Is this a security measure to make sure that there are no unauthorized persons anywhere they are not supposed to be during a launch?
2. It seems that it would be a rather difficult thing for anyone to actually gain access to any critical area because of things being so locked down.
To Whom it may concern, this might be in the wrong section but I don't know where to put it.
I have seen the moon move across the sky over the course of 2-3 hours but why did the moon move so fast last night at the launch.
To Whom it may concern, this might be in the wrong section but I don't know where to put it.
I have seen the moon move across the sky over the course of 2-3 hours but why did the moon move so fast last night at the launch.
Narrow angle camera.
Plus, the moon's apparent motion is faster than many people realize. It moves its own diameter about every two minutes. This is not easily apparent when watching the moon at night, even with a single landmark in front of the moon, because most people have an unconscious tendency to move their heads to keep the landmark aligned with the moon. Aligning two landmarks with the moon provides a reference to keep the head steady. (Or set up binoculars on a fixed tripod, or use a telescope.)
Here's a question that'll make Jim wince ;)
When is an orbiter's birthday? I know PAO are going on the maiden launch date - and that's cool, we'll do likewise. However, I'd of thought it would have been maybe her first powerup at Palmdale or when the orbital first arrived at KSC on the back of the SCA?
How do the Navy work this? Commission date?
When is an orbiter's birthday? I know PAO are going on the maiden launch date - and that's cool, we'll do likewise. However, I'd of thought it would have been maybe her first powerup at Palmdale or when the orbital first arrived at KSC on the back of the SCA?As these things go, today is definitely a big silver anniversary, but I think what it's an anniversary of is a matter of preference. (Not a big deal one way or another.)
Very true, Philip.I grew up in the L.A. area, so the rollout ceremonies and delivery to Florida were a bigger deal there. All the orbiters got their picture in the papers when that happened.
And here's a relatively complete list of her various birthdays/milestones:
January 29, 1979 Contract Award
August 27, 1979 Start long lead fabrication of Crew Module
June 20, 1980 Start fabrication lower fuselage
November 10, 1980 Start structural assembly of aft-fuselage
December 8, 1980 Start initial system installation aft fuselage
March 2, 1981 Start fabrication/assembly of payload bay doors
October 26, 1981 Start initial system installation, crew module, Downey
January 4, 1982 Start initial system installation upper forward fuselage
March 16, 1982 Midfuselage on dock, Palmdale
March 30, 1982 Elevons on dock, Palmdale
April 30, 1982 Wings arrive at Palmdale from Grumman
April 30, 1982 Lower forward fuselage on dock, Palmdale
July 16, 1982 Upper forward fuselage on dock, Palmdale
August 5, 1982 Vertical stabilizer on dock, Palmdale
September 3, 1982 Start of Final Assembly
October 15, 1982 Body flap on dock, Palmdale
January 11, 1983 Aft fuselage on dock, Palmdale
February 25, 1983 Complete final assembly and closeout installation, Palmdale
February 28, 1983 Start initial subsystems test, power-on, Palmdale
May 13, 1983 Complete initial subsystems testing
July 26, 1983 Complete subsystems testing
August 12, 1983 Completed Final Acceptance
October 16, 1983 Rollout from Palmdale
November 5, 1983 Overland transport from Palmdale to Edwards
November 9, 1983 Delivery to Kennedy Space Center
June 2, 1984 Flight Readiness Firing
August 30, 1984 First Flight (41-D)
Was wondering why STS 131 is scheduled to carry 7 crew members where every other remaining mission carries 6?
Thank you.
And here's a relatively complete list of her various birthdays/milestones:Hope this is OK, but for grins a couple of screenshots from maybe five seconds of a local news report during STS-5; the rest I missed. Unfortunately, this was the only tape I owned at the time and I was more focused on the mission (it was EOM day at the time).
January 29, 1979 Contract Award
August 27, 1979 Start long lead fabrication of Crew Module
June 20, 1980 Start fabrication lower fuselage
November 10, 1980 Start structural assembly of aft-fuselage
December 8, 1980 Start initial system installation aft fuselage
March 2, 1981 Start fabrication/assembly of payload bay doors
October 26, 1981 Start initial system installation, crew module, Downey
January 4, 1982 Start initial system installation upper forward fuselage
March 16, 1982 Midfuselage on dock, Palmdale
March 30, 1982 Elevons on dock, Palmdale
April 30, 1982 Wings arrive at Palmdale from Grumman
April 30, 1982 Lower forward fuselage on dock, Palmdale
July 16, 1982 Upper forward fuselage on dock, Palmdale
August 5, 1982 Vertical stabilizer on dock, Palmdale
September 3, 1982 Start of Final Assembly
October 15, 1982 Body flap on dock, Palmdale
January 11, 1983 Aft fuselage on dock, Palmdale
February 25, 1983 Complete final assembly and closeout installation, Palmdale
February 28, 1983 Start initial subsystems test, power-on, Palmdale
May 13, 1983 Complete initial subsystems testing
July 26, 1983 Complete subsystems testing
August 12, 1983 Completed Final Acceptance
October 16, 1983 Rollout from Palmdale
November 5, 1983 Overland transport from Palmdale to Edwards
November 9, 1983 Delivery to Kennedy Space Center
June 2, 1984 Flight Readiness Firing
August 30, 1984 First Flight (41-D)
Thanks, Chris, but wouldn't NASA want to maximize upmass on "131" as well?
Didn't we do this topic a few weeks ago? I was whining about how you'd cope with an underburn if you'd already targetted for a prebank or something like that.
Thank you all for your answers as to what a prebank is.
Now, just so I'm understanding this, what you're asking Danny is why not launch with 800 additional lbs of cargo that's not provided for under standard mission rules, burn extra OMS propellant during ascent to get you to orbit -- leaving you with insificiant fuel to do a standard OMS deorbit, then, at the end fo the mission (or AOA) you intentionally perform a D/O burn with an underburn and the prebank to get the Orbiter to E/I faster?
Wouldn't that carry a lot more risks than potential benefits?
Loss of an OMS tank while at station is probably loss of crew anyway.
Loss of an OMS tank while at station is probably loss of crew anyway.
Why? Sudden thrust on the shuttle tearing it from the PMA resulting in ISS/STS depressurization?
Been wondering this for a while:
Does the shuttle have the largest (by dimensions) payload capacity of all launch systems in use today? Wikipedia says it's 4.6m by 18m in size, how much of that can be used for a single payload?
But if STS looses an OMS tank while at ISS, the crew can remain aboard ISS until the LON arrives. No LOC, right?
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
Re my whining about prebanks and underburn.
My point was that you use prebank as a backup option in case of an underburn. So if you've already targeted for a prebank scenario, and then you suffer an underburn, what do you do then? You can't prebank, because you've already targetted for an prebank.
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
The ROFI systems powering up.
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
The ROFI systems powering up.
I think it is the SRB's Aux Power Units powering up. And they are turbines.
Danny Deger
Re my whining about prebanks and underburn.
My point was that you use prebank as a backup option in case of an underburn. So if you've already targeted for a prebank scenario, and then you suffer an underburn, what do you do then? You can't prebank, because you've already targetted for an prebank.
That's what I'm thinking too. I know Danny's question was hypothetical, but I wouldn't expect NASA to plan for a pre-bank.
Ok. Danny's been talking of 60 degree alpha entry by the Shuttle.
I assume this means a rapid deceleration, instability, and low cross range entry profile.
1. Would it have made a difference to Columbia? Downsides?
2. Earlier Shuttle concepts had high angle entry with "belly flop" manuver. What were the limits of this high drag approach on TPS that caused it to go away?
3. RCC leading edge certainly takes more thermal load than the foamed glass bricks on the underside. But what about the heat capacity/ thermal distribution? Or do we still just melt aluminum too quickly, regardless of RCC hole size?
Thank you.
edit:
Anyone? Anyone? Bueller?
Ok. Danny's been talking of 60 degree alpha entry by the Shuttle.
I assume this means a rapid deceleration, instability, and low cross range entry profile.
1. Would it have made a difference to Columbia? Downsides?
2. Earlier Shuttle concepts had high angle entry with "belly flop" manuver. What were the limits of this high drag approach on TPS that caused it to go away?
3. RCC leading edge certainly takes more thermal load than the foamed glass bricks on the underside. But what about the heat capacity/ thermal distribution? Or do we still just melt aluminum too quickly, regardless of RCC hole size?
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
The ROFI systems powering up.
I think it is the SRB's Aux Power Units powering up. And they are turbines.
Danny Deger
SRB HPU start is T-27secs with SRB nozzle steering checks at T-21secs
snip
The fear of going into a spin - potentially a hypersonic spin.
snip
So no downsides?
snip
Faget's orbiter had a high drag profile pushing stability - was it due to perceived TPS limitations or fear of entering a flat spin. Also, was dynamic, adaptive profiles and aborts to other landings considered or not.
Do you have any idea of the figure of merit of how much -meaning are we talking a drastic decrease or a linear relationship?
The pilot was I think aware of the issue soon into entry - too late to change profile (e.g, adaptive), although I think I heard he altered yaw and pitch to attempt to mitigate. It doesn't seem like he had much other in the way of options to mitigate.
Even the theory of a crack or deformation from laminar flow on the leading edge is a significant issue for entry, so you would want to fly a profile to unstress it in a safety culture. Was the high alpha entry more likely to be distrusted because of it being untried, or simply considered ineffectual for a potential issue -e.g. the cure being worse than the disease?
snip
When was the commit to do the procedure? Prior to entry or during entry?
That's very creepy.
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
The ROFI systems powering up.
I think it is the SRB's Aux Power Units powering up. And they are turbines.
Danny Deger
SRB HPU start is T-27secs with SRB nozzle steering checks at T-21secs
I thought they started at T-19. I am certainly not a reliable source on this though, so you are probably correct. But I do recall STS-51 "aborted" at T-19 because one didn't start.
Danny Deger
Faget's orbiter:
(http://history.nasa.gov/SP-4221/p208.jpg)
http://history.nasa.gov/SP-4221/ch5.htm#208 (http://history.nasa.gov/SP-4221/ch5.htm#208)
http://forum.nasaspaceflight.com/index.php?topic=9004.0 (http://forum.nasaspaceflight.com/index.php?topic=9004.0)
Faget's orbiter:
(http://history.nasa.gov/SP-4221/p208.jpg)
http://history.nasa.gov/SP-4221/ch5.htm#208 (http://history.nasa.gov/SP-4221/ch5.htm#208)
http://forum.nasaspaceflight.com/index.php?topic=9004.0 (http://forum.nasaspaceflight.com/index.php?topic=9004.0)
It would have had to have done a very high alpha entry with those thin wings. I don't know about high alpha stability of this design.
What is the whirring noise heard usually at about T-15 seconds? it sounds like what you'd expect the high-pressure turbos to sound like but this is much too early for them, so I can only guess its air being forced through the pipes and out of the nozzles as water runs through the sound suppresion system?
The ROFI systems powering up.
I think it is the SRB's Aux Power Units powering up. And they are turbines.
Danny Deger
SRB HPU start is T-27secs with SRB nozzle steering checks at T-21secs
I thought they started at T-19. I am certainly not a reliable source on this though, so you are probably correct. But I do recall STS-51 "aborted" at T-19 because one didn't start.
Danny Deger
"There are two self-contained, independent Hydraulic Power Units (HPUs) on each SRB. Each HPU consists of an auxiliary power unit (APU), fuel supply module, hydraulic pump, hydraulic reservoir and hydraulic fluid manifold assembly. The APUs are fueled by hydrazine and generate mechanical shaft power to drive a hydraulic pump that produces hydraulic pressure for the SRB hydraulic system. The two systems operate from T-28 seconds until SRB separation from the ET."
Sorry for bringing up the prebank again, but surely a 180 degree prebank puts your TPS facing upwards, and the crew cabin directly into the face of hot burny firey danger?
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
Also, I know the banking is done pre-EI, so when does it come out of the prebank after EI?
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It might be facing the ground but it's still facing away from the direction of travel. Travel is more-or-less parallel to the ground, so upside down with nose pointing down at a steep angle still puts the heat on the belly.
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It is actually very easy to visualize.
Quote by elmarko:
Actually, that's a request for L2, potentially. Is there any kind of documentation about the DVIS system? I'd be really interested, as someone who sometimes deals with audio routing and the like (we have radio studios at my university job).
You're wonderful, thank you so much!
Is there any kind of orientation training manual kind of thing for new users, or do they just get given the manual?
You're wonderful, thank you so much!
Is there any kind of orientation training manual kind of thing for new users, or do they just get given the manual?
I don't recall even getting the manual. DVIS is one of those things you learn by having a senior sit next to you and show you how to use it. It has some fancy features but 90% of what a flight controller will ever use it for can be learned in ten minutes.
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It is actually very easy to visualize. Take a foam orbiter toy. Shove a stick into the belly at a 40 degree angle below the nose. That is the relative wind vector. It is also the X axis of the stability axis frame. That is the key. The bank is performed about stability axes, not body axes.
Now orient the toy so that you're looking down the stick at the belly. You're seeing the orbiter from the relative wind point of view. As long as the relative wind is aligned with the stick, the proper angle of attack (alpha) of 40 and sideslip angle (beta) of zero are maintained.
Now rotate the orbiter toy about the stick so that the belly is on top and the nose is pointed 40 degrees down. That's a prebank of 180. But the relative wind is still looking at the black belly, not the white tiles.
That's the key. When you perform a "roll" during entry you are rolling about the stability axes (the stick) and not the body axes (the nose). If you rolled 180 about the body axes you'd wind up with the top (white tiles) facing the wind. But a roll about stability axes always keeps the black side facing the wind.
It's really hard to visualise it.
I don't suppose anyone fancies a crack at drawing a diagram or something, because to me all I can think of is the orbiter banking past 90 degrees and then after 90 the white stuff is facing the ground...
It is actually very easy to visualize. Take a foam orbiter toy. Shove a stick into the belly at a 40 degree angle below the nose. That is the relative wind vector. It is also the X axis of the stability axis frame. That is the key. The bank is performed about stability axes, not body axes.
Now orient the toy so that you're looking down the stick at the belly. You're seeing the orbiter from the relative wind point of view. As long as the relative wind is aligned with the stick, the proper angle of attack (alpha) of 40 and sideslip angle (beta) of zero are maintained.
Now rotate the orbiter toy about the stick so that the belly is on top and the nose is pointed 40 degrees down. That's a prebank of 180. But the relative wind is still looking at the black belly, not the white tiles.
That's the key. When you perform a "roll" during entry you are rolling about the stability axes (the stick) and not the body axes (the nose). If you rolled 180 about the body axes you'd wind up with the top (white tiles) facing the wind. But a roll about stability axes always keeps the black side facing the wind.
Jorge, I have read this explaianation over and over and still can't picture it. where can I find a drawing of this?
Even stick figures will help as I am not a member of L2.
Thanks
Oxford750
Ok - stick figures it is :-) And I am not positive that I got this right, but I will try. In my pic, the upper Orbiter is with bottom towards ground and travelling to the 'left' of pic...arrow indicates direction of air/wind that Orbiter is 'seeing' upon its surfaces/wings. (angle0of-attack of wings is approximate but should give general idea)
Lower pic is after Orbiter 'rolls' 180 over onto its 'belly', so to speak. However, notice how its the 'bottom' that is striking the 'wind'? Yes, the top is facing downwards, but nothing else has changed for the most part, particularly the angle-of-attack of the wings -v- airflow. Its a position kind of like when an airplane is about to touchdown on landing (if that helps?)...
I realize my terms are not standard, but trying to 'dumb it down' (no offense to anyone!). Jorge's explanation got me FINALLY picturing all this in my head, and I am (used to be anyways) a licensed pilot, LOL! Thanks, Jorge..seriously, it helped me more than you may realize!
Anyways, hope that helps, and I truly hope that I am showing things correctly... not too shabby for a quick Paint sketch, 'eh?
Alex
Edit - Jorge beat me to the pic...and I like his pic much better :-)
To whom it may concern:
How can the (small compared to ISS) shuttle, or even the russian segment, for that matter, boost the orbit of the ISS? I mean don't you need MORE more thrusters spread out along the truss on both sides (like the shuttle) to boost the mass of ISS.
Thanks
Oxford750
Ok - stick figures it is :-) And I am not positive that I got this right, but I will try. In my pic, the upper Orbiter is with bottom towards ground and travelling to the 'left' of pic...arrow indicates direction of air/wind that Orbiter is 'seeing' upon its surfaces/wings. (angle0of-attack of wings is approximate but should give general idea)
Lower pic is after Orbiter 'rolls' 180 over onto its 'belly', so to speak. However, notice how its the 'bottom' that is striking the 'wind'? Yes, the top is facing downwards, but nothing else has changed for the most part, particularly the angle-of-attack of the wings -v- airflow. Its a position kind of like when an airplane is about to touchdown on landing (if that helps?)...
I realize my terms are not standard, but trying to 'dumb it down' (no offense to anyone!). Jorge's explanation got me FINALLY picturing all this in my head, and I am (used to be anyways) a licensed pilot, LOL! Thanks, Jorge..seriously, it helped me more than you may realize!
Anyways, hope that helps, and I truly hope that I am showing things correctly... not too shabby for a quick Paint sketch, 'eh?
Alex
Edit - Jorge beat me to the pic...and I like his pic much better :-)
Ok - stick figures it is :-) And I am not positive that I got this right, but I will try. In my pic, the upper Orbiter is with bottom towards ground and travelling to the 'left' of pic...arrow indicates direction of air/wind that Orbiter is 'seeing' upon its surfaces/wings. (angle0of-attack of wings is approximate but should give general idea)
Lower pic is after Orbiter 'rolls' 180 over onto its 'belly', so to speak. However, notice how its the 'bottom' that is striking the 'wind'? Yes, the top is facing downwards, but nothing else has changed for the most part, particularly the angle-of-attack of the wings -v- airflow. Its a position kind of like when an airplane is about to touchdown on landing (if that helps?)...
I realize my terms are not standard, but trying to 'dumb it down' (no offense to anyone!). Jorge's explanation got me FINALLY picturing all this in my head, and I am (used to be anyways) a licensed pilot, LOL! Thanks, Jorge..seriously, it helped me more than you may realize!
Anyways, hope that helps, and I truly hope that I am showing things correctly... not too shabby for a quick Paint sketch, 'eh?
Alex
Edit - Jorge beat me to the pic...and I like his pic much better :-)
Wow I never knew that the shuttle did that to "bleed off speed" or do I have it wrong. After seeing that I realized that I DID have the "right" picture in my mind, I just needed a conformation.
Thanks AlexInOklahoma
Wow I never knew that the shuttle did that to "bleed off speed" or do I have it wrong. After seeing that I realized that I DID have the "right" picture in my mind, I just needed a conformation.
Thanks AlexInOklahoma
To whom it may concern:
How can the (small compared to ISS) shuttle, or even the russian segment, for that matter, boost the orbit of the ISS? I mean don't you need MORE more thrusters spread out along the truss on both sides (like the shuttle) to boost the mass of ISS.
Thanks
Oxford750
It's not so much the quantity or size of the thrusters as much as where they're located and how much time is needed for the burn.
Note that either the Russian segment or Progress thrusters can used for reboosts (and usually are).
Thanks for that answer however the other problem I am having is with the center of gravity. I mean is the shuttle "not" on the "wrong" side of the stations center of gravity as opposed to Directly beneth it, (ie the thusters at the nose and the tail of the shuttle are an equall distance from the "middle" of the payload bay) therefore imparting the station to "roll" and or "yaw" and the same thing with the russain segment ?This probably belongs in ISS Q&A, but anyway... the thrust doesn't have to be exactly through the center of the stacks CG. You can counter the torques with other thrusters, it just burns some additional propellant.
This probably belongs in ISS Q&A, but anyway... the thrust doesn't have to be exactly through the center of the stacks CG. You can counter the torques with other thrusters, it just burns some additional propellant.
Thrust a long the long axis of the station (i.e. a Progress or ATV docked on the end of Zvezda firing rearward facing engines) is pretty close to the CG, and AFAIK this is the preferred configuration to do reboosts.
snip
Well, more accurately the orbiter *could* do that if it needed to. To my knowledge, we've never done a prebank of 180. I kinda doubt it's ever gone past 90, actually.
where can I find a drawing of this?
Thanks for that answer however the other problem I am having is with the center of gravity. I mean is the shuttle "not" on the "wrong" side of the stations center of gravity as opposed to Directly beneth it, (ie the thusters at the nose and the tail of the shuttle are an equall distance from the "middle" of the payload bay) therefore imparting the station to "roll" and or "yaw" and the same thing with the russain segment ?This probably belongs in ISS Q&A, but anyway... the thrust doesn't have to be exactly through the center of the stacks CG. You can counter the torques with other thrusters, it just burns some additional propellant.
Thrust a long the long axis of the station (i.e. a Progress or ATV docked on the end of Zvezda firing rearward facing engines) is pretty close to the CG, and AFAIK this is the preferred configuration to do reboosts.
What is this on the discovery ???Vents 1 and 2.
I never noticed those. What do they do?
They're close to the RCS system, do they vent out the remaining RCS fuel once the shuttle is in the atmosphere and RCS is useless?
During the STS-125 mission they attached a soft docking mechanism to Hubble to de-orbit it safely. I understand that this is because they don't want it there when the gyroscopes fail and they loose control of it. But what about the KH-12 spy satellite (or the other KHs) which are about the same size and mass as Hubble, what will happen to them when there gyroscopes fail?
Or is the safe de-orbiting of Hubble just because of the big public awareness of Hubbe compare to KH-12?
(sorry if this is the wrong section, couldn't find a good one)
During the STS-125 mission they attached a soft docking mechanism to Hubble to de-orbit it safely. I understand that this is because they don't want it there when the gyroscopes fail and they loose control of it. But what about the KH-12 spy satellite (or the other KHs) which are about the same size and mass as Hubble, what will happen to them when there gyroscopes fail?
Or is the safe de-orbiting of Hubble just because of the big public awareness of Hubbe compare to KH-12?
(sorry if this is the wrong section, couldn't find a good one)
Why are there quindar tones on UHF comm, but not on A/G1 and A/G 2?
During the STS-125 mission they attached a soft docking mechanism to Hubble to de-orbit it safely. I understand that this is because they don't want it there when the gyroscopes fail and they loose control of it. But what about the KH-12 spy satellite (or the other KHs) which are about the same size and mass as Hubble, what will happen to them when there gyroscopes fail?
Or is the safe de-orbiting of Hubble just because of the big public awareness of Hubbe compare to KH-12?
(sorry if this is the wrong section, couldn't find a good one)
KH-12 has propulsion systems. Hubble doesn't.
During the STS-125 mission they attached a soft docking mechanism to Hubble to de-orbit it safely. I understand that this is because they don't want it there when the gyroscopes fail and they loose control of it. But what about the KH-12 spy satellite (or the other KHs) which are about the same size and mass as Hubble, what will happen to them when there gyroscopes fail?
Or is the safe de-orbiting of Hubble just because of the big public awareness of Hubbe compare to KH-12?
(sorry if this is the wrong section, couldn't find a good one)
KH-12 has propulsion systems. Hubble doesn't.
That's something I didn't know. So the question that pops up in my head is why don't Hubble have propulsion?
What kind of propulsion does KH-12 have and how long does it last? I know this is classified but a qualified guess?
It is because Hubble is NASA and KH-12 is DOD. DOD follows the international rules on satellite and upperstage disposal, and NASA makes up its own.
It is because Hubble is NASA and KH-12 is DOD. DOD follows the international rules on satellite and upperstage disposal, and NASA makes up its own.
Danny, you are painting NASA with a too broad of brush. NASA follows the proper protocols for orbital debris and its requirements are more stringent than the FAA's or international laws.
During the STS-125 mission they attached a soft docking mechanism to Hubble to de-orbit it safely. I understand that this is because they don't want it there when the gyroscopes fail and they loose control of it. But what about the KH-12 spy satellite (or the other KHs) which are about the same size and mass as Hubble, what will happen to them when there gyroscopes fail?
Or is the safe de-orbiting of Hubble just because of the big public awareness of Hubbe compare to KH-12?
(sorry if this is the wrong section, couldn't find a good one)
KH-12 has propulsion systems. Hubble doesn't.
That's something I didn't know. So the question that pops up in my head is why don't Hubble have propulsion?
Concerns over contamination of the optics.
About 90 minutes.
Quick question, sorry if its been asked before, but POA mentioned on NASA tv last night that Discovery's crew was installing a chair for Kopra so he can adjust to gravity easier on entry. Is this the usual chair you would see on mid-deck or how does it differ?
Thanks.
It's a recumbent seat, so Kopra will be lying down.
It's a recumbent seat, so Kopra will be lying down.
Thanks! If I may ask, how is it positioned, doesn't seem to be much room on mid-deck. So he will be laying down with aspect to the shuttle being horizontal, would the head be towards the nose then?
Sorry there for a minute I was picturing a seat laying down while shuttle is vertical. *face palm*
Here's a link to a picture from STS-79:
It's a recumbent seat, so Kopra will be lying down.
Thanks! If I may ask, how is it positioned, doesn't seem to be much room on mid-deck. So he will be laying down with aspect to the shuttle being horizontal, would the head be towards the nose then?
Sorry there for a minute I was picturing a seat laying down while shuttle is vertical. *face palm*
If they're expecting difficulty with afternoon weather in Florida, why not try a descending node landing? Is the boundary layer DTO the reason?The issue with noctilucent clouds is in the summer (well, northern hemisphere summer).
If they're expecting difficulty with afternoon weather in Florida, why not try a descending node landing? Is the boundary layer DTO the reason?
If they're expecting difficulty with afternoon weather in Florida,
If they're expecting difficulty with afternoon weather in Florida, why not try a descending node landing? Is the boundary layer DTO the reason?
Ascending node or decending node don't really matter when the weather concerns are in and around the 30 nmi circle of KSC. Still violates constraints. Plus a decending node would take the vehicle over the US during the final phase of entry and that is something that is avoided as much as possible post-STS-107.
Descending node is 12 hours earlier so that's what I was thinking - not the route chosen. But Rob mentioned bad weather in the mornings too, so there goes that idea!I think generally those opportunities are more like 4-6 orbits later:
I've noticed that most landings at KSC lately have been at RWY15. The last one at RWY33 was STS-120. Is 15 favored due to weather?
Dudes, I just cannot find a reference to the price of the Shuttle in todays dollar, anyone have an approx value?
I've noticed that most landings at KSC lately have been at RWY15. The last one at RWY33 was STS-120. Is 15 favored due to weather?
I know one of the criteria is to not have a huge turn to line up on the runway. Anything over about 300 degrees is frowned on because it become more difficult to fly these large turns for many different reasons.
Danny Deger
what was the white plume coming out of Discovery's wings shortly before touchdown??
What do the V070 numbers mean, catalog numbers I would assume? I
what was the white plume coming out of Discovery's wings shortly before touchdown??http://en.wikipedia.org/wiki/Wingtip_vortices
A question on the filament wound casing SRBs intended for polar flight from SLC-6 at Vandenberg AFB:
I have managed to find one black&white image of the FWC SRM segments stacked together, and it seems like they only have field joints where each segment is stacked with the previous segment but no factory joints like on the steel segments.
Is this correct? Was this a weight-saving feature of the FWC SRM segments along with the case material change? Also, was the ET Attachment Ring built into the aft SRM segment like it was on to be the ASRM?
Thanks for the answers. On the ETAR: Was it a 270° ring like on the standard steel segments or was it a full 360° ring that would be used after the STS-51L accident?A question on the filament wound casing SRBs intended for polar flight from SLC-6 at Vandenberg AFB:
I have managed to find one black&white image of the FWC SRM segments stacked together, and it seems like they only have field joints where each segment is stacked with the previous segment but no factory joints like on the steel segments.
Is this correct? Was this a weight-saving feature of the FWC SRM segments along with the case material change? Also, was the ET Attachment Ring built into the aft SRM segment like it was on to be the ASRM?
yes and no
Quick question, sorry if this is the wrong thread but upon shuttles retirement, for which ever shuttle goes out west (IF it happens) why land the orbiter at KSC instead of just landing at EDW and keep it there?
I realize that the OPF is only in KSC but I'm trying to think outside of the box here. What all is going to go into preping the shuttle for displays, would any of it be able to be done out at EDW?
Quick question, sorry if this is the wrong thread but upon shuttles retirement, for which ever shuttle goes out west (IF it happens) why land the orbiter at KSC instead of just landing at EDW and keep it there?
I realize that the OPF is only in KSC but I'm trying to think outside of the box here. What all is going to go into preping the shuttle for displays, would any of it be able to be done out at EDW?
No, OPF is required for down loading all the hazardous commodities and passivating all the hazardous systems.
What do the Square root symbols (that are shown before many of the steps in the crew checklists) actually mean?
For example, this is from the ascent checklist:
√ ADI (two) – LVLH
√ H → +400 (θmax = 75°)
AT FINE COUNT:
√ Pitch Dn to α = -2°
√ MECO, ET SEP
√ Pitch Up
√ MM602
Go to RTLS ---MECO--- (FB)
What do the Square root symbols (that are shown before many of the steps in the crew checklists) actually mean?
For example, this is from the ascent checklist:
√ ADI (two) – LVLH
√ H → +400 (θmax = 75°)
AT FINE COUNT:
√ Pitch Dn to α = -2°
√ MECO, ET SEP
√ Pitch Up
√ MM602
Go to RTLS ---MECO--- (FB)
They are check marks meaning check this item
What do the Square root symbols (that are shown before many of the steps in the crew checklists) actually mean?
For example, this is from the ascent checklist:
√ ADI (two) – LVLH
√ H → +400 (θmax = 75°)
AT FINE COUNT:
√ Pitch Dn to α = -2°
√ MECO, ET SEP
√ Pitch Up
√ MM602
Go to RTLS ---MECO--- (FB)
They are check marks meaning check this item
What do the Square root symbols (that are shown before many of the steps in the crew checklists) actually mean?
For example, this is from the ascent checklist:
√ ADI (two) – LVLH
√ H → +400 (θmax = 75°)
AT FINE COUNT:
√ Pitch Dn to α = -2°
√ MECO, ET SEP
√ Pitch Up
√ MM602
Go to RTLS ---MECO--- (FB)
They are check marks meaning check this item
It has been a while, but I think a key to a checkmark is there should be no action at this step. But if something is not correct, maybe an action is needed.
No check mark means an action (i.e. a switch throw) is needed at the step. Maybe someone with more active brain cells and closer to training can confirm.
Danny Deger
what is the job/purpose of the person sat at the FD's left during ascent and entry (and occasionally during orbit ops).
And also what does the person/s next to the Capcom do?(from watching a few of the MCC replays on youtube there always seems to be one or a couple of people sat there just staring at the big screens the whole time)
And also what does the person/s next to the Capcom do?(from watching a few of the MCC replays on youtube there always seems to be one or a couple of people sat there just staring at the big screens the whole time)
Dudes, I just cannot find a reference to the price of the Shuttle in todays dollar, anyone have an approx value?
That is a very complex question with many different answers. First of all, do you mean a launch, or the "price" of an Orbiter.
Danny Deger
Dudes, I just cannot find a reference to the price of the Shuttle in todays dollar, anyone have an approx value?
That is a very complex question with many different answers. First of all, do you mean a launch, or the "price" of an Orbiter.
Danny Deger
Danny, just the Orbiter would work fine.. thanks
snip
On second thought, make it three times, then round it to an even $5B since there's no way to know this figure past one significant digit.
snip
On second thought, make it three times, then round it to an even $5B since there's no way to know this figure past one significant digit.
You forgot to add Florida sells tax ::)
Danny Deger
what is the job/purpose of the person sat at the FD's left during ascent and entry (and occasionally during orbit ops).
And also what does the person/s next to the Capcom do?(from watching a few of the MCC replays on youtube there always seems to be one or a couple of people sat there just staring at the big screens the whole time)
Assistant FD
And another question, (and vaguely related) every TPS tile on the orbiters has a small white circle which as I understand is for "instrumentation" purposes, does this mean that there is a sensor/thermocouple type thing behind every single one of them? (surely not!), Are these "white dots" holes drilled into the tile or something more superficial?
I apologize if this has been asked/answered, but there are simply too many pages to sort through. Node 3 was originally intended to be placed on Unity's nadir CBM, with PMA-3 being attached to the Earth-facing port of Node 3. Was it ever NASA's intention to dock an orbiter to PMA-3 while it was on Node 3? Thanks!
I apologize if this has been asked/answered, but there are simply too many pages to sort through. Node 3 was originally intended to be placed on Unity's nadir CBM, with PMA-3 being attached to the Earth-facing port of Node 3. Was it ever NASA's intention to dock an orbiter to PMA-3 while it was on Node 3? Thanks!
At the time that Node-3 was slated for that location, I don't think NASA had plans to dock an Orbiter to PMA-3.
The tailcone breaks apart and is carried inside the SCA.
The tailcone breaks apart and is carried inside the SCA.
since the STS-128 is arriving with showers all around, I would assume there is a risk of rain shortly after touchdown of the SCA. Are they not worried about getting the shuttle wet, or do they have some way to get the entire SCA and shuttle undercover quickly, since the demating and towing of the shuttle will take some time?There's no complete cover at either the mate-demate device at Dryden or at the SLF. There's concern about lots of rain, as it would take longer to dry out the blankets and tiles, but they can handle some rain on the ground.
since the STS-128 is arriving with showers all around, I would assume there is a risk of rain shortly after touchdown of the SCA. Are they not worried about getting the shuttle wet, or do they have some way to get the entire SCA and shuttle undercover quickly, since the demating and towing of the shuttle will take some time?There's no complete cover at either the mate-demate device at Dryden or at the SLF. There's concern about lots of rain, as it would take longer to dry out the blankets and tiles, but they can handle some rain on the ground.
There's no concern of an Orbiter getting rained on while on the SLF/at the MDD. STS-117/Atlantis got a pretty good soaking after her return to KSC on the SCA. They simply dried out her blankets and tiles once she was back in OPF-1.Thanks for clarifying. Bigger issue to have steady rain -- like we're getting in Atlanta the last few days -- out at Dryden. At KSC, they can demate and tow her into the OPF to get out of any rain. At Dryden, there's at least one case (STS-98) where rain at Dryden soaked some of the tiles enough that it took extra time to "bake" the moisture out with heat lamps when Atlantis got back to Florida. And the rain there keeps the ferry from getting started, which increases the time outdoors.
1) How long does that take, though?
2) Would there be a call for some sort of covering device?
3) Not that matters in this late stage in the program, of course, but was it ever a concern in the past before they realised it wasn't a big deal?
Hello!
I'd like to know what are temperatures on that altitude the space shuttle fly?
Thanks
2) Why would there need to be a covering device when it's no problem if the vehicle gets rained on while at Dryden/on the SLF/at the MDD.
Surely there'd be a breakpoint where you decide "Yeah, actually it is worth it..."Maybe, but it would probably be IF the landing sites were in different climates. As noted, the orbiter is only going to be exposed at the SLF for probably a couple of shifts. Dryden/Edwards is in the middle of a desert -- they generally don't get a lot of rain, and the humidity there is often in the teens. (It's as dry there as it is muggy in Florida in the summer.)
2) Why would there need to be a covering device when it's no problem if the vehicle gets rained on while at Dryden/on the SLF/at the MDD.
I was trying to determine how much of a "non problem" it was - like, how much time it takes to dry out the blankets and tiles vs the cost and effort of covering everything.
Surely there'd be a breakpoint where you decide "Yeah, actually it is worth it..."
During STS-128's approach to Edwards, I recall Rob Navias commented that the twin sonic booms herald the shuttle's approach as it passes through the sound barrier.
I always thought the sonic shock wave is continuous throughout supersonic flight, not just at the mach 1 transition. I guess it's not surprising for a non-technical person to get this wrong, but in the STS-127 crew presentation airing today on NTV, Chris Cassidy made the following comment during the landing replay "...as we come through mach 1, if you've been there, you can hear the two sonic booms."
Now I'm wondering... do I have it wrong?
I'd like to know what are temperatures on that altitude the space shuttle fly?
Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
I imagine it has some sort of I-loaded value at liftoff, and then it doesn't change during 1st stage (because it's open loop, so there's no inputs from the system), and then during the cycles of convergence they change.
Whether that means going lower or higher would depend on the initial value, obviously.
Any insight from Jorge/Mkirk?
Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
I imagine it has some sort of I-loaded value at liftoff, and then it doesn't change during 1st stage (because it's open loop, so there's no inputs from the system), and then during the cycles of convergence they change.
Whether that means going lower or higher would depend on the initial value, obviously.
Any insight from Jorge/Mkirk?
Guidance doesn't compute TMECO until MM103.
Appears at liftoff, according to Ascent Guidance workbook. I imagine as guidance converges the prediction changes.
So thats the question really...it appears at liftoff, but does it display XX:XX...crazy values, too high values, too low values...and then once into MM103 settles down into a good value?
I imagine it has some sort of I-loaded value at liftoff, and then it doesn't change during 1st stage (because it's open loop, so there's no inputs from the system), and then during the cycles of convergence they change.
Whether that means going lower or higher would depend on the initial value, obviously.
Any insight from Jorge/Mkirk?
Guidance doesn't compute TMECO until MM103.
Mach 25 is right!
TMECO is not even shown on the PASS or BFS ASCENT TRAJ 1 Displays (first stage, OPS 102). It appears on PASS & BFS ASCENT TRAJ 2 (second stage OPS 103) during staging. The crew will check that both the PASS and BFS independently come up with stable estimates for MECO within ~ 10 seconds of staging (guidance convergence). Both of the PASS & BFS predictions should closely agree with each other. The time will be displayed as something like 08:32.
Mark Kirkman
Mach 25 is right!
TMECO is not even shown on the PASS or BFS ASCENT TRAJ 1 Displays (first stage, OPS 102). It appears on PASS & BFS ASCENT TRAJ 2 (second stage OPS 103) during staging. The crew will check that both the PASS and BFS independently come up with stable estimates for MECO within ~ 10 seconds of staging (guidance convergence). Both of the PASS & BFS predictions should closely agree with each other. The time will be displayed as something like 08:32.
Mark Kirkman
Thanks..thats narrowed it down. So although the TRAJ display layout is basically the same there is essentially a TRAJ display for MM101,102 and 103. TMECO is not present until MM103 when it appears on the display, and (hopefully!) rapidly converges to a sensible TMECO.
Of course the BFS has two vastly different TRAJ displays (1 & 2)...and TRAJ 1 doesn't have TMECO and TRAJ 2 does.
There is no way to determine whats on the different PASS TRAJ displays and when from the DPS dictionary.
I've always thought TRAJ 1 and TRAJ 2 on the BFS seem to provide a clearer look at the ascent situation than the single PASS TRAJ. The PASS TRAJ has a lot of 'screen real-estate' taken up with RTLS stuff. Presumably on a normal ascent the crew will watch the BFS TRAJ displays more than pass (or maybe they are all equally covered in the 'instrument scan').
Okay, manifest question. A FAWG manifest dated April 21, 2005 had STS-119/ISS 15A delivering the S-6 truss prior to the launch of Node 2 and the international partner lab modules. We know that 119 was postponed until after those modules were delivered to the station in order to allow those labs to get up and running sooner. When was the manifest changed, and is there any memo, press release, or other documentation availalbe re this change?Have you tried searching NSF? I found a story on the timing by just plugging "15A site:nasaspaceflight.com" into Google.
Well ok, the Ascent Guidance workbook says that:
* (pages 6-18 and 6-20) ASCENT TRAJ 1 and 2 are available in the BFS only (1 comes up at MM102/SSME Ignition, 2 comes up at MM103/SRB SEP)
* (page 6-22) XXX ASCENT TRAJ is available in the PASS and that it comes up automatically at SSME start (does that mean it remains on a CRT throughout the entire ascent? And if so, kneecaps original question of what the TMECO field displays before MM103 still applies).
Hence, I'm a little confused.
It seems that certain documents conflict here. My brain hurts. :)
Thanks for your answers so far, though!
Okay, manifest question. A FAWG manifest dated April 21, 2005 had STS-119/ISS 15A delivering the S-6 truss prior to the launch of Node 2 and the international partner lab modules. We know that 119 was postponed until after those modules were delivered to the station in order to allow those labs to get up and running sooner. When was the manifest changed, and is there any memo, press release, or other documentation availalbe re this change?Have you tried searching NSF? I found a story on the timing by just plugging "15A site:nasaspaceflight.com" into Google.
Actually, this probably ends up being at least as much an ISS question as a shuttle question...15A was in front of 10A in the assembly sequence going back to before STS-107.
Edit: actually, it also involves RTF and VSE and probably ESAS, too.
Okay, manifest question. A FAWG manifest dated April 21, 2005 had STS-119/ISS 15A delivering the S-6 truss prior to the launch of Node 2 and the international partner lab modules. We know that 119 was postponed until after those modules were delivered to the station in order to allow those labs to get up and running sooner. When was the manifest changed, and is there any memo, press release, or other documentation available re this change?
This ought to be fairly well known but I cant seem to find any info anywhere:
How much do the expendables cost on the shuttle per launch, im talking about the cryo's, ET, srb propellant, tyres etc.
Come to think of it, is there a document covering these somewhere (a budget breakdown or such)?
1) Why was MPLM Donatello never flight certified
2) and what made Raffaello get chosen for PLM?
3) One more MPLM question. Why has Leonardo been flying so much recently rather than Raffaello?
Thanks :)
what made Raffaello get chosen for PLM?
Interesting post.what made Raffaello get chosen for PLM?
It appears that PLM will be Leonardo, not Raffaello.
http://www.collectspace.com/ubb/Forum30/HTML/000371.html (September 4, 2009)
"According to ISS Program Manager Mike Suffredini just two days ago, the MPLM to be adapted as the PLM is Leonardo (currently on-orbit with STS-128), not Raffaello. Suffredini did say the plan could change, but currently, Leonardo is it."
1) Why was MPLM Donatello never flight certified
2) and what made Raffaello get chosen for PLM?
3) One more MPLM question. Why has Leonardo been flying so much recently rather than Raffaello?
Thanks :)
Your third question is answered by your second question. They need time to refit the MMOD panels on Raffaello and do whatever else needs to be done to convert the MPLM into the PLM.
The answer to the first question is: $$$. By forgoing flight certification for Donatello, they save money that can then be spent elsewhere. Donatello was only going to have one flight anyway (was going to be 128 I believe).
Interesting post. It was Suffredini that publicly identified Raffaello (FM-2) as the flight module to become the PLM earlier this year
You're right -- my mistake.Interesting post. It was Suffredini that publicly identified Raffaello (FM-2) as the flight module to become the PLM earlier this year
I doubt it was Michael Suffredini. It was Daniel Hartman, manager of Integration and Operations in ISS Program.
http://www.collectspace.com/ubb/Forum30/HTML/000371.html
"Dan Hartman, NASA's manager for the integration and operations of the International Space Station, addressed this topic today (May 6) during a press conference: "The study is back on the table so we're looking at adding what we call a 'PLM', a permanent logistics module to the International Space Station. And I believe it is 'Unit 2' and I'm not quite sure what that one [MPLM] is specifically called"
I think part of the reason you might be getting confused is because the PASS TRAJ displays were recently modified (in OI-32, STS-120 I believe) – the picture I posted reflects my understanding of what the current displays look like for nominal ascent.
Probably a dumb question and has been answered before although I wasn't able to find it on a search. With the SSME having LO2 and LH as fuel, when the engines are first started, is it with the Liquid or gaseous O2 and H. I was just wondering how it is vaporized before the engines are started or is it liquid when it ignites and during the flight?
Only liquid is fed to the engines. The start sequency is complex and I never understood it completely. For example in a running engine the hydrogen runs in tubes in the nozzle to cool it. This vaporizes the hydrogen. When I taught an MPS class, I crossed my fingers no one whould ask how the darn thing starts. I would admit I didn't have a clue, but had the name and number of a booster flight control they could bug.
I found saying "I don't know" was better than making up stuff.
Danny Deger
Probably a dumb question and has been answered before although I wasn't able to find it on a search. With the SSME having LO2 and LH as fuel, when the engines are first started, is it with the Liquid or gaseous O2 and H. I was just wondering how it is vaporized before the engines are started or is it liquid when it ignites and during the flight?
Only liquid is fed to the engines. The start sequency is complex and I never understood it completely. For example in a running engine the hydrogen runs in tubes in the nozzle to cool it. This vaporizes the hydrogen. When I taught an MPS class, I crossed my fingers no one whould ask how the darn thing starts. I would admit I didn't have a clue, but had the name and number of a booster flight control they could bug.
I found saying "I don't know" was better than making up stuff.
Danny Deger
Thanks DD, so I guess it wasn't a dumb question after all. Maybe a post on L2 would get an answer. I checked the SSME Bible and it gives a lot of the information, but will take some time to digest for me. "Download 2"
http://forum.nasaspaceflight.com/index.php?topic=4413.0
snip
Apparently only liquid head pressures and the ASIs sparking is actually needed to start, but I'd love to hear an expert explain or illustrate this!
I think a key must be to get a fire going to blow hot gas through the turbines that drives the main pumps. I don't think there is any kind of starter that spins the pump up.
I think a key must be to get a fire going to blow hot gas through the turbines that drives the main pumps. I don't think there is any kind of starter that spins the pump up.
One of the first things that happens is the Main Fuel Valve ramps fully open, this allows LH2 to get to the preburners. Both the Oxidizer preburner and Fuel preburner valves also ramp open (but not fully) in the same time period. I'm thinking that the requirement for head pressure to start simply forces LOX and LH2 into the preburners (and the ASIs (igniters).
Pressure has forced LOX and LH2 into the preburners. This burns which causes a small amount of hot gas, this spins the turbines which in turn causes more LOX and LH2 to reach the preburners (which causes the pumps to spin faster, pumping more to the preburners, and so on).
At some point the igniters will stop since combustion in the preburners will become self sustaining.
This link has been posted here before...the material there is at least historically related:
http://www.enginehistory.org/ssme.htm
It has a spark plug in the preburner that uses a LH rich fuel for the turbo pumps and then they adjust the final fuel mixture in the Main combustion chamber. Not sure if they have just the one spark plug for ignition or one in the preburner and one in the MCC.
It has a spark plug in the preburner that uses a LH rich fuel for the turbo pumps and then they adjust the final fuel mixture in the Main combustion chamber. Not sure if they have just the one spark plug for ignition or one in the preburner and one in the MCC.
There are six "spark plugs". ASIs, Augmented Spark Igniters. They are found in pairs (for redundancy) in both pre burners and in the main injector.
The fuel:oxidizer ratio is controlled by the fuel preburner oxidizer valve (FPOV) only and is NOT adjusted at the MCC.
The thrust level is controlled by the oxidizer preburner oxidizer valve (OPOV) and the FPOV moves to maintain the correct mixture.
I believe the MOV (Main Oxidizer Valve, lets LOX into the MCC) is open 100% during the entire mainstage.
Digest the flow paths through the engine and (it took me quite a long time), you'll have a eureka moment when it all kind of makes sense.
It's a beautifully complex but remarkably simple engine in many ways..I think 'elegant' is the better word.
In 28.5 degree shuttle missions, does the shuttle make a 90º counterclockwise roll program??Yes.
Is there a reason they flew 17 days apart, or was it just that they wanted to go as many as possible in 1985?The latter -- they were working towards a flight rate of 24 flights per year. (This has been discussed here before.) Since the 51-B payload was a Spacelab module (already loaded), that probably shortened the pad time a little bit.
The latter -- they were working towards a flight rate of 24 flights per year.
Question regarding Ferry Flights:The shape of the wing provides some lift, but given the relatively slow airspeed while on the SCA it probably doesn't help a lot
Does the Shuttle's wings provide any lift during the flight, or is the orbiter just dead weight atop the SCA?
Why is the orbiter not placed on the Orbiter Transporter System when it is taken off of the mate/demate device at KSC? Was the MDD not designed to lower the orbiter with enough precision? Thanks.
Why is the orbiter not placed on the Orbiter Transporter System when it is taken off of the mate/demate device at KSC? Was the MDD not designed to lower the orbiter with enough precision? Thanks.
The wheels have to be replaced anyway after a flight, it is faster to just tow it to the OPF.
Before they got the Orbiter Transporter System the orbiters were towed during rollover too.
Why is the orbiter not placed on the Orbiter Transporter System when it is taken off of the mate/demate device at KSC? Was the MDD not designed to lower the orbiter with enough precision? Thanks.
The wheels have to be replaced anyway after a flight, it is faster to just tow it to the OPF.
Before they got the Orbiter Transporter System the orbiters were towed during rollover too.
Edit: OK I just read on another post the cart was built for a long tow at Vandenburg. This almost makes sense, bearing temps or something might go out of specs for a long tow -- even then I don't see what is wrong with a long tow. But why then move the darn thing to KSC and use it instead of just towing to the VAB for stacking.
Edit: OK I just read on another post the cart was built for a long tow at Vandenburg. This almost makes sense, bearing temps or something might go out of specs for a long tow -- even then I don't see what is wrong with a long tow. But why then move the darn thing to KSC and use it instead of just towing to the VAB for stacking.
The "tow" route was hilly. Also the OTS allows for the gear to be retracted in a better facility
Edit: Why was there a need to tow on hilly terrain at Vandie? Sounds like a really bad place for shuttle OPS is there was not enough room to avoid hilly terrain. Even then, we have machines called "earth moving equipment" to level a road bed.
You haven't been to VAFB. Launch pads were in canyons. The tow route was more than 5 (maybe twenty) miles. The OMCF was on the north base and SLC-6 was on the south base.
Edit: Why was there a need to tow on hilly terrain at Vandie? Sounds like a really bad place for shuttle OPS is there was not enough room to avoid hilly terrain. Even then, we have machines called "earth moving equipment" to level a road bed.
You haven't been to VAFB. Launch pads were in canyons. The tow route was more than 5 (maybe twenty) miles. The OMCF was on the north base and SLC-6 was on the south base.
Why is the orbiter not placed on the Orbiter Transporter System when it is taken off of the mate/demate device at KSC? Was the MDD not designed to lower the orbiter with enough precision? Thanks.
The wheels have to be replaced anyway after a flight, it is faster to just tow it to the OPF.
Before they got the Orbiter Transporter System the orbiters were towed during rollover too.
You meant to say tires didn't you. The brakes were redesigned in about 1995 to allow for multiple uses. The old brakes broke up with a single use and tended to stick and what not. Really, really bad brakes. You couldn't use them, let up, then use them again. The pads would fracture at the first use and then when released, fractured pieces of brake pad would do nasty things to the brake assembly with the second application. They were an accident ready to happen and NASA fixed them. They also added the drag chute for crew safety at about this time.
Danny Deger
With the SSME having LO2 and LH as fuel, when the engines are first started, is it with the Liquid or gaseous O2 and H. I was just wondering how it is vaporized before the engines are started or is it liquid when it ignites and during the flight?
And when the tank seperates on orbit does the doors seal the same as landing gear doors (Do they come down) or do they slide over to cover the connection point?
What if it failed to close?
Why does it take 1 week normally from the time the shuttle is connected to the Tank and Boosters in the VAB to roll it out? Once connected what tasks do they go through? Are there many, or just a few but are time consuming?
And when the tank seperates on orbit does the doors seal the same as landing gear doors (Do they come down) or do they slide over to cover the connection point?
The doors are hinged on the inboard side, and after ET sep they flip 180 degrees to close.
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/sep/umbdoors.html
Photo here:
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=43554QuoteWhat if it failed to close?
The doors can be closed manually via EVA. The area around the doors is (just barely) reachable by an astronaut in a foot restraint on the tip of the OBSS at the end of the RMS.
If the doors can't be closed at all, LOV/C.
And when the tank seperates on orbit does the doors seal the same as landing gear doors (Do they come down) or do they slide over to cover the connection point?
The doors are hinged on the inboard side, and after ET sep they flip 180 degrees to close.
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/sep/umbdoors.html
Photo here:
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=43554QuoteWhat if it failed to close?
The doors can be closed manually via EVA. The area around the doors is (just barely) reachable by an astronaut in a foot restraint on the tip of the OBSS at the end of the RMS.
If the doors can't be closed at all, LOV/C.
And when the tank seperates on orbit does the doors seal the same as landing gear doors (Do they come down) or do they slide over to cover the connection point?
The doors are hinged on the inboard side, and after ET sep they flip 180 degrees to close.
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/sep/umbdoors.html
Photo here:
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=43554QuoteWhat if it failed to close?
The doors can be closed manually via EVA. The area around the doors is (just barely) reachable by an astronaut in a foot restraint on the tip of the OBSS at the end of the RMS.
If the doors can't be closed at all, LOV/C.
Jorge; two follow-ups, if I may:
(1) Regarding the manual closure of the ET umbilical doors, how is this done? Via a hand crank of some kind?
(2) Prior to the OBSS era, how would the EVA crewmember accomplish this without the extra reach provided by the boom? Thanks.
And when the tank seperates on orbit does the doors seal the same as landing gear doors (Do they come down) or do they slide over to cover the connection point?
The doors are hinged on the inboard side, and after ET sep they flip 180 degrees to close.
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/sep/umbdoors.html
Photo here:
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=43554QuoteWhat if it failed to close?
The doors can be closed manually via EVA. The area around the doors is (just barely) reachable by an astronaut in a foot restraint on the tip of the OBSS at the end of the RMS.
If the doors can't be closed at all, LOV/C.
Jorge; two follow-ups, if I may:
(1) Regarding the manual closure of the ET umbilical doors, how is this done? Via a hand crank of some kind?
There is no crank. What the crew would do depends on the failure mode. If centerline latch, open the latch manually and allow the motors to close the doors. There are two motors on each door, geared such that a jam in one motor cannot prevent the other motor from closing the door. An EVA astronaut could probably not close the door manually with a dual motor failure, but two independent failures like that is highly unlikely.Quote(2) Prior to the OBSS era, how would the EVA crewmember accomplish this without the extra reach provided by the boom? Thanks.
Prior to the EVA, the crew would improvise a bolo using a bag full of clothes and an EVA safety tether. The EVA crewmember would translate to the aft end of the payload bay along the EVA slidewire on the sill, secure the tether end of the bolo to the slidewire, then sling the bolo such that the bag catches in the gap between the inboard elevon and the aft fuselage (this would likely take several attempts). The EVA cremember would then attach his own safety tether to the bolo, translate down the bolo to the elevon, then pull himself over the side. The umbilical doors are reachable from the underside of the elevon.
This EVA was considered unlikely to work and consequently not taken seriously by most astronauts.
Nevertheless, there was (and maybe still is) a high-fidelity mockup of the ET umbilical doors in the highbay of JSC building 9 for EVA training.
50 – approximate percent of the 15,000-pound shuttle performance increase necessary to fly to the International Space Station that is provided by the Super Lightweight Tank
Following the Wikipedia ET page (http://en.wikipedia.org/wiki/Space_Shuttle_external_tank) to this Lockheed Martin page (http://www.lockheedmartin.com/ssc/michoud/ExternalTank/ByNumbers.html) I found this quote:Quote50 – approximate percent of the 15,000-pound shuttle performance increase necessary to fly to the International Space Station that is provided by the Super Lightweight Tank
What provides the other 50%?
What causes the tyvek (previously AFRSI) covers to blow off of the aft RCS thrusters once the SSMEs ignite?The covers have always been paper, never "tiles" -- they burn.
Following the Wikipedia ET page (http://en.wikipedia.org/wiki/Space_Shuttle_external_tank) to this Lockheed Martin page (http://www.lockheedmartin.com/ssc/michoud/ExternalTank/ByNumbers.html) I found this quote:Quote50 – approximate percent of the 15,000-pound shuttle performance increase necessary to fly to the International Space Station that is provided by the Super Lightweight Tank
What provides the other 50%?
Besides, AFRSI is a thermal blanket material, not a tile material.What causes the tyvek (previously AFRSI) covers to blow off of the aft RCS thrusters once the SSMEs ignite?The covers have always been paper, never "tiles" -- they burn.
What causes the tyvek (previously AFRSI) covers to blow off of the aft RCS thrusters once the SSMEs ignite?The covers have always been paper, never "tiles" -- they burn.
They come off (mostly) when the main engines start on the pad before booster ignition.What causes the tyvek (previously AFRSI) covers to blow off of the aft RCS thrusters once the SSMEs ignite?The covers have always been paper, never "tiles" -- they burn.
I have heard the acoustics from SRB ignition take them off.
Danny Deger
They come off (mostly) when the main engines start on the pad before booster ignition.What causes the tyvek (previously AFRSI) covers to blow off of the aft RCS thrusters once the SSMEs ignite?The covers have always been paper, never "tiles" -- they burn.
I have heard the acoustics from SRB ignition take them off.
Danny Deger
Yes. The ones on the forward RCS were changed after STS-107 to get them to release early (and more completely) in first stage before they can become a debris risk.They come off (mostly) when the main engines start on the pad before booster ignition.
How about the ones on the forward pod? Do they survive the main engines starting?
Following the Wikipedia ET page (http://en.wikipedia.org/wiki/Space_Shuttle_external_tank) to this Lockheed Martin page (http://www.lockheedmartin.com/ssc/michoud/ExternalTank/ByNumbers.html) I found this quote:Quote50 – approximate percent of the 15,000-pound shuttle performance increase necessary to fly to the International Space Station that is provided by the Super Lightweight Tank
What provides the other 50%?
In the unlikely event that the Shuttle lost both OMS thrusters could the Shuttle reenter simply by letting its orbit decay? I imagine this depends very strongly on its altitude and orientation. How soon would the Shuttle's orbit decay if it presented the maximum possible area normal to its velocity vector? Could it survive such a reentry, provided it reoriented itself in time? Could it keep the crew alive for long enough to do this?
Yep. The +X RCS jets.In the unlikely event that the Shuttle lost both OMS thrusters could the Shuttle reenter simply by letting its orbit decay? I imagine this depends very strongly on its altitude and orientation. How soon would the Shuttle's orbit decay if it presented the maximum possible area normal to its velocity vector? Could it survive such a reentry, provided it reoriented itself in time? Could it keep the crew alive for long enough to do this?
No but it could use its RCS thrusters
Yep. The +X RCS jets.In the unlikely event that the Shuttle lost both OMS thrusters could the Shuttle reenter simply by letting its orbit decay? I imagine this depends very strongly on its altitude and orientation. How soon would the Shuttle's orbit decay if it presented the maximum possible area normal to its velocity vector? Could it survive such a reentry, provided it reoriented itself in time? Could it keep the crew alive for long enough to do this?
No but it could use its RCS thrusters
No but it could use its RCS thrusters
No but it could use its RCS thrusters
Where would things go wrong if you tried the orbital decay route? Not trying to say it would be a good idea, just trying to understand.
No but it could use its RCS thrusters
Where would things go wrong if you tried the orbital decay route? Not trying to say it would be a good idea, just trying to understand.
wrong entry angle. Too shallow
wrong entry angle. Too shallow
What happens if you enter at too shallow an angle? Do you then descend too fast and burn up? I remember from playing with Orbiter that counterintuitively, if you are descending too fast you have to dive.
Shuttle orbits are high enough that they will not decay naturally within the lifetime of the crew. Therefore this approach is not viable (literally!) and the discussion is moot.
I know, but I'm just curious. You've explained it would take too long, which seems understandable enough. Jim said the reentry angle would be too shallow and I don't understand what's wrong with that and I'd like to know. Feel free not to answer!I'm assuming it takes too long because the entry angle is too shallow; at that altitude it takes a long time for atmospheric resistance to significantly affect your velocity. By descending more steeply, you reach the denser part of the atmosphere more quickly.
It's pretty simple - if you don't have something to put brakes on the shuttle, it will stay up there for a LONG LONG time. I'm not sure what's confusing?
So what happens once you skip out?
What happens if you enter at too shallow an angle?
Yep. The +X RCS jets.In the unlikely event that the Shuttle lost both OMS thrusters could the Shuttle reenter simply by letting its orbit decay? I imagine this depends very strongly on its altitude and orientation. How soon would the Shuttle's orbit decay if it presented the maximum possible area normal to its velocity vector? Could it survive such a reentry, provided it reoriented itself in time? Could it keep the crew alive for long enough to do this?
No but it could use its RCS thrusters
Doesn't have to be just the +X jets, fast flip and prebank can also contribute to getting the needed delta V. This topic has been covered a lot here so a search might find you some more detailed answers.
Mark Kirkman
I did some googling and it turns out there is something called an entry corridor which determines the range of angles suitable for reentry. Too steep and you burn up, too shallow and you skip out of the atmosphere again. I don't know if this applies to return from LEO as well as lunar returns, but I suppose it does. So what happens once you skip out? Since you would have lost some energy your orbit would still be decaying. How steep would the next angle be? Could it be that the angle gets progressively steeper with every skip until finally you burn up?
I'm assuming you're talking about the atmosphere there, rather than on the orbiter itself. I just searched for an ESTEC standard that I ran across somewhere several years ago, but I can't find it now. Maybe you can come up with more creative Google terms than me.
Basically, the individual atoms or molecules are really hot (>1000K), but they are so far apart that it would "feel" really cold (<100K).
Edit: here's a ton of models
http://ccmc.gsfc.nasa.gov/modelweb/
I'd like to know what are temperatures on that altitude the space shuttle fly?
I recently saw some footage of slow motion MLP cameras during launch and I could see some kind of dirt covering up the cameras. I understand that is SRB exhaust. Does this 'dirt' contaminates the ocean when the SRBs fly over it??
could you please explain it up??I recently saw some footage of slow motion MLP cameras during launch and I could see some kind of dirt covering up the cameras. I understand that is SRB exhaust. Does this 'dirt' contaminates the ocean when the SRBs fly over it??
SRBs do not pollute the ocean.
is that 'dirt' covering the cameras not part of SRB exhaust?? in case they are part of it, does it fall into the ocean?? in case they fall into the ocean, is it toxic??
1) What is the pitch angle of the orbiter when attached to the External Tank?
-Other ways to answer this question
a) What is the offset of the orbiter at the aft of the ET and what is the offset at the bipod assembly at the forward attachment?
2) What are the dimensions of the SRB Thrust Beam inside the Intertank? This is the beam that connects the port and starboard SRBs at the forward attachment point. It also accounts for the dampening of the oscillations that originate from the SRBs.
3) I am looking for structural drawings of the orbiter itself. Mostly for wing profile and the like, but I would like to also see how the orbiter was designed as a structure. If I need to get approval from a NASA official to gain access to the drawings, please let me know. I am very interested in the orbiters design, both scientifically and for my own personal knowledge.
Anybody know success rate (%) of shuttle first launch attempt?
Why the switch in flight engineers on STS-129? Randy Bresnik is the ascent FE; Leland Melvin is FE on entry. There is surely a reason for this. . .anybody know why?I believe it was mentioned during the crew news conference pre-flight.
During this afternoon's countdown coverage on NTV, the PAO rolled a cool time-lapse video of Atlantis sitting on the MLP inside the VAB, looking down from above. It showed the crawler enter the VAB, drive under the MLP and back out of the VAB carrying the stack. I'd never seen it from that perspective before.See this post in the LC-39 Q&A thread: http://forum.nasaspaceflight.com/index.php?topic=14430.msg386436#msg386436
I noticed what appeared to be three large vans or buses and a smaller vehicle lined up on top of the MLP, near the edge opposite the shuttle. These vehicles remained in place as the stack left the VAB. Does anyone know what these vehicles are for and how they get them off the platform?
See this post in the LC-39 Q&A thread: http://forum.nasaspaceflight.com/index.php?topic=14430.msg386436#msg386436
Another question... Is STS-129 taking a recumbent seat for Nicole Stott to save weight (since there's only six crew going uphill) or is that standard procedure for bringing home long-duration ISS crew members?More the latter -- it's been standard procedure since Shuttle-Mir.
Plus it depends on your definition of "attempt"
I think what Rob is getting at is, for example, was there an "attempt" to launch STS-51E? And was that counted in the AP story?Plus it depends on your definition of "attempt"attempt: /əˈtɛmpt/,
Noun
The action of trying at something.
Can someone explain what the green areas are on the MCC display of launch? Some sort of crossrange display or predicted locations?Can't explain it (Mark or the JSC folks can), but I believe that's the Downrange Abort Evaluator "footprint" in the Group Outplane display that's up during ascent. There's a detailed explanation in one of the docs on L2.
Can someone explain what the green areas are on the MCC display of launch? Some sort of crossrange display or predicted locations?
Been meaning to ask for a while.
I have a question about Shuttle docking with the ISS.'Cause Hollywood is usually stupid when it comes to spaceflight and actual space hardware. (Talking about the non-fantasy/sci-fi kind; in those almost anything is considered probable.)
In a number of movies with the shuttle in them (mainly James Bond 007, Moonraker) it shows the shuttle docking using the side hatch. Why isn't that used? Is it becuase of the docking configuration of the docking ports?
Odd question, this, but here goes.The twang effect.
Why are the engines started 6 and a bit seconds before SRB ignition.
Odd question, this, but here goes.The twang effect.
Why are the engines started 6 and a bit seconds before SRB ignition.
(Sorry, doing this as bottom post)I think what Rob is getting at is, for example, was there an "attempt" to launch STS-51E? And was that counted in the AP story?Plus it depends on your definition of "attempt"attempt: /əˈtɛmpt/,
Noun
The action of trying at something.
Guys, I have a question,
I went to the STS-129 Atlantis launch and weather permitting I want to go back to KSC for it's landing. I have been doing some research on landings and trying to understand the ground tracks to KSC when coming back from ISS. I looked at STS 118, 119, 121, 122, 123, 124 and 127 and they all follow a similar pattern. Generally, the approach is from the South on the first orbit try and then it shifts a little to the West for the next orbit. Same pattern if landing 15 or 33.
But STS-120 landing on 33 is WAY different. It approached form the Northwest!
Does anyone know why that was.
Thanks
Has a wind shear for the ascent trajectory ever delayed a Shuttle launch? No need to address RTLS aspects of this question or 51L.There were a few launches in the 80s that were delayed due to upper level winds, though not sure if shear was a specific problem for all of them...for example, 51-A:
The STS 51-A mission was scheduled for launch on November 7, 1984, but the launch was scrubbed during the planned hold at T-20 minutes because the data indicated that the predicted winds-aloft would apply shear loads in excess of the design limits of the vehicle.
Has a wind shear for the ascent trajectory ever delayed a Shuttle launch? No need to address RTLS aspects of this question or 51L.
I think NASA used to scrub "all the time" before the first stage flight profile data could be uplinked to the shuttle while it was sitting on the pad (DOLILU).Do you recall approximately (or specifically) when that was first used? I recall some delays for a few launches in the RTF1 period, but those were with longer launch windows and some flights were able to launch later in the window for the day.
Is the ODS used today for docking with ISS substantially similar to the one used for Shuttle-Mir? Is the same hardware still in use?
When the shuttle performs its separation burn from the station, does it depart retrograde or prograde?
I'm wondering when it makes its pass overhead later that evening, who is in trail?
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...
Has it ever been seen?
When the shuttle performs its separation burn from the station, does it depart retrograde or prograde?
I'm wondering when it makes its pass overhead later that evening, who is in trail?
Retro, which puts the shuttle in the lead and ISS in trail (retro = lower, lower = faster).
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...
Has it ever been seen?
The undocks and flyarounds are always planned so the station can be viewed and photographed in daylight.
What exactly does the double sonic boom sound like? I don't think I've ever heard even a single sonic boom.
A boom, then another boom? I'm not sure how else to describe it - you might do a YouTube hunt.
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...
Has it ever been seen?
The undocks and flyarounds are always planned so the station can be viewed and photographed in daylight.
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...
Has it ever been seen?
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...
Has it ever been seen?
The shape of the graph of the throttle on the y-axis and time on the x-axis. Looks like a little bucket. ---_---That makes perfect sense. Thanks Hungry.
I'm really hoping someone can weigh in on the range of the sonic boom, asked here yesterday:
Hi folks,
I have a number of questions with photos.
1) Where does this reflection of ISS come from?
2) Since these vent openings are on the nose (near the star tracker ports) are they closed for reentry? If not how come hot gases don't go in them?
3) What is this rescue sign for?
4) Why are some tiles "blacker" than others?
5) What are these "white lines" (they look like mose code) in downlinks from the shuttle?
6) What are these "smaller" connection on the T0 Ubilicals. I know the "bigger" ones are for the fuel that goes to the ET?
Also has anyone ever asked the crews if the orange suits are harder to put on/take off in spce or on the ground?
Thanks Oxford750
Thanks folks.
In reguards(spell) to the RESCUE sign on the right side of the shuttle, I thought the only two escape routes where the hatch and/or the overhead windows on the flight deck.
Thanks again for the answers to my questions.
Oxford750
The white lines in the downlink video are, if I recall correctly, some kind of timecode or data stream.
What is the source of the glow around the shuttle right around MECO from the ET cams? It's not all from the thrusters is it?
RCS engines are responsible for gettin proper orientation before re-entry (nose of shuttle goes up, angle 40) ??
I read that the slidewire baskets were considered for use with the on pad abort of sts 41D, but the controllers were afraid to have the astronauts use the untested escape system because it had never been tested with a human occupant.
Is there a reason why it was not tested with a human before the Challenger accident?
I haven't seen the video, but I heard that the poor tech screamed all the way down.
As I understand, this system is designed to get the crew out of harm's way of an imminent explosion, hence made for speed not necessarily safety. It would never be considered for use during a normal abort.
I haven't seen the video, but I heard that the poor tech screamed all the way down.
As I understand, this system is designed to get the crew out of harm's way of an imminent explosion, hence made for speed not necessarily safety. It would never be considered for use during a normal abort.
Which females in the astronaut corps can spacewalk that are active at this time? What males cannot?
Because it has to go from 0 to 100 mph no matter what. The kinetic energy of LEO is an order of magnitude greater than the potential energy.
Still begs the question how much fuel does the shuttle have to burn to just get it to the top of the gantry ? i.e the amount of extra payload it could carry if the pad itself were at this height ?
What was the first mission to use an OMS burn during the ride uphill?Already asked in this thread...question post is here:
Similarly, what was the first mission to roll to a heads-up position during launch?
My query is - if the shuttle main engines burn 1000 gallons per second and if it takes 7 seconds to clear the tower why do they not just build a bit of a hill first
I'm trying to get a better understanding of how attitude is specified for the orbiter. I've read through many of the docs available on L2 and resources on the web, but still have a few questions.
I believe that for LVLH attitude, Euler angles are specified in a pitch-yaw-roll (2-3-1) sequence, but I don't know whether the convention is to give the angle to rotate the body frame to the LVLH frame or vice-versa. Is there a standard convention for this?
Obviously, it makes a difference in the sign of the angles, but does it also make a difference in the sequence? In other words, if the PYR angles are (40, -10, 60) to rotate the LVLH frame to the body frame, is it correct that the Euler angles to rotate from the body frame to the LVLH frame are (1) also pitch-yaw-roll sequence and (2) the same values with opposite signs, that is (-40, 10, -60)?
Do the same answers apply to the inertial (M50) attitude, which I think is also pitch-yaw-roll sequence, and the LVIY attitude used during ascent?
Space shuttle Challenger STS 7 was suppose to be the first landing at KSC, but i have heard that it was delay from low clouds at the area and landed at Edwards instead. why didn't they land Challenger at KSC the next day.The flight control team declared one of the APUs (#3) suspect due to an underspeed during its initial run for the flight control system checkout the day before landing. Would also note that this was early in the program and I wouldn't assume the flight rules were the same as today.
I heard that Shuttle Columbia STS-107 had some delays in 2000, 2001, and 2002, what was the problems?
On the first space shuttle Columbia there was some problems like falling tiles which delay launch but i have heard that there some other delays. i don't know what were the other delays.
I read that the engines are throttled back to remain a 3G acceleration mostly for crew comfort. Would a higher slightly higher acceleration limit allow for a higher payload mass? If so, how much?
What is the structural limit of acceleration for a shuttle?
Why did Columbia never visit the ISS?1: Mostly because of her higher empty mass.
Was it just how it happened on the manifest?
Would she have been the orbiter picked to visit Hubble?
Why did Columbia never visit the ISS?1: Mostly because of her higher empty mass.
Was it just how it happened on the manifest?
Would she have been the orbiter picked to visit Hubble?
2: See 1.
3: She did get to visit HST, in March 2002 on STS-109/HST SM3B. And she was scheduled for HST SM4.
if columbia wasn't destoryed it would have flown to bring hubble back to earth for the STS-144 Mission.
if columbia wasn't destoryed it would have flown to bring hubble back to earth for the STS-144 Mission.
I'm not sure STS-144 was ever officially instated as a flight that would return HST. I know it was proposed, but perhaps someone can confirm the status of this flight at the time of the STS-107 accident.
Thanks. Many websites suggest it's just for crew comfort.I read that the engines are throttled back to remain a 3G acceleration mostly for crew comfort. Would a higher slightly higher acceleration limit allow for a higher payload mass? If so, how much?
What is the structural limit of acceleration for a shuttle?
3 g's for the structural limit.
Thanks. Many websites suggest it's just for crew comfort.I read that the engines are throttled back to remain a 3G acceleration mostly for crew comfort. Would a higher slightly higher acceleration limit allow for a higher payload mass? If so, how much?
What is the structural limit of acceleration for a shuttle?
3 g's for the structural limit.
How much extra payload would a limit of 3.2 or 3.5 G have allowed?
How much extra payload would a limit of 3.2 or 3.5 G have allowed?
Negative, once you account for the structural strengthening needed for the stack to withstand the higher g.
But neglecting structural limits and assuming the stack can withstand it, what would the ballpark increase be? I imagine not much as the throttling comes near MECO anyway with low gravity losses.
Yeah, surely the stack is designed to withstand much greater than the load it will actually achieve during a mission. Other engineered structures are designed to take multiples of the actual expected load before failure.
But neglecting structural limits and assuming the stack can withstand it, what would the ballpark increase be? I imagine not much as the throttling comes near MECO anyway with low gravity losses.
Yeah, surely the stack is designed to withstand much greater than the load it will actually achieve during a mission.
Other engineered structures are designed to take multiples of the actual expected load before failure.
Thanks. Many websites suggest it's just for crew comfort.I read that the engines are throttled back to remain a 3G acceleration mostly for crew comfort. Would a higher slightly higher acceleration limit allow for a higher payload mass? If so, how much?3 g's for the structural limit.
What is the structural limit of acceleration for a shuttle?
What do the two triangles on the shuttle's HUD (see picture) represent? In the landing videos I've seen, they appear to be fixed at about 20 degrees glideslope; do the triangles indicate the ideal approach glideslope, or are they used for something else?
Yes, I was referring to those two triangles. I know they're used for the flare, but what are they used for before the preflare?What do the two triangles on the shuttle's HUD (see picture) represent? In the landing videos I've seen, they appear to be fixed at about 20 degrees glideslope; do the triangles indicate the ideal approach glideslope, or are they used for something else?
You're referring to the two horizontal triangles on the sides of the flight director bug? Those are also used as cues for preflare and final flare.
When the US signed an agreement with Russia on the ISS/Shuttle-Mir campaigns Russia offered to sell the US the Buran docking module for use on the STS, yet the US declined and instead developed their own derived from the existing US internal airlock.
The Buran docking system was capable of autonomous dockings yet the US airlock has to utilize a crew of at least five. If the US used the Buran docking system, could it have performed an autonomous docking (or at least lighten the crew work load)
and if so why was it not chosen?
I've seen a few posters on this site say something to the effect of "If a human were within 2 miles of the shuttle, the acustics would stop the human heart."
That is not quite correct. The US did purchase (and continues to purchase) the APAS docking mechanism developed for Buran, and simply adapted it to the existing US airlock and a new US-developed truss structure to form the Orbiter Docking System (ODS).
No. The Kurs system included with the Buran docking system was not compatible with the GNC systems on the shuttle and it would have taken a lot of time and money to make them compatible. The top-level program goal was a Shuttle-Mir docking in 1995 and it simply would not have been possible in the constrained budget environment.
The truss on the Buran docking system was not suitable for the shuttle orbiter's payload bay. Buran's trunnion system was designed to take loads in both the longeron and keel trunnions so their truss had only one longeron trunnion pin on each side, with pitch torque being absorbed through the keel. The orbiter's trunnion system is designed to take loads only through the longeron trunnions so it requires two longeron trunnion pins on each side.
The Buran docking system had a telescoping mount to extend the APAS mechanism above the payload bay moldline to improve clearance during docking. This was necessary for Buran since Kurs is not capable of as much precision during docking as a hand-flown docking, so a failed capture can results in much more dispersed bounce-off states. But the mount must retract before the payload bay doors can be closed, or the mechanism jettisoned via pyros. This was deemed unsafe.
The systems in the Buran airlock were not compatible with existing orbiter systems and would have required extensive adaptation. (The systems needed to interface the orbiter power system with the APAS were extensive enough by themselves).
No. The Kurs system included with the Buran docking system was not compatible with the GNC systems on the shuttle and it would have taken a lot of time and money to make them compatible. The top-level program goal was a Shuttle-Mir docking in 1995 and it simply would not have been possible in the constrained budget environment.
Was there ever any consideration for installing Kurs in between the Mir and ISS programs? I know that there was time in between the two to allow so, however perhaps the US built system could not accommodate it.
QuoteThe truss on the Buran docking system was not suitable for the shuttle orbiter's payload bay. Buran's trunnion system was designed to take loads in both the longeron and keel trunnions so their truss had only one longeron trunnion pin on each side, with pitch torque being absorbed through the keel. The orbiter's trunnion system is designed to take loads only through the longeron trunnions so it requires two longeron trunnion pins on each side.
Hmm, this was not mentioned in the Energiya-Buran book that I am reading right now that mentioned the offer to sell the Buran Docking system to the US.
I would have assumed with the US shuttle that the crew would have taken over for the last part of docking, I suppose though that autonomous docking really is not needed on the STS since a crew is required anyhow.
A few small questions that I just thought about:
1) If the ROFI sparklers failed to ignite at T-10, would this automatically cause an RSLS/GLS abort?
2) how did they find out about the "twang" and impliment it into the launch sequence before STS-1?
1. yes
2. General engineering sense. Push on a cantilevered object and it is going to move.
Did they simply underestimate how long it would take for the vehicle to return to vertical?
Did they simply underestimate how long it would take for the vehicle to return to vertical?
Wouldn't that have been caught prior to launch, during the FRF?
http://www.myvideo.de/watch/2431762/Columbia_Flight_Readiness_Firing_FRF
You would think so, but it still leaves the question unanswered ;)
You would think so, but it still leaves the question unanswered ;)
The question being, why didn't it launch at T-0?
The countdown was set up for SSME start at T-4. When the timing of the twang was determined (6 seconds), the countdown development was too far along to change, so SRB ignition was set at T+2 sec (the guidance has nothing to do with it) . The countdown was updated for later launches.
Regarding twang, does anyone have a graph of the displacement from one of the FRFs? Just curious what the cycles look like and how quickly it dissipates. Maybe a request for L2 Historical....
If power cannot be transferred from ISS to Shuttle, why not?
When the Shuttle docks with ISS, is does any power transfer occur via the APAS docking port? I vaguely recall some limited amount of power, plus data and commands can be sent via the docking system, but I don't know how or if any of this is actually implemented.That's the job of the Station to Shuttle Power Transfer System(SSPTS). However, only Discovery and Endeavour is equipped with SSPTS
If power cannot be transferred from ISS to Shuttle, why not?
If power cannot be transferred from ISS to Shuttle, why not?
http://en.wikipedia.org/wiki/Electrical_system_of_the_International_Space_Station#Station_to_shuttle_power_transfer_system
It goes through one of the X-connectors on the APAS as indicated by this graphic: http://www.nasa.gov/images/content/181949main_08_abbot_preflight.jpgIf power cannot be transferred from ISS to Shuttle, why not?
http://en.wikipedia.org/wiki/Electrical_system_of_the_International_Space_Station#Station_to_shuttle_power_transfer_system (http://en.wikipedia.org/wiki/Electrical_system_of_the_International_Space_Station#Station_to_shuttle_power_transfer_system)
Good information. Question: does the power flow through APAS, or is there a drag-through cable?
Okay, so the 8 Kw passes through the APAS X connector, and then somehow passes via the ODU into the PTU for use by Shuttle, if necessary. Any idea how and where the power gets from APAS into the Shuttle? Does the ODU have some capability of shunting that much power from APAS?That is taken care of by the PTU which is a direct replacement for the earlier APCU which was only capable of transferring power to the station. The new PTU and it's associated wiring on the orbiter is capable of transfers both to and from the station, IE it can transfer power both ways.
Just curious.
That is taken care of by the PTU which is a direct replacement for the earlier APCU which was only capable of transferring power to the station. The new PTU and it's associated wiring on the orbiter is capable of transfers both to and from the station, IE it can transfer power both ways.
I am looking for the subsystem mass properties breakdown for the space shuttle. I formally had a digital copy of an old book that compared the mass of several space craft including the orbiter but cannot remember the name. This would be fine or even better a spreadsheet of the orbiter subsystem mass and cg.
No cable. The PTU is all integrated with the ODS and the orbiter EPS.That is taken care of by the PTU which is a direct replacement for the earlier APCU which was only capable of transferring power to the station. The new PTU and it's associated wiring on the orbiter is capable of transfers both to and from the station, IE it can transfer power both ways.
I guess I should have asked if the PTU sits in the ODU, or whether there is a honking big extension cord from APAS through the ODU into the nether regions of Shuttle.
OV-103 and OV-105 previously carried the
standalone version of the APCU described above, but
have been upgraded to the newer Station/Shuttle
Power Transfer System (SSPTS). Operated via
switches on panel A15 that were formerly used by the
EDO Cryo Pallet System (which is no longer used),
SSPTS consists of two power transfer units (PTUs),
each of which has a single APCU voltage step-up
converter similar to the ones discussed above, and two
voltage step-down orbiter power converter unit
(OPCU) converters. The OPCU allows 120 volt DC
power from the ISS solar arrays to be transferred to
the shuttle’s main buses A and B at 28 volts. The
OPCU portion of SSPTS offloads some electrical load
from the orbiter’s FCs onto the ISS solar arrays; the
reduction in load on the FCs reduces the cryo usage,
which is then used for mission extension days. The
APCU portion of SSPTS is usable at any point in the
mission, while the OPCU portion is only usable after
docking to the ISS. Data is visible to the crew on SM
SPEC 179 POWER TRANSFER.
Before any power can be converted either by an APCU
or OPCU, the PTUs must be connected to the
shuttle’s main buses. PTU 1 is associated with main
A, and PTU 2 is associated with main B. To connect
the PTU to the main bus, the CNTL PWR circuit
breakers on A15 row B must be pushed in first. These
breakers power the PTU/MAIN BUS switches and
talkbacks. Upon successful connection between a PTU
and main bus, the associated talkback will turn from
OFF to ON. At this point, an APCU may be
activated to convert orbiter DC power for payload
requirements, and, after docking, the OPCU can be
activated to convert ISS DC power for shuttle main
bus requirements.
No cable. The PTU is all integrated with the ODS and the orbiter EPS.
If both engines fail (I know, REALLY unlikely) but the RCS is still functioning, can it be used to circularze the orbit?
After MECO and ET jettison, I breathe a little easier. I know, nothing for sure until wheels stop, but you see where I'm headed. But, as I was turning off my television at 4:24am this morning, the following question came to mind. What if there is an OMS failure when the OMS 2 burn is supposed to occur? I understand this is probably very unlikely. My guesses are the following, but obviously I'm posting here because I don't know.
If it is a single OMS engine failure, use the good one, get in a cirular orbit and work it out from there. Is the rendevous off if the second OMS engine can not be recovered?
If both engines fail (I know, REALLY unlikely) but the RCS is still functioning, can it be used to circularze the orbit? My guess is yes, but now you would need it to deorbit too. So would they get stable and work the problem, or just reenter and treat it as and AOA? My thought is that a stable orbit is the safest place to be even if that means you're on a back up system to deorbit.
Ok, so a lot of questions and I'm probably missing something, but I would be interested if anyone knows the procedures for such an event. Thanks.
If both engines fail (I know, REALLY unlikely) but the RCS is still functioning, can it be used to circularze the orbit?
I think it is impossible to make such manouvers with RCS. OMS are required to change parameters of the shuttle orbit. Fail of two OMS engines would mean a LOM probably but im not sure (better wait for someone with good knowledge :)) and in this situation it would end with re-enter and land in KSC. Dunno if it is possible but I remember tha I read here some post about such a operation with using only RCS to back from LEO.
And wanna ask about some shuttle first minutes of flight. Look at this graphic, it has a polish words but take a look on shape of this trajectory in function of time.
(http://i187.photobucket.com/albums/x9/PhD_airQ/Terminator-STS.jpg)
This graph is based on some today seen on Fox News graphic which showed similiar graph (on line Y there was altitude in km, on X line time of flight). So time for question - there is a conclusion in my mind after looking at this graph that shuttle is climbing to initial orbit to fifth minute, after that she doesn't get much km of altitude more. What's most interesting it seems to loose some altitude after fifth minute of flight (and before meco) - can You explain my why that happen? What is energetic sense of loosing this few kms on da begining?
Thanks for answers,
greetz,
Mike
It's trading some potential energy (altitude) for kinetic energy (speed). The idea is to get above the atmosphere as quickly as possible without overstressing the structure, then performing a long shallow dive to get more speed.
How its possible if it is only few km of altitude?Keep in mind that the orbiter-ET combo is rapidly loosing mass while trust is constant. Combined with that long shallow dive it helps to accelerate. That shallow dive is partly caused of the modest level of trust after SRB separation. The trust level barely maintains 1g for half a minute.
What do u mean with 'overstressing the structure' - pressure which came from changing of acceleration? (Cause there are no aerodynamic stressing above - lets say 80 km of altitude).
edit: Second question - theoritically could the shuttle climb higher without going to this shallow dive? I mean climb further to point where she would get a required speed. I can imagine that it would cost a lot of fuel but wanna just ensure myself..Shuttle is inserted in orbit at perigee. After MECO it is coasting (gaining) altitude without burning precious propellant.
what is the OMS propellent budget?
assent, circulation, orbit, deorbit, reserve, residual...
How its possible if it is only few km of altitude?Keep in mind that the orbiter-ET combo is rapidly loosing mass while trust is constant. Combined with that long shallow dive it helps to accelerate. That shallow dive is partly caused of the modest level of trust after SRB separation. The trust level barely maintains 1g for half a minute.
What do u mean with 'overstressing the structure' - pressure which came from changing of acceleration? (Cause there are no aerodynamic stressing above - lets say 80 km of altitude).
Think at the analogy of throwing a stone. When the stone leaves your hand it still will climbs upwards for a while.
Without the shallow dive the stuttle would need to spend longer time in the thicker layers of the atmosphere.Quoteedit: Second question - theoritically could the shuttle climb higher without going to this shallow dive? I mean climb further to point where she would get a required speed. I can imagine that it would cost a lot of fuel but wanna just ensure myself..Shuttle is inserted in orbit at perigee. After MECO it is coasting (gaining) altitude without burning precious propellant.
what is the OMS propellent budget?
assent, circulation, orbit, deorbit, reserve, residual...
Those figures would likely vary depending on the mission and payload mass. (and will also vary depending on the orbiter involved since they don't all have identical masses)
For each mission, the Flight Day Execute Package document will give the best figures for propellant remaining at the start of the flight day, and each PAD burn update will give calculated total orbiter mass.
If you're asking how much propellant is loaded at the beginning of a mission, I believe all tanks are filled completely both front and rear.
One more thing - does someone know a document or page (whatever) where are described in detail all manouvers like this interesting one 5 minutes after launch?
Why TORVA? Does using twice orbital rate minimize prop usage for the arc? If so, the orbital mechanics there are not intuitive to me.
Ok, thanks for answers. One more thing - does someone know a document or page (whatever) where are described in detail all manouvers like this interesting one 5 minutes after launch?
I am not sure what you mean by "all manoeuvres like this interesting one 5 minutes after launch".
There aren't that much going on at that specific time frame.
1. How is this performing (i mean by RCS or ...)?.
2. Does Soyuz make also similiar action with 'shallow dive'? I guess not since it has stronger construction..
3. Next question which came to my mind is if there could be greater g-load without throttling down with SSMEs around 7:22 time of flight.
2. no, it is a launch vehicle specific (STS) maneuver driven by unique contraints
2. no, it is a launch vehicle specific (STS) maneuver driven by unique contraints
Abort posturing
What is the limit of g-load shuttle could withstand (in theory) - twice, tripple more than 3g?
What is the limit of g-load shuttle could withstand (in theory) - twice, tripple more than 3g?
Has been answered before, a search might turn up a number since my foggy memory can't find it in the old long term storage.
I know its not much more than 3g's, stronger structure tends to mean heavier structure.
Is the docked ISS-shuttle TEA attitude the same for every flight, or is it specific to each shuttle mission?
Is there a single TEA, or multiple options to choose from? I recall reading that the primary docked attitude is partially to shield the orbiter's TPS from MMOD damage, but I didn't know how the TEA factors into attitude selection.
Any idea what the TEA is for this STS-130?
Any idea what the TEA is for this STS-130?
Biased ISS -XVV, as has been standard since STS-107, and is almost certain to remain so for the remaining flights.
Thanks, that makes sense.Any idea what the TEA is for this STS-130?
Biased ISS -XVV, as has been standard since STS-107, and is almost certain to remain so for the remaining flights.
Does the terminology "biased -XVV" essentially mean start with -XVV (or whatever the particular reference) and rotate predetermined amounts about one or more of the PRY axes?
I can't find a post on it. What's the ballast for in the Orbiter aft compartment? I know it's CG, but for which phase(s) of flight?
I can't find a post on it. What's the ballast for in the Orbiter aft compartment? I know it's CG, but for which phase(s) of flight?
Entry/landing for both nominal and aborts (assumes a prop dump for the aborts).
Something really serious like a major fire. What happens if it takes longer than 8 hours to get the situation under control so they can go back on the station? Or, if it happens near the end of a 6 hour space walk and they only have 2 hrs of life support left?
This may have been addressed in some earlier post but....
Given the limited number of remaining STS flights, why bother recovering the SRB's at this point?
OK, you have a point -- except for the last launch, after which there won't be any more SRB's used. One would have to think that the "R&D" element value would be diluted to nearly nothing at this point, having examined so many SRB's in the past.
I just watched the STS-130 ascent video from inside the cabin and have a couple of questions:
1) I was surprised to see the crew open their helmets not long after SRB separation. Is this a recent procedure? I don't recall seeing this in earlier flights.
2) I noticed a flickering light reflecting off the crew's helmets, apparently emanating from outside and in front of the vehicle. It began about midway through ascent and continued until MECO. What could be causing that?
2. The SSME plume
If it's the rhytmic flashes, I'd say that's mostly the APU plume.Yes, the reflections are rhythmic. However, the light source appears to be coming from the front of the orbiter, based on position of reflections on front of helmets.
1) I was surprised to see the crew open their helmets not long after SRB separation. Is this a recent procedure? I don't recall seeing this in earlier flights.
That has been done ever since they started wearing the suits. The reason is that the suits are preasurized with pure oxygen and they are open loop (gas is vented out of the suit into the cabin instead of being rerouted back to the ECS) that leads to the concentration of O2 in the cabin building up more the longer they are in use, which is a fire hazard (remeber Apollo1). That is also why they don't close the visors at all durring entry after the preasure test.
That has been done ever since they started wearing the suits. The reason is that the suits are preasurized with pure oxygen and they are open loop (gas is vented out of the suit into the cabin instead of being rerouted back to the ECS) that leads to the concentration of O2 in the cabin building up more the longer they are in use, which is a fire hazard (remeber Apollo1). That is also why they don't close the visors at all durring entry after the preasure test.
I guess they can close those visors real fast in a depress event.
Now that Node 3 and cupola are installed in the ISS, will there be significant changes for future shuttle docking procedures from STS-131 onwards?
Seeing the launch footage of the shuttle, I was trying to understand what happens around external tank separation...
1. It seems to see some RCS firing after 10 seconds from zero-thrust (well before separation), am I correct? Which RCS?
2. The -Z thrust starts exactly at sep or before?
3. How many seconds after sep starts the +X thrust?
1. No (if you are referring to the 10 second period prior to MECO).
2. -Z translation occurs after the SEP Command is issued, not before. However, RCS firings can occur during the mated coast phase for attitude/rate control. These firings are managed by the "Trans Dap" (transition digital auto pilot).
3. +X is a manual input by the Commander which occurs 2 seconds after the general purpose computers transition to OPS 104 (this transition occurs when the -Z achieves a delta V of 4 feet per second).
Mark Kirkman
Forgive me if it's in the wrong place, but on the NASA TV map, what is the yellow line that goes roughly north-south?
STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
Historical artifact.
In that case, why cant they rename the missions again? I mean with A's and ULF'sSTS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
Historical artifact.
STS -132 is named as ULF4 (Utilities and Logistics) while STS-131 is 19A (Assembly)? STS-132 carries MRM1 to be installed in the ISS while STS-132 carries MPLM Leonardo. I thought STS-132 must be an assembly flight while STS-131 must be a Utilities and Logistics flight. Any comments on this naming?
I have another nasa tv question. When they are covering the shuttle launch/landing, they generally show a screen showing the earth, and the current orbit of the ISS and shuttle.
On this screen, there several circles/shapes with letters inside (SAA,TCSS...). What are those shapes? Also, there are some other indications on the screen, and some other satellites. Any descriptions?
Search the shuttle Q&A thread
Search the shuttle Q&A thread
Any good tips for that? On the previous question about the graphic I felt certain there should be some old posts with the answer, but after about 10 minutes of searching I hadn't found anything I could refer to. So I just posted what's probably a redundant answer.
Wondering what all the elements of that graphic are were some of my first questions when I was watching missions. I wish I knew of an easier resource to point at (or a way to create one).
--
Darren
OK, you have a point -- except for the last launch, after which there won't be any more SRB's used. One would have to think that the "R&D" element value would be diluted to nearly nothing at this point, having examined so many SRB's in the past.
If 133 remains the last flight, its SRBs will be recovered to reveal any problems that may affect its LON rescue flight, 335.
If 135 is baselined, or if 335 must be launched, you have a point. Barely.
What is the advantage of 3G throttling over shutting down one engine a little earlier?
What is the advantage of 3G throttling over shutting down one engine a little earlier?
With throttling you
1. still have attitude control with all the engines,
2. you don't have step changes to your guidance system caused by the shut down and
3. you preserve your full engine out capability.
or the lack thereof, can apparently be dealt with in the event of a single engine failure (STS-51F).
Why NASA decided STS-133's (planned last mission) duration to be only 8 days.This mission will be different than the usual logistics mission, because the PMM will be left on board the station and is not returned to the shuttle's payload bay. Hence the ISS crew will be able to unload it at their leisure.
1. Discovery has SSTP and can tap into station power - Hence can stay longer in the space station?
2. Due to no more flights (or may be STS-135) isnt it better to do more science and experiments by staying more?. Some unique things they can do with the shuttle will be lost foreever.
3. Crew will have more time for transfers from the PMM to the ISS (and hence PMM can carry more equipement?)
4. What will have the largest impact if 8 days is to be changed to say 13 days?
5. May be more time in space means high risk of space debris problem? Is this the only reason why it is planned as a 8 day mission?
Is it possible to produce a blended thermal protection system instead of using tiles.
Could this not then be fitted to the shuttles?. I know pending fleet retirement but would this be possible.
Is it possible to produce a blended thermal protection system instead of using tiles.
Could this not then be fitted to the shuttles?. I know pending fleet retirement but would this be possible.
It is "blended". Tiles transition to blankets.
1.What is the MPLM that Atlantis is supposed to carry for STS-133 LON mission? Is it Rafaello?
2.When will the processing of the MPLM will begun?
3.(Read some where that although Donatello is the most advanced, it would stay in the ground ! )
This one? - http://tinyurl.com/yeurn9l
When did NASA stop using T 38s to follow the shuttle as it landed?There were a couple of 'firsts' after that: first heavyweight/Spacelab landing (STS-9), first KSC landing (STS-41B, postponed from STS-7). Don't recall any after that.
From pictures I can see they were used as late as STS 6.
During TCDT, does the orbiter hatch remain opened throughout the entire test?
Partially. Once crew ingress is complete, they cycle the hatch closed, perform a simulated cabin leak test and then open the hatch again.During TCDT, does the orbiter hatch remain opened throughout the entire test?Believe so -- it was during the STS-114 test that was carried live.
one brief question on a more historical subject.
When docked to ISS, the tail points downwards (albeit not straight down) the PLB along the direction of the velocity vector to protect the TPS on the belly. Anyone knows what the orbiter attitude was during the Shuttle-Mir missions?
Question: Which MPLM will become the PLM (permanent logistics module) and what mission is it flying on and what CBM is it going to be stuck to? PLM is basically a giant closet for ISS right?
Does anyone know the number of SSMEs that are currently in the shuttle program inventory? Also, is there a hard limit on the number of flights per SSME or does it just depend on the conditions on inspection. Also, is the shuttle budget detailed enough to indicate the real cost of servicing and test firing the SSME for flight certification? Of course you go on the NASA website and do a search and can't find any of this information.
Historically some engines have flown more than this - these were in earlier versions, and many had block conversions between times. STS-93 seems to have had quite a well used set with 22, 17 and 19 flights on engines 1, 2, and 3 respectively.STS-93 had tight performance margins; among other weight reduction efforts, it was flown with Phase 2 engines. (As opposed to the Block IIA versions that were being flown otherwise.)
Did I read correctly, that IF somehow NASA gets a extension on the shuttle, it would take close to 2 years to produce the next tanks needed for more flights?
Here's a math problem for our rocket scientists in the audience :)
What would be the performance increase of STS if NASA were to (hypothetically) launch from St. Anthony, Newfoundland (which is at approximately 51.6 degrees North)?
Put a different way, do we benefit from the due east launch to ISS there, or does the slower rotation of the Earth there more than cancel out the benefits of a due-east launch?
For the purposes of this question, you can ignore the usual gotchyas like "it's too cold there!" or "That's in Canada!".
Asked on the STS-131 thread, but I'll ask here as well. Is the ATA flying on 131 the same one that returned on 128? Thanks!
Asked on the STS-131 thread, but I'll ask here as well. Is the ATA flying on 131 the same one that returned on 128? Thanks!
IIRC they sad the tank returned on STS-128 was going to be filled up and flown back up again.
Hi guys
Does anyone know why the STS 130 files aren't on NASA's site ?
http://www.nasa.gov/centers/johnson/news/flightdatafiles/foia_archive.html (http://www.nasa.gov/centers/johnson/news/flightdatafiles/foia_archive.html)
Can some one explain how the payload canister is installed into the Shuttle's payload Bay?. is the payload removed form the canister at the pad and installed or is the canister being just loaded into the pay load bay?
Not directly...I think this has been answered in the Q&A threads before, but I'm not finding a specific post at the moment. There was an early thread that outlines things, though:Can some one explain how the payload canister is installed into the Shuttle's payload Bay?. is the payload removed form the canister at the pad and installed or is the canister being just loaded into the pay load bay?
They move the payloads from the canister to the Payload bay at the launchpad. The canister is just used for transporting the payloads to the launchpad from the processing facility.
Not directly...I think this has been answered in the Q&A threads before, but I'm not finding a specific post at the moment. There was an early thread that outlines things, though:
http://forum.nasaspaceflight.com/index.php?topic=8826.0
Here's a math problem for our rocket scientists in the audience :)
What would be the performance increase of STS if NASA were to (hypothetically) launch from St. Anthony, Newfoundland (which is at approximately 51.6 degrees North)?
Put a different way, do we benefit from the due east launch to ISS there, or does the slower rotation of the Earth there more than cancel out the benefits of a due-east launch?
For the purposes of this question, you can ignore the usual gotchyas like "it's too cold there!" or "That's in Canada!".
As a first order approximation, the advantage from the due east azimuth and the disadvantage of the lower rotation speed cancel out. They'd cancel out exactly if the Earth were a perfect sphere. In the real world, KSC has a slight advantage due to the Earth's equatorial bulge.
Edit: found my earlier, more detailed answer:
http://forum.nasaspaceflight.com/index.php?topic=4392.msg402349#msg402349
What is the advantage of 3G throttling over shutting down one engine a little earlier?
Your question has been moved to another thread so if this thread gets deleted you know where to look - http://forum.nasaspaceflight.com/index.php?topic=17437.msg567352#msg567352
Someone else on the forum most likely has more information than me, but as far as I know Shuttle seats are a variant of the SR-71 Blackbird's seats.
Thanks Jorge. The last picture probably shows the newest seat design.
If a LON during STS-131 is required the shuttle is planned to stay attached for close to 30 days (don't remember exact number of days) so there is nothing that stops the shuttle from staying longer.For this mission it was estimated at ~FD27, so a couple of days less than that on docked time. That would probably have different cryo margins for the power necessary to do a post-undocking disposal re-entry (in that hypothetical) vs. a normal post-undocking timeline that has a significant power load prior to re-entry.
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.
OK, I know this is not going to happen, but...........Frequently asked question...short answer is no. I'll see if I can find the thread again...
Would it be possible, and if it was, would it be a good idea to leave a shuttle (with a spacehab in the payload bay) attached to the ISS as an improvised new module?
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.Real limiting factor is the crew.
OK, I know this is not going to happen, but...........Frequently asked question...short answer is no. I'll see if I can find the thread again...
Would it be possible, and if it was, would it be a good idea to leave a shuttle (with a spacehab in the payload bay) attached to the ISS as an improvised new module?
Edit -- here:
http://forum.nasaspaceflight.com/index.php?topic=13950.0
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.
Yes, join L2, which is amazing.
http://www.nasaspaceflight.com/l2/
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.
Did my Entry Guidance Work Book get posted here??
Reply to [email protected]
Danny Deger
Considering how important the Ku Band Attenna is for communicating video to the ground how come they don't have two on the shuttles ?It's important, but not mission critical (they still have S-band for data and communications). It's not like other systems where loss of the functionality might have more severe consequences to the mission (like a minimum duration, for example -- not the case for this). There have been multiple missions with loss of one or both modes of the Ku antenna and those all accomplished their mission objectives.
It's important, but not necessarily mission critical (they still have S-band for data and communications). It's not like other systems where loss of the functionality might have more severe consequences to the mission (like a minimum duration, for example -- not the case for this). There have been multiple missions with loss of one or both modes of the Ku antenna and those all accomplished their mission objectives. In this case, even assuming that both modes of the antenna have failed, the question isn't so much whether or not the mission objectives can be accomplished, but how differently they might be accomplished than the plan going into the mission.
The STS-125 case is the unique case. Would have to check, but it might have been handled differently for that mission.It's important, but not necessarily mission critical (they still have S-band for data and communications). It's not like other systems where loss of the functionality might have more severe consequences to the mission (like a minimum duration, for example -- not the case for this). There have been multiple missions with loss of one or both modes of the Ku antenna and those all accomplished their mission objectives. In this case, even assuming that both modes of the antenna have failed, the question isn't so much whether or not the mission objectives can be accomplished, but how differently they might be accomplished than the plan going into the mission.
But since the Columbia disaster ku has been more important since it's crucial for the safety, with the OBSS inspection. In this case this is solved since they can use station ku but what would they have done if they lost ku during STS-125? Then they wouldn't have any chance at all to down-link the inspection video.
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.
It's my understanding, also, that it's possible to turn down the fuel cells only so far before they start choking on their own exhaust, so to speak -- there have been a couple of recent shuttle missions where there was a concern that it would be necessary to throttle the fuel cells up to keep them operational, which would have required cutting the mission short. I have no idea if the fuel cells can be shut down and restarted on orbit -- I know Apollo's couldn't, it required Ground Support Equipment. Or, perhaps NASA just isn't interested in experimenting with the Shuttle these days.
What are the internal factors that limit Shuttle visit times at ISS? Yes, I know there are constraints due to visiting vehicles not docking with ISS while Shuttle is attached, but I am trying to figure out why otherwise the Shuttle could not stay attached for 30 days, now that ISS can provide power and other consumables to Shuttle.
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.
It's my understanding, also, that it's possible to turn down the fuel cells only so far before they start choking on their own exhaust, so to speak -- there have been a couple of recent shuttle missions where there was a concern that it would be necessary to throttle the fuel cells up to keep them operational, which would have required cutting the mission short. I have no idea if the fuel cells can be shut down and restarted on orbit -- I know Apollo's couldn't, it required Ground Support Equipment. Or, perhaps NASA just isn't interested in experimenting with the Shuttle these days.
Fuel cells were not my system, but I understand the "essential" dc busses can be used to start a cell on orbit. I just heard this as cross talk while I was teaching astronauts how to fly the darn thing.
Danny Deger
In reality, the autopilot flies the entire 30-minute re-entry, and the astronauts do not take over the controls of the shuttle until the final 2 minutes of the glide. The astronauts COULD fly the entire re-entry by hand, but it is officially discouraged by NASA. The reason is obvious. These speeds and altitudes are way outside of normal human conception, so our ability to "hand-fly" these approaches is next to nil.
In the history of Shuttle missions (the 100th mission has just come to a close as I write this), the real space shuttle has been hand-flown for the entire re-entry only ONCE, by an ex-marine pilot, as I understand it, who was ready for the ultimate risk and challenge.
The X-Plane manual states that the re-entry has been flown manually, which frankly, I find hard to believe.This may be related http://forum.nasaspaceflight.com/index.php?topic=17623.msg427231#msg427231 (you'll have to read through some noise and back and forth to get the whole picture)
Has anybody got more information on this?
The fuel cell H2 boils off (the boiloff is still used to produce electrical power). The shuttle needs the fuel cells to provide power post undocking, no H2, no electricity.It's too late for that now, but had such a requirement been in place earlier in the program, could the Shuttle have been relatively easily designed/modified to support this? Say by using active cooling with power supplied by the ISS or by using differently designed APUs for electrical power as well as hydraulics during deorbit and descent?
Edit: or using noncryogenic fuel cells...
The simplest solution was just to carry more cryo, and it was indeed designed in early. The EDO pallet first flew in the early 90's, taking up some mass and space in the payload bay, and Endeavour and Columbia were plumbed to accommodate it. IIRC, Columbia even flew a 17 day mission. She had it on -107, which is why later analysis showed the crew could have lasted about a month in orbit at minimum power consumption, long enough, perhaps, to rush Atlantis to the pad.
The electric APU was a separate proposed mod. Not sure where the energy would have come from. More cryo fuel cells, charging batteries to deliver big currents to the hydraulic pumps during entry?
The simplest solution was just to carry more cryo, and it was indeed designed in early. The EDO pallet first flew in the early 90's, taking up some mass and space in the payload bay, and Endeavour and Columbia were plumbed to accommodate it. IIRC, Columbia even flew a 17 day mission.Sort of -- IIRC, there were multiple 16-day EDO missions that used one or two weather extension days. STS-80 used two and flew for almost 18 days. Most of the EDO mods were removed from Endeavour during the OMDP period that brought in the set of changes to fly to ISS.
1. The simplest solution was just to carry more cryo, and it was indeed designed in early.
2. The electric APU was a separate proposed mod. Not sure where the energy would have come from. More cryo fuel cells, charging batteries to deliver big currents to the hydraulic pumps during entry?
The simplest solution was just to carry more cryo, and it was indeed designed in early. The EDO pallet first flew in the early 90's, taking up some mass and space in the payload bay, and Endeavour and Columbia were plumbed to accommodate it. IIRC, Columbia even flew a 17 day mission. She had it on -107, which is why later analysis showed the crew could have lasted about a month in orbit at minimum power consumption, long enough, perhaps, to rush Atlantis to the pad.
Hi all.
I have been looking at defintions to what "nadir" means (the point below the observer that is directly opposite the zenith on the imaginary sphere against which celestial bodies appear to be projected) and "still can't wrap my head around it".
Can anyone simplify it for me.
Thanks
Oxford750
The X-Plane manual states that the re-entry has been flown manually, which frankly, I find hard to believe.
Story confirmed here:That's a fun one -- read his recounting of the 51-I launch.
http://www.jsc.nasa.gov/history/oral_histories/EngleJH/EngleJH_6-3-04.pdf
Anyone aware of plans for a new edition of the Jenkins STS book after the program ends? I'd love to pick up a copy of the 3rd edition (2001), but as it's 9 years and 30+ missions out of date I'd prefer to wait on an update if one is forthcoming.Yes:
You should still get the older editions. Looking through all three editions that I have, there are slight differences from one to another. Anyway, how could you possibly stand to wait! :)
Why can Soyuz land in a few hours after undocking but shuttle takes at least one whole day (Depending when late inspection happens)?
Thanks
A Columbia question, in two parts, based on this picture:In the CAIB report, Volume 1.
http://upload.wikimedia.org/wikipedia/en/c/c8/Spacehab_S107e05359.jpg
1) What's the innermost RCC panel that can be seen on this picture? Obviously you can't see all the way to the damaged panel, which IIRC was number 8.
2) The shuttle's port wing looks like it has some dirt or discoloration on it, whereas the starboard wing looks pristine. Could this be ejecta from the foam impact?
Quick question: In picture below (link), what is the red stuff repairing the cracked tiles (I'm assuming its some sort of repair)?
http://twitpic.com/1ejcrh/full
Question re: OBSS placement during undocking and fly around, why is it placed in that manner (i.e. perpendicular across the payload bay)
and does it have a term associated with it?
Question re: OBSS placement during undocking and fly around, why is it placed in that manner (i.e. perpendicular across the payload bay)
Minimize loads on RMS/OBSS during a period of high orbiter RCS thruster activity.Quoteand does it have a term associated with it?
"Undocking position".
Question re: OBSS placement during undocking and fly around, why is it placed in that manner (i.e. perpendicular across the payload bay)
Minimize loads on RMS/OBSS during a period of high orbiter RCS thruster activity.Quoteand does it have a term associated with it?
"Undocking position".
Great! Thanks Jorge!!
Provided that STS-134 slips into November is a descending node entry possible?
Also in the case of a descending node entry, is the way of launch/orbit insertion etc different (compared to an ascending node entry)?
1. How was it possible for Columbia on STS-80 to stay upto 17 days in orbit since it did not have SSTP ?
2. What is the maximum duration that Atlantis can stay up in Space ? (it also does not have a SSTP). I read some where that Shuttles were originally to stay upto 28 days in orbit. Is that correct?
1. How was it possible for Columbia on STS-80 to stay upto 17 days in orbit since it did not have SSTP ?
2. What is the maximum duration that Atlantis can stay up in Space ? (it also does not have a SSTP). I read some where that Shuttles were originally to stay upto 28 days in orbit. Is that correct?
How does Atlantis do that and the others can't? More refined orbiter design, I would obviously guess?
Haha, thats nuts, but I understand the reasoning.
Apart from the SSPTS, and the Extended Duration Orbiter, are there any other things that affect it? As I mentioned, over the years orbiter design was refined, so perhaps did that play any part in extending possible duration?
Which is sort of what I said then? I guess.
No, the limiting factor was cryogens (O2 and H2) onboard. Most orbiters could carry 4 tank sets but 102 and 105 could carry 5. So 102 could stay on orbit longer than newer vehicles.Why 102 and 105 -- did the fittings for the tank sets cost enough dry mass, or obstruct part of the payload bay, to make it worthwhile to spread around the capability? In practice, did the orbiters fly with less than their max # of tank sets? And, were the four sets in the EDO pallet the same in capacity to the standard four sets in each orbiter (ie, Atlantis could have doubled her duration had she ever flown with it, 102 and 105 a bit less)?
Apart from the SSPTS, and the Extended Duration Orbiter, are there any other things that affect it? As I mentioned, over the years orbiter design was refined, so perhaps did that play any part in extending possible duration?
No, the limiting factor was cryogens (O2 and H2) onboard. Most orbiters could carry 4 tank sets but 102 and 105 could carry 5. So 102 could stay on orbit longer than newer vehicles.
Actually the baseline is 5 tank sets for all the vehicles.
OV-103 will remove her 5th tank set for STS-133 for weight savings.
Why 102 and 105 -- did the fittings for the tank sets cost enough dry mass, or obstruct part of the payload bay, to make it worthwhile to spread around the capability? In practice, did the orbiters fly with less than their max # of tank sets? And, were the four sets in the EDO pallet the same in capacity to the standard four sets in each orbiter (ie, Atlantis could have doubled her duration had she ever flown with it, 102 and 105 a bit less)?
Thanks, -Alex
On some of the ascent launch videos around t -10 seconds i hear something that I think is "Nav init".
What does that mean and what is being performed / checked?
Also, right after liftoff both CDR and PLT say "auto" and "small numbers".
What are they referring to?
Thanks!
-Giles
Which all the vehicles have. OK call it standard instead of baseline...semantics.
Actually the baseline is 5 tank sets for all the vehicles.
OV-103 will remove her 5th tank set for STS-133 for weight savings.
No, the baseline is 3. The 4th and 5th are kits.
Which all the vehicles have. OK call it standard instead of baseline...semantics.
Tank Set 3 is a kit also.Which all the vehicles have. OK call it standard instead of baseline...semantics.
No, standard/baseline what ever, is 3 tank sets. 4 & 5 are options. They may have been left in for every ISS flight but they are not part of the standard orbiter. The documentation has to account for them being installed on each mission.
Bottom line is all the remaining orbiters have flown 5 tank sets for >15 years. I was just correcting an error in which it was stated that 103 & 104 didn't have the 5th tank set.
You could look at seat yourself at
http://www.panoscan.com/CubicDemos/Shuttle.html
Quicktime VR allows you to look all around
re: NAV INIT, Auto
Thank you very much DaveS and Mark.
Any idea on "Small numbers" ?
Thanks again!
-Giles
Sure! Here;
I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
You could look at seat yourself at
http://www.panoscan.com/CubicDemos/Shuttle.html
Quicktime VR allows you to look all around
Ok, so we have an idea of where the orbiters may end up going, but what will end up happening to the sims?
Sure! Here;
I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
http://www.youtube.com/watch?v=_vLl3K8yzOk
Around 42 second mark just after crew calls roll program.
Also, could you please comment on;
1:02
"1000 low"
1:23
"1500 low"
What caused this and how did the crew know?
Thank you!
Sure! Here;
I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
http://www.youtube.com/watch?v=_vLl3K8yzOk
Around 42 second mark just after crew calls roll program.
Also, could you please comment on;
1:02
"1000 low"
1:23
"1500 low"
What caused this and how did the crew know?
Thank you!
Yeah the “small numbers” call sounds like a reference to the BFS ADI Digitals. During the roll maneuver the crew will cross check the values for R (roll), P (pitch), & Y (yaw) on the BFS version of the Ascent Trajectory Display against what they are seeing on the ADI (attitude director Indicator). The PASS (primary) computers are controlling the maneuver and that is where the info on the ADI is coming from but by verifying that the error values on the BFS Traj Display are small the crew knows that the BFS computer closely agrees with where the PASS computers are taking the vehicle. If the values were large then that would be a clue that the BFS does not agree with the PASS computers.
My best guess for the second set of numbers you asked about during throttle down is that the crew is cross checking the values on the Ascent ADI cue card which is attached with Velcro to the forward panels next to the two ADIs (a copy of the cue card is always in the Ascent checklist). The card provides a rough estimate of values for pitch, altitude (in thousands of feet), altitude rate (climb rate in feet per second) at a given time (in first stage) or a given velocity (in second stage). These are the pre-flight predictions of what the trajectory should be and can be affected by the real time conditions on launch day such as ambient temperature (which affects solid rocket booster performance) or winds, etc…
While there are some so called formal or standard intercom callouts made within the cockpit, each crew develops their own pattern/rhythm and you will notice these differences if you watch different ascent videos from other missions or sims.
Mark Kirkman
Chandra flew on 102 which is why I stated "remaining orbiters" :P
Bottom line is all the remaining orbiters have flown 5 tank sets for >15 years. I was just correcting an error in which it was stated that 103 & 104 didn't have the 5th tank set.
<15 years, AXAF launched in 1999
Why was the clean launch pad approached, which was used for Saturn V, not used for the Space Shuttle? Was it due to the weight of the SRBs?
The need to install payloads at the pad drove the RSS
The need to install payloads at the pad drove the RSS
Why was there such a need? Why couldn't the payloads be installed in the VAB?
No clean room. Also, the payloads don't want to be in the orbiter for more than 4 weeks
No clean room. Also, the payloads don't want to be in the orbiter for more than 4 weeks
I think also that the Air Force wanted the ability to install and change payloads at the pad.
I would like to better understand how the shuttle rendezvous with the ISS. I've practice a bit in Orbiter, but I'm not sure it's a very accurate approach the one I do there.
So, after MECO, the shuttle it's on a stable, closed orbit. What parameters does this first orbit generally have (periapsis, apoapsis, inclination)?
At what point on orbit are the first corrections made, and how?
When is the inclination correction made, and how does the real shuttle does that?
I guess that the rendezvous maneuverer follows the inclination correction. How does a shuttle get close to ISS? What comes to mind is a shuttle orbit something like 350x180 km (first being approximatively the altitude of ISS, second being high enough to avoid significant atmospheric drag) and then wait to catch ISS, usually takes 2-4 days in Orbiter, if launched accordingly (real date and time for a specific mission). Is this a realistic, fuel efficient, approach?
Though recent research had increased confidence that they indeed would serve, what made tiles more attractive yet was that NASA could count with reasonable assurance on using ablative heat shields as a backup. Ongoing work with ablatives had cut their cost dramatically while reducing their weight to 15 pounds per square foot, matching the weight of the tiles.
I am interested to know more about the KU band failure on the previous mission- what was the cause, how was it diagnosed, how was it fixed, what checks / fixes if any were done on Atlantis. I do not have L2 access.
As I understand, it was a deployment failure. It was fixed on the ground and now it's up and running.No, it was a transistor failure in the deployed assembly (in the exciter), not a deploy mechanism failure.
I am interested to know more about the KU band failure on the previous mission- what was the cause, how was it diagnosed, how was it fixed, what checks / fixes if any were done on Atlantis. I do not have L2 access.
Thanks!
Is there any video that NASA has released that keeps the camera on the ET rolling after seperation and shows it as it re enters until the camera burns up?ET camera 101:
She walked into MCC about 10 mins ago. Doesnt appear to be a shift change going on.Edit -- nope, I was wrong. It wasn't a break, it was a shift change -- an upcoming shift change. There's always a handover period between shifts and she (Orbit 2 FAO) was coming into the flight control room with the rest of the Orbit 2 team to get ready to take the handover from the ascent team.
What is the name for the structure at the base of the orbiter that partially shields the SSMEs from the SRB plumes?
http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_coord.html#body_flap doesn't mention any kind of active cooling for the body flap. What keeps it from melting?
http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_coord.html#body_flap doesn't mention any kind of active cooling for the body flap. What keeps it from melting?
It has tiles
The tank would move away from the orbit due to the release of the stored energy in the sep bolts.
I have a question regarding the ET SEP event. As I watched it today during the 132 launch, I was wondering about the forces involved during this key event.
As the orbiter initiates ET SEP, does the tank have a downward force component that naturally pulls it away from the orbiter? In other words, if the orbiter did not perform any RCS firings, what are the tank dynamics at the moment of separation? Would the tank automatically drift downward relative to the orbiter? Or are the orbiter RCS firings required to achieve separation?
Obviously the orbiter is using RCS firings to increase the separation, but are these required (tank will not separate without the RCS firings), or desired (easier to achieve photography)?
Thanks,
David
I have a question regarding the ET SEP event. As I watched it today during the 132 launch, I was wondering about the forces involved during this key event.
As the orbiter initiates ET SEP, does the tank have a downward force component that naturally pulls it away from the orbiter? In other words, if the orbiter did not perform any RCS firings, what are the tank dynamics at the moment of separation? Would the tank automatically drift downward relative to the orbiter? Or are the orbiter RCS firings required to achieve separation?
Obviously the orbiter is using RCS firings to increase the separation, but are these required (tank will not separate without the RCS firings), or desired (easier to achieve photography)?
Thanks,
David
The RCS firings do help to create safe relative motion. They are required in the RTLS case, because ET SEP occurs at a lower altitude and the combination of propellant slosh and aerodynamic forces can result in recontact.
Have any bean-counters published an estimate recently of how much it would cost to modify an external shuttle propellant-tank to fit a cluster of shuttle rocket motors at its base; to fit four attachment points instead of two for the SRB's; and to fit a payload carrying platform on top of the propellant tank to lift a 200 ton payload into orbit?
fit four attachment points instead of two for the SRB's;
In this (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=17437.0;attach=221861)picture, the third panel, the one at the right, with the shuttle simulation/visualization, what is the software they use on MCR during shuttle missions?
Looks like something available for WindowsXP,
is it available for public use?
fit four attachment points instead of two for the SRB's;
If we ever see the day when a vehicle is built up in the VAB with two five-segment solids, we're all going to hold our breath as that vehicle is transported out to a pad. Ten segments will be massive!
A vehicle with sixteen segments (four SRBs of four segments each) would not successfully complete the trip.
Some questions regarding calls (as it sounds to me) made on the flight loop for the STS-132 ascent;
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=5954 (http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=5954)
"OMS PDO" or "ON PDO" (8:45)
"trend of minus 6" (9:35)
"fine count" (12:44)
Thanks!
Some questions regarding calls (as it sounds to me) made on the flight loop for the STS-132 ascent;
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=5954
"OMS PDO" or "ON PDO" (8:45)
"trend of minus 6" (9:35)
"fine count" (12:44)
The woman seen in the STS 132 crew walkout is Janet Kavandi...
DEPUTY DIRECTOR, FLIGHT CREW OPERATIONS, JOHNSON SPACE CENTER.
Has a GPC ever been outvoted / failed during a mission?
Would that necessitate an immediate return?
...I think it had something to do with failed solder joints or something...
Also, what is the story behind the GPC failure during the first Enterprise entry / landing test;
"GPC light." "Big X on computer #2"
?
Thanks!
...I think it had something to do with failed solder joints or something...
Also, what is the story behind the GPC failure during the first Enterprise entry / landing test;
"GPC light." "Big X on computer #2"
?
Thanks!
I remember hearing the story when I was listening to these:
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-885JFall-2005/LectureNotes/index.htm
Maybe it was lecture 16?
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-885JFall-2005/LectureNotes/detail/embed16.htm
Old GPCs has me curious. I remember reading multiple posts on here about why dont they upgrade the computer hardware on the orbiters since they date back to a 1960/70 design. The response was understandably that the computers have proved themselves, and that to update them would be too costly. So, when were the GPC's replaced, and how are they better?
Yes, multiple times, but more frequently with the old GPCs than the current ones.
Old GPCs has me curious. I remember reading multiple posts on here about why dont they upgrade the computer hardware on the orbiters since they date back to a 1960/70 design. The response was understandably that the computers have proved themselves, and that to update them would be too costly. So, when were the GPC's replaced, and how are they better?
Yes, multiple times, but more frequently with the old GPCs than the current ones.
Has a GPC ever been outvoted / failed during a mission?
Would that necessitate an immediate return?
Also, what is the story behind the GPC failure during the first Enterprise entry / landing test;
"GPC light." "Big X on computer #2"
?
Thanks!
Yes, I believe that's what I was actually thinking of. Thanks, Jorge. :)...I think it had something to do with failed solder joints or something...
Also, what is the story behind the GPC failure during the first Enterprise entry / landing test;
"GPC light." "Big X on computer #2"
?
Thanks!
I remember hearing the story when I was listening to these:
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-885JFall-2005/LectureNotes/index.htm
Maybe it was lecture 16?
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-885JFall-2005/LectureNotes/detail/embed16.htm
Failed solder joints sounds more like the multiple GPC fail scenario from STS-9.
...
Early 1990s, went from the AP-101B to the AP-101S, binary-compatible with the old GPC, has the I/O Processor (IOP) integrated into the GPC case, twice as much memory (enables the entry software to be stored in an upper-memory archive for quick recall in case of emergency deorbit), solid state memory instead of core.
Early 1990s, went from the AP-101B to the AP-101S, binary-compatible with the old GPC, has the I/O Processor (IOP) integrated into the GPC case, twice as much memory (enables the entry software to be stored in an upper-memory archive for quick recall in case of emergency deorbit), solid state memory instead of core.
I remember reading someware once that after the Challenger accident, they were able to reconstruct some of the data from the GPCs memory. The ferrite core cells maintained its magnetized state after the power failed. That wouldn't happen with modern, solid state memory.
Early 1990s, went from the AP-101B to the AP-101S, binary-compatible with the old GPC, has the I/O Processor (IOP) integrated into the GPC case, twice as much memory (enables the entry software to be stored in an upper-memory archive for quick recall in case of emergency deorbit), solid state memory instead of core.
I remember reading someware once that after the Challenger accident, they were able to reconstruct some of the data from the GPCs memory. The ferrite core cells maintained its magnetized state after the power failed. That wouldn't happen with modern, solid state memory.
I hadn't heard that about Challenger, but I believe they were able to reconstruct some of the last moments of Columbia in that manner.
“No problems or issues were noted during the ascent phase,” listed the official MER report. “The Reusable Solid Rocket Booster (RSRB) shutdown occurred at 134/18:22:09 GMT [00/00:02:06 Mission Elapsed Time (MET)] and the separation was visible.
“A nominal Orbital Maneuvering System (OMS) assist maneuver was performed following SRB separation. Ignition occurred at 134/18:22:24.3 GMT (00/00:02:16 MET, and the maneuver was 90.2 sec in duration. MECO occurred at 134/18:28:34 GMT (00/00:08:32 MET).
What is this OMS assist maneuver, and under what circumstances would it be required?The OMS engines fire during second-stage flight as additional thrust. In effect, the shuttle is both a hydrolox and hypergolic rocket at that point. The effect is quite small, naturally, but apparently it adds a little extra mass delivered to ISS, part of seeking to maximize every bit of performance out of STS.
Many thanks, Martin
What is this OMS assist maneuver, and under what circumstances would it be required?The OMS engines fire during second-stage flight as additional thrust. In effect, the shuttle is both a hydrolox and hypergolic rocket at that point. The effect is quite small, naturally, but apparently it adds a little extra mass delivered to ISS, part of seeking to maximize every bit of performance out of STS.
Many thanks, Martin
A while back, someone mentioned (IIRC) that this was controversial when first proposed, operating both MPS and OMS simultaneously adding risk?
-Alex
What is this OMS assist maneuver, and under what circumstances would it be required?The OMS engines fire during second-stage flight as additional thrust. In effect, the shuttle is both a hydrolox and hypergolic rocket at that point. The effect is quite small, naturally, but apparently it adds a little extra mass delivered to ISS, part of seeking to maximize every bit of performance out of STS.
Many thanks, Martin
A while back, someone mentioned (IIRC) that this was controversial when first proposed, operating both MPS and OMS simultaneously adding risk?
-Alex
Yes, wasn't Mike Mullane tasked to work on it and he found himself being bitterly opposed by John Young? Mullane refers to it in "Riding Rockets" I think.
I just had a throw away question not important enough for its own thread.
I was thinking of an Ares 1-like rocket, but where the second stage is positioned so that it can also contribute to the thrust during lift off, throttling back to keep acceleration constant as total mass drops, and then is restarted or throttled up when the first stage drops away.
However this would put the exhaust of the second stage, being on top, rather close to the solid first stage. I was wondering if that was acceptable for solid rockets or rules this idea out. Also I was wondering what seriously considered plans most resembled this.
I always wondered why they didn't just not load that OMS propellant, I wasn't sure whether the extra thrust produced outweighed the amount of OMS that was burnt.i seem to remember that very questioned was asked, answered and discussed somewhere on here....
There was a "Fail to sync" of GPC @ on the first free flight of Enterprise, it occured right at separation from the SCA (747).
If you look on this site (NSF) you should be able to find the ALT Program Flight Test results document (I don't know the exact title) and it should go into a lot of detail on what happend. If it is not here you might try the NASA Tech Reports server.
Mark Kirkman
However, the problem was reproduced at the vendor's facility when the flight unit (input-output processor, serial number 7) was subjected to low-level vibration testing at 0.01 g2/Hz. Subsequent inspection revealed a solder crack at a prom lead on the queue page (fig. 7-3). The solder had failed to wick in a plated-through hole. The unit had been acceptance tested at 0.04 g2/Hz after 1848 hours of field run time.
When is the inclination correction made, and how does the real shuttle does that?
The shuttle launches in-plane with ISS, so no "inclination correction" maneuver is necessary. There is a placeholder for a planar correction burn (NPC) on flight day 2, but it is normally only needed to take out dispersions.
Does anybody know if it has ever been a mission in which they had problems in opening/closing the payload bay doors? Furthermore do you know if there is any document explaining how the payload bay can be closed by means of EVA? I remember reading in Skywalking that Tom Jones briefly describe the procedure but I don't have the book with me and anyway I'd like to read some document explaining this contingency EVA in more details.
When is the inclination correction made, and how does the real shuttle does that?
The shuttle launches in-plane with ISS, so no "inclination correction" maneuver is necessary. There is a placeholder for a planar correction burn (NPC) on flight day 2, but it is normally only needed to take out dispersions.
I have a few related questions about rendezvous and ascent G&C, specifically about the target orbital plane.
I read in the Ascent Guidance and Flight Control Workbook (in L2, I believe) that the I-loaded target orbital plane (IY) is defined by the longitude of the ascending node and the inclination. Are these specified relative to M50?
I assume the IY values are based on the longitude of the ascending node and inclination of the ISS orbit. If so, are they based on those values at T-0 or is it more complicated than that?
The layman's explanation of selecting T-0 is that it is the moment when the ISS plane passes directly above the launch site, but I have a feeling that's the simplified version. Nodal regression rates differ by altitude and inclination, and the shuttle generally orbits at a lower altitude until rendezvous. Therefore, I would guess that in order to match the ISS plane at rendezvous, the orbiter's initial plane would have to be slightly different. How is this difference accounted for (i.e., how is IY calculated, given the ISS orbital elements)? Are there any other factors that affect the calculation of IY? In practice, how different is IY from the ISS plane at T-0?
an Ares 1-like rocket, but where the second stage is positioned so that it can also contribute to the thrust during lift off, [putting] the exhaust of the second stage, being on top, rather close to the solid first stage. [...] what seriously considered plans most resembled this.
Side mount SDLV
an Ares 1-like rocket, but where the second stage is positioned so that it can also contribute to the thrust during lift off, [putting] the exhaust of the second stage, being on top, rather close to the solid first stage. [...] what seriously considered plans most resembled this.
Side mount SDLV
KelvinZero seems to be suggesting an in-line arrangement, where the second stage (ground-started) SSMEs are turned outward (presumably on gimbals) such that their exhaust plumes pass by the first stage.
What about in the extreme case where the gimbals point the throttled back SSMEs out at 90 degrees during the first stage of flight?
Tractor-style abort motors do something like this, don't they?
I just had a throw away question not important enough for its own thread.
I was thinking of an Ares 1-like rocket, but where the second stage is positioned so that it can also contribute to the thrust during lift off, throttling back to keep acceleration constant as total mass drops, and then is restarted or throttled up when the first stage drops away.
However this would put the exhaust of the second stage, being on top, rather close to the solid first stage. I was wondering if that was acceptable for solid rockets or rules this idea out. Also I was wondering what seriously considered plans most resembled this.
That's a missed opportunity from NASA PAO.Couldn't agree with you more.
They really should provide an app which shows the big MCC map, indicating ISS, Shuttle, Soyuz, Progress, ATV, HTV, COTS & CCDev, plus Hubble of course :)
They should do it as a screensaver and/or an active wallpaper. I think there would be thousands of people who would use it as their default screens. It would be good 'advertising' for NASA.
Ross.
Regarding entry attitude. What dictates the attitude? Why isn't it always the same attitude for every entry? Why arent they "nice" whole numbers. Do the 10th's of a degree really matter?
Looking at reply #82 in this thread;
http://forum.nasaspaceflight.com/index.php?topic=21764.75
Regarding entry attitude. What dictates the attitude? Why isn't it always the same attitude for every entry? Why arent they "nice" whole numbers. Do the 10th's of a degree really matter?
Looking at reply #82 in this thread;
http://forum.nasaspaceflight.com/index.php?topic=21764.75
That is the attitudes in relation to LVLH (local vertical local horizon), inertial and the sun. They are constantly changing during entry. The angle of attack is what is fixed.
Thanks for the reply. Sorry, I should have been more specific. I am referring to the numbers called up to the crew for the maneuver to the deorbit position. Why isn't it always the same attitude for every entry? Why arent they "nice" whole numbers. Do the 10th's of a degree really matter?
What is the name of the screen on the right side?
What is it showing?
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=21764.0;attach=229194;image
Thanks!
Regarding entry attitude. What dictates the attitude? Why isn't it always the same attitude for every entry? Why arent they "nice" whole numbers. Do the 10th's of a degree really matter?
Looking at reply #82 in this thread;
http://forum.nasaspaceflight.com/index.php?topic=21764.75
That is the attitudes in relation to LVLH (local vertical local horizon), inertial and the sun. They are constantly changing during entry. The angle of attack is what is fixed.
Thanks for the reply. Sorry, I should have been more specific. I am referring to the numbers called up to the crew for the maneuver to the deorbit position. Why isn't it always the same attitude for every entry? Why arent they "nice" whole numbers. Do the 10th's of a degree really matter?
Thanks!
Not quite sure what you're referring to here, then.I think I am confused. Let me read the info you kindly provided me and see if I can figure it out.
Thank you Jim. Do you know more about the Mach speeds for the throttle bucket in the ascent checklist?
I have questions regarding the shuttle fly-around upon leaving MIR.
Was this performed back then as is currently with ISS?
If so, on STS 63 was this maneuver flown by shuttle PLT Collins?
Thanks.
Not so sure if this is specifically a shuttle question.
Many have mentioned that the use of Saturn heritage equipment has kept the program costs astronomical. Is the reason for such high infrastructure costs due to the old age/labor intensive operations or is it due to the sheer size fo things like the pad/MLP/VAb? I know that for Ares V a new crawler/transporter was looked at (see l2), could a newer ML/CT and newer HLV infrastructure save much reoccurring costs?
Even more interesting... what is the lettering on the pink tags surrounding it.
Often wondered why the shuttle airlock was internal pre ISS and not placed in the payload bay as it is now. It would have generated a lot of additional space in the crew compartment. Was it to do with useable space in the payload or center of gravity?
Often wondered why the shuttle airlock was internal pre ISS and not placed in the payload bay as it is now. It would have generated a lot of additional space in the crew compartment. Was it to do with useable space in the payload or center of gravity?
Often wondered why the shuttle airlock was internal pre ISS and not placed in the payload bay as it is now. It would have generated a lot of additional space in the crew compartment. Was it to do with useable space in the payload or center of gravity?
It was to maximize the useable length of the payload bay. That was a big part of the reason why Columbia was used to launch Chandra, it was the only one it could fit into. Even after they developed the external airlock and docking system, they didn't remove the internal airlocks until they were committed to building the ISS. The high inclination orbit meant that the shuttle couldn't cary payloads heavy enough that they would take up the entire bay anyways.
By the way, I have seen drawings dating back to 1982 that show the basic design of the exterior airlock, so even back then, they were thinking about it.
Yes Payload bay,...my error.Often wondered why the shuttle airlock was internal pre ISS and not placed in the payload bay as it is now. It would have generated a lot of additional space in the crew compartment. Was it to do with useable space in the payload or center of gravity?
The former (assuming by "payload" you mean "payload bay").
(...) Even after they developed the external airlock and docking system, they didn't remove the internal airlocks until they were committed to building the ISS. (...)Does that mean that they actually flew some missions with two airlocks: with the newly installed external airlock and docking system, and with the internal airlock not yet removed? If so, which missions were they, and did they at least remove some parts of the internal airlock to save some weight?
(...) Even after they developed the external airlock and docking system, they didn't remove the internal airlocks until they were committed to building the ISS. (...)Does that mean that they actually flew some missions with two airlocks: with the newly installed external airlock and docking system, and with the internal airlock not yet removed? If so, which missions were they, and did they at least remove some parts of the internal airlock to save some weight?
More specifically, all the OV-104 Shuttle-Mir missions. When OV-103 and OV-105 made their dockings they both had the permanent ODS configuration used today.(...) Even after they developed the external airlock and docking system, they didn't remove the internal airlocks until they were committed to building the ISS. (...)Does that mean that they actually flew some missions with two airlocks: with the newly installed external airlock and docking system, and with the internal airlock not yet removed? If so, which missions were they, and did they at least remove some parts of the internal airlock to save some weight?
Most of the Shuttle-Mir missions flew in this config.
(...) Even after they developed the external airlock and docking system, they didn't remove the internal airlocks until they were committed to building the ISS. (...)Does that mean that they actually flew some missions with two airlocks: with the newly installed external airlock and docking system, and with the internal airlock not yet removed? If so, which missions were they, and did they at least remove some parts of the internal airlock to save some weight?
Most of the Shuttle-Mir missions flew in this config.
I assumed there must have been something to blow out the overhead panels and the pressure structure.
I assumed there must have been something to blow out the overhead panels and the pressure structure.
Yes, there was and the handle to do it was in the center console
Old GPCs has me curious. I remember reading multiple posts on here about why dont they upgrade the computer hardware on the orbiters since they date back to a 1960/70 design. The response was understandably that the computers have proved themselves, and that to update them would be too costly. So, when were the GPC's replaced, and how are they better?
Yes, multiple times, but more frequently with the old GPCs than the current ones.
Early 1990s, went from the AP-101B to the AP-101S, binary-compatible with the old GPC, has the I/O Processor (IOP) integrated into the GPC case, twice as much memory (enables the entry software to be stored in an upper-memory archive for quick recall in case of emergency deorbit), solid state memory instead of core.
At what point in the approach phase do the guidance modes displayed on the HUD change (e.g. from OGS to FLARE, and FLARE to FINAL)? Are these based on altitude, or something else?
What is the maximum altitude that would be achieved during an RTLS abort?
Has it been ever used the Stabilized Payload Deployment System(SPDS)? I didn't know the existance of this mechanism before DaveS posted that link a couple of posts ago.
What is the contingency plan if the flash evaporator fails after reentry burn?
In a contingency situation, would one risk shutting down an APU? (Or for early failure, delaying startup of #2 and #3?) I assume that's the biggest heat load. IIRC, the flight surfaces still travel at full speed with two APUs.What is the contingency plan if the flash evaporator fails after reentry burn?Timing of the failure is everything (how long after TIG), but generally you would rely on the “Cold Soak” of the radiators, which was conducted prior to payload bay door closure, and use of the ammonia boilers to provide enough cooling thru landing.
In a contingency situation, would one risk shutting down an APU? (Or for early failure, delaying startup of #2 and #3?) I assume that's the biggest heat load. IIRC, the flight surfaces still travel at full speed with two APUs.What is the contingency plan if the flash evaporator fails after reentry burn?Timing of the failure is everything (how long after TIG), but generally you would rely on the “Cold Soak” of the radiators, which was conducted prior to payload bay door closure, and use of the ammonia boilers to provide enough cooling thru landing.
-Alex
When the APU's are up the hyd hx dumps heat (a lot actually) to the freon loops. It's the other way on orbit.In a contingency situation, would one risk shutting down an APU? (Or for early failure, delaying startup of #2 and #3?) I assume that's the biggest heat load. IIRC, the flight surfaces still travel at full speed with two APUs.What is the contingency plan if the flash evaporator fails after reentry burn?Timing of the failure is everything (how long after TIG), but generally you would rely on the “Cold Soak” of the radiators, which was conducted prior to payload bay door closure, and use of the ammonia boilers to provide enough cooling thru landing.
-Alex
No, the orbiter's Auxialiary Power Units (APUs) would be operated as normal. There should be sufficient cooling from the Radiator Cold Soak and (earlier) than normal operation of the Amonia Boiler [at entry interface as opposed to the nominal activation at ~120,000 feet].
APU/HYD cooling is really a separate animal entirely and not part of the ECLSS Freon Cooling Loops except for an interface thru the Hydraulic/Freon Heat Exchanger which is used to pick up heat [as opposed to rejecting it to the loop] from the loops to help keep the hydraulic fluid warm.
Mark Kirkman
(Space Shuttle Hugger)
When the APU's are up the hyd hx dumps heat (a lot actually) to the freon loops. It's the other way on orbit.In a contingency situation, would one risk shutting down an APU? (Or for early failure, delaying startup of #2 and #3?) I assume that's the biggest heat load. IIRC, the flight surfaces still travel at full speed with two APUs.What is the contingency plan if the flash evaporator fails after reentry burn?Timing of the failure is everything (how long after TIG), but generally you would rely on the “Cold Soak” of the radiators, which was conducted prior to payload bay door closure, and use of the ammonia boilers to provide enough cooling thru landing.
-Alex
No, the orbiter's Auxialiary Power Units (APUs) would be operated as normal. There should be sufficient cooling from the Radiator Cold Soak and (earlier) than normal operation of the Amonia Boiler [at entry interface as opposed to the nominal activation at ~120,000 feet].
APU/HYD cooling is really a separate animal entirely and not part of the ECLSS Freon Cooling Loops except for an interface thru the Hydraulic/Freon Heat Exchanger which is used to pick up heat [as opposed to rejecting it to the loop] from the loops to help keep the hydraulic fluid warm.
Mark Kirkman
(Space Shuttle Hugger)
Also the ammonia boilers are designed to be used below 100,000 ft, not sure if earlier activation would be effective.
And finally it would take multiple failures for a total loss of FES cooling.
Hi all.
In this period I’m trying to understand the mechanics of the rendezvous maneuver with the ISS. Now I understand in which way the shuttle gets in proximity of the station, it’s a matter of orbital mechanics, neither more nor less. What I can’t understand is what happen during the manual phase of the maneuver.
For example see the first picture attached. The shuttle is after MC4, that’s to say the manual phase has taken over. We have to get from point 1 to point 7. how does the shuttle get there? It’s my understanding that RCS is fired in the direction of travel (+X axis) in order to increase the velocity of the shuttle, lifting therefore the altitude slowing down at the same time. This because the lower the altitude and the faster the orbital speed. Is that correct? Or is there anything else that happen? Or maybe the RCS is fired downward (+ Z axis) so that the Shuttle goes up?
After the R bar pitch maneuver the Shuttle goes in front the station for a V bar approach. With reference to the second picture attached, is my understanding that through continuous firings of the RCS system the altitude of the shuttle respect to the station’s altitude is constantly changed in order to continually slow down till when the station “hit” the shuttle itself. I’ll explain this better. Always with reference to the second picture, at point 8 the shuttle fires the RCS upwards so that it goes in a slightly lower orbit than the station. In this way the shuttle goes a little bit fastener. Then a second faring (point 9) this time downward, taking the shuttle in a slightly higher orbit than the station has, decreasing this time the speed. And the story goes in this way till to docking. I’m trying to find another explanation but it seems to me the only one reasonable taken into account the principle of orbital mechanics.
Any help is very appreciated.
Thanks
Davide
Hi Jorge. Thanks for the explanation. I’d like however to ask you few other questions for clarifications.
1) when MC4 is fired, the trajectory followed by the shuttle for getting from point 1 to point 7 (always with reference to first picture of my first post) is basically dictated by orbital mechanics, there is no manual action taken by the CDR. Is that correct? The CDR takes over manually only during the Vbar approach, right?
The MC4 is computed by Mission Control or by shuttle onboard computers?
2) During the Vbar approach, which is the physical phenomena thanks to which the shuttle can get till to the ISS? I mean, I understand that the CDR makes firings in order to stay centered with the ISS, but than why (from an orbital mechanical point of view) the shuttle slows down so that it can dock with the station? Or put it in another way, why does the shuttle goes toward the station rather then station keeping? If station keeping is required, how is performed and how you can resume the motion toward the station for docking?
3) Given a inertial reference system, let’s say a system centered on the Earth and fixed, is the shuttle that goes toward the ISS or is the ISS going toward the Shuttle?
4) For missions like STS-92 and STS-98 I suppose an Rbar approach has been used. In this case, was this Rbar approach the same of the Rbar approach used for the Shuttle-Mir missions?
No, the CDR takes over manually after the MC4 burn is completed, and flies the rest of the approach manually. Only translation is performed manually; rotation is performed by the digital autopilot (DAP), except for a period during the RPM when the DAP is in free drift and the orbiter is not under active control at all.
When the orbiter is approaching ISS on the Vbar (whether by the CDR performing -Z or by naturally "turning the corner" at Vbar arrival), the orbiter is traveling retrograde relative to ISS and is therefore flying too slow to remain at that orbital altitude, and will tend to drop. The CDR counters this tendency by performing +X translations, creating a series of small "hops" on the Vbar. The size of the hops is a matter of CDR preference. In theory it is possible to perform a Vbar approach using nothing but +X, and a few CDRs have approached that ideal, but total perfection is elusive, alas.
STS-88, 96, 101, 106, and 92 performed -Rbar approaches, in which the orbiter flew 180 degrees around ISS and approached from above. This type of approach was not used during Shuttle-Mir.
STS-88, 96, 101, 106, and 92 performed -Rbar approaches, in which the orbiter flew 180 degrees around ISS and approached from above. This type of approach was not used during Shuttle-Mir.Could be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches? One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link (http://klabs.org/richcontent/general_technology/shuttle_rendezvous_with_hubble.pdf)) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST. It may just be that the memory of the LDEF rendezvous, with the orbiter flying out in front and then over the top, sticks out to me.
STS-97 and 98 performed +Rbar approaches, with the orbiter approaching from below and yawing to a tail-forward orientation at 600 ft. This is essentially the same approach used for Shuttle-Mir missions STS-76, 79, 81, 84, and 86.
Could be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches? One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST. It may just be that the memory of the LDEF rendezvous, with the orbiter flying out in front and then over the top, sticks out to me.
FWIW, I threw in a screen capture of a figure from another reference, in NTRS:
http://hdl.handle.net/2060/20070018243
Jorge would definitely be a good person to take that...here's another interesting paper by John Goodman:QuoteCould be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches? One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST. It may just be that the memory of the LDEF rendezvous, with the orbiter flying out in front and then over the top, sticks out to me.
FWIW, I threw in a screen capture of a figure from another reference, in NTRS:
http://hdl.handle.net/2060/20070018243
I read both links you posted...they are both very good. One thing that I can't understand is the difference between inertial and Rbar approach.
Jorge would definitely be a good person to take that...here's another interesting paper by John Goodman:QuoteCould be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches? One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST. It may just be that the memory of the LDEF rendezvous, with the orbiter flying out in front and then over the top, sticks out to me.
FWIW, I threw in a screen capture of a figure from another reference, in NTRS:
http://hdl.handle.net/2060/20070018243
I read both links you posted...they are both very good. One thing that I can't understand is the difference between inertial and Rbar approach.
http://klabs.org/DEI/lessons_learned/shuttle/cr-2007-2136974.pdf
Based on more foggy memory, I was looking for whether or not a Ti Delay had ever needed to be used; the reference above notes one usage on STS-49, but has details on other historical events. (Some of those early missions with lots of flight testing would be fun to go back and revisit, like 41-B.)
QuoteCould be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches? One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST. It may just be that the memory of the LDEF rendezvous, with the orbiter flying out in front and then over the top, sticks out to me.
FWIW, I threw in a screen capture of a figure from another reference, in NTRS:
http://hdl.handle.net/2060/20070018243
I read both links you posted...they are both very good. One thing that I can't understand is the difference between inertial and Rbar approach.
STS-88, 96, 101, 106, and 92 performed -Rbar approaches, in which the orbiter flew 180 degrees around ISS and approached from above. This type of approach was not used during Shuttle-Mir.Could be bad memory, but it seemed like there were more -R bar approaches prior to Shuttle-Mir...or were those inertial approaches?
STS-97 and 98 performed +Rbar approaches, with the orbiter approaching from below and yawing to a tail-forward orientation at 600 ft. This is essentially the same approach used for Shuttle-Mir missions STS-76, 79, 81, 84, and 86.
One of the papers on rendezvous that I stumbled onto recently (on HST mission rendezvous, link (http://klabs.org/richcontent/general_technology/shuttle_rendezvous_with_hubble.pdf)) seems to suggest that the +R bar approaches started during Shuttle-Mir were then applied to at least some orbiter rendezvous approaches to other spacecraft, such as HST.
ok it's getting clearer and clearer, but I still have few questions, if you don't mind.QuoteNo, the CDR takes over manually after the MC4 burn is completed, and flies the rest of the approach manually. Only translation is performed manually; rotation is performed by the digital autopilot (DAP), except for a period during the RPM when the DAP is in free drift and the orbiter is not under active control at all.
The translation in performed along all the 3 axis or only along two axes?
I mean translation along the Rbar shouldn't be controlled since the motion along this vector is due to the MC4 burn which, you've said, aims to take the shuttle to a position 600ft under the station.
QuoteWhen the orbiter is approaching ISS on the Vbar (whether by the CDR performing -Z or by naturally "turning the corner" at Vbar arrival), the orbiter is traveling retrograde relative to ISS and is therefore flying too slow to remain at that orbital altitude, and will tend to drop. The CDR counters this tendency by performing +X translations, creating a series of small "hops" on the Vbar. The size of the hops is a matter of CDR preference. In theory it is possible to perform a Vbar approach using nothing but +X, and a few CDRs have approached that ideal, but total perfection is elusive, alas.
so the orbiter is travelling retrograde relative to ISS because after having turned the corner the GC is higher then the GC's station and therefore the shuttle goes slower, right?
why do you say that the shuttle is flying to slow to and tends to drop?
in the diagram I posted I see a firing aimed to lower shuttle altitudine so it doesn't seem it tends to drop. what am I missing?
QuoteSTS-88, 96, 101, 106, and 92 performed -Rbar approaches, in which the orbiter flew 180 degrees around ISS and approached from above. This type of approach was not used during Shuttle-Mir.
I didn't know of this kind of approach. which is the reason behind this kind of approach?
is there anything peculiar respect to a +Rbar approach, or is just a mirror copy of a +Rbar approach?
OT: just for curiosity, are you a flight controller? how do you know all this things?
Anyone know what the black upper wing chines on Columbia was? It doesn't look like to be HRSI tiles or black painted FRSI blankets.
Which component causes the GOX streams coming from the SSME nozzles and is there anything specific that triggers it?
If the orbiter pitches up, wouldn't plume impingement from the FRCS force the ET to pitch down a bit?Don't know, all that I know is that from the ET cam the horizon stays pretty much stationary the FOV, only slowly moving, I guess from any non-zeroed post-MECO rates.
Here's a question about something has bugged me for a while now.
In all the animations of ET sep from the the orbiter post-MECO the ET is always shown as pitching down relative to Earth and the orbiter. But here's the part that's bugging me: Just about every launch since RTF in 2005 with the ET Cam shows the ET as being stationary WRT to the horizon after sep.
So, is the animations wrong or is the ET really pitching down after ET sep?
In all the animations of ET sep from the the orbiter post-MECO the ET is always shown as pitching down relative to Earth and the orbiter. But here's the part that's bugging me: Just about every launch since RTF in 2005 with the ET Cam shows the ET as being stationary WRT to the horizon after sep.What is the vintage of the animation? If it's old, as in flight test era, perhaps they were trying to depict the operation of the (no longer employed) tumble system.
Almost all of the umbilcle well and post sep flight deck photos of the tank are almost side on to the tank. That means that a line from the camera (on the orbiter) is perpendicular to the longitudinal axis of the tank which would indicate that the tank is not pitching.
I originally posted this in the Exportation Alternatives section but didn't get an answer, thought I might get one here.
I saw this image
(http://www.nasaspaceflight.com/wp-content/uploads/2010/06/A8.jpg)
in the "Completed SD HLV assessment highlights low-cost post-shuttle solution"
http://www.nasaspaceflight.com/2010/06/sd-hlv-assessment-highlights-post-shuttle-solution/
I was wondering how much force is taken up by the nose tripod of the Shuttle/ET connection, and how much the ET would have to be reengineered to make this work? Is it really a practical low cost alternative?
Thank you for your time,
Steve
I heard many years ago from a long forgotten source that the parachute door of STS-95 fell off during launch and nearly hit one of the H2 lines on one of the SSME's (No. 1, IIRC). Can I get confirmation about that please?It did hit the nozzle of the center engine:
While thinking about it...can I get a rundown of What-if scenarios? What if it did hit the H2 line? Would the valve to that cooling loop be closed intime to prevent anything worse to happen? RUD? RTLS? TAL?See STS-93. Three coolant tubes were ruptured on the center engine during ignition and H2 leaked leading to a LOX LLCO some 0.15 seconds prior to targeted MECO.
I have an airlock question here.
On STS-96/2A.1, STS-101/2A.2a, and STS-106/2A.2b, how did the crews perform spacewalks? The LDM was in the payload bay and the access tunnel connected to the aft hatch of the ODS where spacewalks were usually carried out when docked to the ISS. Of course, the zenith hatch was connected to the PMAs.
The logical explanation, of course, would be if the spacewalks were to be conducted out the SPACEHAB transfer tunnel, however the ICC was present on each of these three missions above the chamber, so no spacewalking hatch could be added.
Mind you, Quest was installed on 7A (STS-104) in 2001, well after the last of the three aforementioned missions.
How did the six astronauts (Barry, Jernigan, Lu, Malenchenko, Voss, and Williams) exit the station on these missions?
I have an airlock question here.
On STS-96/2A.1, STS-101/2A.2a, and STS-106/2A.2b, how did the crews perform spacewalks? The LDM was in the payload bay and the access tunnel connected to the aft hatch of the ODS where spacewalks were usually carried out when docked to the ISS. Of course, the zenith hatch was connected to the PMAs.
The logical explanation, of course, would be if the spacewalks were to be conducted out the SPACEHAB transfer tunnel, however the ICC was present on each of these three missions above the chamber, so no spacewalking hatch could be added.
Mind you, Quest was installed on 7A (STS-104) in 2001, well after the last of the three aforementioned missions.
How did the six astronauts (Barry, Jernigan, Lu, Malenchenko, Voss, and Williams) exit the station on these missions?
The ICC was mounted aft of the Tunnel Adapter that was used for the EVAs
Allright, thanks – Just for curiosity, the shortened version of that tunnel cannot feature an airlock when the ICC is attached, correct?
Lastly, what hatches need to be closed to operate the airlock in the tunnel while docked to ISS (would station hatches need to be closed?)
Allright, thanks – Just for curiosity, the shortened version of that tunnel cannot feature an airlock when the ICC is attached, correct?
Lastly, what hatches need to be closed to operate the airlock in the tunnel while docked to ISS (would station hatches need to be closed?)
The tunnel length is driven by the location of the spacehab module wich is driven in turn by CG requirements. If the spacehab module was mounted forward for some reason, the ICC would simply be mounted behind it.
They would never have flown a SpaceHab or SpaceLab module without the tunnel adaptor to act as an airlock. It would be required in the case of a late EVA to manually close the playload bay doors. You couldn't use to ODS hatch of the external airlock because A) they would never risk the suits around the ODS mechanism and B) there wouldn't be enough room to get back in after the doors were closed.
The Tunnel Adaptor had internal hatches at either end to minimize the air lost when cycling it. Those would have been the only hatches that needed to be closed.
How long are the transfer tunnels (long and short), just out of curiosity?
How long are the transfer tunnels (long and short), just out of curiosity?
They vary. 22 inches to several feet
The Airlock is in the tunnel adaptor, not the tunnel itself. The adaptor is about 50" in inside diameter while the tunnel is about 40"
How long are the transfer tunnels (long and short), just out of curiosity?
They vary. 22 inches to several feet
22 inches in length is enough for an airlock? I can't find data on transfer tunnels anywhere (googled them of course, etc.), but the short SPACEHAB tunnel looks at shortest 5 feet – though I am bad at estimation. So essentially, you're saying that the transfer tunnel is 22 inches LONG, or in Diameter?
I originally posted this in the Exportation Alternatives section but didn't get an answer, thought I might get one here.
I saw this image (clipped)
in the "Completed SD HLV assessment highlights low-cost post-shuttle solution" (clipped)
I was wondering how much force is taken up by the nose tripod of the Shuttle/ET connection, and how much the ET would have to be reengineered to make this work? Is it really a practical low cost alternative?
Thank you for your time,
Steve
The Airlock is in the tunnel adaptor, not the tunnel itself. The adaptor is about 50" in inside diameter while the tunnel is about 40"
How long are the transfer tunnels (long and short), just out of curiosity?
They vary. 22 inches to several feet
22 inches in length is enough for an airlock? I can't find data on transfer tunnels anywhere (googled them of course, etc.), but the short SPACEHAB tunnel looks at shortest 5 feet – though I am bad at estimation. So essentially, you're saying that the transfer tunnel is 22 inches LONG, or in Diameter?
Here are a couiple of photos of the adaptor from the early Shuttle/Mir flights where the external airlock was mounted in Bay 3 and the Adaptor was mounted between the crew compartment and the EA. On later flights, this was reversed.
Here are a couple of photos of the adaptor from the early Shuttle/Mir flights where the external airlock was mounted in Bay 3 and the Adaptor was mounted between the crew compartment and the EA. On later flights, this was reversed.
This begs the question of why the Adapter/APAS was not mounted as close to the SpaceHAB module as possible, to put the APAS closer to the vehicle c/g.
Okay, so in place of the tunnel itself, you CAN use just the tunnel adaptor to connect the ODS to the SPACEHAB itself, but diameter aside it's a whole 5 feet in length for the tunnel adaptor?
Okay, so in place of the tunnel itself, you CAN use just the tunnel adaptor to connect the ODS to the SPACEHAB itself, but diameter aside it's a whole 5 feet in length for the tunnel adaptor?
No, there are many reasons why
My point, due to spacing and the cargo attach points in the payload bay, a tunnel of around 22 inches was required.
The module was required to be as far back in the bay as possible for CG reasons.
Okay, so in place of the tunnel itself, you CAN use just the tunnel adaptor to connect the ODS to the SPACEHAB itself, but diameter aside it's a whole 5 feet in length for the tunnel adaptor?
No, there are many reasons why
My point, due to spacing and the cargo attach points in the payload bay, a tunnel of around 22 inches was required.
The module was required to be as far back in the bay as possible for CG reasons.
…So it's ~2 feet long and 50 inches in diameter? Seems awful short because an EMU spacesuit is way larger than 22 inches :)
Okay, so in place of the tunnel itself, you CAN use just the tunnel adaptor to connect the ODS to the SPACEHAB itself, but diameter aside it's a whole 5 feet in length for the tunnel adaptor?
No, there are many reasons why
My point, due to spacing and the cargo attach points in the payload bay, a tunnel of around 22 inches was required.
The module was required to be as far back in the bay as possible for CG reasons.
…So it's ~2 feet long and 50 inches in diameter? Seems awful short because an EMU spacesuit is way larger than 22 inches :)
I am only talking tunnel, not tunnel adapter and ODS. A tunnel adapter is always required with a Spacehab module. The tunnel is the remaining straight section.
Okay, alright, I think I understand what you are saying now. I attached a graphic of the payload bay as visible from the station during the STS-118 rendezvous sequence, and I added numbers representing the payloads. Please tell me if I am correct:
1). ODS
2). SPACEHAB Tunnel Adaptor (which is about 5 feet?)
3). SPACEHAB Short Tunnel (~22 inches)
4). SPACEHAB Logistics Single Module (LSM)
5). S5 Truss short spacer
6). External Stowage Platform (ESP)-3
1). ODS
2). SPACEHAB Tunnel Adaptor (which is about 5 feet?)
3). SPACEHAB Short Tunnel (~22 inches)
4). SPACEHAB Logistics Single Module (LSM)
5). S5 Truss short spacer
6). External Stowage Platform (ESP)-3
1). ODS
2). SPACEHAB Tunnel Adaptor (which is about 5 feet?)
3). SPACEHAB Short Tunnel (~22 inches)
4). SPACEHAB Logistics Single Module (LSM)
5). S5 Truss short spacer
6). External Stowage Platform (ESP)-3
That tunnel is not the 22 inch one, which was used on the first few missions without ODS
Also, it is SPACELAB Tunnel Adaptor
Okay, so how many tunnels are there, when were they used, and which one was used for STS-118?
Okay, so how many tunnels are there, when were they used, and which one was used for STS-118?
There might have been 4 different tunnels.
STS-107 had a unique one
MIR/ISS
the early missions
and the one for last two missions
I think I recall hearing that those were vents of some sort but not sure.Well, they aren't listed in any documents I have come across. The only deactivated vents are vents 4 and 7 on the mid-body, none on the aft compartment.
How are the SRM segment stacking order determined? I've always thought that there's no real order, they just take one and stack it. But recently I have gotten reason to question this.
I know that, but I was more curious on the stacking order of the actual segments in the VAB.How are the SRM segment stacking order determined? I've always thought that there's no real order, they just take one and stack it. But recently I have gotten reason to question this.
I am sure someone smarter than me can give the best answer, but to my knowledge they are stacked to make propellant grains and casting sets. Meaning, you want to make sure you have the same propellant on both sides since some propellant can burn faster or stronger than others. Matching the sets prevents asymmetric thrust.
Hope that helps!!!
Jeff
It would be great if someone could confirm this.
Thanks. So the actual umbilical ports on the orbiter is in the Midbody Payload Umbilical well that is covered by the last "S" in "States"?It would be great if someone could confirm this.
Good deduction. Those are the receptacles for the RBUS hydrogen umbilical foot fittings. Very similar to the orbiters T-0 umbilical, just smaller. If you look further to the rear towards the base heat shield you will see another similar opening, that's one of the fittings for the orbiters umbilical. Draw a straight line up from that opening and you will see the other fitting, mounted externally on a bracket due to the slope of the base heat shield. It doesn't show up too well in that photo but I'm sure you can find another shot that shows it in more detail.
Anyone know the equatorial diameter of the EO-2/EO-3 balls on the ET? Also, what color do they have? Some photos show it as mix between gold and bronze, while other photos show it as a gray metal look.
Thanks for information. For now I'll go with the metallic color.Anyone know the equatorial diameter of the EO-2/EO-3 balls on the ET? Also, what color do they have? Some photos show it as mix between gold and bronze, while other photos show it as a gray metal look.
Here is a description of the EO-2 & EO-3 inteface to the orbiter:
ET/Orbiter Aft Left Attachment
[...] The direct physical interface with the Orbiter is formed by a large hemispherical surface at the bipod apex that engages with the Orbiter socket. Attachment hardware is Orbiter-provided, and consists of a 2.5-inch diameter tension bolt coupled with a frangible nut housed in the Orbiter.
The forged aluminum-alloy ball interface fitting, weighing approximately 530 pounds, joins the tubular thrust strut and the I-section vertical strut to provide the Orbiter interfacing hemispherical surface. This surface is machined to a 5.275-inches spherical radius, but is flattened 4- 1/2 inches- above the spherical center to compensate for an Orbiter protuberance. A Z-axis bore of 2.875-inches diameter extends 1.5 inches below this flattened surface, where it enlarges to a 5.5-inch diameter and continues through the base of the fitting. This 5.5-inch diameter cavity allows installation of the interface bolt and associated torquing tool.
I don't have any information on color.
Can some one explain what the "Scottish flag" looking things near to the nose of the orbiter?Just a cover for the purge/checkout and servicing panels for the FRCS module.
while we are talking about things during rollover, i have noticed there is some tape on the bottom of the wings. it is always toward the wingtip and is shaped in a squarish pattern that comes to a point (hope that made sense). Anyone know what THAT is for?? Thanks!
Does anyone know what the yellow electronics(?) box in the screenshot is used for?
H/B-4 ET checkout cell. The ET is ET-137 being prepared for lift-to-mate with the SRBs in H/B-3.Does anyone know what the yellow electronics(?) box in the screenshot is used for?
Do you have the context of the photo? All I can tell is that there is a ET in the vertical position in the background. Is the photo from Michoud, a checkout cell in the VAB or a stacking bay?
I know thi smust have been covered before but it would take me too long to dig it out from the 5 parts of Q&A.
is there a reason why payload are installed at the launch pad and not at the OPF before rollover and mate, or at the VAB before rollout ?
thanks in advance ....
I know thi smust have been covered before but it would take me too long to dig it out from the 5 parts of Q&A.
is there a reason why payload are installed at the launch pad and not at the OPF before rollover and mate, or at the VAB before rollout ?
thanks in advance ....
A. VAB doesn't have a clean room
b. the DOD had a requirement for late as possible installation.
c. Most payloads like a vertical orientation
d. The payload would spend months in the orbiter if installed at the OPF
I know thi smust have been covered before but it would take me too long to dig it out from the 5 parts of Q&A.
is there a reason why payload are installed at the launch pad and not at the OPF before rollover and mate, or at the VAB before rollout ?
thanks in advance ....
I have noticed that Atlantis has never carried an MPLM. Is there a technical reason why not or was it just luck of the draw? Thanks.Pure luck of the draw, she was configured and even rolled over the the VAB twice for STS-114 pre-Columbia and STS-121 before it was reassigned to Discovery.
Is there anybody knows how long it takes to traslate the payload from the changeout room to payload bay?
Is there anybody knows how long it takes to traslate the payload from the changeout room to payload bay?
Minutes
Why does Harwood and/or NASA say the shuttle launches from a starting altitude of 23 ft below sea level?
Why does Harwood and/or NASA say the shuttle launches from a starting altitude of 23 ft below sea level?
This is a footnote from a table of ascent data produced by NASA in one of their "Math and Science @ Work" publications:
"Note: Notice from the table that the altitude is negative at liftoff. Zero altitude can be described as a specific distance from the center of the Earth. Since the Earth is not perfectly spherical the location of the launch just happens to be below this specified point. Also, because this is a calculated number, some degree of error may be present."
http://www.nasa.gov/pdf/466711main_AP_ST_ShuttleAscent.pdf
Velocity is defined as the rate of change of the vertical position.
How is the AoA maintained through entry? Is it only done by the elevons or does the bodyflap as I suspect help out?
Thanks. So, alone the elevons cannot maintain the 40° AoA and needs the assistance from the bodyflap? Is that correct?How is the AoA maintained through entry? Is it only done by the elevons or does the bodyflap as I suspect help out?
both
Is there anybody knows how long it takes to traslate the payload from the changeout room to payload bay?
Minutes
Is there anybody knows how long it takes to traslate the payload from the changeout room to payload bay?
Minutes
um, just curious, how do you figure minutes? If you're talking installing into the orbiter from the PCR, quite a bit more than minutes
The bodyflap positioning during entry is a function of mach number. The bodyflap position is used primarily to keep the elevons within a given range of operation and prevent "saturation".THat's what I thought about it, but does it aid in the AoA maintenance? The reason for these questions is some disagreement between me and another developer of the SpaceShuttleUltra project.
I've got a complete listing of the various inputs to the entry DAP that includes the specifics for each individual input (body flap, pitch jets, etc.). I'll check it again, but as near as I can tell, the elevons are sufficient for AoA control, provided the body flap is periodically adjusted to ensure the elevons have full authority. The body flap is fixed until mach 16 during entry, that much I remember.Thanks. BTW, what kind of aerosurface data do you use in the Shuttle Fleet? We actually had strengthen the elevons to be able to maintain the 40° AoA which has lead to the orbiter being far to responsive to RHC control inputs. Maybe you would like to help us with this so we get it right?
Why is it handled like this?How else would you get these engines installed in the shuttle aft compartment? It's a very tight fit, I understand.
Looking at images 2010-1918 & -1920, the SSME looks to be cantilievered from the nozzle. That came as a surprise to me.
Why is it handled like this?
I would have guessed it would be handled more like image 2009-6813.
Thanks, Martin
Hey guys, I was wondering if anybody could tell me what all these feed lines, pipes, etc. are on the SSME, and a brief description please? Listed below are 3 different angles from an SSME used on the previous mission.
The twin Solid Rocket Boosters have a decibel level of 180 (right? wrong?). Can someone tell me how that is calculated please?
Ok... How is the 180 db level of the SRB's thrust measured?
I've got a complete listing of the various inputs to the entry DAP that includes the specifics for each individual input (body flap, pitch jets, etc.). I'll check it again, but as near as I can tell, the elevons are sufficient for AoA control, provided the body flap is periodically adjusted to ensure the elevons have full authority. The body flap is fixed until mach 16 during entry, that much I remember.
(wasn't sure if this should go in Q&A or be a separate thread)
This is more of a historical shuttle Q, but when/why was the decision made to go with hydrogen for the Space Shuttle instead of kerosene?
Would it have made any sense to use the F-1 engines instead of developing the SSMEs?
(wasn't sure if this should go in Q&A or be a separate thread)
This is more of a historical shuttle Q, but when/why was the decision made to go with hydrogen for the Space Shuttle instead of kerosene?
Performance. Kerosene is better for first stages due to density and T/W, but for the rest of the climb to orbit hydrogen is more efficient.QuoteWould it have made any sense to use the F-1 engines instead of developing the SSMEs?
No. It might have made sense to use the F-1 engines instead of the SRBs, though.
Perhaps loudness is measured in the far field, then an "equivalent loudness at a notional 1M" is calcuated as 180dB?
Is there a particular reason why the Spacehab modules were flat on the top rather than being rounded like Spacelab?
Can anyone enlighten me to the issue just before STS-117 launched around the T-35 second mark?
On the net, you can hear something about "ET Helium Inject Delta P #2 .. (pao talking) .. We are go"
Was this the ET pressurization issue that was noted a few days after launch?
Before the recent STS-133 OV-103 ROMS XFEED flange issue, I wasn't familiar with the term AHC. In what applications are AHCs (Air Half-Couplings) typically used on the vehicles? How do they differ from other types of connectors?
I have been looking at this every day for awhile on the KSC video feeds. Does anyone have a hi res photo of this wall?
Seems like barely enough time to pull out the SSMEs, install three new ones, and launch...Didn't always do that; different spares/logistics situation back then. The engines came out in that case, but after the post-firing inspections, maintenance, and retesting, they went back in the same orbiter and flew on that ship's next flight. (Same thing for some other orbiters and engine sets at the time.)
What was the reason for only can doing 3 launch attempts in a row? fuel-cells?
What was the reason for only can doing 3 launch attempts in a row? fuel-cells?
where it can't generate enough electricity
Hi all,
I have a question about the fuel used.
Where is stored the H2 and O2 before tanking operations?
And from where it come, where is produced?
Thanks
Alberto from Italy
Relating to the issues from earlier this week on the main engine controllers, at what point in the countdown would the failure of an engine controller no longer trigger a cutoff or hold?After liftoff, I believe.
Not sure where to post this but theres a super cool space shuttle graphic on space.com
http://www.space.com/missionlaunches/infographic-space-shuttle-nasa-spacecraft-101102.html (http://www.space.com/missionlaunches/infographic-space-shuttle-nasa-spacecraft-101102.html)
there' is a lot of info on Emergency Orbiter Egress procedures, but not a whole lot about Emergency Ingress/Rescue procedures. I was wondering this because on the side hatch of the orbiters have the following Rescue instructions:
1. Insert Tool-Unlock
2. Rotate to Vent Detent
3. Wait 2 minutes
4. Rotate to Hard Stop
anyone know who carries the special tool (if it is a special tool)? also why wait two minutes....that's a long time in an emergency!
thanks!!
thanks for the reply! that's what i thought too, but aren't the orbiters pressurized to 14.7psi (1atm), the same as outside pressure?
Just checking here: the monoball on the bipod yoke, is that one is ejected along with the rest of the yoke structure at ET sep? Or does it remain with the orbiter and is removed post-flight in the OPF during turn-around ops?
If you used a single Space Shuttle main engine for the first stage of a normal rocket how much would it's payload to LEO be? and how do you work it out?
Some basic questions about rocket fuel tanks, I think, but connected with Discovery's current hold-up:
The leak occurred in a pipe carrying excess hydrogen away from the tank. How can it occur that there is EXCESS hydrogen when the tank is not completely full? I would think all fuel is required to end up in the tank?
How does boil-off work? When the fuel is in the tank, a sealed vessel, how does liquid H2 disappear?
Thanks,
Luc
Thanks Lee!
I guess the trouble of cooling a rocket to keep the fuel liquid just would be too cumbersome to make it practical or worthwhile?
When a Shuttle stack is at the pad, are the forward SRB attach points accessible for examination? Speculatively, if as the STS-133 tank were being filled there had been relative motion at one of those points, could it have led to both observed failures, i.e. pulled the GUCP out of alignment and placed the intertank stringer under out-of-specification transient loads?
Does anyone know how many stringers there are on the ET intertank? Also how much are they separated by (in degrees)?
Thank you very much.Does anyone know how many stringers there are on the ET intertank? Also how much are they separated by (in degrees)?
Eighteen external stringers per normal skin panel with 6 panels per intertank. The two machined thrust panels do not have stringers, but instead have external stiffening ribs (26 longitudinal & 7 circumferential) formed by milling the solid metal.
Each panel occupies 45 degrees, so the stringers are separated by 2.5 degrees on those panels that have them.
REALLY dumb question, but my mind has gone completely blank.Can't install payloads in the VAB. No clean environment (environmental control is opening doors), no access to the payload bay for installing payloads.
Why can't they roll out the stack to the pad with the payload already installed?
uncovered.Sorry Jim but here you are wrong. Both the forward and aft hoist points on the orbiter is covered with TPS while in the VAB prior to rollout.
Thanks Lee!
I guess the trouble of cooling a rocket to keep the fuel liquid just would be too cumbersome to make it practical or worthwhile?
From the shuttle processing threads, it sounds like they are doing NDE of the stringers from inside the intertank. How does that work? Do they have a guy clambering around on top of the dome of the LH2 tank?
I had to do a double-take at this picture on Wikipedia:
http://upload.wikimedia.org/wikipedia/commons/f/fe/STS-103_Hubble_EVA.jpg
This is from STS-103/Discovery, a Hubble servicing mission. But that thing in the foreground sure looks like an Orbiter Docking System. Why is it there -- did NASA just not bother to remove it between ISS flights?
Here's a question for the GN&C experts around here:
What does the shuttle GN&C software look at during entry to command the roll reversals? I know that the rolls are closed-loop guidance commanded so it must be some dynamic values that it looks at and decides it time to command a roll in one direction or the other.
Since NASA removed the internal airlocks from the orbiters, the ODS airlock doubles as the EVA airlock for shuttle-based EVAs. The APAS can be removed from the top of the ODS (and was, for STS-125) but it was not necessary to remove it for STS-103, so it remained.
This image is so cool! It is apparently the inside of the STS-133 intertank. It certainly gives the impression the LOX tank is is directly supported by the thrust beam. Is that correct?
trying to get perspective on that pic....how tall is the thrust beam (the part we are looking at)?
trying to get perspective on that pic....how tall is the thrust beam (the part we are looking at)?
trying to get perspective on that pic....how tall is the thrust beam (the part we are looking at)?
You can clearly see one of the SRB beams in this memorable image from 2003:
(http://images.ksc.nasa.gov/photos/2003/low/KSC-03PD-3154.gif)
http://science.ksc.nasa.gov/gallery/photos/2003/captions/KSC-03PD-3154.html
Ross.
Hi all.
I was reading this paper http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750021700_1975021700.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750021700_1975021700.pdf) about the early conceptual studies for the manipulator system (aka robotic arm) of the shuttle. At page 40 there is an interesting paragraph explaining two configurations studied for the end effector.
My question is: why these early concept were discarded? I mean for which reason it has been chosen the configuration that we know for the robotic arm end effector?
during the last press conference for STS-133, Gerst mentioned that shuttle performance is reduced starting in the Feb timeframe. Is that due to warm temperatures reducing propellant performance??
2. I believe it is the transition period. There is a summer and winter flight profile and they have to use a compromise profile during the transition.
or perhaps gravitational effects related to the slightly different distance from the Sun?
Can you (or someone else) please elaborate on that? What is different about the summer and winter flight profiles and why are they necessary?
I have a question regarding this NASA photo taken of the STS 5 launch.
I'm guessing that it is somewhere east of the Delta 2 launch pads (17), or is it actually south of that near Port Canaveral?
Thank you.
For the ET, how long does it take for the foam to cure and turn to the familiar orange color the ET has?
I assume that lift-off occurs within tight tolerances in respect of cross-range to the orbital plane of ISS.
How big is this offset measured i kilometers in case of a "default" ascent profile ?
How come the ET only can handle 13 cycles? What drives that it can't have more? And have a tank ever gotten close to the max 13 cycles?
1. I would assume that the feed lines on the orbiter are hard points, while the tripod mount would act like a ball joint of sorts to accommodate this movement. Is this correct?
2. Does this increase boil off for the short duration the ET is in flight?
3. On ascent does the foam provide a good barrier (relative to the interior) from atmospheric heating?
4. I have read that the ET is discarded with high pressure in the 2 tanks to aid in reentry burn up. Somewhat like a balloon just ready to pop. What would happen to the ET on reentry if there was no internal pressure? Wouldn’t it still break up and burn satisfactorily?
5. What happens to all of the fuel and oxidizer still in the feed lines inside the orbiter upon ET jettison (from the disconnects all the way to the combustion chamber)?
6.For that matter what about the amount still in the feed lines on the ET?
This seems to be the place for random questions.
Who are the closest people to the shuttle when it launches and where are they located (other than the astronauts)? I'm guessing that there are people to assist with emergency egress if it is needed, but that's just a guess.
... is it possible that the GUCP caused the stringer crack seen on the 1st launch attempt?
Are the domes of the Lo2 and LH2 tanks inside the intertank also foam covered or is something else used? To show what I mean look at http://www-pao.ksc.nasa.gov/kscpao/images/medium/2010-5953-m.jpg and http://www-pao.ksc.nasa.gov/kscpao/images/medium/2010-5943-m.jpg
I was looking at a picture of Discovery in the VAB online this morning, and it was a shot showing alot of the surface of the MLP, and I was starting to wonder, at launch how much damage is done to the MLP and how much refurb work goes into it before the next launch? Does it get repainted every time also? I was looking at it and I dont see any burn marks, etc which Id expect to see from the SME and the SRB's. Also do any of the large pipes around the SRB area get torn up, etc during a launch? Does anyone have pictures of the MLP after a launch?
Also I have always wondered, what are the 2 large peices that are on the MLP that are on in front of each wing, is that a deflector for the flames at lift off?
The extended stay could give the ISS a much-need science boost.
Any chance of using Discovery or Endeavor instead of Atlantis for STS-135, since those orbiters are better equipped for docking to ISS (as those two orbiters can stay an extended duration because they are equipped and upgraded with SSPTS).
I was looking at a picture of Discovery in the VAB online this morning, and it was a shot showing alot of the surface of the MLP, and I was starting to wonder, at launch how much damage is done to the MLP and how much refurb work goes into it before the next launch? Does it get repainted every time also? I was looking at it and I dont see any burn marks, etc which Id expect to see from the SME and the SRB's. Also do any of the large pipes around the SRB area get torn up, etc during a launch? Does anyone have pictures of the MLP after a launch?
Looking at pictures of the shuttle's underbelly and the colour contrast between new tiles and old tiles got me thinking....how many flights have the oldest tiles seen? Do tiles have a maximum number of reentries lifetime or do they only get replaced when they get damaged? Or are the majority of tiles the same ones each orbiter came with at delivery?
Is it possible for the shuttle to land on water in case of an emergency?
For OV-104, almost 84 percent of the tiles on the vehicle are from the original build. And many of the replacements were for reasons other than TPS failure (for instance, all of the ETB-8 and BRI-18 were added just because we wanted the better tile).
What was the use for the extra LH2 line seen on the first shuttle flights? For example STS-1.You mean the large thick line right next to the 17" LOX feedline? That's the LOX anti-geyser line. Starting with the LWTs, the LOX anti-geyser line was replaced with a direct GHe injection which goes through the right aft vertical strut.
From a NYT article published just after Columbia was lost.
Ross.
What was the reason for the odd foam color of the ET used on STS-124? In the videos it looks like some foam was darker as if it was left in the sun for some time. Look http://i.ytimg.com/vi/p1mvfhvMzlQ/0.jpg The whole bottom area looks like that for this ET.
There wouldn't be some kind of map as to which tiles are still "original" would there? or a "statistically this area has needed more replacement than other areas" map? I imagine the tiles on the underside that get chewed up the most, particularly near the landing gear due to landing debris.
Do all Mission Specialists get training to be a Flight Engineer?
What were the abort modes like for the planned shuttle launches from VAFB ? What would the equivalent of a TAL be?
What were the abort modes like for the planned shuttle launches from VAFB ? What would the equivalent of a TAL be?
They are the same, except the down range abort was initially called TPL. NASA later changed TAL to mean Transoceanic Abort Landing. The AOA drove the crossrange requirement. NASA was looking for other airfields in Washington and Alaska to reduce the range.
What were the abort modes like for the planned shuttle launches from VAFB ? What would the equivalent of a TAL be?
They are the same, except the down range abort was initially called TPL. NASA later changed TAL to mean Transoceanic Abort Landing. The AOA drove the crossrange requirement. NASA was looking for other airfields in Washington and Alaska to reduce the range.
I was always under the impression that downrange was south. Thanks for clearing that up.
Hi all.
do you know if during the development of the structure of the orbiter engineers had to overcome some particular difficulty? or if during construction they had some kind of problem that forced to change the design of the structure (i.e. a given structural component made bigger or with a different size)?
thanks.
Davide
What were the abort modes like for the planned shuttle launches from VAFB ? What would the equivalent of a TAL be?
They are the same, except the down range abort was initially called TPL. NASA later changed TAL to mean Transoceanic Abort Landing. The AOA drove the crossrange requirement. NASA was looking for other airfields in Washington and Alaska to reduce the range.
I was always under the impression that downrange was south. Thanks for clearing that up.
It is, Washington and Alaska were for AOA. Christmas Islands were looked at for TAL. There would have been SCA range problem with getting an orbiter off these islands.
It is.
Wrong holiday. Christmas Island is in the Indian Ocean.
The shuttle TAL site in the Pacific was Mataveri International Airport on Easter Island.
The shuttle TAL site in the Pacific was Mataveri International Airport on Easter Island."Shuttle Down"
The shuttle TAL site in the Pacific was Mataveri International Airport on Easter Island."Shuttle Down"
I beg to differ
http://en.wikipedia.org/wiki/Kiritimati
but you are right, it was Easter Island
Hi all.
do you know if during the development of the structure of the orbiter engineers had to overcome some particular difficulty? or if during construction they had some kind of problem that forced to change the design of the structure (i.e. a given structural component made bigger or with a different size)?
thanks.
Davide
Every time one blew up on the test stand, they changed designs :)
For example I think the helium purge between the tubine section and the pump section on one of the two turbopumps was the result of a test stand failure.
Danny Deger
Hi all.
do you know if during the development of the structure of the orbiter engineers had to overcome some particular difficulty? or if during construction they had some kind of problem that forced to change the design of the structure (i.e. a given structural component made bigger or with a different size)?
thanks.
Davide
This has been driving me crazy for years. Why do SSME's 2 and 3 move closer together at about T-2 seconds?
Why was the Shuttle crew cabin atmosphere selected to be one atmosphere? Why not half an atmoshere, say? This would be a comprise between the Apollo and Shuttle atmospheric pressures. Does anyone know how much the mass saving would be?The reason for using aluminum over titanium was actually manufacturer experience. Not many airframe manufacturers had experience with large titanium airframes. By using aluminum many more could bid on the orbiter contract.
A second question is about the material used on the orbiter. As I understand it, titanium wasn't used for the structure because of scarcity concerns (seems unbelievable to me), but could have the orbiter that replaced Challenger used it?
Because we live in one atmosphere
Because we live in one atmosphere
So I take it you don't know.
Because we live in one atmosphere
Because we live in one atmosphere
That's not really a reason. We lived in one atmosphere during Apollo, yet Apollo didn't use one atmosphere.
[/quote
Yes, it is. Look at what Apollo goals were and look what the shuttle's goals were. Or do I have spell it out?
I was reading in the article on the front page about the roll out of Discovery, and how once back from her flight she will spend some time in storage in the VAB due to another vechicle will be taking over OPF-3, which it stated could be the X-37. Why would something that small get a facility as large to house and take care of a shuttle?? Was just suprsed to read that today. They could fit a fleet of the X-37's in there...lol.
Because we live in one atmosphere
So I take it you don't know.
That is exactly the reason and everything falls from it. Habitability, science, international relations, etc
Because we live in one atmosphere
So I take it you don't know.
That is exactly the reason and everything falls from it. Habitability, science, international relations, etc
I think what Jim means to say is that the goals of the two different programs dictated why the pressures were set this way.
In Apollo, the goal was simply to get to the moon via whatever means possible. The astronauts were all hardened ex-military or test pilots and stuff, as such they were used to tolerating extreme conditions and it was just part of getting the job done. They NEEDed the lower pressure to make the cabin lighter and get to the moon and back.
In shuttle, the original goal was to be able to bring up any old regular joe to space. It was supposed to be a shirt-sleeve environment just like an airliner. So launch G forces were limited to 3 to make it more comfortable, whereas I believe Saturn V launches were upwards of 6Gs. 3G is like a fast roller coaster, 6G and most untrained people would probably pass out. Same goes for the cabin pressure, they tried to keep it as similar to ground level as possible so that it would be as familiar and "normal" an environment as possible.
A second question is about the material used on the orbiter. As I understand it, titanium wasn't used for the structure because of scarcity concerns (seems unbelievable to me), but could have the orbiter that replaced Challenger used it?AIUI, most of the world titanium deposits (at least as available in the 1960s & 70s) were in the Soviet Union. I've read that the SR-71 was in large part built with Soviet titanium, for which the CIA needed to set up a series of front companies to contrive the purchases. Titanium metalworking and welding was also in its infancy.
AIUI, most of the world titanium deposits (at least as available in the 1960s & 70s) were in the Soviet Union. I've read that the SR-71 was in large part built with Soviet titanium, for which the CIA needed to set up a series of front companies to contrive the purchases. Titanium metalworking and welding was also in its infancy.
Because we live in one atmosphere
So I take it you don't know.
That is exactly the reason and everything falls from it. Habitability, science, international relations, etc
I think what Jim means to say is that the goals of the two different programs dictated why the pressures were set this way.
In Apollo, the goal was simply to get to the moon via whatever means possible. The astronauts were all hardened ex-military or test pilots and stuff, as such they were used to tolerating extreme conditions and it was just part of getting the job done. They NEEDed the lower pressure to make the cabin lighter and get to the moon and back.
In shuttle, the original goal was to be able to bring up any old regular joe to space. It was supposed to be a shirt-sleeve environment just like an airliner.
Hmm... Must be a new member. You'll learn, lol.
A pure O2 question. Does it make EVA's easier if the spacecraft has a pure O2 atmosphere?
I suspect that it's mostly a function of time. ... Presumably, he has plenty of work to do, and his personal compromise is brutal efficiency against politeness.
Jim is a prolific poster, and NSF is always fortunate to have someone of encyclopedic knowledge willing to answer so many questions here.
Columbia question:
If Columbia was limited to less glamorous missions because of its weight, was anything special required to get it to Hubble's high orbit on STS-109? Did it need an OMS burn during launch, for example? Or does the nearly-empty cargo bay of a Hubble servicing mission make the difference, i.e. maybe Columbia could not have launched Hubble but she could service it?
I could think of three possibilities offhand; which is correct?
Are the Space Shuttle windows made of:
!) Polycarbonate?
2) Tempered glass?
3) or a combination of the two (laminate)?
I could think of three possibilities offhand; which is correct?
Are the Space Shuttle windows made of:
!) Polycarbonate?
2) Tempered glass?
3) or a combination of the two (laminate)?
What was the need for the extra LH pressurization line seen on the first two external tanks for STS-1 thru 5?There was not an extra LH2 press line on the first batch of SWTs. The large thick line right next to the 17" LOX feedline was a LOX-anti-geyser line.
I see. I wondered what the small pipe seen here http://www.axmpaperspacescalemodels.com/images/stack1a.gif on the left side of the LH2 portion of the ET was used for. Thanks for clearing that up.Yes. That is the GH2 press line.
I've noticed, watching the sts-1 launch on youtube, that the rcs on the attached image is open. But on later missions they start closed and are 'blown' open at launch. What was the reason for this change?
I noticed in the video in the STS-1 thread I made why in the video the LOX vent arm/ hood is retracted so early in the launch count as compared to today's missions?The answer is in this technical conference paper on NTRS: http://hdl.handle.net/2060/19820015490
Can someone please remind me where the RTLS dump port for the Centaur LH2 system was on the orbiter?
By how much would the payload to LEO increase if the Shuttle flew unmanned and therefore could use a more agressive ascent profile?
Thanks! So there wasn't a dedicated LH2 dump port located below the RBUS umbilical port on the orbiter?Can someone please remind me where the RTLS dump port for the Centaur LH2 system was on the orbiter?
vertical stablizer
By how much would the payload to LEO increase if the Shuttle flew unmanned and therefore could use a more agressive ascent profile?
As nothing to do with the crew, it is structural limits
I found this 70s shuttle concept picture and I wonder what the intention was for the canard like structe on the nose.. Minuature solar panel?
I think some of the early concepts had deployable RCS pods.I found this 70s shuttle concept picture and I wonder what the intention was for the canard like structe on the nose.. Minuature solar panel?
IIRC, even as late as 1975, after the positions of the RCS had been finalized, they still had doors covering them. The full-scale mock-up that NAA-Rockwell built, for example, had them.
What is the use of these white paper covers on the ET? http://homepage.mac.com/georgegassaway/GRP/Scale/ShuttleData/STRUTS_interfaces/Shuttle_Umbilical_Hydrogen.jpg From launch videos showing close ups of this area, they aren't removed prior to launch either.They are early indicators of a H2 fire. The reason for that is that hydrogen burns with an invisible flame only visible to IR cameras. So to maximize the detection chances, some patches of paper were added to the left-aft struts.
What is the use of these white paper covers on the ET? http://homepage.mac.com/georgegassaway/GRP/Scale/ShuttleData/STRUTS_interfaces/Shuttle_Umbilical_Hydrogen.jpg From launch videos showing close ups of this area, they aren't removed prior to launch either.They are early indicators of a H2 fire. The reason for that is that hydrogen burns with an invisible flame only visible to IR cameras. So to maximize the detection chances, some patches of paper were added to the left-aft struts.
Here's a shuttle question I can't find an answer for...
What was the reason why the name of the shuttle was moved from the payload bay door to behind the cockpit? Similarly, adding the orbiter name on the top of the wing?
If I recall correctly, Columbia and Challenger were the only two to have the name on the payload doors, but then it was moved on Columbia during an overhaul.
Similarly, you had the dark sections on the wing root of Columbia, which eventually went away. Maybe this was due to changes in the thermal protection?
Here's a shuttle question I can't find an answer for...
What was the reason why the name of the shuttle was moved from the payload bay door to behind the cockpit? Similarly, adding the orbiter name on the top of the wing?
If I recall correctly, Columbia and Challenger were the only two to have the name on the payload doors, but then it was moved on Columbia during an overhaul.
Similarly, you had the dark sections on the wing root of Columbia, which eventually went away. Maybe this was due to changes in the thermal protection?
Where are the antennas on the orbiter that transmit shuttle telemetry during launch, what band is used and what transmission format?4 omni-directional S-band antennas placed around the Xo576 bulkhead. They can be either PM or AM. UHF is available as back-up in case S-band is not available.
Where are the antennas on the orbiter that transmit shuttle telemetry during launch, what band is used and what transmission format?
Where are the antennas on the orbiter that transmit shuttle telemetry during launch, what band is used and what transmission format?4 omni-directional S-band antennas placed around the Xo576 bulkhead. They can be either PM or AM. UHF is available as back-up in case S-band is not available.
No. They're located around the bulkhead, ahead of the doors. Not inside the payload bay.Where are the antennas on the orbiter that transmit shuttle telemetry during launch, what band is used and what transmission format?4 omni-directional S-band antennas placed around the Xo576 bulkhead. They can be either PM or AM. UHF is available as back-up in case S-band is not available.
Thank you.
That's the aft-crew cabin bulkhead at the front of the payload bay, right? So these transmit through the payload bay doors?
No. They're located around the bulkhead, ahead of the doors. Not inside the payload bay.
Why was the EVA translation slidewires removed from all the orbiters prior to RTF after the Columbia accident? They made a brief comeback on STS-125 but then was removed again following the flight.
Hi all.
to your knowledge, do you know if there is any contingency procedure in case some of the doors of the purge and vent system along the side of the mid fuselage don't open during the ascent?
Thanks
regards
Davide
The question is why they were in danger of running out of LOX Drainback hold time when the count was held at T-5 minutes? If LOX Dranback hadn't yet started then it shouldn't have been an issue and they could at least have waited until the end of the launch window.
In that case then shouldn't they have waited at T-9 a bit longer so as to maximize available time? They could have picked up the count when there were 9 minutes left in the launch window and then scrubbed when they got to T-5 if the issue hadn't been resolved.
In that case then shouldn't they have waited at T-9 a bit longer so as to maximize available time? They could have picked up the count when there were 9 minutes left in the launch window and then scrubbed when they got to T-5 if the issue hadn't been resolved.
In the hope that those extra 4 minutes (between t-9:00 and t-5:00) would give the SRO team time to fix the problem without slipping the launch time at all.
The whole launch window was only 5 min long, so they were not going to get any more time by adding t-9:00 hold
This is a bit confusing:
The NTD during the T-20 briefing (which for some unknown reason was done during the T-9 hold not the T-20) said that LOX Drainback hold time was 1 minute 59 seconds. SRO is not go and they decide to take the count to T-5 minutes.
When they get to T-5 minutes they have 3 minutes of hold time as you say but this is where the confusion is:
If LOX Drainback starts at T-5 minutes and holding then after 1 minute and 59 seconds they should have scrubbed.
If LOX Drainback starts at T-5 minutes and counting then 1 minute and 59 seconds of LOX Drainback hold time should have still been available when they picked up the count although as you say only 3 seconds remained in the launch window.
As drainback begins, the warmer LOX flows into the engines and warms them. At a certain point, with this warm LOX flowing through them, the engine temps violate the max temps allowed for engine start.
As drainback begins, the warmer LOX flows into the engines and warms them. At a certain point, with this warm LOX flowing through them, the engine temps violate the max temps allowed for engine start.
Actually, I thought it was the other way around, as the line drains down, colder fluid from the tank replaces it and the engines can get to cold to start.
Either way, you are correct in that the Drainback hold time didn't drive the choice of when to start the extra hold.
So you can hold at T-5 minutes then for as long as the launch window allows?
If you have a long launch window, you would just continue to hold at T-9mins.That's interesting, on the January 7 launch attempt of STS-61-C (not to be confused with the eventful January 6 launch attempt), the count was held at T-9 minutes for some time due to weather. Then they decided to recycle back to T-20 minutes and count back down to T-9 minutes where after waiting for a second time they scrubbed due to weather. Going back to T-20 seems a bit pointless here if you can hold at T-9 for as long as you want.
If you have a long launch window, you would just continue to hold at T-9mins.That's interesting, on the January 7 launch attempt of STS-61-C (not to be confused with the eventful January 6 launch attempt), the count was held at T-9 minutes for some time due to weather. Then they decided to recycle back to T-20 minutes and count back down to T-9 minutes where after waiting for a second time they scrubbed due to weather. Going back to T-20 seems a bit pointless here if you can hold at T-9 for as long as you want.
I was going by what it said in "Some Trust in Chariots" book about Challenger which claims there were recycles on both days,
January 6 was T-31 seconds - T-20 minutes - T-9 minutes - SCRUB.
January 7 was T-9 minutes - T-20 minutes - T-9 minutes - SCRUB.
This is according to the book.
One final question also: Was any advantage gained on STS-133 by counting down to T-5 when they did rather than holding at T-9 minutes and picking up the count at the last possible moment and the scrubbing if the issue wasn't resolved when the clock reached T-5 minutes?
I was resuming the count at T-9 minutes 1 second before the end of the launch window even if the range was still no-go. The clock would then count down to T-5 minutes and if they didn't have a go by that time then the launch would be scrubbed. You wouldn't lose any time if you did it that way.
The launch window clsoed at 16:53:27 EST. T-5 is as low as you would want to go in the count as going beyond there would invovle starting the APUs and if you are not going to launch you don't want to start them. If you resumed at 16:44:27. What I'm saying is that you could have resumed the count at this time regardless of the range. The range would still have had the extra 3 minutes of the T-9 hold plus the time to count down from T-9 to T-5 to troubleshoot the issue before a scrub would have to be decalred. The clock would have reached T-5 minutes at 16:48:27, the same point at which a scrub would have been declared by the way you did it.
I wasn't saying not have a hold at T-5. Keep the hold in there to stop the clock at T-5 minutes. The clock would reach T-5 minutes exactly 5 minutes before the end of the window and would then hold so a scrub could be declared. The count would have entered the T-5 hold at the exact same time that STS-133 would have been scrubbed even f you had already counted down to T-5 and waited there.
I wasn't saying not have a hold at T-5. Keep the hold in there to stop the clock at T-5 minutes. The clock would reach T-5 minutes exactly 5 minutes before the end of the window and would then hold so a scrub could be declared. The count would have entered the T-5 hold at the exact same time that STS-133 would have been scrubbed even f you had already counted down to T-5 and waited there.
So you are not allowed to specify a hold point then if are targetting the end if window. So in the event that you were to target the end of the window and you resumed the count at T-9 minutes and you needed to stop the clock would you call a hold, inform the crew you are going to scrub and then call GLS cutoff or would you just directly call GLS cutoff regardless of how far down the count you were?
Thanks for the replies everyone, I have a better understanding now.
I've actually never heard a HOLD! HOLD! HOLD! call on a shuttle launch but then manual hold requets after T-9 minutes do seem quite rare.
I thought that was only after T-31 seconds. If a hold is called before that time it doesn't automatically mean a cutoff.
In one of the ascent reports on L2, it mentions a 2-second "RCS window protect firing" occurring about 10 seconds before the OMS assist burn. I haven't seen this term before, and a quick search doesn't show any other mentions of this burn.
Can someone provide some insight into this burn?
Ok, thanks, but isn't oxygen awfully corrosive, at least when liquid? Why don't they use the liquid hydrogen?They don't want hydrogen around the engines at SSME ignition. If you watch a shuttle countdown you see the gaseous hydrogen around the SSME's is deliberately burned off just before the SSME's are ignited.
Ok, thanks, but isn't oxygen awfully corrosive, at least when liquid? Why don't they use the liquid hydrogen?
During the STS-133 countdown, I thought I heard that the limiting factor in how long the T-5 hold (for the range issue) could last was LOX drainback (rather than the end of the full 10 minute launch window) ... and that ultimately they got the count restarted with only 2 seconds of hold time left (again, LOX drainback limited). But LOX replenish doesn't terminate until T-4:55, so they would have been replenishing during the hold ... so I would have expected a T-5 hold to be able to last up until the point where the resulting T-0 would be out of the 10 minute launch window. Am I missing something?
Today the SSMRS had to get the OBSS out of the payload bay and hand it off to the Shuttle Arm. Before docking the Shuttle Arm could get its own OBSS. Was today just about clearance issues?More like interference issues. The SRMS can't reach the forward OBSS grapple fixture due PMA2/Node2 being in the way.
Today the SSMRS had to get the OBSS out of the payload bay and hand it off to the Shuttle Arm. Before docking the Shuttle Arm could get its own OBSS. Was today just about clearance issues?
hi all.
few questions about the TPS.
1. in which way tiles, gap fillers and filler bars are removed?
2. in which way tiles are repaired if there is for instance damage like scratches or gouges?
thanks
What's the difference between air to ground & space to ground
and how does the 'big loop' actually work?
Quote from: sivodavehi all.
few questions about the TPS.
1. in which way tiles, gap fillers and filler bars are removed?
2. in which way tiles are repaired if there is for instance damage like scratches or gouges?
thanks
Hi guys...nobody of you has any answer to my questions? I'm doing a research work about this subject and I'm curious to know the answers to these questions.
thanks
Davide
Quote from: sivodavehi all.
few questions about the TPS.
1. in which way tiles, gap fillers and filler bars are removed?
2. in which way tiles are repaired if there is for instance damage like scratches or gouges?
thanks
Hi guys...nobody of you has any answer to my questions? I'm doing a research work about this subject and I'm curious to know the answers to these questions.
thanks
Davide
Don't give up. It's a weekend, and some of the folks who could accuratly answer are probably busy working STS-133. :)
I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
I believe during roll-out to the pad, the public is still allowed to see it from the pad tourist location/gantry. I think that would be your best bet.
I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
I believe during roll-out to the pad, the public is still allowed to see it from the pad tourist location/gantry. I think that would be your best bet.
Yes, but rollouts occur during non-public tour times.
Both STS-134 and STS-135 will target rollouts in the evening/overnight hours.
Regarding the Shuttle I was wondering if anyone knew why the main engines of the shuttle were attached to the Shuttle itself. It would of made sense to me if the shuttle had the capability to store a significant amount of fuel on board and there was some sort of fuel depot architecture that would allow the shuttle to refuel in orbit. Now I understand that the current architecture does make the engines reusable, but as I understand it the need to completely rebuild the engines at every launch makes the re-usability hardly any better than the expendable one.
What is involved in servicing between missions?Regarding the Shuttle I was wondering if anyone knew why the main engines of the shuttle were attached to the Shuttle itself. It would of made sense to me if the shuttle had the capability to store a significant amount of fuel on board and there was some sort of fuel depot architecture that would allow the shuttle to refuel in orbit. Now I understand that the current architecture does make the engines reusable, but as I understand it the need to completely rebuild the engines at every launch makes the re-usability hardly any better than the expendable one.
The orbiter does have a significant amount of prop onboard. However, they are not used by the SSMEs. They do not function for the duration of the flight after MECO. You essentially answered your own question about why they are on the back of the orbiter so they can be reused.
The engines are also not "completely rebuilt".
Nowadays they may not be, but earlier in the program they were wrestling with e.g. cracked turbopump turbine blades. SSME saw a lot of redesign work over the past thirty years to get them to this stage, with the most recent upgrades even in 2007.Regarding the Shuttle I was wondering if anyone knew why the main engines of the shuttle were attached to the Shuttle itself. It would of made sense to me if the shuttle had the capability to store a significant amount of fuel on board and there was some sort of fuel depot architecture that would allow the shuttle to refuel in orbit. Now I understand that the current architecture does make the engines reusable, but as I understand it the need to completely rebuild the engines at every launch makes the re-usability hardly any better than the expendable one....
The engines are also not "completely rebuilt".
Nowadays they may not be, but earlier in the program they were wrestling with e.g. cracked turbopump turbine blades. SSME saw a lot of redesign work over the past thirty years to get them to this stage, with the most recent upgrades even in 2007.
The RSS is also extended for a tanking test, which STS-134 is scheduled to perform, immediately followed by pyld installation, so there will be a couple of days where the RSS will be extended.I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
No,
Even though PR shots always show the vehicle uncovered, in real life, the shuttle is always covered.
It is uncovered only a few times during a mission.
1. rollout
2. APU hot fire
3. Payload installation into the PCR
4. launch
Only 1 & 4 happen every mission. The other two happen occasionally and only for a day
The RSS is also extended for a tanking test, which STS-134 is scheduled to perform, immediately followed by pyld installation, so there will be a couple of days where the RSS will be extended.I would very much like to get a photo of my ( now 6 month old ) son with a shuttle stack behind him. I'm thinking probably not until STS-135 Atlantis as he's still fussy on long car rides. The question is is there a reliable opportunity to get such photos without the RSS blocking the view?
No,
Even though PR shots always show the vehicle uncovered, in real life, the shuttle is always covered.
It is uncovered only a few times during a mission.
1. rollout
2. APU hot fire
3. Payload installation into the PCR
4. launch
Only 1 & 4 happen every mission. The other two happen occasionally and only for a day
One of the ladies on ISS during STS-133 (couldn't tell which one) just said something really odd to me during the daily highlights. They were equalizing the pressure between ISS and the PMM and there was a lot of flow audible.
What she said was, "it smells like....space". Another crew member said "yep" to that. What does that mean?
One of the ladies on ISS during STS-133 (couldn't tell which one) just said something really odd to me during the daily highlights. They were equalizing the pressure between ISS and the PMM and there was a lot of flow audible.
What she said was, "it smells like....space". Another crew member said "yep" to that. What does that mean?
One of the ladies on ISS during STS-133 (couldn't tell which one) just said something really odd to me during the daily highlights. They were equalizing the pressure between ISS and the PMM and there was a lot of flow audible.
What she said was, "it smells like....space". Another crew member said "yep" to that. What does that mean?
They smell the same thing when returning EVA crewmembers enter the station. The vacuum/atomic oxygen causes a unique smell.
They smell the same thing when returning EVA crewmembers enter the station. The vacuum/atomic oxygen causes a unique smell.
Ozone seems more likely; surely at one atmosphere atomic oxygen would combine to form molecular oxygen virtually instantaneously.Jim may not be referring to the smell of atomic oxygen any more than the "smell" of vacuum, but rather the effects that the free radicals have on e.g. organic materials.
What exactly is this fitting sticking out of the side of the aft compartment used for?That's the vent port of Flash Evaporator#2. The vent port for Flash Evaporator#1 is on the port side.
I used to think that it was for a jack stand to support the aft end in the OPF (like the fore end is) but I found out that they use the main landing gear or the ET salad bowls for that, so that isn't what its for.
So what will happen with the SRB casings that were recovered after Discovery's launch last week since now the final 2 remaining flights already have thier SRBs prepped? And what will happen to the ones from Endevour and Atlantis since they would have no reason to refurb them
More specifically, it's the FES starboard topping duct nozzle plug with a desiccant attached to it. The port topping duct nozzle plug is opposite and fwd of that (close to the 50-1 door) is the FES hi load duct nozzle plug.What exactly is this fitting sticking out of the side of the aft compartment used for?That's the vent port of Flash Evaporator#2. The vent port for Flash Evaporator#1 is on the port side.
I used to think that it was for a jack stand to support the aft end in the OPF (like the fore end is) but I found out that they use the main landing gear or the ET salad bowls for that, so that isn't what its for.
Thanks.More specifically, it's the FES starboard topping duct nozzle plug with a desiccant attached to it. The port topping duct nozzle plug is opposite and fwd of that (close to the 50-1 door) is the FES hi load duct nozzle plug.What exactly is this fitting sticking out of the side of the aft compartment used for?That's the vent port of Flash Evaporator#2. The vent port for Flash Evaporator#1 is on the port side.
I used to think that it was for a jack stand to support the aft end in the OPF (like the fore end is) but I found out that they use the main landing gear or the ET salad bowls for that, so that isn't what its for.
I wondered what that small metal tube was sticking out of side of the aft fuselage near the body flap. Thanks fellas for clearing that up. :)On the black upper wing chines: Not tiles exactly. That was just a thermal coating paint applied to already existing LRSI and FRSI TPS while she was still OPF1 prior to the first flight.
Why were Columbia's wings given the extra black tiles on the top of the wings and the other orbiters didn't? I'm also curious as to why she wasn't given a total AFRSI cover like OV-103, 104, and 105? She still had the old tiles covering the forward fuselage.
I see. Hmm, my guess is had Columbia's accident not happened, she would look somewhat similar to the other orbiters.
I see. Hmm, my guess is had Columbia's accident not happened, she would look somewhat similar to the other orbiters.
In this STS-123 launch video clip from inside the cabin;
http://www.youtube.com/watch?v=doT6OcGULNo&feature=related
"bias in the PC booster" 1:47
what does that mean?
whats with the counting right after liftoff?
also, is that a C&W alarm going off at 3:09 ?
Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Why is that necessary especially after a decent number have flown?
Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Why is that necessary especially after a decent number have flown?
1) To serve as an end-check of process integrity and prevent "escapes".
2) Define "decent number". The number of shuttle flights to date (133) would not even suffice for a flight-test program for a typical airliner or military plane. It is still very much an experimental vehicle.
Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Why is that necessary especially after a decent number have flown?
1) To serve as an end-check of process integrity and prevent "escapes".
2) Define "decent number". The number of shuttle flights to date (133) would not even suffice for a flight-test program for a typical airliner or military plane. It is still very much an experimental vehicle.
Well by airliner standards it was experimental, but as far as space vehicles go few vehicles have a longer track record.
Great video. Thanks for posting.Sounds like you haven't seen it before. I would have thought full members would have seen it by now. :) Glad to see i havent rehashed something. :)
PC 'ducer, not booster. PC means "chamber pressure" and 'ducer is short for transducer. Bias means the 'ducer is reading differently than it should.So in this case, PC should have been 0 since it was pre-ignition?
Counting up to roll program, I think, but I'm not an ascent guy.I thought that as well.... just wondering why I havent seen it done on other launches.
PC 'ducer, not booster. PC means "chamber pressure" and 'ducer is short for transducer. Bias means the 'ducer is reading differently than it should.So in this case, PC should have been 0 since it was pre-ignition?
I'm guessing that this is a known "signature" and therefore doesnt mandate a scrub / troubleshooting? Is there a limit to where a bias would raise eyebrows?
QuoteCounting up to roll program, I think, but I'm not an ascent guy.I thought that as well.... just wondering why I havent seen it done on other launches.
Well by airliner standards it was experimental, but as far as space vehicles go few vehicles have a longer track record.
Quick question for you guys.
Why is it that NASA never bothered to place a flight data recorder in the space shuttles?
Quick question for you guys.
Why is it that NASA never bothered to place a flight data recorder in the space shuttles?
Downlinked telemetry. There is also MADS which records some measurements that aren't down listed
Was wondering what the out lined plan is when Discovery comes home today, and she is rolled back to the OPF today, what steps and time frame will it take for her to be decommissioned and how much of her internals will she actually loose? After seeing pictures of how enterprise was gutted, I'd hate to see the orbiters have it happen to
...After seeing pictures of how enterprise was gutted, I'd hate to see the orbiters have it happen to
...After seeing pictures of how enterprise was gutted,where can these pictures be found?
...After seeing pictures of how enterprise was gutted,where can these pictures be found?
thanks!
There's some in Jenkins. You might try googling "enterprise" + " crew cabin" or "payload bay"
has any data from the protuberance tests been released and if so, where can it be found?
thanks
Joe Engle mentioned that the experimental entry maneuvers of STS-2 heated up the wings a little extra and reduced the total number of flights that Columbia would be allowed to make. Do we know the number of flights a shuttle could make before its structure would be considered too fatigued? Just wondering how the number 39 (for Discovery) compares to that number.
What was used to simulate the tiles for Enterprise? I know from the CAIB report that the RCC is made from fiberglass.Polystyrene foam
Joe Engle mentioned that the experimental entry maneuvers of STS-2 heated up the wings a little extra and reduced the total number of flights that Columbia would be allowed to make. Do we know the number of flights a shuttle could make before its structure would be considered too fatigued? Just wondering how the number 39 (for Discovery) compares to that number.
The vehicle, 102 included, is certified for 100 missions each. Obviously there are inspections performed every flow and more detailed inspections during OMDP. However, from a structure and system standpoint, there has been and is nothing suggesting that number is less.
Columbia was also still certified for 100 missions at the time of her loss.
Only 39 out of 100 possible is sadder than I thought. Still at the top of her game, as they keep saying.
Only 39 out of 100 possible is sadder than I thought. Still at the top of her game, as they keep saying.
Can somebody please tell me when TAL aborts were first developed/invented for use? I seem to remember they weren't an option for every single flight (as in, they weren't there from STS-1), and for some reason I'm seeing "STS-8" and "Joe Engle" in my head, I remember reading about an astronaut, could have been him, developing it in a simulator and then they did more work on it and it became an official option.
Am I pulling this out of my bum, or did it actually happen?
When they were being designed, the original 'life' of an orbiter was expected to be less than 10 years (having flown 100 times in less than that timeframe)..
The B-52 has been flying longer than that, but it has needed re-certifying a few times now in its history, again because of its age.
Although they haven't flown as often as originally foreseen, and are still in great condition, the three remaining orbiter's airframes are still quite a bit older than the design was originally intended to last (Discovery was fast approaching 3 times its original design intent). So the same basic re-certification is just needed for the Orbiter fleet, purely because of their age. CAIB were simply bringing this need to NASA's attention, if they wanted to use Shuttle much beyond 2010.
Ross.
Can somebody please tell me when TAL aborts were first developed/invented for use? I seem to remember they weren't an option for every single flight (as in, they weren't there from STS-1), and for some reason I'm seeing "STS-8" and "Joe Engle" in my head, I remember reading about an astronaut, could have been him, developing it in a simulator and then they did more work on it and it became an official option.
Am I pulling this out of my bum, or did it actually happen?
They were available STS-2
IIRC, I read somewhere that the STS-2 crew worked on the "abort to Rota" prior to STS-1; however, it wasn't a certified abort mode at that point.Can somebody please tell me when TAL aborts were first developed/invented for use? I seem to remember they weren't an option for every single flight (as in, they weren't there from STS-1), and for some reason I'm seeing "STS-8" and "Joe Engle" in my head, I remember reading about an astronaut, could have been him, developing it in a simulator and then they did more work on it and it became an official option.
Am I pulling this out of my bum, or did it actually happen?
They were available STS-2
Thanks Jim. Was I right with my story about it being developed in the sim by one of the crew, though? Any ideas who?
During Discovery's STS-133 return the following was radioed up to the crew;
"9% adjust on the speed brake"
what does that mean?
Also, I'm probably imagining things, but did the pitch angle of the orbiter at touchdown seem higher than previous landings?
Thanks
Since I believe there are parts of ascent where the only abort option is TAL, what would have been done if an engine failed during that time on STS-1? Would they have been within the ejection seat envelope at that time?
yes, yes.. that i know... and i understand what the values mean when MCC says "spreadbreak 15%. However, this is the first time ive heard the term "x% adjust on the speedbreak" in the same call up.
The speed brake is the "fins" that come out of the vertical stabilizer.
yes, yes.. that i know... and i understand what the values mean when MCC says "spreadbreak 15%. However, this is the first time ive heard the term "x% adjust on the speedbreak" in the same call up.
The speed brake is the "fins" that come out of the vertical stabilizer.
that is what im asking about....
thanks!
Question:
I saw a couple of years ago an article about Atlantis that said her retirement should be urged, because of a problem with her aging tanks(cryo tanks?). Can someone clarify that for me?
Thanks
Thanks, Jim. Just to clarify: does that mean that after STS-1 it was expected that TAL would be a certified abort mode, so it was designed as a unique ascent trajectory? Or was the STS-1 ascent supposed to be the "normal" one, but instead things were changed to allow TAL aborts? Just trying to get the historical perspective on what was planned and when things changed.
Question:
I saw a couple of years ago an article about Atlantis that said her retirement should be urged, because of a problem with her aging tanks(cryo tanks?). Can someone clarify that for me?
Thanks
I remember what you're talking about. They were helium tanks that were old, and spares were not available. One analysis found that they would burst before they leaked, which would be catastrophic. Another analysis found that they would leak before they burst. That's all I remember.
IIRC, something like this was done again on STS-26, to reduce the "exposure" to TAL.Since I believe there are parts of ascent where the only abort option is TAL, what would have been done if an engine failed during that time on STS-1? Would they have been within the ejection seat envelope at that time?
STS-1 was shaped to work without TAL.
Question:
I saw a couple of years ago an article about Atlantis that said her retirement should be urged, because of a problem with her aging tanks(cryo tanks?). Can someone clarify that for me?
Thanks
I remember what you're talking about. They were helium tanks that were old, and spares were not available. One analysis found that they would burst before they leaked, which would be catastrophic. Another analysis found that they would leak before they burst. That's all I remember.
Additionally, the tanks are now pressurized in a stepped fashion to 80% and than up to 100%.
And even so, an engine failure that forces a TAL abort does not equate to "eject right now". They would have gotten the vehicle thru re-entry and into a steady state glide and then ejected when the conditions were right.Since I believe there are parts of ascent where the only abort option is TAL, what would have been done if an engine failed during that time on STS-1? Would they have been within the ejection seat envelope at that time?STS-1 was shaped to work without TAL.
And even so, an engine failure that forces a TAL abort does not equate to "eject right now". They would have gotten the vehicle thru re-entry and into a steady state glide and then ejected when the conditions were right.Since I believe there are parts of ascent where the only abort option is TAL, what would have been done if an engine failed during that time on STS-1? Would they have been within the ejection seat envelope at that time?STS-1 was shaped to work without TAL.
I have a question from the STS 133 launch
What is drainback hold ?
True, but I was addressing his question about the ejection seat envelope. Theoreticaly, if there had been an abort on STS-1 between the RTLS and the AOA zones (I know Jim, they designed the ascent to avoid that condition) They would have ended up in gliding decent with no place to land. Then they would have ejected.I have never heard of a TAL that results in an ejection on the entry side. All TALs result in a landing. If TAL weather is bad, the launch is scrubed.And even so, an engine failure that forces a TAL abort does not equate to "eject right now". They would have gotten the vehicle thru re-entry and into a steady state glide and then ejected when the conditions were right.Since I believe there are parts of ascent where the only abort option is TAL, what would have been done if an engine failed during that time on STS-1? Would they have been within the ejection seat envelope at that time?STS-1 was shaped to work without TAL.
On the speed brake adjust. If I recall, close to landing the speed brake is set at one altitude then adjusted later. Both are done fairly low and are done automatically. Maybe someone else can confirm this.
On the speed brake adjust. If I recall, close to landing the speed brake is set at one altitude then adjusted later. Both are done fairly low and are done automatically. Maybe someone else can confirm this.
You are correct Danny, retract is at 3000 feet and adjust is at 500 feet. The "adjust" is at 500 feet because from a time perspective 500 occurs half between 3000 feet and touchdown.
Mark Kirkman
Here's a couple of papers I'm aware of covering the tile protuberance experiments (DTO 900):thank you
PC 'ducer, not booster. PC means "chamber pressure" and 'ducer is short for transducer. Bias means the 'ducer is reading differently than it should.thank you
I *think* the ducer in question returns psia, not psig, so it should have been reading around 14.7 since the nozzle was exposed to ambient pressure.
What's the bank angle of the shuttle in the HAC and is this variable dependant on energy levels?
Which mission had the OBSS used as part on an EVA?
how do the sparklers when shoot the tail service masts
i am talking about the hydrogen burnoff system that is activated atThey are pyrotechnics (fireworks).
T-10 seconds
how are they produced
how are they produced
pyros.
What do they use anyway? The same material as sparklers or something else?I don't know exactly what they use in these, but the stars used in most fireworks are mostly potassium perchlorate as a combusting agent mixed with a binding agent and various salts for color.
I have a question from the STS 133 launch
What is drainback hold ?
IMO, the best answer on this was referred to in those posts a few pages back, which was Mark's (mkirk):I have a question from the STS 133 launch
What is drainback hold ?
Scroll on back a few pages in this very thread for a detailed answer to this question when it was asked right after the launch of STS-133.
What do they use anyway? The same material as sparklers or something else?I don't know exactly what they use in these, but the stars used in most fireworks are mostly potassium perchlorate as a combusting agent mixed with a binding agent and various salts for color.
I think that's been asked before. the limiting docked time for the shuttle is the ability of the fuel cells to provide power. Shutting them down and running all shuttle systems from SSPTS is not an option so eventually your fuel cells run out of a power.
Has the shuttle ever done a FD4 rendezvous to the ISS?
I think that's been asked before. the limiting docked time for the shuttle is the ability of the fuel cells to provide power. Shutting them down and running all shuttle systems from SSPTS is not an option so eventually your fuel cells run out of a power.
So if the shuttle is complete out of power is there also the radiation cooling (payload bay) affected?
Not shuttle directly but what is the bay in the back of the VAB used for. I know it had Saturn V's roll out of it in years past I believe but not sure now. Thanks
Not shuttle directly but what is the bay in the back of the VAB used for. I know it had Saturn V's roll out of it in years past I believe but not sure now. Thanks
that is where the ET's are processed and a contingency shelter for a shuttle stack
Not shuttle directly but what is the bay in the back of the VAB used for. I know it had Saturn V's roll out of it in years past I believe but not sure now. Thanks
that is where the ET's are processed and a contingency shelter for a shuttle stack
Is there any layman's explanation for what LOX drainback is all about, specifically re: the STS-133 launch hold. Thanks!It's getting more attention; some posts in the last few pages here, and I highlighted Mark Kirkman's primer several posts back:
Is there any layman's explanation for what LOX drainback is all about, specifically re: the STS-133 launch hold. Thanks!It's getting more attention; some posts in the last few pages here, and I highlighted Mark Kirkman's primer several posts back:
http://forum.nasaspaceflight.com/index.php?topic=17437.msg709924#msg709924
Maybe not a layman's explanation, but I'd still encourage Shuttle geeks to read it.
Is there any layman's explanation for what LOX drainback is all about, specifically re: the STS-133 launch hold. Thanks!It's getting more attention; some posts in the last few pages here, and I highlighted Mark Kirkman's primer several posts back:
http://forum.nasaspaceflight.com/index.php?topic=17437.msg709924#msg709924
Maybe not a layman's explanation, but I'd still encourage Shuttle geeks to read it.
Thanks Phil, that'll work! I'll boil it down from there.
Has the shuttle ever done a FD4 rendezvous to the ISS?
Yes, on STS-88 (Node 1 installation on the ODS required the extra day).
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
What was the chute's condition post flight?
Thank you!I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
Thank you!I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
Is that chute compartment door hinged, or does it usually pop off on a nominal chute deploy?
What was the reason that it fell off?
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
No. That would have been impossible since all it did was briefly contact a hatband on SSME#1.I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
As mentioned above it was STS-95. The door fell off during SSME start. There was some analysis and concern that the chute could have been damaged from the various thermal environments and so it was not used.
There aren't any other missions that I can recall where we just didn't use the chute and there have been no failures of the system as a whole (maybe some tears hear and there).
Didn't the door cause an SSME nozzle leak?
I seem to recall that on one Shuttle mission, the Orbiter's drag chute was not deployed on landing, as it had been decided against it, because a cover (or something similar) had fallen off earlier during the mission.
Which mission was this?
Had there also been other missions, where the drag chute was not deployed (on those missions equipped with a chute, of course)?
Has there ever been a failure of the drag chute?
...Has there ever been a failure of the drag chute?
How were STS flights numbered before Challenger? I'm confused with all the -D, -L, etc. designations.
How were STS flights numbered before Challenger? I'm confused with all the -D, -L, etc. designations.
First digit - planned year of flight (4 = 1984, for example), second digit = 1 for Florida and 2 for Vandenberg (you'll notice the 2 was never used as that site was decommissioned after Challenger), then the flights were "numbered" within each year by letter (A, B, C, .....).
This wasn't a particularly popular approach.
How were STS flights numbered before Challenger? I'm confused with all the -D, -L, etc. designations.
Done purely to avoid having an STS-13, by all accounts (known to me anyway).
If they had kept that numbering system, I wonder what they would have done in 1994 when the single-digit fiscal years would have begun producing duplicate flight numbers. Maybe they anticipated that the system would not outlive the incumbent Administrator who requested it?
I was wondering if anyone had explored the idea of creating a new shuttle orbiter that would interface with the current systems.
There has been a great deal of advancement in the past 34 years, since the last space shuttle was built. We have entirely new aerospace materials that are being widely used now including lithium aluminium and carbon fiber. We have far better computers and monitors with fiber optic communications. We have new materials for heat shields. We have more advanced sensor systems for detecting problems.
I also heard from an engineer that worked on the shuttle that the technology exists that would eliminate the necessity of disassembling the SSME after every flight thus reducing labor considerably.
I am not saying we should spend the money to do it, but it is an intellectual curiosity of mine.
I think there is a kit made to wire up the shuttle to do all of the manual only switch throws and button pushes. Lowering the gear is probably number one on this list.It's called the Remote Orbiter Kit. It is esentialy a cable bundle. One end connects to the racks in AV bay 3 on the mid deck. The other end connects directly to the switches that the crew would otherwise have to manually throw. The astronauts would physically open up the panels and directly connect the wires to the contacts on the back of the switches. The cable is stored on the ISS. It connects to the controls for the Payload Bay Doors, startup and shutdown of the APUs, deployment of the air data probes, deployment of the landing gear and deployment and jetison of the drag chute. I believe (but I can't confirm) that they would have to upload a special version of PASS to use it.
I think there is a kit made to wire up the shuttle to do all of the manual only switch throws and button pushes. Lowering the gear is probably number one on this list.It's called the Remote Orbiter Kit.
It is esentialy a cable bundle. One end connects to the racks in AV bay 3 on the mid deck.
The other end connects directly to the switches that the crew would otherwise have to manually throw. The astronauts would physically open up the panels and directly connect the wires to the contacts on the back of the switches. The cable is stored on the ISS. It connects to the controls for the Payload Bay Doors, startup and shutdown of the APUs, deployment of the air data probes, deployment of the landing gear and deployment and jetison of the drag chute.
I believe (but I can't confirm) that they would have to upload a special version of PASS to use it.
I take it the unmanned shuttle would have landed at Edwards?
I take it the unmanned shuttle would have landed at Edwards?
Correct, that's what the plan has in it. But there also is plenty of talk that it'd be safer just to let it burn up over the Pacific this late in the game.
I take it the unmanned shuttle would have landed at Edwards?
Correct, that's what the plan has in it. But there also is plenty of talk that it'd be safer just to let it burn up over the Pacific this late in the game.
My understanding was that Vandenberg was the preferred landing site (if there was to be one), having the lowest risk to the public or ground resources.
For the folks who asked, the RCO capability has been discussed here frequently:I take it the unmanned shuttle would have landed at Edwards?
Correct, that's what the plan has in it. But there also is plenty of talk that it'd be safer just to let it burn up over the Pacific this late in the game.
My understanding was that Vandenberg was the preferred landing site (if there was to be one), having the lowest risk to the public or ground resources.
I don't think Vandenberg has a MSBLS anymore, so they couldn't use the autoland there. Plus, they wouldn't have braking or nose wheel steering so keeping it on the runway durring rollout might be interesting.
1. With regard to the MMU retirement was it deemed too risky after Challenger because of known problems or was its retirement due to more of a general change in NASA culture becoming more risk averse?
2.Have there been any serious thoughts of bringing the MMU out of retirement during the Shuttle program?
3.Any opinion and elaboration is appreciated.
.
1. With regard to the MMU retirement was it deemed too risky after Challenger because of known problems or was its retirement due to more of a general change in NASA culture becoming more risk averse?
2.Have there been any serious thoughts of bringing the MMU out of retirement during the Shuttle program?
3.Any opinion and elaboration is appreciated.
.
It was retired because there is no known use for it, not for any safety or risk reasons.
I realize this is off-topic, but has there been any thought given about using the MMU for a mission to an asteroid? Walking wouldn't be terribly practical.1. With regard to the MMU retirement was it deemed too risky after Challenger because of known problems or was its retirement due to more of a general change in NASA culture becoming more risk averse?
2.Have there been any serious thoughts of bringing the MMU out of retirement during the Shuttle program?
3.Any opinion and elaboration is appreciated.
.
It was retired because there is no known use for it, not for any safety or risk reasons.
To elaborate, the MMU was originally deemed necessary because the orbiter was thought to be too cumbersome to maneuver in close proximity to spacecraft not specifically designed for it. The orbiter turns out to be more nimble than that, and all missions for the MMU *that were actually funded* could be done by a combination of maneuvering the orbiter and EVA astronauts in foot restraints (either on the tip of the RMS or, as we saw on STS-49 and 87, on the payload bay sill).
If there was ever a chance the MMU could have been revived, it would have been at the start of the ISS era when the issue of rescue during ISS stage EVAs was addressed. But the MMU was deemed too expensive for that role and the cheaper SAFER was developed instead.
Other than that, revival of the MMU has not been seriously considered.
If there was ever a chance the MMU could have been revived, it would have been at the start of the ISS era when the issue of rescue during ISS stage EVAs was addressed. But the MMU was deemed too expensive for that role
Certainly the latter. Was this Constellation mission video merely an artist's rendering, or was the MMU seriously analyzed for this purpose?Quote from: Robotbeat link=topic=17437.msg715827#msg715827I realize this is off-topic, but has there been any thought given about using the MMU for a mission to an asteroid? Walking wouldn't be terribly practical.
Huh? Are you talking about a single person strapped in an MMU and blasting off to an asteroid or an MMU being used to explore an asteroid?
If it's the former the MMU doesn't have the Delta-V - If it's the latter this scenario was depicted in a Constellation mission video.
what they should have done was goto the bolted joints by aerojet alot safer than the current design
If the O-ring leak on 51L had occurred in a different location such that it didn't burn through the strut, it was still going to cause an underspeed due to the loss of pressure. My question is, what would have been the result of that underspeed? ATO? AOA? TAL? I'm asking because I have a vague memory of reading about this but endless searching hasn't turned up anything and I want to know if I'm just imagining it.
If the O-ring leak on 51L had occurred in a different location such that it didn't burn through the strut, it was still going to cause an underspeed due to the loss of pressure. My question is, what would have been the result of that underspeed? ATO? AOA? TAL? I'm asking because I have a vague memory of reading about this but endless searching hasn't turned up anything and I want to know if I'm just imagining it.
As I recall, the delta P between the motors was still very small at LOS. That would imply that the motor was still generatating most of the thrust it was supposed to. Your question is one of magnitude and has a lot of unknown variables (would the leak keep getting worse and the presure in the case drop more or not? where would the vehicle be at staging in reguards to where it was supposed to be?) Without knowing those things, I don't think there is a way to determine what the final outcome would have been.
It would not be far off course. The side force was not that great compared
to the thrust of the SRBs; the issues were that 1) the torque from the side
force could have exceeded control authority, and 2) there could have been
enough underspeed at SRB sep that the SSMEs alone couldn't make it up
during second stage, resulting in an ATO.
Next, realize that the ascending and descending nodes are around 12 hours apart. So, in one case you might have to sleep-shift a bit forward (earlier) during the mission to meet that timeline, in the other case you might have to sleep-shift later (by a total of up to a maximum of 12 hours), thus "earning" some extra time in the mission because you are living 25 hour days or so during the mission.The principle is correct, but ascending and descending nodes are ~6 hours apart.
Next, realize that the ascending and descending nodes are around 12 hours apart. So, in one case you might have to sleep-shift a bit forward (earlier) during the mission to meet that timeline, in the other case you might have to sleep-shift later (by a total of up to a maximum of 12 hours), thus "earning" some extra time in the mission because you are living 25 hour days or so during the mission.The principle is correct, but ascending and descending nodes are ~6 hours apart.
Okay, I've thought about this all day, and I don't understand why these are 6 hours apart and not 12. Can someone help me please?
Next, realize that the ascending and descending nodes are around 12 hours apart. So, in one case you might have to sleep-shift a bit forward (earlier) during the mission to meet that timeline, in the other case you might have to sleep-shift later (by a total of up to a maximum of 12 hours), thus "earning" some extra time in the mission because you are living 25 hour days or so during the mission.The principle is correct, but ascending and descending nodes are ~6 hours apart.
Okay, I've thought about this all day, and I don't understand why these are 6 hours apart and not 12. Can someone help me please?
They would be 12 hours apart if the landing site was on the equator.
Next, realize that the ascending and descending nodes are around 12 hours apart. So, in one case you might have to sleep-shift a bit forward (earlier) during the mission to meet that timeline, in the other case you might have to sleep-shift later (by a total of up to a maximum of 12 hours), thus "earning" some extra time in the mission because you are living 25 hour days or so during the mission.The principle is correct, but ascending and descending nodes are ~6 hours apart.
Okay, I've thought about this all day, and I don't understand why these are 6 hours apart and not 12. Can someone help me please?
They would be 12 hours apart if the landing site was on the equator.
Let me try to paraphrase to see if I've got this. The ascending node is going to move largely from South-West to North-East while the descending node is going to move largely from West to East. This means the descending node is going to travel a lot farther East from initiation than the ascending node is, and this is because of the latitude of the landing site and because of the inclination of the orbit. So, to extremely simplify, the ascending node is going from the bottom of the sine wave to the top (looking on a flat map instead of a globe), while the descending node is going from a little left of the top peak of the sine wave to a little right of the top peak.
As I watch LC39B coming down in pieces, I am wondering about the initial construction of the two FSS towers.
I have read the FSS were the tops of two of the three towers from the MLP's in the Saturn era. What I am wondering about is the process they used to get them off the MLP and onto the ground.
I doesn't seem likely they could have lifted the whole thing off the MLP in one chunk. How many sections did they have to cut it into? Comparable to the sections they are lobbing off the top of 39B right now?
If anyone has any historical links to the Shuttle pad transition from Saturn to Shuttle, I would appreciate it. Thanks.
Basically, yes -- though the exact locations on the since curves are a little off.
I've searched online and have found many dead ends and conjecture to this question. I hope this is the right place to ask. What is the Space Shuttle return cargo payload mass?
What happens if an ISS module gets damaged and needs repair beyond a spacewalk?
Anyone else see an issue here?
What happens if an ISS module gets damaged and needs repair beyond a spacewalk? Anyone else see an issue here?
Found this which pretty much answers it.... http://www.savethelut.org/MLDocs/ML_History.htmlAs I watch LC39B coming down in pieces, I am wondering about the initial construction of the two FSS towers.
I have read the FSS were the tops of two of the three towers from the MLP's in the Saturn era. What I am wondering about is the process they used to get them off the MLP and onto the ground.
I doesn't seem likely they could have lifted the whole thing off the MLP in one chunk. How many sections did they have to cut it into? Comparable to the sections they are lobbing off the top of 39B right now?
If anyone has any historical links to the Shuttle pad transition from Saturn to Shuttle, I would appreciate it. Thanks.
Nope. Not a LUT remnant. The design is very different to the LUTs. The LUT levels were made up of upside down "V" struts and the LC 39 Observation Gantry doesn't have them.Found this which pretty much answers it.... http://www.savethelut.org/MLDocs/ML_History.htmlAs I watch LC39B coming down in pieces, I am wondering about the initial construction of the two FSS towers.
I have read the FSS were the tops of two of the three towers from the MLP's in the Saturn era. What I am wondering about is the process they used to get them off the MLP and onto the ground.
I doesn't seem likely they could have lifted the whole thing off the MLP in one chunk. How many sections did they have to cut it into? Comparable to the sections they are lobbing off the top of 39B right now?
If anyone has any historical links to the Shuttle pad transition from Saturn to Shuttle, I would appreciate it. Thanks.
Any chance the LC 39 Observation Gantry is also a remnant of the Apollo LUTs? As far as I can tell it serves no current purpose other than a viewing site for tour groups (http://www.kennedyspacecenter.com/lc-39-observation-gantry.aspx) but I've wondered if it ever did something more meaningful.
Nope. Not a LUT remnant. The design is very different to the LUTs. The LUT levels were made up of upside down "V" struts and the LC 39 Observation Gantry doesn't have them.Found this which pretty much answers it.... http://www.savethelut.org/MLDocs/ML_History.htmlAs I watch LC39B coming down in pieces, I am wondering about the initial construction of the two FSS towers.
I have read the FSS were the tops of two of the three towers from the MLP's in the Saturn era. What I am wondering about is the process they used to get them off the MLP and onto the ground.
I doesn't seem likely they could have lifted the whole thing off the MLP in one chunk. How many sections did they have to cut it into? Comparable to the sections they are lobbing off the top of 39B right now?
If anyone has any historical links to the Shuttle pad transition from Saturn to Shuttle, I would appreciate it. Thanks.
Any chance the LC 39 Observation Gantry is also a remnant of the Apollo LUTs? As far as I can tell it serves no current purpose other than a viewing site for tour groups (http://www.kennedyspacecenter.com/lc-39-observation-gantry.aspx) but I've wondered if it ever did something more meaningful.
2) I read someplace that STS-1 was the one flight where the SRBs were lit after T-0. True? If so, what is the reason, to allow a little more time for SSME problems to appear on the pad rather than after launch commit? Cannot find anything online here or elsewhere. The STS-1 video does indeed give a sense that the engines ran longer before SRB ignition.
Mitch
2) I read someplace that STS-1 was the one flight where the SRBs were lit after T-0. True? If so, what is the reason, to allow a little more time for SSME problems to appear on the pad rather than after launch commit? Cannot find anything online here or elsewhere. The STS-1 video does indeed give a sense that the engines ran longer before SRB ignition.
Mitch
2. For STS-1, main engine start was at T-3 and SRB ignition was at T+3. The extra 3 seconds was for the SRB twang to dampen out. Countdown was adjusted to account for this on STS-2.
1. So does this mean: the STS-1 SSMEs started sequentially around T-3, that they would have been ready for liftoff at T-0 except for wating for the twang to dampen?
2. And the reason for liftoff not being defined as T-0.00 is that the exact time required for twang to dampen was not known with encough certainty to have a specific SRB ignition time but rather the twang was empirically observed until it was dampened enough for SRB ignition and that period turned out to be an extra 3 seconds? No doubt the twang had some terrific predictions, mechanically, but perhaps just enough uncertainty in the period of oscillation and severity existed to merit waiting a variable period? Sort of a "mini-hold"?
3. And after that, this observed requirement for approx. 6 seconds from first SSME to SRB igntion was embraced from STS-2 forward, with the entire countdown slid backward those empirically derived approx. 6 seconds so liftoff is defined as T-0.00?
4. If this is all incorrect, and in fact the STS-1 countdown was defined and configured for a planned T+3 liftoff, I fail to understand why that is important - 6 seconds from T-6 to T-0 vs. T-3 to T+3 is six seconds either way.
5. Which raises two interesting questions. 1) If my interpretation is correct, was the twang watched on STS-1 by a human with his finger poised over a button or was there an automatic observation, perhaps accelerometer at the top of the ET, that triggered the continued countdown?
6) Currently, is SRB ignition and liftoff subject to any kind of extra delay for anything, such as excessive twang or other factors (aside from a cutoff obviously)?
1. So does this mean: the STS-1 SSMEs started sequentially around T-3, that they would have been ready for liftoff at T-0 except for wating for the twang to dampen?
2. And the reason for liftoff not being defined as T-0.00 is that the exact time required for twang to dampen was not known with encough certainty to have a specific SRB ignition time but rather the twang was empirically observed until it was dampened enough for SRB ignition and that period turned out to be an extra 3 seconds? No doubt the twang had some terrific predictions, mechanically, but perhaps just enough uncertainty in the period of oscillation and severity existed to merit waiting a variable period? Sort of a "mini-hold"?
3. And after that, this observed requirement for approx. 6 seconds from first SSME to SRB igntion was embraced from STS-2 forward, with the entire countdown slid backward those empirically derived approx. 6 seconds so liftoff is defined as T-0.00?
4. If this is all incorrect, and in fact the STS-1 countdown was defined and configured for a planned T+3 liftoff, I fail to understand why that is important - 6 seconds from T-6 to T-0 vs. T-3 to T+3 is six seconds either way.
5. Which raises two interesting questions. 1) If my interpretation is correct, was the twang watched on STS-1 by a human with his finger poised over a button or was there an automatic observation, perhaps accelerometer at the top of the ET, that triggered the continued countdown?
6) Currently, is SRB ignition and liftoff subject to any kind of extra delay for anything, such as excessive twang or other factors (aside from a cutoff obviously)?
1. Not just for STS-1 but for all missions
2. No, the countdown hadn't accounted for it at the time and they didn't want to change things for STS-1.
3. No, it was slid back only 3 seconds, since SSME start was around T-3 seconds.
4. So that liftoff occurs at T-0/T+0. It is easier for event planning to key off of liftoff.
5. Neither, it was a fixed interval in the countdown
6. no, it is fixed.
Thanks for the clarification Jim.
P.S. Are you back to shooting from the hip?
Here is an STS-1 question for you.
Jim is apparently feeling loquacious ;)
Is the twang video real time, ie true 1:1?
-Alex
Are the hard attach points on the Orbiter for the fuel and oxidiser lines from the ET positioned at (or sufficiently close to) the Orbiter's center of gravity (center of mass)?
Are payloads situated within the payload bay to help define/balance this point (at least for ascent)?
Are the hard attach points on the Orbiter for the fuel and oxidiser lines from the ET positioned at (or sufficiently close to) the Orbiter's center of gravity (center of mass)?
Has a Shuttle launch ever been filmed by a camera mounted in one of the overhead windows of the aft flight deck station? Looks like that would be a pretty spectacular view. Searching here I find nothing.Couple of times that I can think of (with a video camera) -- STS-93 and STS-102...first one was night-time and for the dawn 102 launch after roll to heads down, it's mostly water. The STS-102 video is around online, I believe.
Is there an estimate of the costs incurred for each day a Shuttle launch is delayed? (including only the "basic costs", i.e., without including any potential repairs).
I once read that delayed launches cost $28 million per day, but this figure seems way too high to me just to keep the Shuttle on the launchpad.
Is there an estimate of the costs incurred for each day a Shuttle launch is delayed? (including only the "basic costs", i.e., without including any potential repairs).
I once read that delayed launches cost $28 million per day, but this figure seems way too high to me just to keep the Shuttle on the launchpad.
The $28 million is probably the cost of a scrubed attempt, not a per day cost. The cost of a shuttle sitting on the pad depends on how you want to calculte it. Assuming no actual material cost (nothing is being used up) then you are just talking about the saleries of the people involved who are getting paid anyways. Eventualy, if it sits out there long enough, some material costs will come into play to recharge batteries if nothing else.
FOD question.
1. In looking at the LCA replacement photos in the KSC Media Gallery (http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4), I noted that the first few photos of the guys climbing around in the aft of Endeavor were wearing coveralls (not the full blown bunny suits with booties, but at least coveralls), whereas the later photos of the folks doing the R&R of the LCA were in jeans,sneakers(sorry, "trainers"..), etc.
2. My question is: what precautions are in place at the pad, and especially when working inside the orbiter, for FOD prevention?
3. If you're doing maintenance in essentially "street clothes" are there provisions for removing FOD hazards from pockets, fingers, etc? In one photo, one of the workers was definitely wearing a wedding ring (a no-no where I worked), and in another a wristwatch, so it *appears* (to me, the uninitiated outside observer) that there are very little FOD prevention measures in effect.
4. What about things like FOD stuck in the tread of your sneakers, for example?
Thanks in advance!
Darin
4. What about things like FOD stuck in the tread of your sneakers, for example?4. Tacky mats are used at the entrance.
And if you look closely in those photos, everyone who is actually in the aft is wearing covers over their shoes.
And if you look closely in those photos, everyone who is actually in the aft is wearing covers over their shoes.
Actually, not: http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=52363
The lights are halogen which gives off a blue white light (above 5000 K) the greenish cast is what you get when a digital camera is balanced for sunlight but is shooting under a bluer light.OK, so the STS-114 shot is the more correct one?
The lights are halogen which gives off a blue white light (above 5000 K) the greenish cast is what you get when a digital camera is balanced for sunlight but is shooting under a bluer light.
The lights are halogen which gives off a blue white light (above 5000 K) the greenish cast is what you get when a digital camera is balanced for sunlight but is shooting under a bluer light.
Are you sure? First of all, Halogens are in the 2800-3400K range. Second, that color cast is what you get when you image a single or dual phosphor fluorescent or metal halide when you are daylight balanced. If you shoot a Halogen when you are daylight balanced, you'll get a yellow-orange cast.
The lights are halogen which gives off a blue white light (above 5000 K) the greenish cast is what you get when a digital camera is balanced for sunlight but is shooting under a bluer light.OK, so the STS-114 shot is the more correct one?
I tried a search, but don't think I was crafty enough to come up with the right search terms.
When and how do they remove the shields over the windows?
I tried a search, but don't think I was crafty enough to come up with the right search terms.
When and how do they remove the shields over the windows?
The soft covers are removed by hand during the T-11 hour hold before the RSS (rotating service structure) is retracted.
Mark Kirkman
My question is: how this issues has been handled? the article doesn't say anything else.
The Shuttle's robotic arm (SRMS) was designed to stored on the port side of the payload bay and the KU dish is in the starboard forward corner of the bay, so they didn't interfere with eachother.
Hi all.
I was reading the other day this article regarding a clearance issue between the KU-Antenna and the OBSS. This problem was spotted first for STS-114 also if it appears that was there since the beginning since originally for the Shuttle it was thought to use to robotic arms.
My question is: how this issues has been handled? the article doesn't say anything else.
ps: the article is http://spaceflightnow.com/shuttle/sts114/050519tankingpre/ (http://spaceflightnow.com/shuttle/sts114/050519tankingpre/)
thanks very much.
Thanks AnalogMan that's exactly what I wanted to know. Where did you get the results of the FRR? is it here on the forum? L2 maybe? thanks again
During today's STS-134 launch, specifically during the MCC-H replay at ~16:40 here (http://www.youtube.com/watch?v=2fuaIEYEiLI&feature=share)
after throttling down to keep max of 3G and approaching MECO, there's a "henning up" call from either BOOSTER or FIDO. What does this mean?
To (possibly) add, that's Ground Control (GC) making those calls (30 seconds to TDRS, handing up, on TDRS).During today's STS-134 launch, specifically during the MCC-H replay at ~16:40 [grl=http://www.youtube.com/watch?v=2fuaIEYEiLI&feature=share]here[/gurl]
after throttling down to keep max of 3G and approaching MECO, there's a "henning up" call from either BOOSTER or FIDO. What does this mean?
"Handing up" comm to TDRS (note the timing with respect to the previous TDRS call).
To (possibly) add, that's Ground Control (GC) making those calls (30 seconds to TDRS, handing up, on TDRS).During today's STS-134 launch, specifically during the MCC-H replay at ~16:40
after throttling down to keep max of 3G and approaching MECO, there's a "henning up" call from either BOOSTER or FIDO. What does this mean?
"Handing up" comm to TDRS (note the timing with respect to the previous TDRS call).
I haven't had a chance to watch the whole video, but from the parts I saw, you can hear the earlier calls for the different sources (like the MILA call I heard).
Why do the shuttles have their flaps deployed while rolling over to the VAB?
After lift-off do the launch controllers have any required monitoring to do where in they might see something that requires their contribution to decision making during ascent?
Also in this video someone posted, do the SMEs always bend as they power up? Watch the center engine.
http://www.youtube.com/watch?v=hDCCBgppG4s&feature=related
After lift-off do the launch controllers have any required monitoring to do where in they might see something that requires their contribution to decision making during ascent?
They are involved with safing the pad and they don't see flight telemetry
I heard something happened to one of the SMEs during STS-134's launch. What was the issue? I missed the press conference that mentioned it.Q: Main engine sensor issue ? (Chris G)
Couple of notes to add:I heard something happened to one of the SMEs during STS-134's launch. What was the issue? I missed the press conference that mentioned it.Q: Main engine sensor issue ? (Chris G)
A: It was on a sensor on low pressure fuel turbo pump B channel. It dropped off for a few milliseconds. So the computer threw it out. Its used for an internal calculation for internal flow through turbo pump. If both sensors failed they have a default flow rate value to fall back to.
Yes, they always flex
STS-134 Ascent Team video;
At 1:28 - "Drop any non essential displays at this time"
Who said that (it doesnt appear to be FD) and what does it mean?
also shortly after;
"GC - enable FIDO and I early"
?
Abort request pushbutton, which illuminates a light in the cockpit that the crew uses as one cue for an abort.
I live about 6 hours from Edwards. How far ahead of time do they decide where to land? In other words, do I have to out-guess the weather folks and already be on the road before they officially decide to switch from KSC to California?
Why did shuttle crews abandon wireless headsets for on-orbit comm? They were used many years ago, but disappeared by the midpoint of the program. With improvements in technology, wouldn't they be much better, much more comfortable, and most importantly, leave their hands free (other than a push-to-talk button)—not having to find/reach for the microphone or hold it while talking?
I saw on the astronaut Hall of Fame ceremony one of the crew told the story of how Discovery on 51-D did a flip when the crew tried to vent the leftover cryo from launch out of the T-0 umbilical. Discovery went into a nose down pitch as a result. How did that happen?
I suspected that might be the case, but I dismissed it due to this image (http://farm4.static.flickr.com/3637/3382986095_2a99d501da.jpg). Maybe the view isn't very good?
I suspected that might be the case, but I dismissed it due to this image (http://farm4.static.flickr.com/3637/3382986095_2a99d501da.jpg). Maybe the view isn't very good?
Speaking of the PLBDs: It's fairly well known during the SLC-6 on-pad trials with Enterprise the PLBDs blew open in the high winds and had to be secured using strings of some kind.I suspected that might be the case, but I dismissed it due to this image (http://farm4.static.flickr.com/3637/3382986095_2a99d501da.jpg). Maybe the view isn't very good?
Padrat is correct. The overhanging door makes a more effective seal. The payload bay doors are built with the same principle in mind. The right door overlaps the left by almost 4 inches.
I suspected that might be the case, but I dismissed it due to this image (http://farm4.static.flickr.com/3637/3382986095_2a99d501da.jpg). Maybe the view isn't very good?
I suspected that might be the case, but I dismissed it due to this image (http://farm4.static.flickr.com/3637/3382986095_2a99d501da.jpg). Maybe the view isn't very good?
Hey, this is a purely geeky question, but in ISS and Shuttle Mission Controls, you've probably noticed that everyone has a vertical orange-ish panel that sits off to either the far left or right of their particular stations. They appear to be dedicated touch screens with a bunch of buttons on it. Once in a very rare while, a controller will touch the screen. Does anyone know what these are?Answered a huge number of times in this and other threads. Nevertheless, those buttons select the various voice loops that the controller is listening to or able to speak into via their headset.
I never noticed the overlap for the nose gear door. All the models of the shuttle have both doors the same size.
Speaking of which what is that hose connection port on the inside of the right nose gear door on Discovery? *points to above photo*
Why does the left SRB have additional stiffeners added to it?
This person's model of both boosters shows the difference.
http://i198.photobucket.com/albums/aa234/crowe-t/Space%20Shuttle%20build/IMG_3893.jpg
How come STS-7's ET has the LH2 Gaseous line on the left side of the tank? Wasn't it discontinued after STS-5?
http://www.nasa.gov/images/content/2164main_sts7_et_lo.jpg
Hi folks,
Two questions:
1) Why do they need to "hot fire" the RCS for landing when they just used them for the "fly around?
2) Why is this section of the tank(circled) a different color?
Hi folks,
Two questions:
1) Why do they need to "hot fire" the RCS for landing when they just used them for the "fly around?
1. The aft RCS is used for entry until around Mach 2
Are there any photo's or illustrations of the sensors orbiters use to take the 'air data' late before landing?I guess the best ones may be here: http://historical.ha.com/c/item.zx?saleNo=6052&lotIdNo=50006 (http://historical.ha.com/c/item.zx?saleNo=6052&lotIdNo=50006) (hope the link lasts a while)
What's the source of the bright white-orange light on the base of the vertical stabilizer than you see in night landings, like in this shot:
http://graphics8.nytimes.com/images/2011/06/01/science/space/01shuttle-b/01shuttle-b-popup.jpg
Why was the AFRSI portion changed on the final 3 orbiters? For example you compare Discovery, Endeavour, and Atlantis from when the first flew to today, you notice the amount of AFRSI is less than what was there before. Why?
Just out of curiosity, why did the orbiters land at Edwards for their first flights? I understand that for Columbia and Challenger KSC was not open to landings yet, for Discovery only one KSC landing had taken place before, and for Atlantis there were still issues with the Tires/brakes, but by the time Endeavour flew KSC landings were a regular occurrence, yet she still landed at Edwards. Is there any special reason?
For comparison, the runway at the SLF is 15000' long.Just out of curiosity, why did the orbiters land at Edwards for their first flights? I understand that for Columbia and Challenger KSC was not open to landings yet, for Discovery only one KSC landing had taken place before, and for Atlantis there were still issues with the Tires/brakes, but by the time Endeavour flew KSC landings were a regular occurrence, yet she still landed at Edwards. Is there any special reason?
Just being conservative with a new orbiter, it was a program rule.
BTW, KSC was available for Columbia and Challenger, again just being cautious.
For comparison, the runway at the SLF is 15000' long.
The lakebed runway (17/35) they used at Edwards is currently charted as 39097' long, and I think was even a little longer back when the shuttle was using it. Plus, it didn't really much matter if you wound up a little short or long or off to one side :) (I think there's mention in Wayne Hale's blog, or somewhere here, of a lakebed shuttle landing that technically came in a tad bit short of the threshold.)
Why are Challenger's tiles around the crew hatch different from the other orbiters?
I was asking on the tile pattern of the hatch, not the AFRSI. :)Just a guess, but I would say there was some concern about thermal conditions around the hatch tunnel. It is the one place where the crew cabin structure approaches the outer mold line. Challenger's structure was somewhat different from the later vehicles.
Here is a decal sheet for shuttle models that shows both hatch tile patterns. The one on the left is with all the orbiters except Challenger, the one on the right is what Challenger has. She has extra black tiles. http://www.ninfinger.org/models/pix/rsmdecal.jpg
Why?
Why does the left SRB have additional stiffeners added to it?...
Why does the left booster have these extra straps on parts of it? Above shows the left SRB compared to the right SRB.
Is it true that one of the limitations of the Shuttle's wingspan design was the ability to fit through the transfer aisle during Lift/Mate??
TIA,
Steve
Is it true that one of the limitations of the Shuttle's wingspan design was the ability to fit through the transfer aisle during Lift/Mate??
TIA,
Steve
I see. Though I do wonder why the left booster has more of these than the right one? Does the left booster being closer to the FSS get more strain from the shockwaves at launch?
I've asked; apparently there is none.
Somebody must be supremely confident that it won't happen.
No, there is a contingency plan. Range Safety would order spectators to shelter in-place, and LCC and MCC would lock the doors and take steps to preserve data for the investigation.
No, there is a contingency plan. Range Safety would order spectators to shelter in-place, and LCC and MCC would lock the doors and take steps to preserve data for the investigation.
So, I assume that means that there is zero chance of the orbiter surviving in such a case?
So, I assume that means that there is zero chance of the orbiter surviving in such a case?There are hold down bolts, fractured at the moment the SRBs are lit, but if not blown the SRBs will comfortably tear through them anyways. Imagine what the stack will do as it rotates off the gantry. You can work out how many megajoules are in the tankage, but figure the stack is about two kilotons of mostly propellant. And a bit of a BLEVE.
Semi-related, but is there a public (or L2) list of Shuttle contingency plans?Yes. This: http://www.nasa.gov/centers/johnson/news/flightdatafiles/index.html
I remember hearing somewhere that "the sound from the space shuttle engines and SRB can kill at X distance."
Is that true? If so, what is that distance, or thought to be the distance?
So, I assume that means that there is zero chance of the orbiter surviving in such a case?There are hold down bolts, fractured at the moment the SRBs are lit, but if not blown the SRBs will comfortably tear through them anyways. Imagine what the stack will do as it rotates off the gantry. You can work out how many megajoules are in the tankage, but figure the stack is about two kilotons of mostly propellant. And a bit of a BLEVE.
So, I assume that means that there is zero chance of the orbiter surviving in such a case?There are hold down bolts, fractured at the moment the SRBs are lit, but if not blown the SRBs will comfortably tear through them anyways. Imagine what the stack will do as it rotates off the gantry. You can work out how many megajoules are in the tankage, but figure the stack is about two kilotons of mostly propellant. And a bit of a BLEVE.
To get nit-picky here, the hold down bolts are actually blown about 0.3 seconds before SRB ignition.
What is the aerovent seen on the external tank's intertank used for? Also are there any diagrams or photos of it?
Hi,
does anybody know what is the thickness of the ET thermal insulation foam?
Somehow, I always imagined that it is really tick.
Also, what is the consistency? Can you for example cut a chunk of foam with kitchen knife?
Thanks.
Hi,
does anybody know what is the thickness of the ET thermal insulation foam?
Somehow, I always imagined that it is really tick.
Also, what is the consistency? Can you for example cut a chunk of foam with kitchen knife?
Thanks.
Also, what is the consistency? Can you for example cut a chunk of foam with kitchen knife?
Thanks.
The thickness varies for different parts of the tank. Consistency I guess is harder to answer but the closest analogy I can think of right now is something like styrofoam, and yes it can be cut, shaved, etc.
How fast can each of the individual joints on the RMS move? Also, what are the overall speed limits for the RMS? The RMS speed seems to be limited to 2.0 fps (according to the PDRS documents I've seen), but I'm wondering if this is due to mechanical constraints or just so it doesn't bump into anything.
Im looking for a chart or list of the milestones, speeds, times, MCC calls etc. from T-0 to MECO. I did a search and found the same question asked in the Shuttle Q&A thread number 2, the reply was to see http://science.ksc.nasa.gov/shuttle/countdown/count.html#T-01M00S but it only goes to T-0. Clicking LIFTOFF on that page takes to a countdown clock but no launch info. (Searching for "launch milestone" on a spaceflight forum returns quite a few results!)Try: http://spaceflightnow.com/shuttle/sts135/fdf/135ascent.html
Any ideas?
Im looking for a chart or list of the milestones, speeds, times, MCC calls etc. from T-0 to MECO. I did a search and found the same question asked in the Shuttle Q&A thread number 2, the reply was to see http://science.ksc.nasa.gov/shuttle/countdown/count.html#T-01M00S but it only goes to T-0. Clicking LIFTOFF on that page takes to a countdown clock but no launch info. (Searching for "launch milestone" on a spaceflight forum returns quite a few results!)Try: http://spaceflightnow.com/shuttle/sts135/fdf/135ascent.html
Any ideas?
Note that the times may not be exact to the second --- the precise launch window depends on recent updates of the station's position, and they target the center of the window. Although, this version says updated 8 July, so it should be about on the money.
-Alex
Watching the STS-135 replays, about 8 seconds after SRB sep and just prior to OMS ignition that if you use the background of the earth as a reference you can see what appears to be a tail left / nose right yaw. Why is this?
How much does a couple minute hold like we had on 135 affect the OMS 2 and NC burns?
NC-4 burn updates:
Weight: 248252 lbs
TIG: 01/19:26:23.4 --> 10:55:27 GMT / 5:55:27 Central
TGT PEG7:
dVx: +143.9 (fps)
dVy: 0
dVz: +7.6
1) Watching the STS-135 replays, about 8 seconds after SRB sep and just prior to OMS ignition that if you use the background of the earth as a reference you can see what appears to be a tail left / nose right yaw. Why is this?
2) Next- just after the roll program there always seems to a be slight roll back in the opposite direction. Is this because of the enormous forces involved in the roll that there will always be a need for a correction back?
3) Finally, I have noticed the following on prior launches, including this one; During ascent, if you use the shadows cast on the stack or the Earth as reference you will notice what appears to be slight rolling back and forth around the vertical axis. What causes this?
Thank you!
How much does a couple minute hold like we had on 135 affect the OMS 2 and NC burns?
Compare the values psloss provides to the preliminary values in the attachment to his post. Non-trivial difference!NC-4 burn updates:
Weight: 248252 lbs
TIG: 01/19:26:23.4 --> 10:55:27 GMT / 5:55:27 Central
TGT PEG7:
dVx: +143.9 (fps)
dVy: 0
dVz: +7.6
Lots of questions about that preliminary "PAD", BTW, like almost all the acronyms. The math for {delta}VTOT is clear: sqrt((139^2) + (38.4^2)) = 144.2.
TGO must be burn duration?
But what are R, P, and Y for BURN ATT?
And TGT HA and HP?
Why do they always fire the OMS engines on the way up? Aren't those only supposed to be for maneuvering once in orbit? Why not just use up the SSME propellant (by pushing MECO back a bit) and save the OMS propellant for later?
Why do they always fire the OMS engines on the way up? Aren't those only supposed to be for maneuvering once in orbit? Why not just use up the SSME propellant (by pushing MECO back a bit) and save the OMS propellant for later?
They know how much they need for each mission with margin and burn off the excess. There is a performance benefit by doing this.
I remember asking about this ages ago. I was surprised that they actually got such a good boost from the OMS engines, as opposed to just not loading that propellant in the first place.Why do they always fire the OMS engines on the way up? Aren't those only supposed to be for maneuvering once in orbit? Why not just use up the SSME propellant (by pushing MECO back a bit) and save the OMS propellant for later?
They know how much they need for each mission with margin and burn off the excess. There is a performance benefit by doing this.
Does anybody have a list of all the acronyms used on the radio loop during the shuttle countdown. There were so many I can't remember them all. The ones I figured out (or think I did) were:
CDR - Commander
PLT - Pilot
MS1 - Mission Specialist 1
MS2 - Mission Specialist 2
MMT - Mission Management Team
SRO - Safety Range Officer (thought it was RSO)
But there were many others that I didn't catch or couldn't figure out like NTD.
Not that we'll ever hear a Shuttle countdown again but I was curious who all the acronyms referred to.
Does anybody have a list of all the acronyms used on the radio loop during the shuttle countdown. There were so many I can't remember them all. The ones I figured out (or think I did) were:SRO = Superintendent of Range Ops
CDR - Commander
PLT - Pilot
MS1 - Mission Specialist 1
MS2 - Mission Specialist 2
MMT - Mission Management Team
SRO - Safety Range Officer (thought it was RSO)
But there were many others that I didn't catch or couldn't figure out like NTD.
Not that we'll ever hear a Shuttle countdown again but I was curious who all the acronyms referred to.
Sorry if this is the wrong place to post this, but I have a question about the net mass of the MPLM cargo on this mission. The Flight Operations and Integration PDF on L2 lists the mass of the MPLM as 25,478 lbs up, and this page (http://mplm.msfc.nasa.gov/mission.html) indicates that the empty mass of an MPLM is 9000 lbs, so the cargo should be 16,478 lbs. However this article (http://www.spaceflightnow.com/shuttle/sts135/110711fd4/index.html) says that the MPLM cargo came to 9,403 lbs. Where is the discrepancy?
Does anybody have a list of all the acronyms used on the radio loop during the shuttle countdown. There were so many I can't remember them all. The ones I figured out (or think I did) were:
CDR - Commander
PLT - Pilot
MS1 - Mission Specialist 1
MS2 - Mission Specialist 2
MMT - Mission Management Team
SRO - Safety Range Officer (thought it was RSO)
But there were many others that I didn't catch or couldn't figure out like NTD.
Not that we'll ever hear a Shuttle countdown again but I was curious who all the acronyms referred to.
Someone doesn't read my articles then ;) NTD Is NASA Test Director (NTD). I've used that in about 100 articles.
Moving to Shuttle Q&A
Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
they are pointed at the CG of the stack.
What happens after SRB and ET separation? It changes and so the orbiter has to make burns at a weird orientation?Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
they are pointed at the CG of the stack.
What happens after SRB and ET separation? It changes and so the orbiter has to make burns at a weird orientation?Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
they are pointed at the CG of the stack.
The SSMEs gimbal to handle the transient at SRB sep. If you watch the ET camera you can see that it's small and controllable, not a "weird orientation" at all.
ET sep is not an issue since MECO occurs before then.
Sorry if this is the wrong place to post this, but I have a question about the net mass of the MPLM cargo on this mission. The Flight Operations and Integration PDF on L2 lists the mass of the MPLM as 25,478 lbs up, and this page (http://mplm.msfc.nasa.gov/mission.html) indicates that the empty mass of an MPLM is 9000 lbs, so the cargo should be 16,478 lbs. However this article (http://www.spaceflightnow.com/shuttle/sts135/110711fd4/index.html) says that the MPLM cargo came to 9,403 lbs. Where is the discrepancy?[/quote]
Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
they are pointed at the CG of the stack.
What happens after SRB and ET separation? It changes and so the orbiter has to make burns at a weird orientation?Why is the "neutral" thrust vector of the SSMEs angled relative to the stack? I've always wondered why they were set up to where they are sort of pushing the orbiter towards the ET. I assume that because of this the stack doesn't travel exactly in the direction the nose is pointing?
they are pointed at the CG of the stack.
The SSMEs gimbal to handle the transient at SRB sep. If you watch the ET camera you can see that it's small and controllable, not a "weird orientation" at all.
ET sep is not an issue since MECO occurs before then.
What is that tiny hole for on the Forward RCS? You see it in this photo http://upload.wikimedia.org/wikipedia/commons/8/8a/STS-135_Atlantis_port_side_view.jpg
And here with rectangular cover over it. Look to the upper left of the green access panel cover. http://upload.wikimedia.org/wikipedia/commons/3/38/STS-135_Atlantis_Ready_to_Roll.jpg
You see it between the edge of the FRCS module and the thruster nozzles.
I've got a strange question and wonder if anyone knows: As the ET drains during the flight, the forward sections of the tanks are no longer in direct contact with the cryogenic fluids. So how much of a temperature difference do those forward sections see by the time the vehicle reaches MECO? I would imagine that a significant temperature change might cause quite a bit of thermal stress on the fwd sections.
-MG
I would imagine that a significant temperature change might cause quite a bit of thermal stress on the fwd sections.
-MG
What will become of the sims?
Is the source code for the GPC's PASS available to the public? My limited knowledge of the GPC's is that their memory and storage space is significantly less than today's PC's (and that isn't to knock how great they are / specialized for flight) and that compared to today's software out there I'd imagine the source code wouldnt be as big. Also, since this isn't private sector (ala microsoft) and was paid for by tax dollars and not a national security secret (or is it?) I would think that it should be available?
Thanks
First, It very much is a national security secret. Any goverment sponsered sofware dealing with the guidence of rockets in flight is by definition.
Second, Even if the code was available, It's written in a unique language called HAL/S. You'd need a special compiler just to read it.
In all the documentation / resources on here- we don't know how the gimballing is commanded and how the computers maintain control? Thats the secret?
Ok, so redact anything to do with guidance. Or just leave out the launch and ascent. I'd be happy with re-entry and landing.
What will become of the sims?
Is the source code for the GPC's PASS available to the public? My limited knowledge of the GPC's is that their memory and storage space is significantly less than today's PC's (and that isn't to knock how great they are / specialized for flight) and that compared to today's software out there I'd imagine the source code wouldnt be as big. Also, since this isn't private sector (ala microsoft) and was paid for by tax dollars and not a national security secret (or is it?) I would think that it should be available?
Thanks
Sorry if this is the wrong place to post this, but I have a question about the net mass of the MPLM cargo on this mission. The Flight Operations and Integration PDF on L2 lists the mass of the MPLM as 25,478 lbs up, and this page (http://mplm.msfc.nasa.gov/mission.html) indicates that the empty mass of an MPLM is 9000 lbs, so the cargo should be 16,478 lbs. However this article (http://www.spaceflightnow.com/shuttle/sts135/110711fd4/index.html) says that the MPLM cargo came to 9,403 lbs. Where is the discrepancy?
My documentation shows 26700 lbm total, 16008 cargo + packing material, 10692 net cargo.
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
Not power. Purge and cooling.
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
Not power. Purge and cooling.
Probably that if sufficient cooling can't be maintained, you have to start turning more and more things off prematurely.I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
Not power. Purge and cooling.
That's what I thought too, but that link I posted had this:
"We have to hook up within 30 minutes. It's very important to maintain cooling, maintain power in the orbiter,"
To what was he referring?
Makes sense. I keep forgetting that Shuttle is chock full of 70's era solid state electronics - it's a water heater! :)
Why does the orbiter need to stay powered up all the way back to the OPF? Because it still contains APU and RCS fuels? Does someone actually sit on the flight deck during the towback?
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
Not power. Purge and cooling.
That's what I thought too, but that link I posted had this:
"We have to hook up within 30 minutes. It's very important to maintain cooling, maintain power in the orbiter,"
To what was he referring?
I think one gives the orbiter power, one cools the inside and one I think purges the vapors.
Not power. Purge and cooling.
Makes sense. I keep forgetting that Shuttle is chock full of 70's era solid state electronics - it's a water heater! :)
Why does the orbiter need to stay powered up all the way back to the OPF? Because it still contains APU and RCS fuels? Does someone actually sit on the flight deck during the towback?
The fuel cells are supplying power and producing heat. If the heat cant be removed, then the fuel cells would have to shut down.
On STS-135 there was a hold at T-31 seconds. After verifying that the GVA had retracted SPE was GO and it sounded like the NTD was about to tell CGLS to pick up the count when SPE said they needed concurrence with CGLS and ASP to clear the hold. Considering SPE and LD were both GO at this time, why was there this additional delay? I'm sure there wasa a very good reason but had there been less LOX drainback hold time then it could have resulted in a scrub.jcopella elaborated on launch day:
Yes, there a couple of people in the cabin all the way back. After the 135 landing last week, they left Atlantis parked outside the OPF for a few hours while they had the employee and press event. The airstair truck was parked off to the side and the hatch was secured. You could see the people inside thru the cockpit windows. We were chuckling about it wondering who they got to volunter for that duty.
Regarding the shuttle airlock prior to iss. Did the astronauts need to prebreathe for Eva as well?Yes, Anytime you drop from 14.7 psi O2/N2 directly to 4 psi 100% O2 you are going to need to scrub the nitrogen from your blood stream first or else you'll get the bends.
Hi, sorry if this has been answered but I could not find it in a search:
What do the colours mean in contingency abort modes? E.g. "two out blue"?
Hi, sorry if this has been answered but I could not find it in a search:
What do the colours mean in contingency abort modes? E.g. "two out blue"?
The color is a label on the manuver to be flown between abort start and ET seperartion.
Hi, sorry if this has been answered but I could not find it in a search:
What do the colours mean in contingency abort modes? E.g. "two out blue"?
The color is a label on the manuver to be flown between abort start and ET seperartion.
Right, my understanding was it was just a color-coding scheme on the cue card, and the colors themselves didn't have any physical significance.
I remember reading a while back that Dick Scobee was part of the crew that flew the 747 / Enterprise from the Paris Air Show back to the United States.
Can anyone here confirm that?
Thank you.
I remember reading a while back that Dick Scobee was part of the crew that flew the 747 / Enterprise from the Paris Air Show back to the United States.
Can anyone here confirm that?
Thank you.
Yes, he was on the SCA when they stopped at Wright-Patterson on the way over.
The color is a label on the manuver to be flown between abort start and ET seperartion.
Right, my understanding was it was just a color-coding scheme on the cue card, and the colors themselves didn't have any physical significance.
You understand correctly
Probably flight-specific, but if you haven't looked at the workbooks here, then it's a good place to continue:The color is a label on the manuver to be flown between abort start and ET seperartion.
Right, my understanding was it was just a color-coding scheme on the cue card, and the colors themselves didn't have any physical significance.
You understand correctly
Thanks for the information. Is there a list of the contingency modes available anywhere, and in what situations they would have been used?
The color is a label on the manuver to be flown between abort start and ET seperartion.
Right, my understanding was it was just a color-coding scheme on the cue card, and the colors themselves didn't have any physical significance.
You understand correctly
Thanks for the information. Is there a list of the contingency modes available anywhere, and in what situations they would have been used?
Why was rollout done at night? From pictures it looks like at one time there were rollouts during the day but for the last bunch of missions it was always at night.
Prior to the Challenger disaster, pilot astronauts would fly only once as PLT before becoming CDR for their second and subsequent missions.
After 1986, this appeared to change and pilot astronauts would, in most cases, fly TWO missions as PLT before becoming CDR:
So -
1) Why the change?
2) Even post-1986, some astronauts did become CDR after just one mission, so how was this decided?
3) Was there some sort of a "command check" for a new CDR?
4) Towards the end of the Shuttle, PLTs started to become CDR after just one mission again? Why? To get everyone at least one flight?
Interested to hear your thoughts, so thanks in advance!
Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?The elevons.
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
Does anybody have any recollection of the following or know what the proposal actually was? When I was a kid (I'm pretty sure before Challenger) I saw a magazine with drawing that from memory was additional engines at the bottom of the ET. It almost looked like the Ares V/SLS but with the orbiter still there. I know I saw it, the only question in my mind was if this was something real or a mistake made by the magazine that confused some kind of Shuttle Derived vehicle?That sort of sounds like the Sigma EDIN05 concept.
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
Does anybody have any recollection of the following or know what the proposal actually was? When I was a kid (I'm pretty sure before Challenger) I saw a magazine with drawing that from memory was additional engines at the bottom of the ET. It almost looked like the Ares V/SLS but with the orbiter still there. I know I saw it, the only question in my mind was if this was something real or a mistake made by the magazine that confused some kind of Shuttle Derived vehicle?
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?The elevons.
Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?The elevons.
Specifically I believe they use the elevon TRIM control to de-rotate, because doing it the other way was too finicky and resulted in the Columbia wheelie on STS-3
Which aerosurface on the orbiter is used for the post-MLG touchdown derotation?The elevons.
Specifically I believe they use the elevon TRIM control to de-rotate, because doing it the other way was too finicky and resulted in the Columbia wheelie on STS-3
The elevons don't have trim tabs like a conventional aircraft. They are the only "aerosurfaces" on the wings.
Apologize in advance if this has been answered. I did some searching and didn't find it.
Is there a comprehensive, detailed history of all shuttle ferry flights out there somewhere? By "detailed" I mean where they stopped to overnight and when.
Thanks,
S-I
1. Yes, precip would erode the tiles.
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
Orginally, PASS was written by IBM and BFS by Rockwell. It is completely different and only handles the primary flight regimes
The shuttle never actually flew on BFS, right?
BFS was never used.
Can someone remind of the difference(s) between an IPR and a PR?
Not at all. Generally, a PR is a discrepancy taken against a known component, which then can be resolved (i.e. a broken wire). An IPR is a discrepancy in which the cause has not been isolated (i.e. the valve didn't open when commanded) to one component. Usually troubleshooting is required to isolate the problem, at which time the IPR would be upgraded to a PR. At least that was the way it used to be done . . .Can someone remind of the difference(s) between an IPR and a PR?
They are the same. one is just interim.
My other question is are there any pre flight photos of Challenger on STS-51L?
Not at all. Generally, a PR is a discrepancy taken against a known component, which then can be resolved (i.e. a broken wire). An IPR is a discrepancy in which the cause has not been isolated (i.e. the valve didn't open when commanded) to one component. Usually troubleshooting is required to isolate the problem, at which time the IPR would be upgraded to a PR. At least that was the way it used to be done . . .Can someone remind of the difference(s) between an IPR and a PR?
They are the same. one is just interim.
I understand that Columbia was some 8,000 lbs heavier than her sister ships. Exactly where was this extra weight and what was it made up of (ie - airframe, engine mounts, etc)? Did she have extra hardware that the other orbiters did not?
I understand that Columbia was some 8,000 lbs heavier than her sister ships. Exactly where was this extra weight and what was it made up of (ie - airframe, engine mounts, etc)? Did she have extra hardware that the other orbiters did not?
How come the flag on the side of Endeavour is closer to the United States logo than on Discovery?there is more space between letters on Endeavour than on Discovery.
The original question asked for the differences, not the similarities.Not at all. Generally, a PR is a discrepancy taken against a known component, which then can be resolved (i.e. a broken wire). An IPR is a discrepancy in which the cause has not been isolated (i.e. the valve didn't open when commanded) to one component. Usually troubleshooting is required to isolate the problem, at which time the IPR would be upgraded to a PR. At least that was the way it used to be done . . .Can someone remind of the difference(s) between an IPR and a PR?
They are the same. one is just interim.
When one becomes the other, they are the same.
What is the circular white indentation that is in front of the port side front window in the white area between the cockpit and the RCS. It can be seen just above the right side of the orbiter access arm in this photo.
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=25488.0;attach=307518;image (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=25488.0;attach=307518;image)
Star tracker, I think.
Plus Columbia has extra tiles on her wing chines and tail that were covered with thermal blankets on other orbiters. Not much difference, but the tiles did weigh more than the blankets
A fair number of the tiles on Columbia's upper side were replaced with thermal blankets during one of her refurbishments (for weight savings purposes), not sure if that included those areas.
Noel
The chine areas remained covered with extra black tiles for her entire life, and extra black tiles were added in support of the SILTS experiment on the tail after STS-9. Columbia did replace areas of her LRSI tiles with AFRSI, but the distinctive HRSI chines were never replaced.
But of course the spars and test equipment were the main contributors to her extra weight. Attached an image of Columbia rolling out for STS-107 to shot the tail and chines still covered in HRSI.
And Enterprise's airframe was the same as Columbia's, which is why she was never retrofitted for spaceflight? Same heavier construction?
What did Enterprise lack other than TPS? I assume it had (has) fuel cells, APU's, etc? Was there ever any thought post STS-107 of fitting her out? I'm guessing not.
And Enterprise's airframe was the same as Columbia's, which is why she was never retrofitted for spaceflight? Same heavier construction?
What did Enterprise lack other than TPS? I assume it had (has) fuel cells, APU's, etc? Was there ever any thought post STS-107 of fitting her out? I'm guessing not.
And Enterprise's airframe was the same as Columbia's, which is why she was never retrofitted for spaceflight? Same heavier construction?
What did Enterprise lack other than TPS? I assume it had (has) fuel cells, APU's, etc? Was there ever any thought post STS-107 of fitting her out? I'm guessing not.
No, Enterprise (OV-101) was an even earlier airframe than Columbia (OV-102). Columbia's had another year of structures analysis to benefit from prior to construction.
Yes, modernizing OV-101 into a space-rated vehicle was thoroughly looked at prior to the decision to turn the structural test article into Challenger (OV-099). At that point it was found to be easier (time and money) to turn an empty airframe into a real orbiter than to modify Enterprise. The issue was again looked at after the Challenger accident. Again, the answer was that it was cheaper to build Endeavour (OV-105) out of spare parts than it would be to turn Enterprise into an orbital vehicle. The issue was *not* looked at after STS-107 because there were no plans to replace Columbia and OV-101 had sat outside under a essentially a tarp tent for about 10 years at Dulles Airport by that point (now OV-101 is thankfully in a beautiful building).
Again, Enterprise's drawings (engineering drawings) would have been unique to the fleet, even comared with Columbia. Whereas Endeavour's drawings matched that of Discovery (OV-103) and Atlantis (OV-104). Much easier to handle from an analysis standpoint (one analysis fits three of the vehicles). Also, I've heard it said that Enterprise, even in pristine condition, would have cracked in half during entry because the structure was not strong enough in many places. Fixing that would have required more weight and more "uniqueness".
Enterprise is missing most systems (most of the cockpit instrumentation was "donated" to OV-103 for its build). Even the payload bay doors don't work, the thrust structure for the main engines isn't there, there is no fuel cell plumbing, and the list would go on for quite some time. The last photo I have of Enterprise's interior shows that only a mechanical horizon instrument (unique to the ALT flights only) remains in the forward cockpit. The rest is empty spaces where avionics boxes used to be for ALT.
So, bottom line is that Enterprise required lots of work to turn into an orbital vehicle and even if you did all of the work, the result would not have been able to carry as much payload as the sister ships and would have required lots of special analysis because the configuration would have been different than the sister ships.
Andy
Thanks, I was wondering how different it actually was. Sounds like a lot more than TPS! Would love to see flight deck photos, though!
Yes and I believe LH2 is not susceptible to pogo
Quote from: JimYes and I believe LH2 is not susceptible to pogo
Thanks Jim.
I was also wondering another things: since there are three main engines and since each one of them as its own pogo suppression system, are somehow the three pogo systems connected to each other? I mean, does each pogo suppression system get some kind of feedback from the two other systems so that to regulate its action on the engine? because I suppose the pogo vibrations of the three engines should somehow coupled with each other.
Thanks
Davide
This is great information. Is there a formal PDF or other type of study document that lists the various problems with making Enterprise space worthy?
Cheers.
I understand that Columbia was some 8,000 lbs heavier than her sister ships. Exactly where was this extra weight and what was it made up of (ie - airframe, engine mounts, etc)? Did she have extra hardware that the other orbiters did not?
The structure (mostly wings)was made stronger than was needed
Thanks, I was wondering how different it actually was. Sounds like a lot more than TPS! Would love to see flight deck photos, though!
I noticed in a video that on the STS-91 landing, the main gear touchdown, then it rises up again, maybe a foot or two at most, then settles down again..
was this because of certain conditions (wind?) or was there no reason, just happened? Certainly wasn't a major issue, just was curious,, never seen it happen before.
landing replay on youtube:Also some excerpts of the live landing coverage I posted on L2; you can find that from the mission tag:
http://www.youtube.com/watch?v=4o2K6PaDkd0&t=14m44s at 14min 44s mark.
although not shot from a good angle; the actual landing only from HUD camera.
Regarding Columbia, I was under the impression that the black chine areas were actually paint and not tiles. When Columbia arrived at KSC, and rolled over, the chine area wasnt black, however on rollout, it was. I was always told that it was due to engineers thinking that that area might experience more heat and it was treated with a black "paint".
I could be totally wrong, but just something I read somewhere.....
Please correct me if I am wrong.
Thanks!!
I saw a post earlier in this thread asking about source code for PASS. While its dramatically unlikely we'll see that anytime soon, there is a small consolation prize -- the Approach and Landing Test System Software Design Specification _is_ available. It is a 1580 page PDF with complete flowcharts (1977 style flowcharts, with every conditional expression present) of the FCOS and some really interesting stuff on GPC redundancy.It's enormous. Any particularly interesting or revealing bits you've found thus far?
Link here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770075091_1977075091.pdf
The document only covers the system software, not flight software, sadly. But it is still a great document.
I saw a post earlier in this thread asking about source code for PASS. While its dramatically unlikely we'll see that anytime soon, there is a small consolation prize -- the Approach and Landing Test System Software Design Specification _is_ available. It is a 1580 page PDF with complete flowcharts (1977 style flowcharts, with every conditional expression present) of the FCOS and some really interesting stuff on GPC redundancy.It's enormous. Any particularly interesting or revealing bits you've found thus far?
Link here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770075091_1977075091.pdf
The document only covers the system software, not flight software, sadly. But it is still a great document.
-Alex
Opinions may vary, but I'd call it significantly different. The GPC status matrix was in front of the pilot instead of CDR, the fuel cell purge controls were on the upper front panel, the left and right overhead panels of switches were completely missing, panel R1 has three steam gauges on it, there is a ?backup? 'artificial horizon' on the fwd panels, most of the steam gauges are missing off the upper front panel....
It's enormous. Any particularly interesting or revealing bits you've found thus far?
-Alex
Keep in mind many of the details changed before the first orbital flight. I was always impressed that my colleagues were able to get a redundant set working for ALT, which was almost a decade before I got there.
And, SSW (system software) is part of FSW (flight software) as was GN&C (guidance navigation & control), VU (vehicle utility) and SM (systems management). I believe the SSW folks would be upset to not be counted as FSW. They were amazing folks who did amazing things with very little software! They also had the ability to analyze GPC anomalies with amazing detail (when one of the very few GPC anomalies occurred).
Andy
You might also want to read this, if you haven't already...
http://klabs.org/DEI/Processor/shuttle/shuttle_primary_computer_system.pdf
Some of it was a little dated, such as the quality metrics which were even better towards the middle-to-end of the program and the company name, of course. But, there are some good factoids in that paper.
And, yes, GPC sync was definitely working for ALT. Watch the NASA video on the ALT flights ("Go For Sep") and you'll see GPC 2 being voted out of the redundant set right after separation on the first ALT free flight. Can't be voted out if you don't have a synchronization scheme. Just don't consider the document you found to be a final version of (well) anything. When the program ended we were flying OI-34 - lots of time for changes.
Also, I seem to remember hearing that the RCS jets couldn't be commanded at 40 mS, there was some problem with pressure waves in the feed lines or something to that effect that required them to be commanded at 80mS; was the high-priority process constrained to only command the RCS jets every other cycle?
Also, I seem to remember hearing that the RCS jets couldn't be commanded at 40 mS, there was some problem with pressure waves in the feed lines or something to that effect that required them to be commanded at 80mS; was the high-priority process constrained to only command the RCS jets every other cycle?
The constraint was in the DAP rather than the high-frequency executive. To respect the 80 ms limitation, the DAP was only scheduled to run every other HFE cycle.
Everything was a separate process (or multiple processes) in one way or another. Remember they had to fit in their chunks of time, so you had different processes for different activities such as sequencers. Very complicated and required a real-time O/S to handle it 100% (or at least many many 9s) reliably.
This reference is probably a much higher level than you want but it provides an overview of the computing power on the vehicles,
http://www.nasa.gov/mission_pages/shuttle/flyout/flyfeature_shuttlecomputers.html
Andy
Everything was a separate process (or multiple processes) in one way or another. Remember they had to fit in their chunks of time, so you had different processes for different activities such as sequencers. Very complicated and required a real-time O/S to handle it 100% (or at least many many 9s) reliably.
This reference is probably a much higher level than you want but it provides an overview of the computing power on the vehicles,
http://www.nasa.gov/mission_pages/shuttle/flyout/flyfeature_shuttlecomputers.html
Andy
Right, as I understood it, the system SW had the HFE, MFE, and LFE, and all the application SW processes ran at an integer multiple of one of those three executives.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
Why is the inspection necessary. Practically all other rockets seem to do fine without it.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
Actually, it's the opposite. With a higher flight rate, The per flight recovery costs (SRB ship opperations, disassembly and shipping the segments, refurbishing them, etc.) would be the same, but the cost of producing segments from scratch would decrease somewhat as economies of scale began to apply. Reusability as a cost saver was always a misguided concept.The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
If the flight manifest had ever achieved anywhere near the original goal of 50 flights per year, then recovery was the best option. Cheaper to refurbish a rotating set of, say, 12 booster pairs than to buy 100 of them each year. Of course, that never happened.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
If the flight manifest had ever achieved anywhere near the original goal of 50 flights per year, then recovery was the best option. Cheaper to refurbish a rotating set of, say, 12 booster pairs than to buy 100 of them each year. Of course, that never happened.
If post flight inspection was a fundamental requirement of human rating, and if those where the big cost of recovery, I would be tempted to think that it couldn't be lowered by bigger scale of production as easily as manufacturing. May be someone could enlighten me?Post flight inspection was never a "fundamental requirement of human rating" of a launch vehicle. In the case of the STS SRBs, they were originally designed for recovery. Analysis done after several years of flying showed that the cost of recovering and refurbishing was about the same as building new hardware for flight and had the ADDED benefit of providing an opportunity to study hardware that had flown to establish a family history(especially since the hardware in question had experienced a catostrophic failure - This was after 51L). Given that, the question of paying for redesigning and recertificating the booster as expendables was not viable.
If post flight inspection was a fundamental requirement of human rating, and if those where the big cost of recovery, I would be tempted to think that it couldn't be lowered by bigger scale of production as easily as manufacturing. May be someone could enlighten me?Post flight inspection was never a "fundamental requirement of human rating" of a launch vehicle. In the case of the STS SRBs, they were originally designed for recovery. Analysis done after several years of flying showed that the cost of recovering and refurbishing was about the same as building new hardware for flight and had the ADDED benefit of providing an opportunity to study hardware that had flown to establish a family history(especially since the hardware in question had experienced a catostrophic failure - This was after 51L). Given that, the question of paying for redesigning and recertificating the booster as expendables was not viable.
The Shuttle uses SRB that are recoverable. The Ares I and V were to use extended versions of these SRBs. What I have been wondering is whether or not recovery of these SRB is cost effective? Are it cheaper to recover them than it is to simply use expendables, and if so how much cheaper? Lastly if it is more cost-effective than why are they not used by any other launch vehicles today?
This question has been asked before, so feel free to just give me a link if you do not want to fully explain it to me.
Recovery is not for cost but for post flight inspection.
If the flight manifest had ever achieved anywhere near the original goal of 50 flights per year, then recovery was the best option. Cheaper to refurbish a rotating set of, say, 12 booster pairs than to buy 100 of them each year. Of course, that never happened.
If post flight inspection was a fundamental requirement of human rating, and if those where the big cost of recovery, I would be tempted to think that it couldn't be lowered by bigger scale of production as easily as manufacturing. May be someone could enlighten me?
Post flight inspection was never a "fundamental requirement of human rating" of a launch vehicle.
...
If post flight inspection were a requirement of human rating, then the darn things should have been decertified in 1984! Ignoring the blowby evidence shows that that wasn't the case.
IMO, an edict from on high that never again shall solids be used in human spaceflight would be a good thing. Maybe we could get some funding for stacking the remaining casings and letting RSO have some fun on the 4th of July! :):):)
...
If post flight inspection were a requirement of human rating, then the darn things should have been decertified in 1984! Ignoring the blowby evidence shows that that wasn't the case.
IMO, an edict from on high that never again shall solids be used in human spaceflight would be a good thing. Maybe we could get some funding for stacking the remaining casings and letting RSO have some fun on the 4th of July! :):):)
You realize, of course, that the RSRMs were one of the most reliable part of the vehicle by retirement? It's really an engineering question - would you rather have a part that has less chance of failure but if it fails there are no benign modes (most catastrophic). Or, would you rather have a part that has more chance of failure but the failure modes range from benign to catastrophic. Liquids engines have many more moving parts and many more ways of failing than segmented solids.
Of course, cost factors into this discussion as well. Environmental also factors in (those who have been "lucky" enough to breathe the air around 39A/B after a launch can tell you what SRB exhaust mixed with water is like). But, a blanket statement condemming solids doesn't do anyone any good.
Andy
...
If post flight inspection were a requirement of human rating, then the darn things should have been decertified in 1984! Ignoring the blowby evidence shows that that wasn't the case.
IMO, an edict from on high that never again shall solids be used in human spaceflight would be a good thing. Maybe we could get some funding for stacking the remaining casings and letting RSO have some fun on the 4th of July! :):):)
You realize, of course, that the RSRMs were one of the most reliable part of the vehicle by retirement? It's really an engineering question - would you rather have a part that has less chance of failure but if it fails there are no benign modes (most catastrophic). Or, would you rather have a part that has more chance of failure but the failure modes range from benign to catastrophic. Liquids engines have many more moving parts and many more ways of failing than segmented solids.
Of course, cost factors into this discussion as well. Environmental also factors in (those who have been "lucky" enough to breathe the air around 39A/B after a launch can tell you what SRB exhaust mixed with water is like). But, a blanket statement condemming solids doesn't do anyone any good.
Andy
A bit sour? ;)
Liquids are proven, and can be shut down prior to failure by well designed avionics software. Solids are awesome for cargo into LEO. I just wouldn't use them for HSF. A failing solid is a bomb. A failing liquid is probably only going to send turbopump shrapnel tangentially away from its axis of rotation.
Liquids do fail benignly. They give enough notice to abort.
As for valuable technology, SRB is not, we can do without.
The rest of your points are actually in favor of liquids and especially, your use of 51-F. The engine "failure" was benign. And if there was another engine shutdown, crew loss would not be due to the engines, but to the program for not having an intact abort system.
Not sour one bit - I don't have a pony in this race.
However, you might want to go back and look at the history of liquid engine failures before stating that they fail benignly. There are many examples of one engine taking out another. Either type of engine/motor (solid or liquid) carries risk or else we would have never needed to put in many of the Shuttle contingency modes. To dismiss one type without analyzing the risk of the other is not good program management or engineering. I'd also point out that we had 5 pad aborts and 1 ATO, each of which was caused by a shutdown of an SSME (contained SSME failure - even if it was just a sensor). There were hazards with each abort but crew and vehicle survived. There was 1 failure of the SRM (prior to being redesigned) and obviously we know that result. However, the 51F ATO could have easily ended up as a loss of vehicle had a second engine also shutdown (which it came very close to doing).
There are some liquid engine failures that occur so fast that not even the best avionics can prevent the issue (such as a fuel manifold that ruptures very quickly).
Again, if you would like to dismiss an entire technology because of one (yes catastrophic) failure 25 years ago, then you're dismissing a valuable booster. Seems silly to me, but that's your choice.
Not sour one bit - I don't have a pony in this race.
However, you might want to go back and look at the history of liquid engine failures before stating that they fail benignly. There are many examples of one engine taking out another. Either type of engine/motor (solid or liquid) carries risk or else we would have never needed to put in many of the Shuttle contingency modes. To dismiss one type without analyzing the risk of the other is not good program management or engineering. I'd also point out that we had 5 pad aborts and 1 ATO, each of which was caused by a shutdown of an SSME (contained SSME failure - even if it was just a sensor). There were hazards with each abort but crew and vehicle survived. There was 1 failure of the SRM (prior to being redesigned) and obviously we know that result. However, the 51F ATO could have easily ended up as a loss of vehicle had a second engine also shutdown (which it came very close to doing).
There are some liquid engine failures that occur so fast that not even the best avionics can prevent the issue (such as a fuel manifold that ruptures very quickly).
Again, if you would like to dismiss an entire technology because of one (yes catastrophic) failure 25 years ago, then you're dismissing a valuable booster. Seems silly to me, but that's your choice.
Lol! No, I meant the booster exhaust probably tasted a bit sour! Like HCl sour.
In one of the ALT videos, the one where GPC 2 sync is lost, what is 'Go for mode 203'?
What is the distance between each "bay" of the orbiter payload bay?
What is the distance between each "bay" of the orbiter payload bay?
Why is the aft exterior of the engine compartment covered in black tiles? Does that area experience high heat on re-entry? High heat on ascent? Or is it there to accomodate an RTLS abort mode where the vehicle would fly backwards into its own exhaust for a period of time?Radiant heating from the SSMEs on ascent.
If Shuttle had a single-engine cutoff at T+325s (like the Soyuz-U today) headed to the ISS, would that have been a TAL abort?
If Shuttle had a single-engine cutoff at T+325s (like the Soyuz-U today) headed to the ISS, would that have been a TAL abort?Probably mission-dependent, situation-dependent, performance-dependent; I think that would probably be near a single-engine ATO/TAL boundary.
If Shuttle had a single-engine cutoff at T+325s (like the Soyuz-U today) headed to the ISS, would that have been a TAL abort?
How does the Orbiter compute its velocity on ascent? Is it all inertial measurement? The MECO time seems like a very precise calculation of +X velocity and desired orbital plane. I suppose you need to know your mass, thrust (acceleration) and local gravity and you compute from that. Orbital plane I suppose could be an inertial measurement if the gyro drift is small enough during ascent.
I think I might know the answer - PASS source code. Classified! :)
How does the Orbiter compute its velocity on ascent? Is it all inertial measurement? The MECO time seems like a very precise calculation of +X velocity and desired orbital plane. I suppose you need to know your mass, thrust (acceleration) and local gravity and you compute from that. Orbital plane I suppose could be an inertial measurement if the gyro drift is small enough during ascent.
I think I might know the answer - PASS source code. Classified! :)
How does the Orbiter compute its velocity on ascent? Is it all inertial measurement? The MECO time seems like a very precise calculation of +X velocity and desired orbital plane. I suppose you need to know your mass, thrust (acceleration) and local gravity and you compute from that. Orbital plane I suppose could be an inertial measurement if the gyro drift is small enough during ascent.
I think I might know the answer - PASS source code. Classified! :)
No, it is an inertial measurement like all launch vehicles.
The inertial platform is kept aligned during the countdown. Drift is not a factor for launch vehicles since the flight duration is short.
How does the Orbiter compute its velocity on ascent? Is it all inertial measurement? The MECO time seems like a very precise calculation of +X velocity and desired orbital plane. I suppose you need to know your mass, thrust (acceleration) and local gravity and you compute from that. Orbital plane I suppose could be an inertial measurement if the gyro drift is small enough during ascent.
I think I might know the answer - PASS source code. Classified! :)
No, it is an inertial measurement like all launch vehicles.
The inertial platform is kept aligned during the countdown. Drift is not a factor for launch vehicles since the flight duration is short.
Doesn't the orbiter use fiber optic gyroscopes? I've never been sure how those can drift. The mechanical gyro drift makes sense - friction will drag it ever so slightly in the direction of travel so it gradually loses its inertial frame of reference. But a laser? I know it happens, just been a while since physics! :)
STS-135's boosters were a couple of years old, right? Where are the segments stored? At KSC? How did they get to the VAB? I figure a segment has to weigh roughly 1/3 of the total, so say 400,000 lbs? I don't see rail lines leading to the VAB. And, no offense to Mike Rowe, but I don't think the F-150 is going to tow that around. :)The SRM segments are stored in the two Surge facilities north of the VAB once they have completed processing in the Rotation, Processing and Surge Facility(RPSF).
STS-135's boosters were a couple of years old, right? Where are the segments stored? At KSC? How did they get to the VAB? I figure a segment has to weigh roughly 1/3 of the total, so say 400,000 lbs? I don't see rail lines leading to the VAB. And, no offense to Mike Rowe, but I don't think the F-150 is going to tow that around. :)
STS-135's boosters were a couple of years old, right? Where are the segments stored? At KSC? How did they get to the VAB? I figure a segment has to weigh roughly 1/3 of the total, so say 400,000 lbs? I don't see rail lines leading to the VAB. And, no offense to Mike Rowe, but I don't think the F-150 is going to tow that around. :)The SRM segments are stored in the two Surge facilities north of the VAB once they have completed processing in the Rotation, Processing and Surge Facility(RPSF).
This photo shows right aft segment for STS-121 being transported from one of the Surge facilities to the VAB for stacking: http://www-pao.ksc.nasa.gov/kscpao/images/large/06pd0108.jpg
The other surge building is to the left, above the "A" and the RPSF is to the left, above "Launcher Road"
1. Got it. So you can have 4 boosters (2 pair) on site at once?
2. The RPSF has the rail lines running through it, right? What work gets done at KSC versus elsewhere? Elsewhere was out west, wasn't it?
Two linguistic questions...
1)What is the actual definition of the term "close-out"? Does it refer to the final preparations done in a specific part of the orbiter (e.g. aft or crew compartment) before it is closed for flight?
2)Why are key members of the launch team called "test conductors" even though they do a lot more than just supervising tests?
Thanks!
Two linguistic questions...
1)What is the actual definition of the term "close-out"? Does it refer to the final preparations done in a specific part of the orbiter (e.g. aft or crew compartment) before it is closed for flight?
2)Why are key members of the launch team called "test conductors" even though they do a lot more than just supervising tests?
Thanks!
In addition "close out" also refers to the fact that there is no more access allowed to that system or area. For instance, the close out procedure for the orbiters wings include placing kapton tape strips across the access openings in the wing spars so that no one can crawl thru them without removing the tape. That way, they know that nothing in there has changed on launch day.Two linguistic questions...1. Essentially, that is the correct definition
1)What is the actual definition of the term "close-out"? Does it refer to the final preparations done in a specific part of the orbiter (e.g. aft or crew compartment) before it is closed for flight?
If I understand correctly, the Shuttle had an autoland system that was meant to be tested on STS53, but wasn't. Was it ever used?
If I understand correctly, the Shuttle had an autoland system that was meant to be tested on STS53, but wasn't. Was it ever used?
Oh cool! I didn't realize SAIL still existed. What is its fate post-SSP?
If I understand correctly, the Shuttle had an autoland system that was meant to be tested on STS53, but wasn't. Was it ever used?
I almost wanted to write, "yes, every flight", since every flight the autoland was run in SAIL (OV-095) and the other simulators.
If I understand correctly, the Shuttle had an autoland system that was meant to be tested on STS53, but wasn't. Was it ever used?
I almost wanted to write, "yes, every flight", since every flight the autoland was run in SAIL (OV-095) and the other simulators.
I was tempted to write the same thing for a different reason - autoland guidance was used to drive the HUD flight director symbol and the ADI error needles, even when the DAP was in CSS and the crew was manually flying.
I almost wanted to write, "yes, every flight", since every flight the autoland was run in SAIL (OV-095) and the other simulators.
Hi all. A question about the AHMS. I was wondering why it came up on line so late in the program (STS-118 in active mode on all 2 SSMEs)? It seems it was a quite important piece of equipment for the safety of the engines, so why so late.
I was reading an interview with George Hopson from the JSC oral history project and he says that the reason for developping the AHMS was that the previous engine controller wasn't able to tell apart noise (not acustic but the electric noise in the wires) from the real patter of the pump vibrations and therefore was it be in active mode we would have seen many engines shut down during ascent. For this reason the control on the vibrations was never flown in active mode. So once again I'm wondering why they didn't solve this problem earlier?
thanks
Davide
So once again I'm wondering why they didn't solve this problem earlier?
What was the system looking for? Changes in vibrational frequencies of the pumps?
The AHMS [advanced health management system], the big difference between it and the first vibration shut down system was that the first system used composite vibration. In other words the old system used the whole spectrum of frequencies, so any noise was considered along with real vibration. The AHMS only considered synchronous vibration. The pump turns X number of rpm [revolutions per minute]. If you have a vibration that matches the speed that the pump is turning, then that’s synchronous. And if it’s synchronous it’s real.
Hi all.
I was reading that the guidance during the first part of the ascent (up to SRM sep) is open loop. The guidance has in its memory a pre loaded set of attitude positions the orbiter has to have when it reaches a given velocity.
I was wondering why is the guidance control logic up to SRM sep, open loop type? This exclude the possibility to correct any large deviations from a nominal attitude due to some for example some strong gust of wind. Since up to SRB sep the shuttle is still in the lower portion of the atmosphere where the winds are stronger, it would have made sense to use a closed-loop control logic. What have I missed?
thanks
Davide
In first stage there is also feedback from the lateral accelerometers that react to off nominal winds. So there is a response to winds in first stage
This exclude the possibility to correct any large deviations from a nominal attitude due to some for example some strong gust of wind.
Hi all.
I was reading that the guidance during the first part of the ascent (up to SRM sep) is open loop. The guidance has in its memory a pre loaded set of attitude positions the orbiter has to have when it reaches a given velocity.
I was wondering why is the guidance control logic up to SRM sep, open loop type? This exclude the possibility to correct any large deviations from a nominal attitude due to some for example some strong gust of wind. Since up to SRB sep the shuttle is still in the lower portion of the atmosphere where the winds are stronger, it would have made sense to use a closed-loop control logic. What have I missed?
thanks
Davide
But it is safe not being able to make corrections due to winds up to SRB sep? which is the reason for having chosen to adopt this kind of guidance?
QuoteIn first stage there is also feedback from the lateral accelerometers that react to off nominal winds. So there is a response to winds in first stage
but how this information is put into the open loop? if you have this kind of feedback the guidance is not anymore open loop.
QuoteIn first stage there is also feedback from the lateral accelerometers that react to off nominal winds. So there is a response to winds in first stage
but how this information is put into the open loop? if you have this kind of feedback the guidance is not anymore open loop.
Then I guess guidance is not 100% open loop.
But it is safe not being able to make corrections due to winds up to SRB sep? which is the reason for having chosen to adopt this kind of guidance?
From that paper it looks as if open-loop means they are sticking to a fixed velocity-attitude profile that is unaffected by previous deviations, not that there is no feedback at all. Inside that open-loop profile there is apparently another control system that does use feedback. Otherwise you wouldn't need sensors and they'd be playing back actuator commands. As I understand it, PEG does find the best way to get to the desired final conditions based on the current conditions, not on the conditions in the reference profile at the same point in time. In other words open-loop guidance uses feedback to steer the vehicle towards a reference velocity-attitude profile whereas PEG uses feedback to steer it towards the desired final conditions.That is my understanding of ascent guidance.
Most launch vehicles use open loop for their lower stages.
but exactly how are the elevons moved? My guess is that they are moved in order to reduce the lift created on the wings but I'm not sure.
Pre-loaded and purely for load relief (no steering) and prior to max-q.
Andy
but exactly how are the elevons moved? My guess is that they are moved in order to reduce the lift created on the wings but I'm not sure.
The angle of attack vs altitude is known, so the elevons are moved to reduce the loads. The AOA is negative so it is actually a down force on the wings that they are trying to reduce.
It's closed loop at least in the sense that it only happens if needed. I'm looking at an MMT pitch from STS-130 (the ascent performance quick-look) and it states "no elevon load relief". From what I remember the 2 big things that could change in real time were presence/absence of load relief and the throttle bucket settings. I remember the throttle bucket changing a few times but I never remember load relief happening.
Quote from: Specifically ImpulsiveIt's closed loop at least in the sense that it only happens if needed. I'm looking at an MMT pitch from STS-130 (the ascent performance quick-look) and it states "no elevon load relief". From what I remember the 2 big things that could change in real time were presence/absence of load relief and the throttle bucket settings. I remember the throttle bucket changing a few times but I never remember load relief happening.
very interesting...what do you mean for throttle buckt changing? The throttling was always done isn't?
where can I find these performance quick-looks?
Davide
Hi all.
Again another question about the ascent. Before STA-87, the orbiter didn't perform the roll head up towards the end of the ascent. So I was the maneuver for ET sep?
being in an head-down attitude, how could the orbiter avoid colliding with the ET that was just "over" it?
Ah, so that was "Go for the plus x" -- positioning for ET photos.
And "Go for the pitch?"
Hi all.
Again another question about the ascent. Before STA-87, the orbiter didn't perform the roll head up towards the end of the ascent. So I was the maneuver for ET sep?
Same maneuver, 4 fps -Z RCS with an optional +X RCS for ET photography.Quotebeing in an head-down attitude, how could the orbiter avoid colliding with the ET that was just "over" it?
The orbiter is no more likely to collide with the ET in a heads-down vs a heads-up orientation.
Is there any impulse provided for ET sep, or is the RCS required to perform the separation? In other words, does residual tank pressure or something similar serve to "pop" it loose once the disconnect is made?
Is there any impulse provided for ET sep, or is the RCS required to perform the separation? In other words, does residual tank pressure or something similar serve to "pop" it loose once the disconnect is made?
Quote from: wolfpack link=topic=17437.msg803833#msg803833
Is there any impulse provided for ET sep, or is the RCS required to perform the separation? In other words, does residual tank pressure or something similar serve to "pop" it loose once the disconnect is made?
The jets were used. Residual pressure in the feedlines would have been bad, leading to a pitching moment on the tank while it was in close proximity to the orbiter. In fact, if the valves isolating the orbiter from the tank did not all indicate closed, the separation was inhibited until enough time had passed for the tank to vent down.
Including the ribs and radiator panels, how thick are the PLBDs(average thickness if the thickness is not uniform)?
Interesting paper on the ascent loads relief discussed earlier...
http://www.aiaa.org/pdf/industry/Why_the_Wings_Stay_On.pdf
very interesting paper indeed...thanks very much...but just out of curiosity: how did you find it? if I just use the following addresss www.aiaa.org/pdf (http://www.aiaa.org/pdf) I can't get any access. Are there papers from AIAA freely available?
now the question of the day: for the ascent the pilots can see the information regarding the progress of the ascent on three different displays, which are ASCENT TRJ 1 (used up to SRB sep), ASCENT TRJ 2 (used up to ET sep) and ASCENT TRJ (it displays the whole ascent). This is at least what I've understood from what I've been reading lately. My question is: when the ASCENT TRJ is used? Also are the ASCENT TRJ 1 and 2 generated by the PASS or by the BFS?
OI-32 is indeed Operational Increment but it wasn't the 32nd version of the flight software. We skipped numbers (some were "test" OIs) and also occasionally used a letter after the OI number (OI-26B for instance). However the final OI was OI-34.
OI-32 is indeed Operational Increment but it wasn't the 32nd version of the flight software. We skipped numbers (some were "test" OIs) and also occasionally used a letter after the OI number (OI-26B for instance). However the final OI was OI-34.
There was also a wholesale change in the numbering philosophy with, I think, OI-8D giving way directly to OI-20.
Whats the maximum length of time that the SRB retrieval ships can stay at sea for?
I suspect the crew compliment would have a lot to do with sea-time.
Andy
I suspect the crew compliment would have a lot to do with sea-time.
Andy
<Captain> Crew, you're a very nice crew. It's a pleasure to work with you!
<Crew> Captain - thanks for the compliment! We'll stay out another month with you for those nice words!
;D
the Bob Biggs book on the SSME
Do you have a citation or link for this book, Wepush?
the Bob Biggs book on the SSME
Do you have a citation or link for this book, Wepush?
the Bob Biggs book on the SSME
Space Shuttle Main Engine
The First Ten Years
by Robert E. Biggs
http://www.enginehistory.org/ssme.shtml (http://www.enginehistory.org/ssme.shtml)
Why were the sunshades on the early program Hughes sat deploys open before payload bay door opening?
2 questions:
1) Did any payload ever use the full length of the payload bay?
2) Why was parallel staging used? Wouldn't it have been more efficient to use series staging so the 2nd stage tank would have been smaller/lighter and a lot of weight could be jettisoned with the first stage separation? Wouldn't it have eliminated the need for SRBs if you had just a normal liquid first stage. Probably would have looked wierd since you'd have the orbiter side mounted to a smaller ET sitting on top of a first stage.
2 questions:
1) Did any payload ever use the full length of the payload bay?
2) Why was parallel staging used? Wouldn't it have been more efficient to use series staging so the 2nd stage tank would have been smaller/lighter and a lot of weight could be jettisoned with the first stage separation? Wouldn't it have eliminated the need for SRBs if you had just a normal liquid first stage. Probably would have looked wierd since you'd have the orbiter side mounted to a smaller ET sitting on top of a first stage.
1. See AXAF
2. No quick answer. See history of shuttle documents or books.
Were the STA aircraft controlled by something like the Shuttle's DPS? Or were the avionics for them completely different?
Thanks,
2 questions:
1) Did any payload ever use the full length of the payload bay?
2) Why was parallel staging used? Wouldn't it have been more efficient to use series staging so the 2nd stage tank would have been smaller/lighter and a lot of weight could be jettisoned with the first stage separation? Wouldn't it have eliminated the need for SRBs if you had just a normal liquid first stage. Probably would have looked wierd since you'd have the orbiter side mounted to a smaller ET sitting on top of a first stage.
AXAF isn't a bad answer, but there were still some clearances needed for launch vibrations and thermal expansion. This amounted to a few inches.
Some of the Spacelab flights, if you include the tunnel to Spacelab
Some of the Spacelab flights, if you include the tunnel to Spacelab
The tunnel was only there to move the Spacelab to the back of the payload bay for CG considerations. It wasn't a requirement of the payload.
Some of the Spacelab flights, if you include the tunnel to Spacelab
The tunnel was only there to move the Spacelab to the back of the payload bay for CG considerations. It wasn't a requirement of the payload.
No tunnel, no Spacelab (the tunnel also included the Spacelab EVA airlock hatch). *If* the tunnel was chargable to the payload then it was considered payload. Now, I just have to find out whether it was charged to payload or not.
Are you suggesting there was a huge DOD payload?AXAF isn't a bad answer, but there were still some clearances needed for launch vibrations and thermal expansion. This amounted to a few inches.It was the only one I could give on this forum.
As for clearances, that was already accounted for in the 15' dia and 60" length.
AXAF isn't a bad answer, but there were still some clearances needed for launch vibrations and thermal expansion. This amounted to a few inches.
As for clearances, that was already accounted for in the 15' dia and 60" length.
What will NASA do with the Gulfstream Shuttle Training aircraft now? Its not like its fitted to be used as a regular plane especially with one side of the cockpit a replica shuttle cockpit
What will NASA do with the Gulfstream Shuttle Training aircraft now? Its not like its fitted to be used as a regular plane especially with one side of the cockpit a replica shuttle cockpit
sent to museums
Hi all.
a question about re-entry. I was wondering if for re-entry there was something similar to DOLILU. I mean, before giving the go no go for deorbit burn, is there anybody designing (or optimizing) the re-entry trajectory based on the wind profile at the landing location? Something similar to what the DOLILU group did but done for re-entry rather then for the ascent.
Thanks
Davide
Anyone have any information on the velocities when the plasma begins to show and fade during entry?
How is the maneuver to entry attitude accomplished? Through ITEM 27 on MM303?
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
On page 3-14 of the Entry FDF it mentions the De-orbit burn cue card. Where can one find this cue card?
Thanks. Another that has had me looking for ages now: The FDF/page that lists the camera pan/tilt angles used for elevon viewing during FCS C/O.On page 3-14 of the Entry FDF it mentions the De-orbit burn cue card. Where can one find this cue card?
Page CC 8-8.
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
No, Spacelabs like Spacelab 2 were astronomy releated and had strict pointing requirements. Usually microgravity experiments were gravity gradient. Thermal requirements could have also been a reason for not using gravity gradient.
Andy
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
No, Spacelabs like Spacelab 2 were astronomy releated and had strict pointing requirements. Usually microgravity experiments were gravity gradient. Thermal requirements could have also been a reason for not using gravity gradient.
Andy
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
No, Spacelabs like Spacelab 2 were astronomy releated and had strict pointing requirements. Usually microgravity experiments were gravity gradient. Thermal requirements could have also been a reason for not using gravity gradient.
Andy
How accurate was the pointing capability of the Shuttle, and how frequent were the thruster firings to accomplish it?
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
No, Spacelabs like Spacelab 2 were astronomy releated and had strict pointing requirements. Usually microgravity experiments were gravity gradient. Thermal requirements could have also been a reason for not using gravity gradient.
Andy
How accurate was the pointing capability of the Shuttle, and how frequent were the thruster firings to accomplish it?
There's really multiple parts to the first question. First, how accurate was the shuttle's attitude determination? The shuttle used IMUs to maintain its attitude reference, and the IMU platforms slowly drifted over time. Flight Rules required the IMU misalignment be maintained <0.5 deg for safe entry, so to protect for extended loss of comm, an IMU alignment would be performed if the misalignment exceeded 0.25 deg. This was done using the star trackers. The star trackers were accurate within 1-2 hundredths of a degree. The original KT-70 IMUs required alignment about every 12 hours. The HAINS IMUs used at the end of the program could go 48 hours between alignments, and sometimes as much as 96.
Second, how precisely could the shuttle hold attitude? This was a function of the attitude deadband setting in the digital autopilot (DAP). Minimum attitude deadband was 0.033 deg using the vernier RCS thrusters. 0.5 deg for primary RCS, I think.
Obviously there is no simple answer to your second question; thruster firing frequency depended on the deadband width, which thrusters were used, and the environmental torques acting on the vehicle (which in turn were a function of attitude, mass properties, and altitude).
Quick question re: orbiter attitude, was the gravity gradient attitude SOP for all Spacelab/Spacehab research flights?
No, Spacelabs like Spacelab 2 were astronomy releated and had strict pointing requirements. Usually microgravity experiments were gravity gradient. Thermal requirements could have also been a reason for not using gravity gradient.
Andy
How accurate was the pointing capability of the Shuttle, and how frequent were the thruster firings to accomplish it?
There's really multiple parts to the first question. First, how accurate was the shuttle's attitude determination? The shuttle used IMUs to maintain its attitude reference, and the IMU platforms slowly drifted over time. Flight Rules required the IMU misalignment be maintained <0.5 deg for safe entry, so to protect for extended loss of comm, an IMU alignment would be performed if the misalignment exceeded 0.25 deg. This was done using the star trackers. The star trackers were accurate within 1-2 hundredths of a degree. The original KT-70 IMUs required alignment about every 12 hours. The HAINS IMUs used at the end of the program could go 48 hours between alignments, and sometimes as much as 96.
Second, how precisely could the shuttle hold attitude? This was a function of the attitude deadband setting in the digital autopilot (DAP). Minimum attitude deadband was 0.033 deg using the vernier RCS thrusters. 0.5 deg for primary RCS, I think.
Obviously there is no simple answer to your second question; thruster firing frequency depended on the deadband width, which thrusters were used, and the environmental torques acting on the vehicle (which in turn were a function of attitude, mass properties, and altitude).
Excellent answer - the only thing I'd add is that if you made the deadband tighter, you would use more propellant. So, there was a tradeoff for keeping the deadband too tight. Also if you were running microgravity experiments, you might want a wider deadband to minimize the microgravity-disturbing jet firings.
Andy
I guess that's one of the things I was getting at - Station uses CMGs to both keep precise pointing as well as microgravity. Shuttle doesn't have those, so could you do both astronomy-related experiments and microgravity work at the same time? Or would all the microgravity stuff have to wait until periods of free drift?
Does anyone notice a difference in the appearance of the plume of STS 129's launch.
In this view from the VAB roof, it seems that the shuttles exhaust sort of curves to the north before straightening out (26 to 30 seconds into the video).
Anyone know if the wind was blowing from the south?
See clip: http://www.youtube.com/watch?v=3siNkZu7VNE&feature=related
Andy, I was referring to the plume created by the SRB's.
If you look at the video between 25 and 30 seconds in, you will see that the plume is not vertical as it appears in all othe shuttle launches...it actually curves to the north (left) and then straightens out.
Where exactly does the ET bipod attach the orbiter? The aft attachments are with the fuel and oxidizer feedlines, which have umbilical doors. Where was the forward one, and how was it protected thermally? I don't remember ever seeing another door near the nose gear.
Where exactly does the ET bipod attach the orbiter? The aft attachments are with the fuel and oxidizer feedlines, which have umbilical doors. Where was the forward one, and how was it protected thermally? I don't remember ever seeing another door near the nose gear.
It is below the "skinline" of the TPS. It is just a "hole" for a stud to pass through.
Does anyone know how many degrees the orbiter Ku band DA rotates around its hinge attachment to the payload bay to the deployed position?
Does anyone know how many degrees the orbiter Ku band DA rotates around its hinge attachment to the payload bay to the deployed position?
Does anyone know how many degrees the orbiter Ku band DA rotates around its hinge attachment to the payload bay to the deployed position?
I may not be clear on exactly what you are asking but a quick look in the KU Ops Workbook shows 113 degrees to the deployed state. Should also be a diagram in the SCOM if you don't have a copy of that workbook
Mark Kirkman
Yes, I have seen that figure but it is measured from alpha gimbal-stowed to alpha gimbal-deployed, not around the hinge itself, which is what I'm looking for.Does anyone know how many degrees the orbiter Ku band DA rotates around its hinge attachment to the payload bay to the deployed position?
I may not be clear on exactly what you are asking but a quick look in the KU Ops Workbook shows 113 degrees to the deployed state. Should also be a diagram in the SCOM if you don't have a copy of that workbook
Mark Kirkman
Yes, I have seen that figure but it is measured from alpha gimbal-stowed to alpha gimbal-deployed, not around the hinge itself, which is what I'm looking for.Does anyone know how many degrees the orbiter Ku band DA rotates around its hinge attachment to the payload bay to the deployed position?
I may not be clear on exactly what you are asking but a quick look in the KU Ops Workbook shows 113 degrees to the deployed state. Should also be a diagram in the SCOM if you don't have a copy of that workbook
Mark Kirkman
(13 March 1987) --- The Space Shuttle Atlantis is transferred from the giant Vehicle Assembly Building's high bay 1 to high bay 3 as preparations for de-stacking of the orbiter begin. The orbited will be separated from its solid rocket boosters and external fuel tank before being taken to the Orbiter Processing Facility. Once there, it will begin an extended processing flow to undergo return-to-flight modifications and other preparations for the STS-27 mission next year.
Why is Atlantis stacked in this shot during 1987 without SSME's?This was during the stand down after Challenger. They had stacked the orbiter and rolled it out to 39B to fit check the new weather protection system that had been installed and do some tests of the emergency egress procedures.
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-27/html/s87-31470.htmlQuote(13 March 1987) --- The Space Shuttle Atlantis is transferred from the giant Vehicle Assembly Building's high bay 1 to high bay 3 as preparations for de-stacking of the orbiter begin. The orbited will be separated from its solid rocket boosters and external fuel tank before being taken to the Orbiter Processing Facility. Once there, it will begin an extended processing flow to undergo return-to-flight modifications and other preparations for the STS-27 mission next year.
got a picture of it at pad 39-B?
The Space Shuttle Atlantis is rolled out to Launch Pad 39-B in the early morning of Oct. 9, 1986. Atlantis is scheduled to remain at Pad B for seven weeks where it will support checkout of new weather protection structures, a variety of special measurements, launch team proficiency exercises and emergency egress simulations. The 4.2 mile journey from the Vehicle Assembly Building to the launch pad is the first for the shuttle fleet since the Space Shuttle Challenger accident in January of this year.
Folks, I'm looking for the start and stop times for STS-57's single EVA. I know the total elapsed time was 5 hours, 50 minutes, but I cannot for the life of me find when it started or stopped (GMT or MET). Thanks!
Folks, I'm looking for the start and stop times for STS-57's single EVA. I know the total elapsed time was 5 hours, 50 minutes, but I cannot for the life of me find when it started or stopped (GMT or MET). Thanks!
Started EVA at 3:23:59:51 MET
Why is Atlantis stacked in this shot during 1987 without SSME's?
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-27/html/s87-31470.htmlQuote(13 March 1987) --- The Space Shuttle Atlantis is transferred from the giant Vehicle Assembly Building's high bay 1 to high bay 3 as preparations for de-stacking of the orbiter begin. The orbited will be separated from its solid rocket boosters and external fuel tank before being taken to the Orbiter Processing Facility. Once there, it will begin an extended processing flow to undergo return-to-flight modifications and other preparations for the STS-27 mission next year.
Hi all.
this kind I have kind of "silly" question. I find quite curiuos the software for the shuttle was written in a language called HAL/S running on IBM computers. As it's known HAL is the name of the computer on 2001: A Space Odyssey and it's an implict reference to IBM (every letter in HAL is the letter soon after each letter in IBM).
I'd like to know is there is any particular reason for which language for the shuttle software was named HAL.
Hi all.
this kind I have kind of "silly" question. I find quite curiuos the software for the shuttle was written in a language called HAL/S running on IBM computers. As it's known HAL is the name of the computer on 2001: A Space Odyssey and it's an implict reference to IBM (every letter in HAL is the letter soon after each letter in IBM).
I'd like to know is there is any particular reason for which language for the shuttle software was named HAL.
Thanks very much
Davide
Hi all.
this kind I have kind of "silly" question. I find quite curiuos the software for the shuttle was written in a language called HAL/S running on IBM computers. As it's known HAL is the name of the computer on 2001: A Space Odyssey and it's an implict reference to IBM (every letter in HAL is the letter soon after each letter in IBM).
I'd like to know is there is any particular reason for which language for the shuttle software was named HAL.
Thanks very much
Davide
Regarding your "implicit reference to IBM" statement. Quickly off-topic, but both Kubrick and Clarke, before they passed on, said that in creating the HAL acronym, such a relationship never occurred to them, and that it was purely coincidental.
Hi all.
this kind I have kind of "silly" question. I find quite curiuos the software for the shuttle was written in a language called HAL/S running on IBM computers. As it's known HAL is the name of the computer on 2001: A Space Odyssey and it's an implict reference to IBM (every letter in HAL is the letter soon after each letter in IBM).
I'd like to know is there is any particular reason for which language for the shuttle software was named HAL.
Thanks very much
Davide
So here are a couple of questions for all you rocketeers out there:
2/ The Shuttle's SRBs/SRMs were shortly after STS-1 (and before STS-51L) to reduce weight and improve performance. What mods were made? Does anyone have references?
v/r,
F=ma
I did mean the early, pre-Challenger SRB mods. I seem to recall reading somewhere that these 2nd-gen shell walls were ~0.45 inches thick, vs the original 0.50 inches.
From http://choo.fis.utoronto.ca/FIS/Courses/LIS2102/DM.case.html (http://choo.fis.utoronto.ca/FIS/Courses/LIS2102/DM.case.html):
During 1983, the SRBs were modified to use thinner walls, narrower nozzles, and more powerful fuel..."
During STS-135, GLS and OTC were both female...however, in years past, they voices always sounded the same to me, so I thought it was one person....However, for 135, it was obviously two different females. Anyone know who CGLS and the OTC were for STS-135. I am assuming it was Roberta Wyrick as OTC.Different positions, never one person. Ms. Wyrick was OTC and Janine Pape was GLS; both were noted in the launch day thread.
Hi all.
Question on the avionics system. I understand the way in which the redundant set works, however I don't understand if in case of need, both ascent and reentry could be flown with just one GPC in GNC mode running PASS.
Obviously with just on GPC you loose all the FO/FS condition, but would it be theoretically possible flying with just one GPCs? My guess is no, is not possible. Since you should have at least two GPCs for commanding two different strings, otherwise maneuvering with the RCS wouldn't be possible (for example).
which are your thoughts?
thanks
Davide
Hi everyone, quick question regarding SSMEs - I've read that they are referred to from an engineering standpoint mostly as RS-25 engines, but that RS-24 is an alternate designation - is this correct, and, if so, what is the difference between the two models, please?
In addition, I'm aware that the last half or so of the programme used Block II engines, but were the preceding models all Block I standard or were there other variants thereof?
Finally, I've seen the SLS engines being referred to as RS-25D/E - does this mean that they are RS-25D and RS-25E and there is a distinction between the two, or simply that the SLS engines are actually designated as D/E variants?
Many thanks in advance!
Hi all.
Question on the avionics system. I understand the way in which the redundant set works, however I don't understand if in case of need, both ascent and reentry could be flown with just one GPC in GNC mode running PASS.
Obviously with just on GPC you loose all the FO/FS condition, but would it be theoretically possible flying with just one GPCs? My guess is no, is not possible. Since you should have at least two GPCs for commanding two different strings, otherwise maneuvering with the RCS wouldn't be possible (for example).
which are your thoughts?
thanks
Davide
any idea which of them is 51L by any chance?
Ah, fair enough, thanks - any idea which of them is 51L by any chance?
RS-25D is what they have sitting in a building now at KSC since they've gutted the Orbiter's MPS for SLS. There are something like 15 of them IIRC.
Also, yes, there are 15 SSMEs sitting at KSC now.
Also, yes, there are 15 SSMEs sitting at KSC now.
Which are those? I can count only 14 on P&W's chart?
http://collectspace.com/review/sts133_ssmechart-lg.jpg
Also, yes, there are 15 SSMEs sitting at KSC now.
Which are those? I can count only 14 on P&W's chart?
http://collectspace.com/review/sts133_ssmechart-lg.jpg (http://collectspace.com/review/sts133_ssmechart-lg.jpg)
I believe P&W produced a spare SSME (s/n 2062) some time around 2009, which was never intended to be used on the last shuttle missions.
By the way folks, further to my earlier question about RS-24/25, does anyone know what exactly an RS-24 is? Thanks.
Two (rather different) possibilities:
http://en.wikipedia.org/wiki/RS-24
http://en.wikipedia.org/wiki/Space_Shuttle_main_engine
:D
It is for Wikipedia that Colds7ream needs the info so I don't think that's a good source ;)
What's the long-term plan for archival of all the Shuttle program electronic documentation and software? Is it going to be accessible for FOIA requests, etc. in the future? (For the stuff that isn't ITAR'd, of course.) Is the archival plan different for different centers/projects/offices/contracts, or is there going to be one massive set of tapes labeled "Shuttle" somewhere?
What's the long-term plan for archival of all the Shuttle program electronic documentation and software? Is it going to be accessible for FOIA requests, etc. in the future? (For the stuff that isn't ITAR'd, of course.) Is the archival plan different for different centers/projects/offices/contracts, or is there going to be one massive set of tapes labeled "Shuttle" somewhere?
Also slightly related, was the OPAD system ever flown?
HELP!!
There is either a post launch or post landing news conference in which Mike Moses comments that "it is easy to go high and easy to go fast, it is hard to go high AND fast".
He makes this comment when answering a question about how private industry will look to experienced NASA engineers to solve the commercial human spaceflight puzzle.
Does anyone know which news conference that was. Like I said, it was either a post launch or post landing...I just don't know which and I don't know what mission it was on.
Any help would be GREATLY appreciated!!!!
Thanks!!!
Jeff
It seems every Shuttle maneuver resulted in "good burn, no trim required"...at least over the last 20-plus missions. Were there burns which weren't good and did require trim?
If so, how was this done?
What would cause a deficient burn?
Dennis Jenkins has an excellent table on page 300 of the 1997 edition of "Space Shuttle - The History of Developing the NSTS".
The 25th Space Shuttle flight was STS-33 at KSC and STS-51L elsewhere
The 18th Space Shuttle flight was STS-25 at KSC and STS-51G elsewhere
Andy
Any chance you could post those mission designations?
I'd heard STS-51L was STS-33 internally.. was there a STS-22?
Was their ever any planning EARLY in the program (pre 51-L) to have simultaneous shuttle missions (ie - two orbiters, maybe practicing rendevous maneuvers)? Or would that have been overload for MCC in Houston? I know post STS-107 there were the STS-3XX contingency missions - that's not what I'm thinking about.
Payload schedule question
The X-37 was scheduled to fly inside the payload bay of STS-120. This is schedule was back in 2001. What file name should I be looking for back from 2001 with this schedule? Each piece of the puzzle pulls more files and details of the program. Is there a program code for this payload that I might track and follow the history up to the cancellation?
Payload schedule question
The X-37 was scheduled to fly inside the payload bay of STS-120. This is schedule was back in 2001. What file name should I be looking for back from 2001 with this schedule? Each piece of the puzzle pulls more files and details of the program. Is there a program code for this payload that I might track and follow the history up to the cancellation?
I just saw and read in the KSC Media Gallery that Atlantis's robot arm will be eventually used in future spaceflights.The operative word in the Media Gallery captions was "possible," which means that while the hardware will be protected/preserved, presumably there are no definite (funded) plans to fly it again right now.
What could the shuttle's RMS be used for without the shuttle?
I may be remembering it wrong, but I seem to recall hearing that the roll rate for the roll program after liftoff changed (increased) beginning with STS-9 (first high-inclination mission)...anyone know what the roll rates were before and after? (And did they change again?)
Thanks.
(Sorry if repeating this.)
I all.
I'm getting a bit confused: what's the purpurse of the C&W system when both PASS and SM have fauld detection alarm capabilities? is the C&W something "embedded" in PASS and SM or it is something on its own? If I understand well the C&W system is separated from both PASS and SM.
Thanks a mil
Davide
Also remember SM is part of PASS (SM OPS 2, for instance). PASS and BFS had separate SM functions. But fault detection and annunciation were part of GN&C as well (SSME failures came from GN&C).
What could have been done in a scenario where the ET failed to separate? Would it be possible to extend the OMS burn and carry it into some sort of stable(ish) orbit, thus buying time to work the problem? Did crews train for that sort of thing?
Quote from: alk3997Also remember SM is part of PASS (SM OPS 2, for instance). PASS and BFS had separate SM functions. But fault detection and annunciation were part of GN&C as well (SSME failures came from GN&C).
Hi Andy! thanks for the clarification...I tripped my fingers on the keyboard ;D I meant SM and GNC.
I was reading on the SCOM the chapter about the C/W system and I think that now I've got how the whole thing works. Basically there are paramenters that are controlled by hardware only and in case of limit violation, the alarm goes off (like for Class 1 and Class 2 Primary alarms).
Class 2 primary alarms are shown on the C/W annunciation matrix on panel F7 along with aural warnings. The parameters that drive the matrix are 120 and can be set/read via manual inputs on panel R13U.
Class 2 backup alarms are instead triggered by SM software computations but are shown an dedicated display page on the MEDS monitors, and the parameters controlling the alarms can be set/read via SPEC 60 SM TABLE MAINTENANCE page. Regarding these last types of alarms what it gets me a bit confused is the word backup. Why is it called backup? I mean if I've understood well this type of alarms are triggered only by computations of the SM software and don't involve the same parameters that trigger the matrix on panel F7.
Basically it seems to me that the for Class 2 primary and backup alarms there are two different sets of parameters. Especially considering that the Class 2 backup alarms involves also violations of limits from GNC.
Furthermore it looks to me that the paramaters controlling the Class 2 backup alarms can be modified more deeply that the parameters for Class 2 primary alarms.
So bottom line my question is: why Class 2 backup alarms are called "backup"? Backup seems something that is there in case of primary system fails, but in this instance it looks to me that these alarms are quite complementary of Class 2 Primary ones. I mean it seems to me that Class 2 primary and backup alarms go side by side rather then as a emergency plan in case the primary fails.
Where am I right and where wrong?
Thanks very much
Davide
What could have been done in a scenario where the ET failed to separate? Would it be possible to extend the OMS burn and carry it into some sort of stable(ish) orbit, thus buying time to work the problem? Did crews train for that sort of thing?
What could have been done in a scenario where the ET failed to separate? Would it be possible to extend the OMS burn and carry it into some sort of stable(ish) orbit, thus buying time to work the problem? Did crews train for that sort of thing?
Let see...a dry external tank was about 58,000 lbs. So this would be the equivalent of hanging a 58,000 lbs payload over the black-side of the orbiter. The mass would have been well-off the normal cg and been about 1/4 to 1/5 of the total system mass, so I doubt the OMS would have been able to burn optimally.
I'd have to work out how much orbital improvement 23,000 lbs of OMS would have provided with 58,000 lbs of additional mass. Off the top of my head, even if you could get into orbit, you would not have enough to get back out of orbit. That assumes the cg could even be managed. Also the tank would still have residual propellant in it, so the weight figure I used was probably too low, anyway.
Andy
What could have been done in a scenario where the ET failed to separate? Would it be possible to extend the OMS burn and carry it into some sort of stable(ish) orbit, thus buying time to work the problem? Did crews train for that sort of thing?
Let see...a dry external tank was about 58,000 lbs. So this would be the equivalent of hanging a 58,000 lbs payload over the black-side of the orbiter. The mass would have been well-off the normal cg and been about 1/4 to 1/5 of the total system mass, so I doubt the OMS would have been able to burn optimally.
I'd have to work out how much orbital improvement 23,000 lbs of OMS would have provided with 58,000 lbs of additional mass. Off the top of my head, even if you could get into orbit, you would not have enough to get back out of orbit. That assumes the cg could even be managed. Also the tank would still have residual propellant in it, so the weight figure I used was probably too low, anyway.
Andy
Realistically, this scenario is very remote probability due to the high reliability of the pyros and multiple redundancy. There were no published procedures for it, nor any crew training, nor (to my knowledge) did we ever sim it. Therefore what follows is just informed speculation on my part on what would have been *tried* had this happened.
I'd expect them to go ahead and attempt OMS-2 to buy time. I'd expect high RCS activity during OMS burns due to not being able to trim the OMS gimbals through the c.g.. Probably not much that could be done about it for OMS-2. Once in OPS2, I'd expect GNC to develop and uplink a DAP mass properties update which would improve control response a bit, but attitude control would still be sloppy (and involve high RCS usage).
(If this were to happen on a Hubble mission the crew would be hozed already since OMS-2 nominally uses half the OMS prop and deorbit uses the other half. The higher usage for OMS-2 with the ET attached alone would preclude deorbit. And of course they could not reach ISS.)
I'd expect the flight control team to conclude that a standalone EVA would be highly unlikely to fix the problem and that the only hope for the crew would be safe haven at ISS. In this scenario the orbiter is written off anyway, so the fact that there wouldn't be enough prop for deorbit is not a showstopper.
The big challenge would be prox ops and docking to ISS, since the off-center c.g. would cause increased cross-coupling from translational firings. Control would be sloppy, perhaps to the point of being uncontrollable, and both RCS usage and plume impingement loads on ISS would be increased. In particular, +/-Y axis translation (side-to-side) would couple into -Z translation (toward ISS), even worse than what normally happens using Low Z DAP, requiring frequent braking to prevent excessive closure rate.
Ok. Scary stuff!It's in Jorge's answer if you also take into account that you wouldn't know there was an ET sep problem until after MECO.
How would the plans for intentionally orbiting an ET have worked then? If you extend MECO a bit, you can raise the perigee of a direct ascent Orbit high enough that it won't reenter? But then how to circularize the tank's orbit?
I'd expect them to go ahead and attempt OMS-2 to buy time. I'd expect high RCS activity during OMS burns due to not being able to trim the OMS gimbals through the c.g.. Probably not much that could be done about it for OMS-2. Once in OPS2, I'd expect GNC to develop and uplink a DAP mass properties update which would improve control response a bit, but attitude control would still be sloppy (and involve high RCS usage).
I used the search and actually believe I've read all shuttle Q&A responses and couldn't find an answer to this. Is there an engineering or other reason the shuttle side hatch opens the direction it does? It seems to me that when the orbiter it horizontal, up would be fighting gravity and left would be fighting gravity when the orbiter is vertical. That leaves down (the configuration chosen) or right when the orbiter is horizontal. Anyone know why down was chosen over right? Thanks!
I used the search and actually believe I've read all shuttle Q&A responses and couldn't find an answer to this. Is there an engineering or other reason the shuttle side hatch opens the direction it does? It seems to me that when the orbiter it horizontal, up would be fighting gravity and left would be fighting gravity when the orbiter is vertical. That leaves down (the configuration chosen) or right when the orbiter is horizontal. Anyone know why down was chosen over right? Thanks!
It opens down when the orbiter is horizontal, so the crew doesn't have to fight gravity during a post landing situation.
My search skills are lacking. Anyone care to help identify what turbine and/or provide some more context around this turbine blade? By context I mean a larger picture or explanation of this piece installed as ready for flight. Thanks.
Rob
The shuttle is famous for its four computers running the primary software simultaneously and a fifth running the backup flight software. Was this redundancy ever used? Did one of the four ever fail or disagree during a flight? Was the backup computer ever engaged as a backup?
The shuttle is famous for its four computers running the primary software simultaneously and a fifth running the backup flight software. Was this redundancy ever used? Did one of the four ever fail or disagree during a flight? Was the backup computer ever engaged as a backup?
Well, for one thing, I think that's a regular old DEU, not a MEDS screen - but to answer your actual question... I don't know.
Anyone know what font is used for the MEDS displays like in the one attached?
Hi all.
Question on the Orbital DAP, and in particular on the Manual TVC DAP mode. From what I've read till now, in this mode a deflection of the RHC up to the softstop causes to gimbal the OMS engine. If instead the RHC is deflected beyound the softstop, the RCS will be fired continuously.
What I don't understand is, if during this mode, while the RHC is before the softstop, the RCS jets are still fired for keeping the attitude or if instead the RHC deflections are only transformed in OMS engines gimbalining.
Said in other words: is this a mode in which OMS thrust vectoring is accomplished by manual inputs to the OMS engines only or also the RCS is used (I'm always speaking in the case in which the RHC is before the softstop).
Thanks
Davide
Can't believe how quickly I forget this stuff... had to look up the answer for this.
RHC deflection within the softstop will use OMS steering in all three axes
Quote from: JorgeCan't believe how quickly I forget this stuff... had to look up the answer for this.
ah too bad Jorge! you can't forget this things ahah.QuoteRHC deflection within the softstop will use OMS steering in all three axes
Ok so this means that basically the pilots could manually steer the OMS engines? Where did they get information about which direction they had to steer the OMS engines to? From the ADI?
Thanks
Davide
Hi all.
Did the state vector propagation and scheme change when the IMUs where upgraded to the laser ring system?
If yes what changed?
Thanks
Davide
Sorry i misread what i was reading. The gyros were replaced with the ring laser type.
Another question: which is the difference between the AUTO and INRTL mode for the DAP? I mean, in AUTO the DAP kept the attitude automatically without manual input from the crew, but is not equvalent to say that it maintained an inertial attitude?
Either you're still misreading or you're miswriting. The shuttle has never used ring laser gyros in the IMUs, nor the RGAs, nor the SRB RGAs. What's your source for this?
It didn't have to be a "next-generation" shuttle. There were ample ideas and studies performed on many system upgrades and modifications that were never implimented.
The reasons varied of course, from the cost would have been prohibitive to sometimes changing things just to supposedly improve them (when more or less it was working fine or was understood) was not something the always fit within the other confines of the Program.
It didn't have to be a "next-generation" shuttle. There were ample ideas and studies performed on many system upgrades and modifications that were never implimented.
The reasons varied of course, from the cost would have been prohibitive to sometimes changing things just to supposedly improve them (when more or less it was working fine or was understood) was not something the always fit within the other confines of the Program.
I remember the proposed SIGI upgrade. Very slick... but the costs of modifying the FSW to work with SIGI caused a lot of people to freak out. The assumption of a stable-platform IMU was pretty deeply baked-into the software. Re-verifying it would have been a bear.
It didn't have to be a "next-generation" shuttle. There were ample ideas and studies performed on many system upgrades and modifications that were never implimented.
The reasons varied of course, from the cost would have been prohibitive to sometimes changing things just to supposedly improve them (when more or less it was working fine or was understood) was not something the always fit within the other confines of the Program.
I remember the proposed SIGI upgrade. Very slick... but the costs of modifying the FSW to work with SIGI caused a lot of people to freak out. The assumption of a stable-platform IMU was pretty deeply baked-into the software. Re-verifying it would have been a bear.
Prototype software had been made and we were actually "looking forward" to the challenge. The SIGI was tested onboard using PGSCs to record the data (much as MAGR-S was tested).
SIGI was actually very important from the keep GPCs flying until 2025 plan. We would have off-loaded displays first (CAU) and then off-loaded Nav. This way there would have been enough memory available to keep upgrading GPC flight software through 2025 (if the plan to do that had materialized). Much much cheaper than new GPCs (and software).
"CDR, reconfigure heaters".......can anyone explain this call in the countdown?
thanks!
Hi all.
A question regarding proximity operations with the ISS.
I'm reading that after the RPM the orbiter started a Twice Orbital Rate V Bar Approach (TORVA) to reas the V-Bar. In earlier missions to the ISS, like STS-88 it was instead used a Twice Orbital Rate R Bar Approach (TORRA).
Could you please explain me which is the meanig of these two maneuvers? and why they were adopted?
Thanks very much
Davide
"CDR, reconfigure heaters".......can anyone explain this call in the countdown?
thanks!
Long answer, think it's in here, if not I'll deal with it later:
http://forum.nasaspaceflight.com/index.php?topic=27598.0
I asked on the Historical thread re: STS-51C but maybe it's better to try here:
What was the bank limitation for the orbiter, coming around the hack? The commentator says on STS-51C landing coverage that Discovery is in a bank of 87 degrees at one point - I didn't think they ever went that far - was it a mistake, by the commentator, or was that the case? In the video, it does indeed look remarkably accurate...
Quote from: JorgeLong answer, think it's in here, if not I'll deal with it later:
http://forum.nasaspaceflight.com/index.php?topic=27598.0
Hi Jorge.
I've to say that I've found out about TORVA and TORRA just reading few days ago History of Space Shuttle Rendezvous...a very inspiring document I've to say...plenty of good description.
TORVA and TORRA are mentioned at page 137 where it says that twice orbital rate fly-arounds permitted faster transfers with lower propellant consuption and plume impingment. Also it says that the faster rate prevented the Sun from continously staying in the field of view of the crew.
So I'd like to have some more info about it. Why TORVA and TORRA are better and in what they exactly consists?
I see from the diagrams in the quoted document that TORRA and TORVA are performed in the maneuver for passing from the +R bar to the +V bar.
Does the adjective "twice" simply mean that the the passage from +R bar to +V bar is just done at twice the speed than what was done before the maneuver was introduced?
And which is the difference between orbital rate and velocity?
Quote from: sivodave on 01/20/2012 06:53 AM
Quote from: Jorge
Long answer, think it's in here, if not I'll deal with it later:
http://forum.nasaspaceflight.com/index.php?topic=27598.0
Hi Jorge.
I've to say that I've found out about TORVA and TORRA just reading few days ago History of Space Shuttle Rendezvous...a very inspiring document I've to say...plenty of good description.
TORVA and TORRA are mentioned at page 137 where it says that twice orbital rate fly-arounds permitted faster transfers with lower propellant consuption and plume impingment. Also it says that the faster rate prevented the Sun from continously staying in the field of view of the crew.
So I'd like to have some more info about it. Why TORVA and TORRA are better and in what they exactly consists?
I'm not sure what you are asking.
Last thing: twice orbital rate/velocity, i suppose they refer to twice the orbital rate/velocity of the target (ie: ISS) or of the chaser (Shuttle)?
This is the transcript..
PAO: Approaching the Heading Alignment Circle, and Discovery will be beginning the sweeping left turn, coming around for runway 15… left bank 45 degrees now, 40.000 feet, on Heading Alignment Circle, normal energy… orbiter systems in good shape, 36,000 feet, .7 mach on the Heading Alignment Circle, bank 77 degrees… now 87 degrees… airspeed about 264 knots, range 8 miles… and they’ve reported the sonic boom at the Cape… on the Heading Alignment Circle airspeed 258, altitude 24,000 feet, range 9 miles…
another random question, but does anyone know the launch that Rob Navias commented that the orbiter was "flying down hwy (XXX)" (he was referring to the STS mission number as the "why").
completely random, but i can't find the flight commentary.
thanks!!!
This is the transcript..
PAO: Approaching the Heading Alignment Circle, and Discovery will be beginning the sweeping left turn, coming around for runway 15… left bank 45 degrees now, 40.000 feet, on Heading Alignment Circle, normal energy… orbiter systems in good shape, 36,000 feet, .7 mach on the Heading Alignment Circle, bank 77 degrees… now 87 degrees… airspeed about 264 knots, range 8 miles… and they’ve reported the sonic boom at the Cape… on the Heading Alignment Circle airspeed 258, altitude 24,000 feet, range 9 miles…
Yeah he definitely misspoke - I watched the video and my best "GUESS" is he read the numbers for the brake (as in speed brake which might have been opening to 77 percent)...I really have no idea, and I only know enough to make me very dangerous. ;)
As for your original question, the roll/bank during this part of the TAEM Guidance phase (subsonic, on the HAC, and not flying RTLS guidance limits) is ideally around 45 degrees with guidance limiting roll commands to a maximum of 60 degrees.
While normally bank on the HAC is around 45-ish degrees, high winds at altitude (such as a strong tail wind) may require a larger bank angle.
Mark Kirkman
another random question, but does anyone know the launch that Rob Navias commented that the orbiter was "flying down hwy (XXX)" (he was referring to the STS mission number as the "why").
completely random, but i can't find the flight commentary.
thanks!!!
Steer to this location:
http://forum.nasaspaceflight.com/index.php?topic=19476.msg504345#msg504345
Here is the YouTube link. The comment is made at 3:50 into the video.
I looked at a photo of SSME 0003 and the shape of the bell of the engine looks very different from that of the current SMEs that have flown. Why? I also recall in a documentary this engine or a similar early version identical to 0003 exploded during a test.
Not sure if this goes here, but what the heck is the Reusable Launch Vehicle Hangar ?
Also what was the purpose of the OMRCF before it was converted to and OPF, and did NASA intentionally design the facility to be converted to an OPF in the future?
Is November 19, 1985 the correct date for OV-101's arrival at Dulles?
Hi all.
Question about the star trackers. I know that two different types were used, namely the solid state start tracker and the image dissector tube star tracker.
I'd like to know the advantage of the one type respect the other. Which
one was better? could an orbiter have both types at the same time?
Thanks very much
Regards
Davide
Now that my STS-9 recording is no longer imprisoned on Betamax tape, I found a reasonable source for the change at that time. Richard Covey, who was providing astronaut 'color' for CNN during STS-9, noted on launch day that the roll rate was changed from 10 deg/sec to 15.I may be remembering it wrong, but I seem to recall hearing that the roll rate for the roll program after liftoff changed (increased) beginning with STS-9 (first high-inclination mission)...anyone know what the roll rates were before and after? (And did they change again?)
Thanks.
(Sorry if repeating this.)
My memory must be fading. But, remember the rates are a combined (RSS) of roll, pitch and yaw not to exceed 15 deg / sec (if my memory is still good enough for that number). I don't remember the individual gains changing but that was before my time. The roll did last a lot longer (obviously).
QuoteQuote from: sivodave on 02/05/2012 07:53 PMHi all.
Question about the star trackers. I know that two different types were used, namely the solid state start tracker and the image dissector tube star tracker.
I'd like to know the advantage of the one type respect the other. Which
one was better? could an orbiter have both types at the same time?
Thanks very much
Regards
Davide
Yes, the two types could be used interchangeably and mixed on the same flight. I suspect the older ones were simply becoming unsupportable due to their age.
On Columbia, OV-102. Why was she the only one to get the extra black tiles on the wing chines while the rest of the fleet didn't? What purpose did it serve?
On Columbia, OV-102. Why was she the only one to get the extra black tiles on the wing chines while the rest of the fleet didn't? What purpose did it serve?
On Columbia, OV-102. Why was she the only one to get the extra black tiles on the wing chines while the rest of the fleet didn't? What purpose did it serve?
On Columbia, OV-102. Why was she the only one to get the extra black tiles on the wing chines while the rest of the fleet didn't? What purpose did it serve?
I believe that was black paint over the lower temperature white tiles, not the high temperature black tiles. The reason was for some early on "guestimates" at heating, turned out to be unnecessary but was kept anyway, making 102 stand out from the rest of the fleet. 102 had plenty of other distinctive markings as well (SILTS pod and black tiles atop the vertical stabilizer being the 2nd most noticeable difference).
QuoteQuoteQuote from: sivodave on 02/05/2012 07:53 PMHi all.
Question about the star trackers. I know that two different types were used, namely the solid state start tracker and the image dissector tube star tracker.
I'd like to know the advantage of the one type respect the other. Which
one was better? could an orbiter have both types at the same time?
Thanks very much
Regards
Davide
Yes, the two types could be used interchangeably and mixed on the same flight. I suspect the older ones were simply becoming unsupportable due to their age.
Thanks DMeader. Just another question: in what sense the only ones became unsupportable? Unsupportable from a software point of view or maintenance? If they were unsupportable, why they flew with both type together?
Thanks very much
Regards
Davide
I've been looking at the launch attempts for all shuttle missions and have noticed a few examples of recycles back to T-20 minutes for another launch attempt on the same day. The question is, was there ever one of these that actually launched? As all of these missions were in the early days there isn't much information available and the examples I have read about ended up getting scrubbed in the end, for example STS-1 (I beleive) and STS-61-C.Off the top of my head, 51-F is one.
I've been looking at the launch attempts for all shuttle missions and have noticed a few examples of recycles back to T-20 minutes for another launch attempt on the same day. The question is, was there ever one of these that actually launched? As all of these missions were in the early days there isn't much information available and the examples I have read about ended up getting scrubbed in the end, for example STS-1 (I beleive) and STS-61-C.
Some interesting reading on this subject in the S0007 volume 2 recycle control sequence. One strange procedure I noticed is that it says that if a cutoff has occurred after T-16 seconds and the launch is not going to be scrubbed then the sound surpression water tank is to be refilled. From reading previous threads I thought the rule was that if you went below T-31 seconds then you had to scrub so why does S0007 contain procedures for same day launch attempt when the countdown is as low as T-16 seconds?
It was discussed back in 2008 and the suggestion there was that it would take more than a day before another attempt could be made due to the SRB HPUs.That was specific to that 61-C cutoff, which was due to an indication of a HPU overspeed. This would be one of the topics in the case of any cutoff after T-31 -- whatever was "wrong" might be worth analyzing/discussing overnight. And if something appeared to be broken (as with the HPU), then scrub might be the only option.
Out of interest, how long would it have taken to get from a GLS cutoff to resuming the count at T-20 minutes in an STS-93 situation where the issue could have been quickly resolved? It says 1 hour 30 minutes in the S0007 where it says to refill the sound surpression water tank although I'm not sure if this is referring to the time it would take to refill the tank before the count could be resumed.Kind of an interesting topic; there are multiple references to IMU alignment unplanned hold time in the 90 minute range back in the 80s contributing to the length of recycles (51-F on 29 July 1985, 61-C on 6 January 1986, etc.)
Obsviously this would never be an option for an ISS mission like STS-93 but would be intersted to know if it could have been done within the later 2.5 hour launch windows.Nit: STS-93 was the last Shuttle IUS deploy mission; it had a longer window than Mir or ISS rendezvous/docking missions. Probably in the 60 minute range (which was exhausted on the second attempt, due to weather).
That was specific to that 61-C cutoff, which was due to an indication of a HPU overspeed. This would be one of the topics in the case of any cutoff after T-31 -- whatever was "wrong" might be worth analyzing/discussing overnight. And if something appeared to be broken (as with the HPU), then scrub might be the only option.I was referring to mkirk's comments that said you were done for the day once you go past T-31 seconds and that there was a rule about this before STS-61-C was mentioned in that converstation. Having been reading these threads since then I always thought that would be the case until I discovered the S0007 recycle control sequence that contained procedures for a second launch attempt even if there was a cutoff after T-31 seconds. For the December launch attempt though of STS-61-C I note http://www.space-shuttle.com/challenger2.htm says that the countdown was recycled to T-20 minutes but it was hopeless so it would seem that they didn't immediately scrub after the cutoff at T-14 seconds although this could of course just be referring to the fact that the countdown has to be recycled to T-20 minutes after a cutoff regardless of it there is going to be a scrub or not.
Kind of an interesting topic; there are multiple references to IMU alignment unplanned hold time in the 90 minute range back in the 80s contributing to the length of recycles (51-F on 29 July 1985, 61-C on 6 January 1986, etc.)According to the "Some Trust in Chariots" book about Challenger, there was also a recycle on January 7 although exactly why they had to recycle to T-20 minutes and count back down to T-9 minutes when they could have just waited at T-9 minutes until the end of the window is not clear.
After the crew-on-back limits were more strictly enforced, there were a couple of cases in the late 80s and early/mid 90s with long-ish holds that ran close to 90 minutes or a bit longer. The last long one I can think of was with STS-64 in September, 1994.Would these have just been long holds though rather than recycles? Even for STS-51-F I have seen it just referred to as a long hold even though in this case there was a recycle.
My point was that whatever caused the cutoff inside the "go for auto sequence start" GLS milestone might preclude use of any hypothetical capability to recycle. So in the case of the December, 1985, attempt -- or the STS-51 attempt in July, 1993 -- even if there had been an unlimited launch window, the failure that caused the cutoff was also going to require a lengthy R&R (multiple days).Quote from: pslossThat was specific to that 61-C cutoff, which was due to an indication of a HPU overspeed. This would be one of the topics in the case of any cutoff after T-31 -- whatever was "wrong" might be worth analyzing/discussing overnight. And if something appeared to be broken (as with the HPU), then scrub might be the only option.I was referring to mkirk's comments that said you were done for the day once you go past T-31 seconds and that there was a rule about this before STS-61-C was mentioned in that converstation. Having been reading these threads since then I always thought that would be the case until I discovered the S0007 recycle control sequence that contained procedures for a second launch attempt even if there was a cutoff after T-31 seconds.
For the December launch attempt though of STS-61-C I note http://www.space-shuttle.com/challenger2.htm says that the countdown was recycled to T-20 minutes but it was hopeless so it would seem that they didn't immediately scrub after the cutoff at T-14 seconds although this could of course just be referring to the fact that the countdown has to be recycled to T-20 minutes after a cutoff regardless of it there is going to be a scrub or not.It might not have been immediately announced, but it might also have taken longer to review the data back then to see what caused the cutoff. It wasn't long after it was reported the problem was a HPU overspeed that it was reported they were done for the year.
According to the "Some Trust in Chariots" book about Challenger, there was also a recycle on January 7 although exactly why they had to recycle to T-20 minutes and count back down to T-9 minutes when they could have just waited at T-9 minutes until the end of the window is not clear.Possibly the same thing as one of the drivers from the previous day's recycle -- the IMUs needed to be realigned. Forgot to add to earlier post; this has been linked before, but you can see some references to this in the Space Shuttle Missions Summary book:
Refer to the SSMS book link. There were a few other situations like that back then (post RTF after 51L) and that was during a period of time (late 80s/early 90s) when the Shuttle program was upgrading hardware, so it's conceivable that the countdown clock held at T-9 but different procedures were executed. (But that's why I was wondering about upgrades related to either the original IMUs or the HAINS units and whether that changed/extended the unplanned hold capability.)QuoteAfter the crew-on-back limits were more strictly enforced, there were a couple of cases in the late 80s and early/mid 90s with long-ish holds that ran close to 90 minutes or a bit longer. The last long one I can think of was with STS-64 in September, 1994.Would these have just been long holds though rather than recycles?
After the crew-on-back limits were more strictly enforced, there were a couple of cases in the late 80s and early/mid 90s with long-ish holds that ran close to 90 minutes or a bit longer. The last long one I can think of was with STS-64 in September, 1994.The Space Shuttle Missions Summary Book notes another long weather hold I'd forgotten about -- the STS-73 launch attempt on 15 October 1995. It did get a little better than these two shots, but not good enough when the crew-on-back time ran out.
My point was that whatever caused the cutoff inside the "go for auto sequence start" GLS milestone might preclude use of any hypothetical capability to recycle. So in the case of the December, 1985, attempt -- or the STS-51 attempt in July, 1993 -- even if there had been an unlimited launch window, the failure that caused the cutoff was also going to require a lengthy R&R (multiple days).So effectively even though second launch attempt after cutoff below T-31 seconds was allowed in S0007, it's very unlikely it would ever have been used due to the reasons you said above. I can't find any reference to the rule mkirk talked about but if there was a rule then this would not have been in S0007?
Possibly the same thing as one of the drivers from the previous day's recycle -- the IMUs needed to be realigned. Forgot to add to earlier post; this has been linked before, but you can see some references to this in the Space Shuttle Missions Summary book:Interestingly one source I have said that the countdown on January 6 was recycled first to T-9 minutes and then back to T-20 minutes. If the LOX drainback issue resulted in the recycle to T-9 then maybe it was IMU alignement issues that required a recycle back to T-20 minutes. However I am not convinced about this as I believe GLS cutoff was called at T-31 seconds which would have required a recycle all the way to T-20 minutes.
http://www.jsc.nasa.gov/history/reference/TM-2011-216142.pdf
My point was that whatever caused the cutoff inside the "go for auto sequence start" GLS milestone might preclude use of any hypothetical capability to recycle. So in the case of the December, 1985, attempt -- or the STS-51 attempt in July, 1993 -- even if there had been an unlimited launch window, the failure that caused the cutoff was also going to require a lengthy R&R (multiple days).So effectively even though second launch attempt after cutoff below T-31 seconds was allowed in S0007, it's very unlikely it would ever have been used due to the reasons you said above. I can't find any reference to the rule mkirk talked about but if there was a rule then this would not have been in S0007?QuotePossibly the same thing as one of the drivers from the previous day's recycle -- the IMUs needed to be realigned. Forgot to add to earlier post; this has been linked before, but you can see some references to this in the Space Shuttle Missions Summary book:Interestingly one source I have said that the countdown on January 6 was recycled first to T-9 minutes and then back to T-20 minutes. If the LOX drainback issue resulted in the recycle to T-9 then maybe it was IMU alignement issues that required a recycle back to T-20 minutes. However I am not convinced about this as I believe GLS cutoff was called at T-31 seconds which would have required a recycle all the way to T-20 minutes.
http://www.jsc.nasa.gov/history/reference/TM-2011-216142.pdf
So effectively even though second launch attempt after cutoff below T-31 seconds was allowed in S0007, it's very unlikely it would ever have been used due to the reasons you said above. I can't find any reference to the rule mkirk talked about but if there was a rule then this would not have been in S0007?No, sorry if I'm confusing things, too, but if you're referring to the second 61-C launch attempt (6 January 1986), that did not proceed through the "auto sequence start" milestone:
Interestingly one source I have said that the countdown on January 6 was recycled first to T-9 minutes and then back to T-20 minutes.This may have been standard for re-configuring the vehicle at the time for a recycle inside the late GLS milestones.
No, sorry if I'm confusing things, too, but if you're referring to the second 61-C launch attempt (6 January 1986), that did not proceed through the "auto sequence start" milestone:No, the confusion was over why S0007 contained procedures for another attempt on the same day if the countdown was below T-31 seconds when I thought that once you went below T-31 seconds that was it for the day but it has now been clarified that this did not automatically result in a scrub. As you said above though, on the December launch attempt of STS-61-C this was never going to be an option due to the time needed to resolve the issue.
http://forum.nasaspaceflight.com/index.php?topic=10600.msg315235#msg315235
The link in that post (to an archived posting of the 61-C mission report) has a detailed explanation of what happened.
If a rendezvous was required, then the window was (much) shorter (from a little over an hour down to 5 minutes). So there was no time to recycle to 20 minutes.
QuoteQuoteQuote from: sivodave on 02/05/2012 07:53 PMHi all.
Question about the star trackers. I know that two different types were used, namely the solid state start tracker and the image dissector tube star tracker.
I'd like to know the advantage of the one type respect the other. Which
one was better? could an orbiter have both types at the same time?
Thanks very much
Regards
Davide
Yes, the two types could be used interchangeably and mixed on the same flight. I suspect the older ones were simply becoming unsupportable due to their age.
Thanks DMeader. Just another question: in what sense the only ones became unsupportable? Unsupportable from a software point of view or maintenance? If they were unsupportable, why they flew with both type together?
Thanks very much
Regards
Davide
The software didn't "know" which type of star tracker was being flown. There were a lot of pieces of equipment we had to know which type was being used, but not the star trackers. For the other equipment, the selection was usually done with an I-Load (or TMBU update), so it wasn't that difficult as long as there wasn't a late change.
Usually aging equipment that needs to be replaced was due to the inability to find spare parts. I suspect that the image dissector tube was not a very common part and is probably no longer made.
Quite true, though the program had a few spares and we were able to support IDT through the end of the program. Which was a good thing since the IDTs tracked bright rendezvous targets like ISS better than the solid state trackers. We actually reverted the -Z tracker on one orbiter (OV-104) back to IDT for this very reason. At the end of the program, all three orbiters had IDTs in the -Z slot (since that star tracker was prime during rendezvous ops) and solid state trackers in the -Y slot (for tracking dim stars while docked to ISS).
What are the dimensions of the middeck LxWxH?
Where did they put the removeable seats during the mission? Were the 2 seats behind the PLT and CDR on the flight deck removed while in orbit as well?
Were the Flight Readiness Firings done with inert SRB's or loaded SRB's?The FRFs were done with a complete and ready flight-stack. Only things changed between the FRF and the launch were the SSMEs.
And (this could possibly belong in the SRB Q&A thread), what is an inert SRB? Just the empty casings, or loaded with inert mass to simulate propellant?
Did SLC-6 have the centaur Umbilical system when cancelled, or was it planned to be added after a few launches?No Centaur servicing equipment at SLC-6 when the launches were cancelled.
Did SLC-6 have the centaur Umbilical system when cancelled, or was it planned to be added after a few launches?No Centaur servicing equipment at SLC-6 when the launches were cancelled.
Did SLC-6 have the centaur Umbilical system when cancelled, or was it planned to be added after a few launches?
Hi all.
A question about the Space Shuttle final approach during rendezvous. With reference to the attached drawing I don’t understand the difference between an approach along the +V bar and an inertial approach. Which are the differences and how it was possible to fly them?
In a +Vbar approach the orbiter was maintained in a tail-to-Earth attitude after arrival on the +Vbar. In an inertial approach the orbiter was maintained in inertial attitude hold throughout the approach. Piloting techniques were similar; the CDR would maintain a prescribed range-rate profile and keep the target above the payload bay.
Quote from: JorgeIn a +Vbar approach the orbiter was maintained in a tail-to-Earth attitude after arrival on the +Vbar. In an inertial approach the orbiter was maintained in inertial attitude hold throughout the approach. Piloting techniques were similar; the CDR would maintain a prescribed range-rate profile and keep the target above the payload bay.
Thanks for the answer. However I was wondering why the two curves in the diagram are different. My thinking is that with an intertial attitude flown along the +V Bar the orbiter would have then approached the target with not the right relative attitude. Was that the case?
Did SLC-6 have the centaur Umbilical system when cancelled, or was it planned to be added after a few launches?
Don't forget the lift capability would have been limited for polar orbits and this was before the superlightweight tank. So, a massive fueled Centaur would have taken away from what payload weight was available. Also once already in a low Earth polar orbit, what would you have used Centaur for?
Why go to GSO from VAFB? Do you possibly mean SSO?
Why go to GSO from VAFB? Do you possibly mean SSO?
Hi all.
Another question for the rendezvous expert guys.
After Ti burn, how were the MCs burns computed? If I’ve understood well the MCs burns were targeted by the crew since they had more accurate data available during the last part of the approach.
What I’d like to understand is how each MC burn was computed. Because using Lambert to compute the burn, they had to feed the computers with data regarding the point of arrival, along the trajectory. So, for example, which kind of data they provided for executing MC-1 burn to get to the point for MC-2?
Were always all MCs burns done or sometimes they could skip some burn?
Thanks very much
Davide
After Ti burn, how were the MCs burns computed? If I’ve understood well the MCs burns were targeted by the crew since they had more accurate data available during the last part of the approach.
What I’d like to understand is how each MC burn was computed. Because using Lambert to compute the burn, they had to feed the computers with data regarding the point of arrival, along the trajectory. So, for example, which kind of data they provided for executing MC-1 burn to get to the point for MC-2?
Were always all MCs burns done or sometimes they could skip some burn?
Taking for example page 67, I see that at the beginning of the timeline, the crew has to target the burn for MC-1 (preliminary) then MC-1 (intermediate) and finally MC-1 (final). What do they mean? Why are the three different MC-1 burn targets? I also see that in the document there is the target condition for only one MC-1 and not for MC-1 preliminary, or intermediate or final.
Reasoning about it, my guess is that the solution for a given MC was computed three times so to refine it up to when the burn had to be executed. Probably because from when the MC burn preliminary was computed up to when the MC burn final was executed the trajectory could be somehow perturbed. Is my guess correct?
Always at the same page, at minute PET 00:17 is written to perform TARGET MC-1 (final) and then to perform RCS BURN (cue card). I don’t understand if this RCS burn had to be carried out by the crew (PLT is shown in the timeline) or if it was automatic. Or, based on what Jorge has written, the RCS burn had to perform only if the solution computed for the given MC had a Delta-V more than 0.2 ft/s?
Also I see from the same page that for computing the burn solution ORBIT TGT was used. Why was used this display and not MNVR display?
Also I don’t understand if the RPOP was used before MC-4 or after? If I am right RPOP did not communicate with GNC so my guess is that RPOP was used only after MC-4 or to better say for departure from the +R Bar for the final approach. Could you please confirm this?
Does anyone know if there is a technical reason why the LO2 connections are on the starboard side and the LH2 connections are on the port? I’m talking about the ET feed lines, umbilical wells and T-0 panels.
I can’t find a reason why they would be that way, but I can find a reason why they shouldn’t. The LH2 and LO2 dewars at the pads are in the north east and north west corners of the pad respectively and they were there long before the shuttle was designed. That means that the LH2 lines run down side 4 of the MLP which is the starboard side of the shuttle and the LO2 lines run down side 2 which is to port. That in turn means that the lines have to cross over each other on side 1 to get to their respective TSMs. The LH2 lines go up and run under the blast shield and then turn into the tunnel while the LO2 lines run along the face of the MLP before turning up to enter their tunnel. If the connections on the shuttle were reversed the lines could be kept separate and provided with physical barriers to limit gas mixing if there were leaks.
If there isn’t a specific reason for this, is it possible that Marshall just missed it back in the early 70’s? That sound impossible to me, but you never know.
I'll SWAG it...Possible, but I kind of doubt it. The LH2 vent line in the interstage is "behind" the SRB beam while the LO2 J-leg is in front of it. Moving the J-leg to the port side shouldn't have affected the LH2 vent any.
The need for GH2 venting and the fact that the umbilical for that has to be on the FSS, which is to port?
I doubt they "forgot" about the locations of the LC-39 tanks. LC-39 was not necessarily going to be the STS launch site early on.
I'll SWAG it...Possible, but I kind of doubt it. The LH2 vent line in the interstage is "behind" the SRB beam while the LO2 J-leg is in front of it. Moving the J-leg to the port side shouldn't have affected the LH2 vent any.
The need for GH2 venting and the fact that the umbilical for that has to be on the FSS, which is to port?QuoteI doubt they "forgot" about the locations of the LC-39 tanks. LC-39 was not necessarily going to be the STS launch site early on.
I thought of that, but no. By the time they reached the phase B studies in the 1970 time frame (which is when the ET concept firmed up) they were already commited to LC-39 (based on cost, if nothing else). The decision of what side to run the line on probably didn't get made until the phase C/D work in 71 or 72 if not later.
I'm not suggesting that they just "forgot" where the tanks were. Originaly, activities at the cape fell under Marshall's "Launch Opperations Directorate". That included design of the launch pads and equipment. There were some notorious problems with the project management of the swing arms for the SaturnV LUT. Whether or not that had anything to do with what happened subsequently is open to debate, but the fact is that KSC was formed as it's own center and assumed the responsability for launch equipment design and fabrication. By the time the Shuttle came along, the launch pad wasn't really Marshall's problem anymore and so this issue might not have come up on their radar.
Maybe fire suppression, then? That's on the FSS, and it would be harder to extinguish an H2 fire on the starboard side of the stack.Actually, the fire suppresion of a fire involving the vehicle is done by nozzles on the deck of the MLP and on top of the TSMs and is pretty symetrical. The FireX system on the FSS is mostly to cool and protect the FSS itself.
Maybe fire suppression, then? That's on the FSS, and it would be harder to extinguish an H2 fire on the starboard side of the stack.Actually, the fire suppresion of a fire involving the vehicle is done by nozzles on the deck of the MLP and on top of the TSMs and is pretty symetrical. The FireX system on the FSS is mostly to cool and protect the FSS itself.
I'm not trying to shoot down every idea you have. Keep em comming and we may find the answer.
I'll SWAG it...Possible, but I kind of doubt it. The LH2 vent line in the interstage is "behind" the SRB beam while the LO2 J-leg is in front of it. Moving the J-leg to the port side shouldn't have affected the LH2 vent any.
The need for GH2 venting and the fact that the umbilical for that has to be on the FSS, which is to port?
I'll SWAG it...Possible, but I kind of doubt it. The LH2 vent line in the interstage is "behind" the SRB beam while the LO2 J-leg is in front of it. Moving the J-leg to the port side shouldn't have affected the LH2 vent any.
The need for GH2 venting and the fact that the umbilical for that has to be on the FSS, which is to port?
I would say that is the best answer. That means that all H2 lines are on the west side of the flame trench
QuoteAlways at the same page, at minute PET 00:17 is written to perform TARGET MC-1 (final) and then to perform RCS BURN (cue card). I don’t understand if this RCS burn had to be carried out by the crew (PLT is shown in the timeline) or if it was automatic. Or, based on what Jorge has written, the RCS burn had to perform only if the solution computed for the given MC had a Delta-V more than 0.2 ft/s?
It had to be performed by the crew.
QuoteAlso I see from the same page that for computing the burn solution ORBIT TGT was used. Why was used this display and not MNVR display?
The crew keyboard entries for performing various actions were tied to the items on the displays. ORBIT TGT contained the display items for recalling the targeting data and computing the solution. ORBIT MNVR EXEC contained the display items for loading and executing the burn after the solution was computed.
Question re: STS-88. According to the post-mission report, Endeavour conducted a Dual Engine OMS Assist maneuver (102 seconds in duration) at 00:02:14 MET, just after SRB speration. Why was that maneuver performed? Unity's mass? Rendezvous considerations? Something else? Thanks!
Hi Jorge.
Thanks for you answers…they are very clear and I’m seeing the light now!
Just two last things regarding this subject:Quote from: JorgeQuoteAlways at the same page, at minute PET 00:17 is written to perform TARGET MC-1 (final) and then to perform RCS BURN (cue card). I don’t understand if this RCS burn had to be carried out by the crew (PLT is shown in the timeline) or if it was automatic. Or, based on what Jorge has written, the RCS burn had to perform only if the solution computed for the given MC had a Delta-V more than 0.2 ft/s?
It had to be performed by the crew.
When you say that the burn had to be performed by the crew, does this mean that the pilot (or CDR) had to impart commands on the THC for performing the burn, stopping to provide input when the computed Delta-Vs were reached?
Quote from: JorgeQuoteAlso I see from the same page that for computing the burn solution ORBIT TGT was used. Why was used this display and not MNVR display?
The crew keyboard entries for performing various actions were tied to the items on the displays. ORBIT TGT contained the display items for recalling the targeting data and computing the solution. ORBIT MNVR EXEC contained the display items for loading and executing the burn after the solution was computed.
Again just a clarification. Did ORBIT TGT communicate the burn solution to ORBIT MNVR EXEC?
One last question. In [link=http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023479_2011024697.pdf] this [/link] document, at page 81 at the bottom of left column, is written the +R approaches became viable with the addition of proximity operations sensors and for this reason STS-66 was the first mission flying this approach. However STS-32 for retrieving LDEF flew a –R approach. So what was the problem in doing a +R bar approach? –R Bar and +R bar are no practically each other’s mirror copy?
Question re: STS-88. According to the post-mission report, Endeavour conducted a Dual Engine OMS Assist maneuver (102 seconds in duration) at 00:02:14 MET, just after SRB speration. Why was that maneuver performed? Unity's mass? Rendezvous considerations? Something else? Thanks!
Performance enhancement. Wasn't just STS-88. Almost all shuttle missions to ISS performed OMS Assist.
Question re: STS-88. According to the post-mission report, Endeavour conducted a Dual Engine OMS Assist maneuver (102 seconds in duration) at 00:02:14 MET, just after SRB speration. Why was that maneuver performed? Unity's mass? Rendezvous considerations? Something else? Thanks!
flight suit
Since the OMS were hypergolic, the difference between a dump and a burn is symantics.
Question re: STS-88. According to the post-mission report, Endeavour conducted a Dual Engine OMS Assist maneuver (102 seconds in duration) at 00:02:14 MET, just after SRB speration. Why was that maneuver performed? Unity's mass? Rendezvous considerations? Something else? Thanks!
How are the AFRSI and Nomex FRSI blankets replaced? I saw video of how the tiles are replaced, just chisel out the old tiles by hand and clean up the metal surface for the new tile. How are the blankets replaced?
Hi all.
two questions again about rendezvous profile.
1. Why MC2 burn was targeted for being carried out based at a specific elevation angle? Was because in this way the star trakkers/COAS/radar had the best field of view of the target, or some other reason?
2. Which is the difference between an NH maneuver in which the height of the orbit is changed and NC maneuver in which the phase of the orbit is changed? are not the same thing? If you do a NC maneuver for changing the closure rate with the target, are you not changing also the shape (and therefore the height) of the orbit?
I have a question regarding rain on the orbiter. I have read recently that the tiles and thermal blankets absorbed water in the rain and that in the cases where this happened after landing there was sometimes a need to dry them out during processing. I have also read that the absorbed water added a lot of weight and was a constraint for SCA transport.
Here is my question. I attended the launch of STS-128 including the original scrub. At one point during the night of the first attempt there was such hard rain over the pad that the entire stack seemed to disappear like a David Copperfield trick. At this point there was no RSS protecting the Orbiter. Why didn't this rain cause any issue? I would have thought that at the very least it would have added launch weight which would have affected ascent performance. I would also think that there would be issues with the water freezing once it got into space.
Question for you all ...
The Shuttle Carrier Aircraft 747 has two vertical stabilizer surfaces added to the ends of the horizontal stabilizer to improve "directional stability".
Do those two additional surfaces articulate, i.e. move along with the main rudder? Or are they static, and the central rudder is the sole provider of yaw control authority?
Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?Question for you all ...
The Shuttle Carrier Aircraft 747 has two vertical stabilizer surfaces added to the ends of the horizontal stabilizer to improve "directional stability".
Do those two additional surfaces articulate, i.e. move along with the main rudder? Or are they static, and the central rudder is the sole provider of yaw control authority?
Static
Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
What temperature are the gasses fed into the ET as pressurant?
Thanks, Martin
Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?Not really. Remember, in a normal, coordinated turn, the rudder is not used very much if at all. It is used in skid / slip conditions like when making an approach to landing in a crosswind, but the SCA / Orbiter configuration has pretty stringent limits on crosswind velocity. It would also be used in an engine out situation. I don't believe they ever did any testing of that, but that would be one reson why those flights are practically flown as test flights.
Would the Space shuttle have benefited from the use of a fairing during assent?
Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Thinking of an upside down L shapped fairing. Designed to cover the heat shield bottom to top, and the crew compartment. The fairing would be flaired and end near the payload bay doors.
Not sure of the space available between the orbiter bottom and the fuel tank. Hope the idea would not involve adding say 6 inches of needed space.
What temperature are the gasses fed into the ET as pressurant?
Prelaunch
Helium for the LH2 tank and I think nitrogen for the LOX tank
During flight, the SSME provide heated gases.
Would the Space shuttle have benefited from the use of a fairing during assent?
Where would be the fairing?
Thinking of an upside down L shapped fairing. Designed to cover the heat shield bottom to top, and the crew compartment. The fairing would be flaired and end near the payload bay doors.
Not sure of the space available between the orbiter bottom and the fuel tank. Hope the idea would not involve adding say 6 inches of needed space.
What is its weight, attach methods, and how does it come off, nominally and in aborts?
Its weight would reduce payload by the same amount.
Its drag would reduce payload also.
drag should be reduced (if designed right). We have gotten better since the shuttle was designed.
Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
I believe there is still enough control authority in the rudder.
What temperature are the gasses fed into the ET as pressurant?
Prelaunch
Helium for the LH2 tank and I think nitrogen for the LOX tank
During flight, the SSME provide heated gases.
Thanks.
What temp are the gases from the SSMEs at the point they're injected?
Cheers, Martin
Is each bay of the orbiter payload bay of equal length or does they vary in length?
Thanks. That is the kind of schematic I was looking for. It answers the question nicely with the fuselage station numbers.Is each bay of the orbiter payload bay of equal length or does they vary in length?
From the Space Shuttle Systems Summary, 1980.
Hi all.
From the "Ascent Guidance and Flight Control Workbook", available on L2, it shown that there were difference ascent displays. In particular it is shown an ASCENT TRAJ 1, ASCENT TRAJ 2 and an ASCENT TRAJ display.
I'm getting confused because I don't understand when the ASCENT TRAJ display was used. If there were two displays already, one for first and one for second stage, why having a general ASCENT TRAJ display?
thanks very much
Davide
In this article;
http://www.nasaspaceflight.com/2011/07/atlantis-down-processing-mer-review-notes-flawless-return/
“performed flawless, bar typical GPC (General Purpose Computer) errors during rollout.”
What are these errors, causes and where can I find out more about this?
Thanks
Hi all.
From the "Ascent Guidance and Flight Control Workbook", available on L2, it shown that there were difference ascent displays. In particular it is shown an ASCENT TRAJ 1, ASCENT TRAJ 2 and an ASCENT TRAJ display.
I'm getting confused because I don't understand when the ASCENT TRAJ display was used. If there were two displays already, one for first and one for second stage, why having a general ASCENT TRAJ display?
thanks very much
Davide
ASCENT TRAJ was the display used by PASS for both first and second stage. ASCENT TRAJ 1 and 2 were the respective BFS displays for first and second stage. Starting with the OI-32 software version (STS-120), PASS used similar displays to the BFS and were also called ASCENT TRAJ 1 and 2.
The old ASCENT TRAJ display was designed mainly to assist RTLS aborts and wasn't very useful for nominal ascents.
Anyone know the Zo coordinates for the bottom of the PLB bays? I don't mean the floor of the midbody, but just the bays that give the payload bay the familiar semi-circular shape. According to the Mechanical Systems Workbook, the sill longerons are at Zo410.00.
Thanks, alk. Being a computer guy, the software and GPCs had always interested me and I always like reading your posts.
305 or 308.4 per the diagram above. it says the longerons are at 414...I don't think Zo414.0 is for the longerons but rather payload bay door hinge line. Based on my research the PLBD door hinge lines are at Yo±95 with the longerons at Yo±90. And the shape of the longerons from bottom to top roughly corresponds to a 5" square.Anyone know the Zo coordinates for the bottom of the PLB bays? I don't mean the floor of the midbody, but just the bays that give the payload bay the familiar semi-circular shape. According to the Mechanical Systems Workbook, the sill longerons are at Zo410.00.
How much time does it take to inspect Space Shuttle TPS tiles after the flight and repair it (damaged ones are replaced I guess)?
Thank you!How much time does it take to inspect Space Shuttle TPS tiles after the flight and repair it (damaged ones are replaced I guess)?
Most of the time between missions.
What takes more time: inspection or repairs?How much time does it take to inspect Space Shuttle TPS tiles after the flight and repair it (damaged ones are replaced I guess)?
Most of the time between missions.
Hi all.
one question about deorbit burn.
Which is the reason for which during the deorbit the Orbiter was placed with the belly up? As long as you have tail-first is shouldn't be important if the belly is up or down, right?
My guess is that in this was, at completion of the burn it would have been faster maneuvering to the entry attitude of 40 degrees of angle of attack and that maybe in this way the pilots had a better situation awarness.
What do you think?
Thanks very much
Davide
Hi wolfpack.
I kept reading a little bit about this subject and I think I've now understood what you are saying. So if my understanding is correct, the reason is that for all duration of coasting from deorbit burn to EI, the Orbiter kept an inertial attitude.
If this is the case, I've though another question. Maneuvering to burn attitude was done 20 minutes before the burn. If the orbiter kept this attitude inertially, does this not mean that the burn was not completely along the +x axis, but had also a +z component?
or the inertial attitude was kept only AFTER the deorbit burn, while up to the deorbit burn the Orbiter had a LVLH attitude?
Thanks very much
Davide
That's correct; a constant inertial attitude means that the shuttle is always rotating in an LVLH frame. The inertial burn attitude will result in the correct LVLH attitude at TIG.Hi wolfpack.
I kept reading a little bit about this subject and I think I've now understood what you are saying. So if my understanding is correct, the reason is that for all duration of coasting from deorbit burn to EI, the Orbiter kept an inertial attitude.
If this is the case, I've though another question. Maneuvering to burn attitude was done 20 minutes before the burn. If the orbiter kept this attitude inertially, does this not mean that the burn was not completely along the +x axis, but had also a +z component?
or the inertial attitude was kept only AFTER the deorbit burn, while up to the deorbit burn the Orbiter had a LVLH attitude?
Thanks very much
Davide
Perhaps the maneuver was done such that the attitude was for a completely +x burn at TIG? I'm not sure, this will have to be answered by Jorge or someone else with the expertise.
My assumption (which is probably incorrect) is that things are done to minimize propellant consumption.
Hi all.Probably to make it easier for the crew if they lost stearing commands on the HSI needles and had to manually navigate the approach using the TACANs. A cylindrical HAC is functionaly similar to a DME arc approach.
a question regarding the HAC. Why at the beginning the HAC was a cylinder and and not a cone? and also why for the OFT missions the HAC (which was a cylinder) was flown following a straight-in approach and not an overhead approach?
Thanks very much
Davide
Hi all.
A question regarding TPS on Columbia. Why throughtout the program up to the last mission the LRSI tiles on the nose and upper wing surface where not replaced by the AFRSI as in the other Orbiters?
And also why were the black tiles kept in place on the glove area of the wings?
Thanks very much
Davide
And also why were the black tiles kept in place on the glove area of the wings?
The black chine areas on Columbia were to minimize on-orbit thermal stresses on the underlying structure; later vehicles incorporated structural changes that made the extra thermal absorption unnecessary.
So that suggests that somewhere in their archives NASA has some detailed test data that shows Al-2219 and Al-Li 2195 in a given thickness develops a certain amount of crack behavior when subjected to n cycles of pressure/cryo exposure.Aluminum alloys always tend to have a fatigue limit based on the number of cycles they are exposed to a given level of cyclic stress. If a crack develops stress is concentrated at its tip and the crack propagates. Increasing thickness in high-stress areas and/or checking carefully for cracks are the only general countermeasures I am aware of, though careful avoidance of corrosion and crack-initiating stress concentrations can help.
Assuming you have access to that sort of data, what is the typical solution if you need to increase the number of safe cycles? Is it mostly a question of thickening the material up and just taking the weight penalty?
-MG.
I'm not enough of a rocket scientist to crunch the numbers, so I'll ask.
How much of a payload increase to ISS orbit would an STS with 3 SSME's at 109% bring?
Then, add 5-seg SRB's to the 109% SSMEs, and how much does it increase (assuming the stack can take those loads)?
Hey Dave SThanks for the tip on the handbook, it covers it nicely there.
The space shuttle approach landing and rollout flight procedures handbook has a great run down of the spread brake logic. Do you have access to that? Also I think I covered it as well in an earlier q&a. If those don't help let me know and I will try and cover it again.
Mark Kirkman
Hi all.
I'm looking for documents explains the start and shutdown sequences of the SSMEs. I've got all the handbooks, workbooks available on L2 and I've also searched on NTRS but I haven't found anythig that explains in details what happen instant by instant during SSME start and shutdown. They all explains very well how they worked during flight but not at the begining or end.
Thanks very much for your help.
Davide
This is rather good... (http://www.enginehistory.org/SSME/SSME3.pdf)
Which was the reason for igniting the engine in a staggered pattern (120 millisec if I'm right)?
Which was the order in which the engines were ignited?3-2-1 (right-left-center).
This part I seem to recall. There's this thing the Shuttle stack does that's called 'twang', which is when the liquids light off, since they are offcenter, the whole stack sways back and forth (quite a bit - I think it's like 2m at the nose). So I would guess that the offset ignition is to minimize the shock loading to the stack's structure from liquid ignition - if they all lit simultaneously, it would be even greater
3-2-1 (right-left-center)
Thanks psloss...do you know why this sequence was chosen? I mean, why not the opposite for example?
Thanks again
Davide
I suspect "twang" of the stack, or loads on the thrust structure have little to do with it.
1) Fluid dynamics in the 17" feed lines. What happens to turbopump inlet pressures if all 3 start at the same time? Would that cause too much of a drop?
2) Nozzles resonate at startup, so best to not have all 3 resonating in phase with one another.
I suspect "twang" of the stack, or loads on the thrust structure have little to do with it. The twang period is measured in seconds (~6 seconds), as is thrust buildup to 100% RPL (~3 seconds). The staggered start is measured in milliseconds (~120 ms).
Sorry, my post wasn't as clear as it could/should have been. I wasn't meaning to imply that the stagger had to do with the twang directly, I was more mentioning the twang to give a sense of the magnitude of the effects on the structure of the engines' thrust.
To the two excellent points you mention, let me add a third suggestion (well, actually, it's another way of looking at your first), which is the inertia of the propellant in the lines. Once things are up and running, the entire line is filled with fuel/oxidizer moving at constant (basically) speed. But of course it starts with all that fluid at rest. So starting the engines with slight delays allows a longer transition from 'no flow' to 'full flow'. (Of course, these inertial effects are what cause the potential temporary pressure drop you mentioned.)
I have a question about manual throttling during ascent. The crew can take over SSME throttling by pressing the takeover switch on the throttle and moving the throttle to within 4% of the commanded value. It seems to me that this would cause the commanded throttle value to change slightly - for example, if the GPCs were commanding 104% thrust, takeover would occur when the throttle was moved to the 100% position, and the SSMEs would be set to 100% thrust. Is this acceptable, or am I missing something here?
Hi all.
A question about the ET. Why the propellant loading started with a slow filling followed after 5% of propellant loaded by a fast loading?
My guess is that when the tanks started to be filled, they were still "hot", at least at room temperature, and therefore upon contact the propellant started to boil. So to avoid a large mass of propellant boiling (possibly quite violently), the filling started at slow rate first so that the tank had time for chilling down and so allowing a faster loading without having everything boiling as cooking pot.
Am I correct?
Thanks very much
Davide
Hi All.
Quick one: I know that Endeavour was the first Orbiter to have the GPS system on board. Had also all the other Orbiters (Columbia included) received the GPS systems?
Thanks very much
Davide
Hi all
Who knows where to take the drawings are the commander seat drive
Thank you!
Hi all
Who knows where to take the drawings are the commander seat drive
Thank you!
Um.... WHAT?
What parts/systems of the Orbiter were actually reusable as opposed to rebuildable? To start the list obviously the primary structure and TPS (even though it required a lot of inspection) would be considered reusable.
I qualify reusable as systems that only required inspection, minor repair and refueling (if applicable) vs. systems that had to be disassembled and have major work done between flights.
The whole orbiter, except for engines
What parts/systems of the Orbiter were actually reusable as opposed to rebuildable? To start the list obviously the primary structure and TPS (even though it required a lot of inspection) would be considered reusable.
I qualify reusable as systems that only required inspection, minor repair and refueling (if applicable) vs. systems that had to be disassembled and have major work done between flights.
The whole orbiter, except for engines
If that's the case, what was it that made the turn around processing take so much longer than the ordiginal plan? Was it just the TPS inspection/repair process?
If that's the case, what was it that made the turn around processing take so much longer than the ordiginal plan? Was it just the TPS inspection/repair process?
How much LH2 and LO2 were stored on board for fuel cells/water generation and where were the tanks?
Also, how were they insulated to keep the liquids from evaporating when the Orbiter was in the sun?
Last, did the shuttle dump wastewater/urine like Apollo or store it like an airliner?
I didn't know the shuttle had more than a meter of space between its bottom and the bottom of the payload bay. Are there publicly available diagrams?
I often wonder if the Shuttle would have actually have been economical if not for the two DoD requirements that were never used (cross range for single orbit and payload bay length).
I often wonder if the Shuttle would have actually have been economical if not for the two DoD requirements that were never used (cross range for single orbit and payload bay length).
Both requirements were used frequently. Crossrange was never used "for single orbit" but it was used for nominal entry to increase deorbit opportunities, and for TAL site availability.
Both requirements were used frequently. Crossrange was never used "for single orbit" but it was used for nominal entry to increase deorbit opportunities, and for TAL site availability.
That was a case of using what they already had, though, wasn't it? The initial requirement was all Air Force, so far as I understand it, and then once they had it anyway, NASA looked at other things they could so with the capability. Please correct me if I'm wrong.
Both requirements were used frequently. Crossrange was never used "for single orbit" but it was used for nominal entry to increase deorbit opportunities, and for TAL site availability.
That was a case of using what they already had, though, wasn't it? The initial requirement was all Air Force, so far as I understand it, and then once they had it anyway, NASA looked at other things they could so with the capability. Please correct me if I'm wrong.
No, NASA agreed it had similar requirement.
I suppose my question could be rephrased more succinctly as "What's so great about Vandenberg" that NASA felt they needed to build the Shuttle as they did rather than get them to shift to some other launchpad for military-related missions to polar orbit.
To be precise, what made them decide this way in 1972 or so? Any knowledge gained after that time is unfair 20/20 hindsight ;)
I suppose my question could be rephrased more succinctly as "What's so great about Vandenberg" that NASA felt they needed to build the Shuttle as they did rather than get them to shift to some other launchpad for military-related missions to polar orbit.
To be precise, what made them decide this way in 1972 or so? Any knowledge gained after that time is unfair 20/20 hindsight ;)
The final shuttle configuration chosen drove the need to use VAFB for the same reasons that existing launch vehicles used VAFB, no overflight of land during launch.
Both requirements were used frequently. Crossrange was never used "for single orbit" but it was used for nominal entry to increase deorbit opportunities, and for TAL site availability.
That was a case of using what they already had, though, wasn't it? The initial requirement was all Air Force, so far as I understand it, and then once they had it anyway, NASA looked at other things they could so with the capability. Please correct me if I'm wrong.
No, NASA agreed it had similar requirement.
Whoops, we're talking at cross purposes. I meant just the cross-range capability of 1500 miles that the Air Force requested. So far as I know, NASA only wanted 400 and only went along because the White House made it clear they weren't go to get approval for the Shuttle unless they met the USAF's needs too.
Even if that was the case, it wouldn't make your claim (that they "were never used") any less wrong.
I'll let the original shuttle program manager (Robert Thompson) do the correcting. Here's his CAIB testimony:
http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html
It was an existing USAF-controlled facility that allowed polar launches without land overflight and was within CONUS for easier logistics. It had the extra benefit (though I don't think this drove the original decision) that the groundtrack for the single-orbit mission never overflew USSR ground stations.
Yikes. You were actually thinking of launching *north* from Barrow!? Never mind abort safety; the *nominal* launch would be headed straight toward the USSR. I can think of a couple more obvious issues with that than abort safety.
I suppose my question could be rephrased more succinctly as "What's so great about Vandenberg" that NASA felt they needed to build the Shuttle as they did rather than get them to shift to some other launchpad for military-related missions to polar orbit.
To be precise, what made them decide this way in 1972 or so? Any knowledge gained after that time is unfair 20/20 hindsight ;)
The final shuttle configuration chosen drove the need to use VAFB for the same reasons that existing launch vehicles used VAFB, no overflight of land during launch.
Were there any (alternative) shuttle configurations under consideration prior to the final selection which would not have required the use of VAFB for polar orbit flights?
I'm not sure what thread this question should be in. It isn't exclusive to shuttle but applies to shuttle. How do the T-0 umbilical quick releases work?
I have always been fascinated by the fact that a connection can be tight enough to prevent LH2 leaks but release quickly and reliably enough to be pulled away at liftoff.
Explosive bolts to the side of the Orbiter, plus cables in high tension attached to the "plates" of the umbilicals, I believe. At T-0 the bolts blow, the cables pull the umbilical plate into to tail service mast, and a very heavy clamshell door falls closed to shield from booster exhaust.
If that's the case, what was it that made the turn around processing take so much longer than the ordiginal plan? Was it just the TPS inspection/repair process?
You had most of it: "inspection, minor repair and refueling" and include testing and payload bay reconfiguring. As part of "refueling" the OMS and RCS pods were removed. As for the middeck, all the lockers and crew accommodations were removed after each flight.
They were only removed for OMDP requirements and if there was a significant issue that required an LRU to be replaced.
They were only removed for OMDP requirements and if there was a significant issue that required an LRU to be replaced.
OMRSD requirements
Was the ET that was shipped to Port Hueneme in California via the Panama Canal in 1985 ever returned to KSC? If not, what became of it?
I've read in a number of books that the plan was to ship and store the ETs at port Hueneme, and then move them by hovercraft to VAFB. Is that inaccurate?
I've read in a number of books that the plan was to ship and store the ETs at port Hueneme, and then move them by hovercraft to VAFB. Is that inaccurate?
Yes, it is inaccurate. That concept changed died in the mid 70's. There is a boat dock created for the standard ET barge at VAFB and Delta IV now uses it.
http://goo.gl/maps/MnQv7
Question about abort boundaries: During ascent, there will be a transition through the following flour states:
(1) If a single engine is lost, the shuttle cannot make a safe/stable orbit period.
(2) If a single engine is lost, the shuttle can make a safe/stable orbit if an ATO is called.
(3) If a single engine is lost, and no ATO is called, the shuttle will not make its desired orbit, but it will (at the time shutdown occurs as a result of ECO sensors going dry) make a safe/table orbit.
(4) If a single engine is lost, and no ATO is called, the shuttle will, on two engines, make it to a normal guidance-initiated shutdown in it's desired orbit.
(Obviously I haven't listed all the abort boundaries above ... just enough to frame my question.)
Is the transition from "ATO" to "Press to MECO" (for single engine failure) at the transition from (2) to (3) above, or from (3) to (4) above?
Or, put another way, during the period of time where flying on two engines without an ATO call will lead to a safe/stable orbit, but not the desired orbit, is the practice to call ATO on single engine loss, or to press to MECO on single engine loss (knowing that it will likely be an ECO-initiated shutdown prior to desired orbit).
Secondary question: When an ATO occurs, does the shuttle always fly to propellant exhaustion (ECO-initiated shutdown)? Or does abort guidance initiate a shutdown when some acceptable orbit has been attained?
Let me preface this by saying that I am nothing near a rocket scientist so this could be a really dumb question.
Could the External Tank have been made 25% or so smaller (and a decent percentage lighter) if the SSMEs didn't ignite until staging? Even with the 25% lighter liquid fuel/oxidizer load could the SRBs alone have lifted the stack off the pad and got it high/fast enough at staging for the SSMEs to take the orbiter the rest of the way into orbit?
I have always wondered if the use of the SSMEs prior to liftoff was a performance issue or if the system was designed that way solely to have the ability to evaluate SSME function prior to liftoff. I would imagine that without a launch escape system there would be a pretty big risk if the engines didn't start at staging.
What are the holes seen in the TPS of the hatch in this photo?
http://www-pao.ksc.nasa.gov/kscpao/images/medium/2012-5774-m.jpg
What are the holes seen in the TPS of the hatch in this photo?
http://www-pao.ksc.nasa.gov/kscpao/images/medium/2012-5774-m.jpg
like the inspection port they stick a borescope thru to check and make sure the latches have all engagedNot quite. They don't use a borescope for this task but a multimeter to measure the electrical resistance. The resistance should be less than 2.0Ω to indicate an successful latching.
Does anybody have (or can draw even if crude) a diagram of the angle of the stack vs. direction of travel during ascent (after roll). For some reason I can't picture how the orbiter was at a negative AoA vs. the slip stream when it seams like the forward direction would be somewhat on the ET side (based upon the drift at liftoff).
Does anybody have (or can draw even if crude) a diagram of the angle of the stack vs. direction of travel during ascent (after roll). For some reason I can't picture how the orbiter was at a negative AoA vs. the slip stream when it seams like the forward direction would be somewhat on the ET side (based upon the drift at liftoff).
There was some hefty ground equipment (on the pad), among other things, that get the SSMEs up and running.
QuoteThere was some hefty ground equipment (on the pad), among other things, that get the SSMEs up and running.
What is this in reference to? The SSMEs started using head pressure from the ET and their own internal igniters. There was no special GSE related to SSME start except for the sparklers. There was, of course, GSE to fill and pressurize the ET, but none related to starting the SSMEs.
Hi all.
A quick question on the SRB. As part of the modification introduced post-Challenger there was the creation of a so called J-seal in lieu of the zinc chromate putty placed between the two motor segments insulation at the field joint.
The reason for adding such seal, was to avoid imperfection (ie: air pockets) in the injection of such potty which could create an easy way for the exhaust to find their way to the joint. However, based on the attached schematics, it seems to me that this configuration had a weak point in the form of a little corner in the slot cut in the insulation. In fact, the small radius corner would constitute stress concentration point for the high pressure-high temperature exhaust for pushing through the insulation and carving the slot further up to the joint.
Does all of this make sense? Where am I wrong in my thinking?
Thanks very much
Davide
Anyone know if the pre-launch aerosurface check (T-3:55) and gimbal check (T-3:25) is commanded by the GLS or is it the RSLS that commands those?
Thanks. Just to be certain: The GLS did all the commanding from T-9 minutes to RSLS Autosequence Start at T-31 seconds?Anyone know if the pre-launch aerosurface check (T-3:55) and gimbal check (T-3:25) is commanded by the GLS or is it the RSLS that commands those?
Dave, that was commanded by the GLS. We had to simulate the GLS when testing the RSLS. The GLS left the engines in their start-up position when completed with the checks.
The tiles are bonded to thin metal plates, which are screwed to the rest of the hatch structure. The plates cover the access's to the hatch locking mechanism and other things (like the inspection port they stick a borescope thru to check and make sure the latches have all engaged). The plates have to be installed after the hatch is closed, so the tiles have holes thru them to allow the fastenesr to be inserted. The bright white stuff is a filler compound that is stuffed over the fastener heads to protect them.
Hi all.Yes installing those panels was the very last vehicle close outs done before launch. After that, they closed out the white room and evacuated the pad. Those were the only TPS closeouts done in the final countdown. everything else was done before fueling.
I was reading some posts posted few posts ago, in particular this reply concerning the tiles sourrounding the hatch:Quote from: JayPThe tiles are bonded to thin metal plates, which are screwed to the rest of the hatch structure. The plates cover the access's to the hatch locking mechanism and other things (like the inspection port they stick a borescope thru to check and make sure the latches have all engaged). The plates have to be installed after the hatch is closed, so the tiles have holes thru them to allow the fastenesr to be inserted. The bright white stuff is a filler compound that is stuffed over the fastener heads to protect them.
Does this really mean that those tiles were manually screwed on the Orbiter just few hours before launch? it seems to me that there is quite a good number of such tiles had to be installed at the "last minute".
Did they also have to unscrew everything once the Orbiter was back home to allow the astronaut to exit? Regarding this question, I would say no since in case of emergency the astronauts could open the hatch by themself from the inside, right?
Thanks
Davide
My best guess is that it was a back up at this point, unless anyone know for sure of ca point me in the direction of some documentation that I can look through for an answer on the cabling used on flights...
Thanks again for everyone's help!
Eric
Is there any information available detailing how much LOX and LH2 was lost to boil-off during the Shuttle Program, either per year or per launch?
I know each launch required about 735,000kg at lift-off, but I'm curious how much more was needed to support each launch and also how much was needed just to keep the cryo-tanks conditioned correctly between flights?
Does anyone know?
3-5k a week at B due to the perlite problem.
3-5k a week at B due to the perlite problem.
3-5k a week at B due to the perlite problem.
What was the perlite problem?
at http://news.nationalgeographic.com/news/2012/04/120416-nasa-space-shuttle-discovery-smithsonian-360-tour-panorama-science/ there is something called "Russian Panel". Anyone know what its purpose was?
Thanks!
How did the ejection seats worked on the sts-1-4? Where there blow away hatches on top? Are there any drawings / diagrams?
at http://news.nationalgeographic.com/news/2012/04/120416-nasa-space-shuttle-discovery-smithsonian-360-tour-panorama-science/ there is something called "Russian Panel". Anyone know what its purpose was?
Thanks!
That is the control panel for the docking system (hint: read the decals: 'hooks', 'latches', 'ring').. . The Docking System was provided by the Russians and made in Russia, I think. The decals and text on the panel are in English, though.
How did the ejection seats worked on the sts-1-4? Where there blow away hatches on top? Are there any drawings / diagrams?
CDR and PLT would have sure one heckuva headache if there weren't some kind of separable section...Heh, sounds like one of John Young's old Gemini quotes.
Anyone know the angle between vertical and the c/l of the OBSS grapple fixtures?Giving this a bump as I never received an answer on this. This is between the vertical of the OBSS only.
How did the TPS cover the forward attach point after ET sep? In the photos I have seen there isn't an apparent door.
How did the TPS cover the forward attach point after ET sep? In the photos I have seen there isn't an apparent door.
How did the TPS cover the forward attach point after ET sep? In the photos I have seen there isn't an apparent door.
There is an "arrowhead" shaped piece of TPS that has a hole in it for the bolt that separates the forward ET bipod. The whole bipod remains attached to the ET, and the bolt is captured in the Orbiter. The hole is a bit below the mold line of the TPS so thermal issues are mitigated on re-entry.
How did the TPS cover the forward attach point after ET sep? In the photos I have seen there isn't an apparent door.
There is an "arrowhead" shaped piece of TPS that has a hole in it for the bolt that separates the forward ET bipod. The whole bipod remains attached to the ET, and the bolt is captured in the Orbiter. The hole is a bit below the mold line of the TPS so thermal issues are mitigated on re-entry.
Does anybody have a link to a good closeup picture of the "arrowhead" either with ET attached or without?
Does anybody have a link to a good closeup picture of the "arrowhead" either with ET attached or without?
That STS-133 picture is great but now I'm confused. I pictured the ET bipod having a ball at the end and this ball going into the hole in the arrowhead and then an explosive bolt holding the ball in. I figured upon ET separation the bolt would blow and the ball would come out of the hole leaving a hole in the orbiter belly.
In that picture, it appears as if the silver colored metal is almost flush with the bronze/gold colored ring.
So what exactly is (was) the attachment/separation method of the forward ET addach point.
AnalogMan - what is the source for your excellent drawing?
3) What was the process of mating this attach point? Was it something like half of the bearing plate and the piston assembly in attached to the orbiter while the other half of the bearing plate, the bolt and the ball attached to the ET and then the two halves joined with fasteners?
I've attached a cross-sectional drawing of the head-end of the bolt
1) What locked the piston in the down position so that it stayed flush with the ball?
2) Related to #1, what locked the ball in the "flat" position?
AnalogMan,
Thanks for posting that. It makes sense now. I have 3 other questions related to this:
1) What locked the piston in the down position so that it stayed flush with the ball?
2) Related to #1, what locked the ball in the "flat" position?
3) What was the process of mating this attach point? Was it something like half of the bearing plate and the piston assembly in attached to the orbiter while the other half of the bearing plate, the bolt and the ball attached to the ET and then the two halves joined with fasteners?
This was an amazing piece of engineering, I guess that's why I'm so interested into such a small part fo the system.
Another interesting tidbit is how the Orbiter is aligned relative to the ET. The center of the forward orbiter fitting is 220.34 inches above the ET center line, and the centers of the aft orbiter fittings are 204.06 inches above the ET center line. So the front is 16.28 inches above the back and, when divided by the 928 inch horizontal separation, trigonometry shows that the Orbiter attachment plane sits 1.0 degree nose-high w.r.t. the ET center line.
Anyone know the angle between vertical and the c/l of the OBSS grapple fixtures?
That is with the starboard MPMs that hold the OBSS in the deployed configuration?Anyone know the angle between vertical and the c/l of the OBSS grapple fixtures?
If you are looking out the aft windows the grapple pin on the forward grapple fixture is rotated 10.5 degrees clockwise from vertical.
True, but the forward attachment is at the outer mold line while the aft attachments are recessed in the umbilical wells so the angle in regards to the belly of the orbiter (which is slightly convex anyways) would be greater than 1 deg. Does anyone know the actual angle of attack of the wings in relation to the ET CL?
That is with the starboard MPMs that hold the OBSS in the deployed configuration?Anyone know the angle between vertical and the c/l of the OBSS grapple fixtures?
If you are looking out the aft windows the grapple pin on the forward grapple fixture is rotated 10.5 degrees clockwise from vertical.
Thanks.That is with the starboard MPMs that hold the OBSS in the deployed configuration?Anyone know the angle between vertical and the c/l of the OBSS grapple fixtures?
If you are looking out the aft windows the grapple pin on the forward grapple fixture is rotated 10.5 degrees clockwise from vertical.
Correct.
Another question: Anyone know if the aft orbiter attachments are bolted when the orbiter is mated to the OTS or if they're unbolted and the orbiter just rests on the attachments when it is mated to the OTS?
Yes but we're not talking tornado/hurricane winds here. They never moved an orbiter with even TS speeds observed. Even sitting on its landing gear in 30kt winds won't move it much.Another question: Anyone know if the aft orbiter attachments are bolted when the orbiter is mated to the OTS or if they're unbolted and the orbiter just rests on the attachments when it is mated to the OTS?
I'm going to hazard a guess and say bolted. Remember the thing has wings! Wind gusts have been known to relocate aircraft. ;)
Why was the OTS needed? Couldn't a lot of development and operational money have been saved by just towing the orbiters on their landing gear? When they went from the OPF to the VAB they could lift them with the cranes and then retract the gear. Had this method been designed from the get go you would think that provisions could have been designed in to allow the gear closeout procedure to be done in the VAB like that.
Why was the OTS needed? Couldn't a lot of development and operational money have been saved by just towing the orbiters on their landing gear? When they went from the OPF to the VAB they could lift them with the cranes and then retract the gear. Had this method been designed from the get go you would think that provisions could have been designed in to allow the gear closeout procedure to be done in the VAB like that.
Why was the OTS needed? Couldn't a lot of development and operational money have been saved by just towing the orbiters on their landing gear? When they went from the OPF to the VAB they could lift them with the cranes and then retract the gear. Had this method been designed from the get go you would think that provisions could have been designed in to allow the gear closeout procedure to be done in the VAB like that.This is how it was done until 1989.
It was needed to transport the Orbiters from the final assembly building at Palmdale to Edwards Air Force Base for ferry flights to KSC. Also would have been needed for operations at VAFB, I believe.
Initially Orbiters were towed on their landing gear at KSC from OPF to VAB. Then the "tow-around" tires were exchanged with flight tires in the VAB. Once the transporter was no longer needed (Palmdale got VAFB's MDD), KSC got it. I believe KSC has Vandenberg's transporter, and the Palmdale one stayed in Cali, only recently to be used in OV-105's parade.
What was the difference between the OLF and the MDD? Was it just the work platforms? Was there anything that could be done with the MDD that couldn't with the OLF?
What is the story behind this photo showing Enterprise and Columbia together?Couple of pictures (I believe NASA pictures) that were taken on one of the occasions when they were briefly together at Dryden. Another pic here:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=17437.0;attach=492192;image
True, but the forward attachment is at the outer mold line while the aft attachments are recessed in the umbilical wells so the angle in regards to the belly of the orbiter (which is slightly convex anyways) would be greater than 1 deg. Does anyone know the actual angle of attack of the wings in relation to the ET CL?
I saw this photo over in the STS-135 walkdown thread. To my uncalibrated eye, it looks like the center of the ball fitting is pretty close to the Orbiter OML. But I don't have any drawings to back that up.
F=ma
DPS question: Is the scratchpad cleared when the crew completes an entry (like ITEM 19 EXEC) or does it remain afterwards?
It remained on the scratchpad until the crew either pressed CLEAR or started a new key sequence.
...
So, what exactly does "Snoopy Maneuver" mean?
...
So, what exactly does "Snoopy Maneuver" mean?
SNOOPY - Shuttle Nose Out-Of-Plane Yaw
...
So, what exactly does "Snoopy Maneuver" mean?
SNOOPY - Shuttle Nose Out-Of-Plane Yaw
Wow, that was fast! Thanks a lot!
What is the purpose of this maneuver? Alignment of the Orbiter's X-axis with the PMA?
On certain launch dates where the beta angle at docking was predicted to be large, the Russians wanted to point the FGB solar arrays out-of-plane for better power generation during approach. This required a 90 degree shuttle yaw to keep the docking mechanism clocked properly. The yaw would have been performed at 170 ft.
This maneuver was actually designed for the STS-71 shuttle-Mir mission and would have been required if the mission had launched in early June 1995. The launch slipped to late June and this allowed the normal approach to be used.
Did any of the retired orbiters have any of their frame / structure inspected / tested to see how well their life expectancy measured up to predictions? I assume that each flight put loads on the structure such that it would fatigue- much like how commercial aircraft are limited to a certain amount of "cycles"?
Thank you.
Second relates to launch. I head it is possible for the crew to fly a manual ascent. How is this achieved?
Via the hand controller and throttle, using guidance generated cues on the ADI. Basically, only useful in few instances, since it is not a backup to a guidance or control system failures since those are still required during "manual" control.
Via the hand controller and throttle, using guidance generated cues on the ADI. Basically, only useful in few instances, since it is not a backup to a guidance or control system failures since those are still required during "manual" control.
Ken Reightler is of the opinion that this was impossible in first stage ascent. I'm inclined to agree. Trying to manually vector SRB's is going to do nothing but flip the vehicle over.
Via the hand controller and throttle, using guidance generated cues on the ADI. Basically, only useful in few instances, since it is not a backup to a guidance or control system failures since those are still required during "manual" control.
Ken Reightler is of the opinion that this was impossible in first stage ascent. I'm inclined to agree. Trying to manually vector SRB's is going to do nothing but flip the vehicle over.
The Flight Rules forbade manual ascent prior to 1:30 anyway.
Jorge, do you remember the split-s abort mode tests?Wow, blast from the past...didn't this come up during the first RTF period?
Jorge, do you remember the split-s abort mode tests?Wow, blast from the past...didn't this come up during the first RTF period?
Still sounds interesting, thanks.Jorge, do you remember the split-s abort mode tests?Wow, blast from the past...didn't this come up during the first RTF period?
Good memory - yes it did. I believe only one crew member was able to successfully fly the split-s (and leave the wings on in post abort analysis). Kind of part abort and part air show.
For those curious it was a proposed contingency abort mode in first stage with three engines out. I believe with the vehicle flying an inverted loop in pitch. That was a long time ago.
Are there any diagrams or photos of the AFRSI on Discovery during the time of STS-26R?You mean the upper surface of the "entire" orbiter, right? Which diagram? The one I see in Chapter X of the 3rd Edition doesn't look like that to me. (From a texture standpoint, the FRSI on a lot of the payload bay door area and parts of the wing upper surface stand out in pictures/person.)
The diagram seen in Jenkin's book shows the AFRSI covering the entire orbiter from nose to aft fuselage. Is this accurate?
Could someone find a larger photo of this and more photos of Discovery at Rockwell Int from the 80s before her first flight?There are some on L2.
Anyone have any data on the clearance between the SRMS End Effector and PLB Camera "B"? This is with the SRMS cradled and stowed and the camera in 0 pan and 0 tilt.
Could someone find a larger photo of this and more photos of Discovery at Rockwell Int from the 80s before her first flight?There are some on L2.
There are also a few from the overland transport, at Dryden (getting spotted in the MDD), and during the first ferry hop to Vandenberg in early November, 1983 -- in the set referred to here:
http://forum.nasaspaceflight.com/index.php?topic=13952.msg1014581#msg1014581
(Not necessarily highlighting the mid-fuselage side walls, but they might be worth looking at.)
Thanks. For some reason I had missed that in the SCOM. Now on to something else.Anyone have any data on the clearance between the SRMS End Effector and PLB Camera "B"? This is with the SRMS cradled and stowed and the camera in 0 pan and 0 tilt.
Somewhere very close to 5 inches.
You can derive this distance from information in the Shuttle Crew Operations Manual (posted on the JSC FOIA page). For example, this document shows the CCTV B pivot point is at X+1294 and says that the camera is sixteen inches long, so it would extend to roughly X+1286. Elsewhere in the document you can figure out that the RMS EE pokes a little past X+1280.
What was the "orientation" of the Shuttle in orbit relative to the earth's surface? Was it always top facing earth or was it top facing sun or did it vary by mission?
Wouldn't the Earth's heat affect the radiators efficiency?What was the "orientation" of the Shuttle in orbit relative to the earth's surface? Was it always top facing earth or was it top facing sun or did it vary by mission?
It varied by mission, but payload bay to earth was the most prevalent.
I was down at KSC today, and we took the launch pad tour. I was curious as we got over to LC-39B to see the lightning protection system up close.
I noticed there's a "spider's web" of wires up top, with a diamond-shaped hole big enough for what looked like the Ares rocket. For STS-125, LON-400 was on the pad out there... Were those wires up top there for that mission as well? They just didn't seem to make a hole big enough for the stack, so I was curious how that would work. Can provide pics if necessary, but I don't have editing tools with me so it'd be a pretty big file..
Thanks!
(P.S. forgive my choice in pics. Thought it would raise a few eyebrows... ;)
I just thought of something: how come certain space-dedicated websites or space historians misinterpret the STS-1 FRF on February 20, 1981 with the actual liftoff on April 12, 1981? I can tell that some of the photos belong to the FRF because of two reasons:
1: No clouds during the FRF, but clouds during the launch.
2: The smoke from the heated Sound Suppression System stands higher than Columbia in the FRF photos because the shuttle just stays on the pad and the engines fire for 20-22 seconds.
Do you think that is a reasonable stating?
Another difference is the brightness in the FRF pictures.
That's a good difference, but also, the weather and the exhaust smoke are two other differences.
I just thought of something: how come certain space-dedicated websites or space historians misinterpret the STS-1 FRF on February 20, 1981 with the actual liftoff on April 12, 1981?Because it doesn't mean as much to them as it does to us? There's a good deal of casually published information online across lots of subjects and this is one of them.
Right, better to look for differences in the test configuration from a launch configuration -- couple others besides the cargo net are the heat shield on the MLP and the OMS engine nozzle bags. Both being details that would probably go unnoticed by a general audience.Another difference is the brightness in the FRF pictures.
Can't depend on that due to photo processing and archiving issues.
Regarding the shuttle hull material.
Is the green hull material painted aluminum or something else? Are the struts titanium or aluminum?
This description of the "original" Shuttle design with the flyback booster was posted on the SpaceX board.
http://www.wired.com/wiredscience/2013/02/where-to-launch-and-land-the-space-shuttle-1972/
How far did they get with the "original" design, before switching to the SRBs and external fuel tank ? I assume they switched due to schedule/funding, or was their some technical reason ?
Regarding the shuttle hull material.
Is the green hull material painted aluminum or something else? Are the struts titanium or aluminum?
Does anyone know the throat and base diameter as well as the length of the OME nozzles?
Why does the Shuttle have wings?
This question was raised at the Columbia + 10 conference last week at GWU. The response was graded as "incomplete"......so I thought this might be a good thread to have the COMPLETE discussion.....
ready....GO!
Why does the Shuttle have wings?
This question was raised at the Columbia + 10 conference last week at GWU. The response was graded as "incomplete"......so I thought this might be a good thread to have the COMPLETE discussion.....
ready....GO!
Better lift over drag equals bigger cross range.
Danny Deger
Was failure and breakup of the ET after discarding induced in some way? Wether through some destructive mechanism, or some sort of intergrated failure points? Or was it purely aerodynamic forces on falling that broke it apart?
Another question along the same lines, is it known how large the fragments that reached the ocean were?
Wasn't the GOX vent valve left open after sep to promote tumbling?No; early tanks had a separate tumble valve, but it was eventually deleted. There's a good deal of film/video shot by the flight crews of the LH2 vent valve relieving, post sep.
What was the average altitude/velocity when the first stage roll program was initiated at?
What was the average altitude/velocity when the first stage roll program was initiated at?
And the entry director, is he based in Houston or KSC?All post-launch activities were controlled from the regular shuttle FCR in the MCC. The FRs were used to support post-landing activities starting at hand-off from MCC to KSC once ground cooling and purge were activated.
What will become of the Orbiter Transporter that was used to transport the orbiters from the OPF to the VAB now that it's use of moving Atlantis is over?
What will become of the Orbiter Transporter that was used to transport the orbiters from the OPF to the VAB now that it's use of moving Atlantis is over?
Sold to another user, given to a museum or sold for scrap. In that order.
Durring the move from the VAB to the KSCVC last year, there were Beyel Brothers logos on the OTS in several locations, but I don't know if that was because they had purchased it or just because they were opperating it at the time.
Two questions:
Were the OMS/RCS pods used interchangeably through the orbiter fleet or did the same pods normally go up with the same orbiter?
When did the removal of the LRSI tiles take place?
They were interchanged.
LSRI tiles where? OMS pods OV-099. whole vehicle, OV-103
So Columbia went through her whole career with the LRSI tiles?OV-102 (only OV-102) did have a significant number replaced with blankets on the mid-fuselage sidewalls during the long stand-down after the 51-L accident. As Jim noted, beginning with OV-103 new vehicles were delivered from Palmdale with extensive use of blankets. IIRC, there's a contemporary video...let me see if I can find it on YouTube. (Edit: sorry, couldn't find it on YT...I think it was played on NASA TV back around the 25th anniversary of STS-1.)
I don't know where I got the impression that the orbiters came from Rockwell with the tiles and were refitted with blankets later on.
For sts-71, the first docking to Mir, what were the reasons to dock with Spacelab instead of SPACEHAB?
As a tangental follow-up to my earlier question:10 OMS Pods (2/vehiclex5) and 5 FRCS modules (1/vehiclex5).
How many OMS and FRCS pods did the fleet have?
As a tangental follow-up to my earlier question:10 OMS Pods (2/vehiclex5) and 5 FRCS modules (1/vehiclex5).
How many OMS and FRCS pods did the fleet have?
True but they could be mixed (OMS pods that is, it's my understanding that FRCS modules were vehicle specific and could not be swapped between vehicles).As a tangental follow-up to my earlier question:10 OMS Pods (2/vehiclex5) and 5 FRCS modules (1/vehiclex5).
How many OMS and FRCS pods did the fleet have?
One set per vehicle
Hello,
An question asked a few pages ago ;D
On launch day one of the crew picks up the phone next to the orbiter access arm.
Are they phoning home ??? ;D ;D
Who gets called and why?
Has +X RCS maneuvers always been used post-MECO or was that a later addition?
Anyone know the targeted date for STS-62A at the time of the loss of the STS-51L mission?A slip to NET mid-July was announced in late November. Given the ongoing schedule slips for the other orbiters in January before the accident and the upcoming planetary windows in May, it may have been further back unofficially by the end of month. (I don't think addressing the hydrogen entrapment pad issue had been factored into publicly announced dates.)
In the MCC replays, at liftoff somebody says "liftoff confirmed".
What is being used to determine "liftoff"?
Also;
What requirements must be met for MET to start counting up?
Thank you.
How was Enterprise connected to the SCA's aft connectors for the ALT series of tests, since the ET umbilical doors had to be closed?
Sorry if this has been asked before.. But after the loss of STS-107, was there ever the slightest talk about replacing Columbia with another shuttle? Or even replacing the entire fleet with new shuttles?
Sorry if this has been asked before.. But after the loss of STS-107, was there ever the slightest talk about replacing Columbia with another shuttle? Or even replacing the entire fleet with new shuttles?
Not new shuttles, but new systems such as OSP, commercial crew, etc.
But after the loss of STS-107, was there ever the slightest talk about replacing Columbia with another shuttle?Perhaps a little, but there was more serious talk and consideration to ending the program at that point.
Or even replacing the entire fleet with new shuttles?No.
Another question: When retracted and the doors closed, does the NLG tires rest on the inside of the doors or is are they above them?
Another question: When retracted and the doors closed, does the NLG tires rest on the inside of the doors or is are they above them?
Are there any contingency plans if the ET doesn't separate?
Are there any contingency plans if the ET doesn't separate?
No survivable scenarios existed
Which brought to mind a question I've wondered about for a while. Lots of SF stories describe various vehicles and structures built from expended Shuttle external tanks. Was it even possible for the Shuttle to take the tank all the way into orbit?
The shuttle was suborbital at the time of ET sep for the specific reason of ET disposal.
The shuttle was suborbital at the time of ET sep for the specific reason of ET disposal.
I understand that...so would this have been a longer main engine burn (was there enough prop for that) or OMS?
On the front of the Shuttles, there are always white streaks near the nose. What is that?
Now here's a personal one for you, Jim. How do you know so much about the Shuttle off the top of your head?
Now here's a personal one for you, Jim. How do you know so much about the Shuttle off the top of your head?http://forum.nasaspaceflight.com/index.php?topic=24176.0
The shuttle was suborbital at the time of ET sep for the specific reason of ET disposal.
I understand that...so would this have been a longer main engine burn (was there enough prop for that) or OMS?
Now here's a personal one for you, Jim. How do you know so much about the Shuttle off the top of your head?http://forum.nasaspaceflight.com/index.php?topic=24176.0
(That is one place to start, but there are others.)
Anyone know the depth of the two ET umbilical wells on the orbiter?
When it comes to shuttle launching, you can see the shuttle do the roll-to-heads-up maneuver thru the ET cam. For night launches such as STS-116, STS-123, STS-126, STS-128, and STS-130, which direction do the shuttles roll? I believe it's the GUIDANCE officer's choice.No, that was the onboard (automated) guidance. That was discussed here in (sort of) real-time on several ascents (STS-132 comes to mind, since the CDR called down that he 'got it'). I'm sure the pros can elaborate, but I'll see if I can find a couple of old posts.
When it comes to shuttle launching, you can see the shuttle do the roll-to-heads-up maneuver thru the ET cam. For night launches such as STS-116, STS-123, STS-126, STS-128, and STS-130, which direction do the shuttles roll? I believe it's the GUIDANCE officer's choice.No, that was the onboard (automated) guidance. That was discussed here in (sort of) real-time on several ascents (STS-132 comes to mind, since the CDR called down that he 'got it'). I'm sure the pros can elaborate, but I'll see if I can find a couple of old posts.
STS-132 -- start here, and continue in chronological order:
http://forum.nasaspaceflight.com/index.php?topic=21594.msg589222#msg589222
STS-122:
http://forum.nasaspaceflight.com/index.php?topic=11773.msg239557#msg239557
There's also a great ascent/aborts procedures handbook on L2 that goes into some technical detail.
In a non malfunction scenario, do the ssme's always gimball together or are there times when one needs to be gimballed "out of sync" with the others?
Some time ago I posted a youtube video of sts-123 launch from inside the cockpit. There was a C&W alarm that sounded. The video is gone :( Anybody know where I can find it? Thanks!Web search: "sts-123 launch cockpit"
Some time ago I posted a youtube video of sts-123 launch from inside the cockpit. There was a C&W alarm that sounded. The video is gone :( Anybody know where I can find it? Thanks!
http://forum.nasaspaceflight.com/index.php?action=profile;u=14524;area=showposts;start=30
"bias in the PC booster" 1:47
what does that mean?
whats with the counting right after liftoff?
also, is that a C&W alarm going off at 3:09 ?
also, compared to the handful of cabin vids ive seen this crew seems more vocal about their emotions ("i love you guys"), and more excited in their tone of voice (engine ig and liftoff) than others.
As a programmer I am fascinated and amazed by flight computers.
In regards to the GPC's, has there ever been a fault during a mission that was attributed to a software bug?
Thanks!
I am looking for a "primer" on open loop vs closed loop guidance.
Why doesn't the shuttle use closed loop from launch all the way up?
Thanks!
I am looking for a "primer" on open loop vs closed loop guidance.
Why doesn't the shuttle use closed loop from launch all the way up?
Thanks!
Because it has to ride out winds aloft. It worries about q alpha vs proper path to orbit
Here is a really good paper explaining the shuttle day of launch trajectory design process; peruse it and you will learn all about q and alpha and much more. The author knows whereof he speaks, he was involved in the process for many shuttle missions. Read through it and come back if you still have questions.I am looking for a "primer" on open loop vs closed loop guidance.
Why doesn't the shuttle use closed loop from launch all the way up?
Thanks!
Because it has to ride out winds aloft. It worries about q alpha vs proper path to orbit
If I understand the part about the winds- if closed loop, correcting for winds might overstress the stack?
q alpha?
That PDF won't load for me. Anyone else?
I am looking for a "primer" on open loop vs closed loop guidance.
Why doesn't the shuttle use closed loop from launch all the way up?
Thanks!
Because it has to ride out winds aloft. It worries about q alpha vs proper path to orbit
If I understand the part about the winds- if closed loop, correcting for winds might overstress the stack?
q alpha?
As a programmer I am fascinated and amazed by flight computers.
In regards to the GPC's, has there ever been a fault during a mission that was attributed to a software bug?
Thanks!
1. The problem you have with closed loop guidance in first stage is how to determine winds in real time and then feeding that back into guidance in time. If you work out a method for measuring the winds aloft in real time while going supersonic, let me know. It's something I've pondered for years. Using a ground system was probably not workable due to the possibility of dropouts for the radio uplink.
2. We always considered it bad form to reach orbit without the wings attached (:-)) and that is what you are trying to prevent by managing dynamic pressure on the various surfaces. So we stayed open loop until second stage. The penalty wasn't that great since you can think of the whole purpose of first stage is just to accelerate enough for second stage flight and get out of the heavier atmosphere.
Am I incorrect in recalling that Challenger encountered high winds / shear and because of that and of the venting / igniting of the fuel leak the computers commanded corrective actions? If so, how is that possible in open loop?
What happens with pressure transducers at supersonic speeds? That's not the information you need or you simply can't react fast enough?
Am I incorrect in recalling that Challenger encountered high winds / shear and because of that and of the venting / igniting of the fuel leak the computers commanded corrective actions? If so, how is that possible in open loop?
Meanwhile, the Shuttle wastewater tank was pressurized by N2, but there is no mention of heating, so presumably it's kept at about room temperature. Thus, the Ostwald solubility coefficient would be about 0.017, yielding a theoretical exit velocity of 15.25 m/s which also agrees very well with the observed velocity.
http://www-personal.umich.edu/~youxue/publications/Zhang2000JVGR.pdf
The shuttle water tanks were in the lower equipment bay, in the pressurized crew module. To a first approximation, they were the same temperature as the middeck, so room temperature is a good bet. No heaters on the tanks.
Do you know if they were at 120 C like the ISS nozzles?
Sorry in advance for my bad English. I would like to ask if there is a specific point through which space shuttles in orbit choose for their re entry in the atmosphere.
Is there a way to calculate from which location above Earth will be initiated a re entry procedure in order for a shuttle to land in South Mexico? And while the re entry is in progress above which parts of our planet will the shuttle fly?
I read somewhere that to get to Canaveral a shuttle in orbit must abandon orbit and fall in the atmosphere when it is above the Indian Ocean.It depends on the actual orbit. For example, the de-orbit burn for STS-107 occurred over Australia. The goal is always the same: put the Entry Interface position approximately 4400 nautical miles from the landing site which in this case was KSC. If I remember correctly, the entry angle targeted was 1.5°. EI always occurred over the Pacific, never the Indian Ocean.
I calculated that if a shuttle wants to land on Yacatan it has to proceed to de-orbit burn over Mauretania in Africa. If it is correct how much time will it take to reach Mexico?I read somewhere that to get to Canaveral a shuttle in orbit must abandon orbit and fall in the atmosphere when it is above the Indian Ocean.It depends on the actual orbit. For example, the de-orbit burn for STS-107 occurred over Australia. The goal is always the same: put the Entry Interface position approximately 4400 nautical miles from the landing site which in this case was KSC. If I remember correctly, the entry angle targeted was 1.5°. EI always occurred over the Pacific, never the Indian Ocean.
Time from de-orbit burn to wheelstop is approximately 1 hour. It's slightly longer if it was a HST service mission due to the higher orbital altitude.I calculated that if a shuttle wants to land on Yacatan it has to proceed to de-orbit burn over Mauretania in Africa. If it is correct how much time will it take to reach Mexico?I read somewhere that to get to Canaveral a shuttle in orbit must abandon orbit and fall in the atmosphere when it is above the Indian Ocean.It depends on the actual orbit. For example, the de-orbit burn for STS-107 occurred over Australia. The goal is always the same: put the Entry Interface position approximately 4400 nautical miles from the landing site which in this case was KSC. If I remember correctly, the entry angle targeted was 1.5°. EI always occurred over the Pacific, never the Indian Ocean.
I know that the Spacelab (LM 1) module is on dispaly at the Udvar Hazy Centre in Virginia alongside Space Shuttle Discovery.
Where is the Spacelab LM 2 module stored?
Thank you.
Can anyone inform me what the average costs where to make an orbiter and strb's reusable again after flight.
What is the average altitude of the shuttle after reentry that it starts to 'fly'
What is the average altitude of the shuttle after reentry that it starts to 'fly'
What is the average altitude of the shuttle after reentry that it starts to 'fly'
What is the average altitude of the shuttle after reentry that it starts to 'fly'
Question on the Payload Bay Doors: Is the lengths of areas Xf and Xa in the attached photo the same in the Z plane?
What are the approximate floor dimensions of the mid-deck?
What was the reason for the first 3 ALT flights to have the tail cone in place?
Has anyone here seen this image before?
This one is a prototype for the CBM, about the time that VonBraun was working on the design for SS freedom.
What was the reason for the first 3 ALT flights to have the tail cone in place?
But why the 3 test with cone while the real orbiter obviously never lands with it
But why the 3 test with cone while the real orbiter obviously never lands with it
Incremental testing. It was deemed too risky to start the testing off the SCA without the tailcone.
There were really only two SCAs?Yes, and the second purchase only came out of recovery from the 51-L accident.
But why the 3 test with cone while the real orbiter obviously never lands with it
What is omicron?
I think I have heard it being read up to the crew from MCC possibly as part of the numbers called up for a burn.
Thanks
What is omicron?
I think I have heard it being read up to the crew from MCC possibly as part of the numbers called up for a burn.
Thanks
Hello
I have seen the Space Shuttle Tile key created by NASA and I was wondering if there was another similar key or information about the whereabouts of various components in the fuselage and payload bay. If anybody has one, it would be greatly appreciated if you could post it.
Is there a list or if I subscribe to L2 can I get that information?
According to this post (http://forum.nasaspaceflight.com/index.php?topic=17437.msg1084552#msg1084552), the Shuttle was not supposed to launch with an empty payload bay. However, the STS-400 Hubble rescue flight was designed to launch with an empty payload bay (and indeed, the 39B modifications wouldn't have allowed a payload anyway).
Can someone explain the discrepancy? Was the trajectory modified as the linked post speculates?
How much ballast? And where would they put it? They can't put it in the payload bay, since 39B was no-go for payload operations during the STS-125 launch campaign. (Or am I wrong about that last bit?)Among other things there are ballast boxes in the aft compartment. There's a good amount of STS-400 documentation on L2...did you look at that? (At least one of the versions there notes that the flight design allowed for those to be empty.)
How much ballast? And where would they put it? They can't put it in the payload bay, since 39B was no-go for payload operations during the STS-125 launch campaign. (Or am I wrong about that last bit?)
Among other things there are ballast boxes in the aft compartment. There's a good amount of STS-400 documentation on L2...did you look at that? (At least one of the versions there notes that the flight design allowed for those to be empty.)
They can put it in while the vehicle was in the OPF.
When the US Air Force entered its requirement for a certain cross range capability, apparently they did so in order to be able to snatch and run with Soviet satellites. then land in the USA all in one single orbit. In reality was this even possible.
I would think that the early Shuttle launches were followed very closely by the Soviets. Any evidence to support that the Soviet military raised their defense conditions when STS would be overflying Soviet territory.
Does anyone know when the OWP doors went up on the FSS?Pad B had the +Y OWP Curtain Wall from the onset it went into service for the shuttle program in 1985 for the STS-51L flow. It was however missing the -Y OWP Curtain Wall on the RSS. This was added later in 1986 in time for the practice sessions with Atlantis in October 1986.
How were the strongbacks attached to/detached from the payload bay doors? My question is two-fold. First, I'd like to know what they attached to and how those attach points were uncovered/covered.
The second part is on the pad, what was used to handle them in the RSS?
At the exhibit, the doors are held by several cables. I think at least 6 or 7 per door.
What were the enterprise tiles made out of and why didn't they have the same issues getting them to stick as the Columbia tiles?
1. In an article I was reading about the TPS and the issues they had early on, it mentioned that there was some ablative TPS installed between elevons. Why was this needed and can it be seen in any pictures?
2. How was the surface kept "flat" when they changed some of the tiles to the blankets? Did they make the blankets the exact same thickness that the tiles were or did they add spacers?
3. What were the enterprise tiles made out of and why didn't they have the same issues getting them to stick as the Columbia tiles?
At the exhibit, the doors are held by several cables. I think at least 6 or 7 per door.
Looks like 6 per door to me:
http://forum.nasaspaceflight.com/index.php?topic=32414.msg1129139#msg1129139
I guess that has to change for the SLS, since there's no orbiter anymore.
Thanks again,
-Mike
Oh that's interesting! I never knew that the liquids flowed through the engines and then all the way up the pipes on the sides to reach the tanks. Thanks, that really explains it. I guess that has to change for the SLS, since there's no orbiter anymore.
(the tanks fill from the bottom up, not from a inlet on top. There is no faucet like a bath tub, just the drain and the propellant comes in through the same orifice that it leaves. Hence the term like fill and drain valves)That makes sense. Since you fill from the bottom, would you have to overcome the pressure generated by the column of fuel/oxidizer? I'm sure that's a basic physics question, but this is an interesting education today.
Quote(the tanks fill from the bottom up, not from a inlet on top. There is no faucet like a bath tub, just the drain and the propellant comes in through the same orifice that it leaves. Hence the term like fill and drain valves)That makes sense. Since you fill from the bottom, would you have to overcome the pressure generated by the column of fuel/oxidizer? I'm sure that's a basic physics question, but this is an interesting education today.
Thanks again,
-Mike
That makes sense. Since you fill from the bottom, would you have to overcome the pressure generated by the column of fuel/oxidizer? I'm sure that's a basic physics question, but this is an interesting education today.
Is the fill/drain line from the MPS in to the ET different than the orifice/17" line that carried the prop from ET to MPS during actual engine firing?
To be complete, how is excess propellant dumped on orbit, though the nozzle and/or the fill and drain valves before the He purge?
I imagine the smaller ones are for pressurizing the LOX and LH2 tanks via the MPS during flight.
I should add the "staining/streaking" aft of the port side (LH2) interface was more pronounced on the TPS than on the starboard side.
What was the first shuttle flight that had full orbital communicatons (so no LOS)?
Quick question about the IUS and PAM-D upper stages. After having deployed the upper stage, the Shuttle had to orient itself, in such a way to use the belly as a shield from the upper stage rocket exhausts. Obviously by the time the upper stage fired the orbiter would have been at a certain distance, but what if some damage occurred to the belly?There was a sequence of post-deploy separation burns with a pretty large one (relatively speaking) at the end, so by the time of upper stage ignition it was fairly great distance.
There was a sequence of post-deploy separation burns with a pretty large one (relatively speaking) at the end, so by the time of upper stage ignition it was fairly great distance.
Press kits say to protect the orbiter windows:QuoteThere was a sequence of post-deploy separation burns with a pretty large one (relatively speaking) at the end, so by the time of upper stage ignition it was fairly great distance.
that's true, but why then taking anyway the precaution of using the belly as a shield? it was fairly distance, it wouldn't have mattered the shuttle attitude at the time of upper stage ignition.
At approximately 45 minutes after ejection from the orbiter,
the pyrotechnic inhibits for the first solid rocket motor are
removed. The belly of the orbiter has been oriented towards the
IUS/DSP combination to protect the orbiter windows from the IUS's
plume. The IUS recomputes the first ignition time and maneuvers
necessary to attain the proper attitude for the first thrusting
period.
I know the Apollo astronauts trained and could theoriticly fly the Saturn V to orbit, but I also remember reading the Shuttle could not because of the complexity of the boost phase. Another gent is telling me this was only true under stage 1 boost (SRB powered) but after they were jettisoned the Shuttle could be manually flown to orbit.
Thought? TIA.
I know the Apollo astronauts trained and could theoriticly fly the Saturn V to orbit, but I also remember reading the Shuttle could not because of the complexity of the boost phase. Another gent is telling me this was only true under stage 1 boost (SRB powered) but after they were jettisoned the Shuttle could be manually flown to orbit.
Thought? TIA.
How would the sim operator have known that?
I have some knowledge of the SMS models, BTW.
How was SRB ignition synchronized? I'm interested in the design of the control system that guaranteed the ignition signals would arrive simultaneously to each SRB. Did it require that the communication wiring from the orbiter to the SRBs be exactly the same length to each one?
What was the maximum acceptable difference in ignition time between the two SRBs?
How was SRB ignition synchronized? I'm interested in the design of the control system that guaranteed the ignition signals would arrive simultaneously to each SRB. Did it require that the communication wiring from the orbiter to the SRBs be exactly the same length to each one?
What was the maximum acceptable difference in ignition time between the two SRBs?
The problem that caused the STS-98 rollback was that on STS-97/4A one of two explosive cartridges called NASA Standard Initiators (NSIs) on the left SRB ETAR that connects the SRB with the ET failed to fire. The second one did fire and SRB sep was successful. The problem was traced to a wiring fault that prevented the separation signal from reaching the NSI.How was SRB ignition synchronized? I'm interested in the design of the control system that guaranteed the ignition signals would arrive simultaneously to each SRB. Did it require that the communication wiring from the orbiter to the SRBs be exactly the same length to each one?
What was the maximum acceptable difference in ignition time between the two SRBs?
The only electrical connection between the Orbiter and the rest of the stack is through the ET umbilicals. The SRBs had cables to the ET. Tom Jones recalls in his book STS-98 being rolled back to inspect/replace those cables because there had been a failure on a previous mission (STS-97?) where the primary pyrotechnics on the hold-down nuts did not fire, but the redundant set did.
The previous posts about CSS during ascent made thing if instead performing CSS during entry and TAEM would have been more realistic and survivable?
Davide
You could certainly fly reentry by hand, from deorbit burn to landing. Crews routinely trained for it.
Engle did most if not all of it on STS-2.
The previous posts about CSS during ascent made thing if instead performing CSS during entry and TAEM would have been more realistic and survivable?
Davide
It's PCMMU or Pulse Code Modulation Master Unit.
At 17:40 What is a (phonetically pronounced) puckamu swap?
It's PCMMU or Pulse Code Modulation Master Unit.
At 17:40 What is a (phonetically pronounced) puckamu swap?
Yes it looks like a stick and a rudder deflection. These were likely a part of a series of inputs that made up a specific DTO (detailed test objective). I would have to see the flight plan notes, entry checklist/cue card to decipher what the exact maneuver(s) were and what the specific objectives were. Generally, as I said before, these were to help derive and validate the exact aerodynamic coefficients used in modeling flight characteristics for the simulators.
Mark Kirkman
Another one of those PCMMU swap cases in one of the runs of a STS-129 ascent sim I was lucky enough to report on for the site:
https://www.youtube.com/watch?v=k0UOu-1aIWo
At 17:40 What is a (phonetically pronounced) puckamu swap?
Yes it looks like a stick and a rudder deflection. These were likely a part of a series of inputs that made up a specific DTO (detailed test objective). I would have to see the flight plan notes, entry checklist/cue card to decipher what the exact maneuver(s) were and what the specific objectives were. Generally, as I said before, these were to help derive and validate the exact aerodynamic coefficients used in modeling flight characteristics for the simulators.
Mark Kirkman
Mark, probably this one (luckily the STS-65 press kit text is online):
DTO 251: Entry Aerodynamic Control Surfaces Test
The DTOs were designed to push the envelope, although usually only by a little bit. I always like the PTIs because we (in the old MCDS cockpit) could see flashing with double-overbright characters. A rare combination that is one of those space-geek type things to remember.
Andy
Yes it looks like a stick and a rudder deflection. These were likely a part of a series of inputs that made up a specific DTO (detailed test objective). I would have to see the flight plan notes, entry checklist/cue card to decipher what the exact maneuver(s) were and what the specific objectives were. Generally, as I said before, these were to help derive and validate the exact aerodynamic coefficients used in modeling flight characteristics for the simulators.
Mark Kirkman
Mark, probably this one (luckily the STS-65 press kit text is online):
DTO 251: Entry Aerodynamic Control Surfaces Test
The DTOs were designed to push the envelope, although usually only by a little bit. I always like the PTIs because we (in the old MCDS cockpit) could see flashing with double-overbright characters. A rare combination that is one of those space-geek type things to remember.
Andy
Actually the one performed on final appears to be part of DTO 254 "Subsonic Aerodynamics Verification". I wouldn't mind seeing the entry maneuvers cue cards from those flights or something else that breaks down the parameters of the test inputs (timing, magnitude, duration, etc).
Mark Kirkman
What is a "long form bus tie" and how does it differ from a regular bus tie?
Thank you
Thanks Mark!
Last one for now;
"4 minutes to spreading" "clear it" "can't be cleared".
?
During the sim run posted here;
http://forum.nasaspaceflight.com/index.php?topic=17437.msg1202400#msg1202400 (http://forum.nasaspaceflight.com/index.php?topic=17437.msg1202400#msg1202400)
at 56 seconds;
I familiar with the engine performance calls (single engine ops 3, two engine TAL, etc etc). But I have never heard of (because it was never needed) it expressed in thirds, ie - "One and two thirds negative return."
What does "One and two thirds" mean?
Thanks Mark!
Last one for now;
"4 minutes to spreading" "clear it" "can't be cleared".
?
Spreading is short for "Spread Spectrum" which is a mode of communications with the TDRS. I'll need to listen to the conversation to understand the context for "clear it" and "can't be cleared".
Oh thank you so much Mark, Andy and Dave, and Phillip.If you are a L2 member, the audio from first part of that ascent sim run is covered in there.
Juicy stuff!
Thanks Mark!
Last one for now;
"4 minutes to spreading" "clear it" "can't be cleared".
?
Spreading is short for "Spread Spectrum" which is a mode of communications with the TDRS. I'll need to listen to the conversation to understand the context for "clear it" and "can't be cleared".
This is just a swag since my comm system knowledge was always a little week (and shame on me for that since it really is an absolutely critical system for a space flight system);
I think INCO is saying he can not manage the comm system for spreading because they are stuck with the SPCs (stored program commands) they had pre liftoff. SPCs allow for antenna and comm system management during ascent.
Mark Kirkman
Whatever happened to the "Tin Whiskers" problem from back in 2006?
Clearly they were able to fly the remainder of the flights without problems, but I never heard what the solution was?
-MG.
Wayne Hale mentions the "Beester Balls" in a talk once at GWU... Aside from me mis-spelling it, what was that again?
Is the audio on this a real RTLS / ditching sim? If so, does anyone know when this sim was conducted?
Is the audio on this a real RTLS / ditching sim? If so, does anyone know when this sim was conducted?The audio has been re-encoded / re-uploaded to YT multiple times; another thread with some help identifying voices from Wayne Hale:
What does the following call from FDO to FD mean?
"we took a thrust update of plus 6"
Thank you.
The audio has been re-encoded / re-uploaded to YT multiple times; another thread with some help identifying voices from Wayne Hale:
http://forum.nasaspaceflight.com/index.php?topic=23001.msg648174#msg648174
The above abort training scenario brought a question to mind. In the event that crew would have to bail out was there any sort of "autopilot" (for lack of a better term) that could keep the craft steady so that the person at the stick actually had time to get from the flight deck to the mid deck and out the hatch without the shuttle starting to tumble from aerodynamic forces and lack of positive input.
... The word "BAILOUT" would appear and start flashing on the Vertical Situation Display indicating the mode had been armed...
Were there any anomalies with the MEDS upgrades during a mission?
We all know about the SSME's #2#3 have a "Start" position, then once up and burning before liftoff, and then move into their "Launch" configuration.
1)I was wondering if the SSME's have a certain position for MECO(Main Engine Cut Off)?
2) If there is a certain MECO gimbal position, is it similar/same to the "Start" position?
TIA
We all know about the SSME's #2#3 have a "Start" position, then once up and burning before liftoff, and then move into their "Launch" configuration.
1)I was wondering if the SSME's have a certain position for MECO(Main Engine Cut Off)?
2) If there is a certain MECO gimbal position, is it similar/same to the "Start" position?
TIA
AFAIK, MECO is the end of MM103 and guidance is closed-loop. I don't see how there can be any predefined gimbal angles immediately prior to MECO. It would be whatever guidance is commanding to keep the vehicle's state and acceleration vectors where they need to be. Granted, this late in the ascent those values would probably be quite similar from flight-to-flight.I do see your point here. Maybe the the possibility of engine bell damage isnt as great in the vacuum of space as it is at approx. sea level while sitting at the pad. The only time that the on vehicle SSME's have a commanded MECO at such low altitudes within the atmosphere is during Flight Readiness Firing and RSLS aborts.
We all know about the SSME's #2#3 have a "Start" position, then once up and burning before liftoff, and then move into their "Launch" configuration.
1)I was wondering if the SSME's have a certain position for MECO(Main Engine Cut Off)?
2) If there is a certain MECO gimbal position, is it similar/same to the "Start" position?
TIA
In the STS-93 mission control video where the booster and its backroom loop can be heard, what are the controllers looking for on their data screens for them to make the call "ignition" ?As in the call being made here at 1:01 of this video.
Thanks
In the STS-93 mission control video where the booster and its backroom loop can be heard, what are the controllers looking for on their data screens for them to make the call "ignition" ?
Thanks
SSVEO IFA List Date:02/27/2003 STS - 95, OV - 103, Discovery ( 25 ) Time:03:56:PM Tracking No Time Classification Documentation Subsystem MER - 1 MMACS-01 MET: 000:00:00:00 GMT: 302:19:19 Problem FIAR SPR IPR 96V-0001 IFA STS-95-V-01 UA PR STR,MECH Manager: Mike Porter 562-922-3887 Engineer: Jeff Goodmark 281-483-0347 Title: Loss of Drag Chute Door (ORB) Summary: During Main Engine ignition at approximately T-5 seconds, ground-based photography showed the drag chute door detach from the Orbiter and impact the rim of SSME bell #1 during its downward descent. In-flight evaluation of the condition led to a decision to not deploy the chute for landing. Initial postlanding inspection showed that the drag chute remained in place undisturbed throughout the flight. Follow-on inspection to determine the condition of the chute and other components in the drag chute compartment is in work, as is an investigation and failure analysis to determine the cause of the door failure. |
Actually we lit the engines in 3, 2, 1 sequence. I did some of the STS-26 and STS-49 FRF flight software testing and I used the countdown as a way to remember the sequence (it still has stuck). BTW, they were 120 mSec apart in start time.Apologies on the FRF/FRR and SSME 1,2 3 positions confusion, inconsistent numbering at best(edit-on my part). Thanks for the corrections.
Engine #1 was in the top position much like bowling pins are numbered.
FRF = Flight Readiness Firing - Testing the MPS/SSMEs
FRR = Flight Readiness Review - a meeting to make sure the vehicle was ready for flight
The shutdown positions were not modified for the FRF. We simply shutdown in 1,2,3 order as if lift-off hadn't occurred (which it hadn't).
1)So whenever the SSME's were shutdown in a nominal fashion as a triplet, the sequence will always be engines #1, #2 and #3 no matter if its a FRF on the pad or MECO sequence on orbit?Same thing as the assumption before with engine gimballing -- shutdown for an abort on the pad isn't the same thing as shutdown at the end of powered flight. As noted before, there's a different set of conditions and criteria. The engines were shutdown together in flight -- with the exception of STS-125, there's video of all the MECOs beginning with STS-114 from the ET camera.
1 b) In other words, anytime the SSME's are nominally started and shutdown as a triplet, SSME in position #1 will always have the shortest burn time of the three?
2)Comparing the STS-26 RTF FRF's for Discovery, and the STS-26 FRF for Endeavours maiden flight, from your perspective, were there any differences or improvements between the two?STS-26 was a mission/flight designation -- there was no "STS-26 FRF" for Endeavour. As alk3997 noted, Endeavour's first flight was STS-49; the FRF was conducted during that launch campaign.
At a nominal MECO the shutdown enable/shutdown command pairs went to all 3 engines simo.
Does anyone know the width of the aft SRB IEA box and the thickness of the holddown post shoes?
I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.1)So whenever the SSME's were shutdown in a nominal fashion as a triplet, the sequence will always be engines #1, #2 and #3 no matter if its a FRF on the pad or MECO sequence on orbit?Same thing as the assumption before with engine gimballing -- shutdown for an abort on the pad isn't the same thing as shutdown at the end of powered flight. As noted before, there's a different set of conditions and criteria. The engines were shutdown together in flight -- with the exception of STS-125, there's video of all the MECOs beginning with STS-114 from the ET camera.
1 b) In other words, anytime the SSME's are nominally started and shutdown as a triplet, SSME in position #1 will always have the shortest burn time of the three?
The pad abort shutdown sequence changed at some point in the 80s, probably during the first RTF; originally it was 1, then 2-3 essentially at the same time. After that, it was 1, then 2, then 3.2)Comparing the STS-26 RTF FRF's for Discovery, and the STS-26 FRF for Endeavours maiden flight, from your perspective, were there any differences or improvements between the two?STS-26 was a mission/flight designation -- there was no "STS-26 FRF" for Endeavour. As alk3997 noted, Endeavour's first flight was STS-49; the FRF was conducted during that launch campaign.
There's a lot of reference material online -- for example, Mark (mkirk) has written several posts in this thread and the previous four Q&A threads. He also wrote a nice main engine overview here:
http://www.interspacenews.com/FeatureArticle/tabid/130/Default.aspx?id=2130
Different than a single engine out during powered flight?At a nominal MECO the shutdown enable/shutdown command pairs went to all 3 engines simo.
Would make for some interesting torque moments at MECO if they didn't! :)
Different than a single engine out during powered flight?At a nominal MECO the shutdown enable/shutdown command pairs went to all 3 engines simo.
Would make for some interesting torque moments at MECO if they didn't! :)
I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.A pad (RSLS) abort had much more in common with a FRF than an in-flight MECO. (Not that it's definitive, but a PAO once referred to the FRF shutdown as an 'induced RSLS abort.')
I hope my "pad abort not being discussed here" wasnt percieved as flippant, I wanted to ensure I wasnt missing something in my reading. Thank you for the clarification and the new info. I have never had good luck with the sites search engine. Your methods will help.I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.A pad (RSLS) abort had much more in common with a FRF than an in-flight MECO. (Not that it's definitive, but a PAO once referred to the FRF shutdown as an 'induced RSLS abort.')
I don't remember all the discussions about pad aborts or FRFs here, either -- I search for them; that phrase -- "RSLS abort" -- would find you most of the discussions here over the years. Either the search function for the site or something like Google to search the site:
https://www.google.com/search?q=%22RSLS+abort%22+site%3Aforum.nasaspaceflight.com
Do the same for "FRF" and you would find that I asked about the pad shutdown sequence here eight years ago, probably not for last time:
http://forum.nasaspaceflight.com/index.php?topic=2377.msg34391#msg34391
Finding phrases in threads (or words) is also much easier if you use the Print button -- then use any modern browser's Find functionality. Over the years, Chris merged scores of splinter threads into the Shuttle Q&A series, so that's the place to start.
I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.A pad (RSLS) abort had much more in common with a FRF than an in-flight MECO. (Not that it's definitive, but a PAO once referred to the FRF shutdown as an 'induced RSLS abort.')
...
I've attached the FRF commentary audio that I was thinking of here. This is from PAO commentary by Jim Ball for the FRF done on OV-104 / Atlantis in 1985. I left in some additional "stuff" on the front and back for a little context, but the part that I was thinking of starts about 130 seconds in.I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.A pad (RSLS) abort had much more in common with a FRF than an in-flight MECO. (Not that it's definitive, but a PAO once referred to the FRF shutdown as an 'induced RSLS abort.')
...
Remember an RSLS abort would occur because the Redundant Set Launch Sequencer (RSLS) software, which was part of OPS 1, determined that a main engine was either "not ready", the SRBs were not ready, the thrust was not at least 90% in an SSME or the Ground Launch Sequencer (GLS) had called an abort (there were probably a few other conditions I'm not remembering). In the later FRFs, the duration of the pad abort was equal to the time to check to see if the SRBs were ready and since they would not be, an abort was called which then shutdown the main engines ending the FRF engine test.
Thanks ALK3997 Just to illustrate some of the things that you have mentioned.I dont remember pad aborts being discussed, but that is another mode/method /config of shutdown. Thanks for the info. And the links. Almost done the previous threads, I have seen some MKirk entries.A pad (RSLS) abort had much more in common with a FRF than an in-flight MECO. (Not that it's definitive, but a PAO once referred to the FRF shutdown as an 'induced RSLS abort.')
...
Remember an RSLS abort would occur because the Redundant Set Launch Sequencer (RSLS) software, which was part of OPS 1, determined that a main engine was either "not ready", the SRBs were not ready, the thrust was not at least 90% in an SSME or the Ground Launch Sequencer (GLS) had called an abort (there were probably a few other conditions I'm not remembering). In the later FRFs, the duration of the pad abort was equal to the time to check to see if the SRBs were ready and since they would not be, an abort was called which then shutdown the main engines ending the FRF engine test.
Hog, the one difference between a Pad Abort (RSLS Abort) and an FRF would be that you don't choose which engine shutdown first in the event of a pad abort. So, therefore the shutdown sequence was different depending upon which engine shutdown first causing the pad abort. If 2 went down, then 3 was shutdown next. It 3 went down, then 2 would be shutdown next.
There was also no BFS during an FRF. It couldn't have been engaged and wasn't needed since no flight was going to take place.
"Interesting, I'm having trouble with the shut down order though."For clarification, I posted 7 FRF's within the textbox itself, and attached a clip labelled STS-68 RSLS as an attachment.(below the textbox-says its been downloaded 3 times), its from a discussion here at NSF.
That may be because you didn't attach an STS-68 RSLS abort video. The last video is the STS-49 FRF on OV-105.
I remember STS-68 RSLS abort well since I was standing to the right of the giant KSC countdown clock at the press site during the launch attempt. That's when I found out that the giant countdown clock was not directly "wired" into the same countdown circuit as the launch control room. The LCC countdown stopped, as it should. The big countdown clock started counting up, which would have been a much bigger problem if that had been real.
As I said, it wasn't an issue since the big countdown clock didn't have the "real" countdown but it sure got my attention at the time. My memories from the STS-68 RSLS abort...
Andy
I am attempting to verify my SSME engine model with known data. There is a lot of publicly available SSME data but there were also modifications to the SSME over time so it is hard to locate a completely consistent data set.This discussed in a thread that I had read recently here at NSF, I have been unable to re-find the thread though. I will let you know if I find it.
Looking at the SSME with the larger throat, throttle set at 109% I calculate (F=mdot*Isp*g) that mdot is about 517 kg/s. Researching the external tank I find that the fuel lines are sized to 491 kg/s rate of fuel flow. How is this discrepancy reconciled?
I was thinking about this discussion with pad aborts. STS-68 was the 65th Shuttle mission and was also the last pad abort in program history. That's over half the program missions without another pad abort. I don't think that was luck.Good points, IIRC one of the STS-93 attempts resulted in an RSLS hold, due to high {H2} in the aft, called at T-0.07. Once Columbia was off the ground, there was a Low LOX cut-off at the end of powered flight, coupled with the redundancy issues you mentioned. The video of the control room loops was interesting to say the least, esp after powered flight.
I believe that was the result of the SSME upgrade program that started just after that pad abort. The Block I, Block IIA and Block II engines were designed to be more reliable (less parts) and have greater margins. The upgraded engine controller also helped. Looking back, the upgrades seemed to have had their desired effect.
It was also the result of the program management accepting that a pad abort was only a few seconds away from being an RTLS and no one wanted to try that abort mode out. Program management accepted a heavier engine in exchange for greater safety. The only other event SSME-wise that I can remember was the loss of redundancy on STS-93 due to the aging wiring problem, but that was outside of the SSMEs.
So, when we look back at these pad aborts, it's important to remember that they led to system improvements later on.
Is it incorrect to refer to the SSME's and their various upgrades as:
RS-25-A
RS-25-B
RS-25-C
RS-25-D, either inside NASA or outside?
So regarding my question of identifying a consistent set of engine parameters for the SSME in order to validate my engine model, it seems clear that using the engine at 109% thrust is not a good choice. It also seems clear that there is no specific designation for a particular engine model so how does one correctly ask the question?There should be clear engine parameters for each engine model: (if these are correct)
Let me ask this. With all of the modifications to the SSME over its lifetime, did the nozzle diameter ever change or was it fixed for all time?
I know the engine throat diameter changed and that the nozzle expansion ratio changed and the combustion chamber pressure changed and of course the thrust and Isp changed. Did the fuel mix ratio change?
So regarding my question of identifying a consistent set of engine parameters for the SSME in order to validate my engine model, it seems clear that using the engine at 109% thrust is not a good choice. It also seems clear that there is no specific designation for a particular engine model so how does one correctly ask the question?There should be clear engine parameters for each engine model: (if these are correct)
Let me ask this. With all of the modifications to the SSME over its lifetime, did the nozzle diameter ever change or was it fixed for all time?
I know the engine throat diameter changed and that the nozzle expansion ratio changed and the combustion chamber pressure changed and of course the thrust and Isp changed. Did the fuel mix ratio change?
FMOF=(engines 2005, 2006 and 2007-STS 1-5)
Phase 1
Phase II
Block 1
Block 1-A
Block II-A
Block II
from Analogmans above post.
Here is Part#1 of a 10 part series, seems detailed.
http://www.enginehistory.org/SSME/SSME1.pdf
Here is Part#1 of a 10 part series, seems detailed.
http://www.enginehistory.org/SSME/SSME1.pdf
I know the engine throat diameter changed and that the nozzle expansion ratio changed and the combustion chamber pressure changed and of course the thrust and Isp changed. Did the fuel mix ratio change?
A very interesting read. I did find that external tank pressurization takes 0.7 lb/s H2 and 1.2 lbs/s O2. This may (?) reduce the chamber mass flow by 1.8 lb/s or 0.8165 kg/s. A small but real amount. ~0.16%
Hello all.
I was interesting to know if the dog-leg maneuver Atlantis underwent during ascent on STS-36 to reach 62 deg of inclination had any effect on the abort modes? Would it have been possible to perform a TAL, for example? What about a RTLS?
Also, how much payload performance Atlantis lost in doing the dog-leg?
Thanks very much
Davide
How much payload mass to ISS was lost on Shuttle launches due to that inclination? My understanding was that the majority of those payloads were limited by CG constraints rather than overall mass. I don't know how many missions were actually up against mass limits, though.
Another question - for Shuttle ascent control/performance, the weight and mass distribution was required, but how precise was this figure? Presumably they didn't weigh every astronaut's breakfast the morning before - but maybe they did and I didn't recall reading about it.
What was the reason for STS-39 and STS-44 being unclassified DoD missions?
Hi all,
i am looking for the title of a presentation that must be somewhere in L2 but I have been unable to locate it. It is either refering to STS-125 or -400 and includes the attached chart comparing orbiter orientation to LOCV risk (aptly named: "Micrometeoroid/Orbital Debris (MMOD) Loss of Crew & Vehicle (LOVC) Risk vs. Space Shuttle Orientation"). I would greatly appreciate it if someone could point me in the right direction.
This is from an MMT/OPO (Mission Management Team/Orbiter Project Office) presentation from flight day 6 of the STS-125 mission "Potential MMOD Damage on Panel 11R".
See page 16 of either of the presentations linked in the first two posts of this L2 thread:
http://forum.nasaspaceflight.com/index.php?topic=17081.0 (http://forum.nasaspaceflight.com/index.php?topic=17081.0)
Watching video of some pre-Challenger launches I noticed the test director using the callsign "LTD" instead of "NTD". Was this designation used for all pre-Challenger launches?Not sure about when it began to be used, but 'L' as in Lockheed (Lockheed Space Operations Company):
Rockwell's Launch Operations, part of the Space Transportation Systems Division, was under contract to NASA's Kennedy Space Center for turnaround, processing, prelaunch testing, and launch and recovery operations from STS-1 through the STS-11 mission.
On Oct. 1, 1983, the Lockheed Space Operations Co. was awarded the Space Shuttle processing contract at KSC for turnaround processing, prelaunch testing, and launch and recovery operations.
Watching video of some pre-Challenger launches I noticed the test director using the callsign "LTD" instead of "NTD". Was this designation used for all pre-Challenger launches? Or was it changed away from NTD in anticipation of SLC-6 launches where the test director wouldn't actually be a "NASA Test Director" and instead be an Air Force officer?
At some point during the post Columbia stand-down, there was a news item regarding an upside-down installed actuator in the rudder/speed brake of Discovery. Is there any documentation about this and/or the work to replace it available?
It's discussed in "Space Shuttle Program Action 11" in the Implementation Plan, which can be found at this link:
http://www.nasa.gov/pdf/58541main_RTF_rev2.pdf
Hello all.
Question about the Malarkey Milkshake performed during STS-39. I'm reading from the mission press information that the OMS firings for plum observations by the SPAS/IBSS were done with only one engine and that this was the first time that a single OMS engine firing was performed.
I'd like to know why they decided to do the firing with only one engine? Was only for fuel savings or for what else?
Thanks very much
Davide
When I was at the Atlantis exhibit a few months ago I noticed the "No Step" markings on the elevons. This would imply that, like an airliner, walking on the other parts of the wing was OK. Was it normal for technicians to walk on the orbiter wings for normal repairs and maintenance?
Also, if I recall, Columbia and Challenger had tiles on part of the wing surface. Were technicians allowed to walk on these?
When the USAF was developing SLC-6 for Space Shuttle launches there were concerns that gaseous hydrogen could fill up the main engine ducts provoking a detonation during lift off, possibly damaging the shuttle.They did. The H2 burn-off ignitors only combust GH2 that is expelled at engine ignition. However there is GH2 that is expelled during the countdown which at SLC-6 would have accumulated in the closed exhaust duct. KSC's LC-39 pads have an open flame trench which blows the GH2 away preventing dangerous build ups.
I don't understand this issue. Why a shuttle on SLC-6 would have this problem? Couldn't they use burnoff preigniters as on the launch pad at the KSC?
Thanks
Davide
Where are the SRB casings now?
What is this feed line next to the LO2 gaseous press line on the ET for STS-1? http://images.ksc.nasa.gov/photos/1981/high/KSC-381C-2366.03.jpg
It's not on the tank for STS-7, which is the same SWET as that for STS-1. http://www.nasa.gov/images/content/2163main_sts7_et_hi.jpg
What is this feed line next to the LO2 gaseous press line on the ET for STS-1? http://images.ksc.nasa.gov/photos/1981/high/KSC-381C-2366.03.jpg
It's not on the tank for STS-7, which is the same SWET as that for STS-1. http://www.nasa.gov/images/content/2163main_sts7_et_hi.jpg
What is this feed line next to the LO2 gaseous press line on the ET for STS-1? http://images.ksc.nasa.gov/photos/1981/high/KSC-381C-2366.03.jpg
It's not on the tank for STS-7, which is the same SWET as that for STS-1. http://www.nasa.gov/images/content/2163main_sts7_et_hi.jpg
anti-geyser line, which was removed for STS-4
Can you describe the functionality of the anti-geyser line? Asked another way, what kind of geyser did they fear may have been created?
Can you describe the functionality of the anti-geyser line? Asked another way, what kind of geyser did they fear may have been created?
Can you describe the functionality of the anti-geyser line? Asked another way, what kind of geyser did they fear may have been created?
I've attached a pdf of a systems brief about the geyser phenomenon that will probably over answer your question.
Can't seem to find any good diagrams of the original tanks, best bet is probably to google early images of the first missions and see if you can get a good image of the lines from those pics.
Mark Kirkman
Does anyone know the average max Q experienced by the stack during ascent? I thinking the average of max Q calculated over all the 135 launches.
No, that's precise enough, thanks.Does anyone know the average max Q experienced by the stack during ascent? I thinking the average of max Q calculated over all the 135 launches.
It's around 700 lbs/sq ft. Are you looking for more precision than that?
Great question.What is this feed line next to the LO2 gaseous press line on the ET for STS-1? http://images.ksc.nasa.gov/photos/1981/high/KSC-381C-2366.03.jpg
It's not on the tank for STS-7, which is the same SWET as that for STS-1. http://www.nasa.gov/images/content/2163main_sts7_et_hi.jpg
anti-geyser line, which was removed for STS-4
Can you describe the functionality of the anti-geyser line? Asked another way, what kind of geyser did they fear may have been created?
How did the tail cone (for approach and landing tests) manage to fit on to the space shuttle when the body flap would get in the way of the cone's bottom wall?
image illustrating my perplexion (http://i.imgur.com/MpnNQwm.png)
The reason I'm asking this is because I'm making a 3D model of the cancelled Japanese space shuttle "HOPE-X", but I'm not sure on how to make the launch vehicle's payload adapter with that body flap in the way.
But how come there isn't an indent at the bottom of the tail cone in the image I posted?There is, but the way the image is framed or zoomed makes it more difficult to see it or gain much perspective. Is that the whole image (sure looks like it's from the MDD at Dryden)?
I can't open the pdf. Could someone get the diagrams and photos from it please?
I cropped it from a Wikipedia picture (I think) found via a Google image search. Sorry for not paying attention to its full context.But how come there isn't an indent at the bottom of the tail cone in the image I posted?There is, but the way the image is framed or zoomed makes it more difficult to see it or gain much perspective. Is that the whole image (sure looks like it's from the MDD at Dryden)?
Link to a shot of buildup at KSC that shows it better (small thumbnail attached):
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=59472
No problem. If you're interested, we have a few videos shot just prior to the end of the program out at Dryden (now Armstrong) on L2 (and also some footage courtesy of NASA).I cropped it from a Wikipedia picture (I think) found via a Google image search. Sorry for not paying attention to its full context.But how come there isn't an indent at the bottom of the tail cone in the image I posted?There is, but the way the image is framed or zoomed makes it more difficult to see it or gain much perspective. Is that the whole image (sure looks like it's from the MDD at Dryden)?
Link to a shot of buildup at KSC that shows it better (small thumbnail attached):
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=59472
If Challenger had not been lost, would it have been able to participate in ISS assembly and resupply? Or would it's weight have prevented it from most ISS flights like Columbia? I have read that Challenger could carry 2500 lbs more that Columbia, but still far less than the rest of the fleet.
If Challenger had not been lost, would it have been able to participate in ISS assembly and resupply? Or would it's weight have prevented it from most ISS flights like Columbia? I have read that Challenger could carry 2500 lbs more that Columbia, but still far less than the rest of the fleet.
Would certainly have been used to build/service a Space Station Freedom @ 28.5 deg inclination.
I think the events of 51-L and the decision to build ISS are too far removed from one another in time to answer without a LOT of speculation.
I think I was mainly wonder how or if Challenger could have been used in place of Atlantis or Discovery at ISS if another orbiter had been used for 51-L and one of those was lost instead. Could a fleet of Challenger, Atlantis and Endeavour have serviced ISS as it is currently built?
I have read that Challenger could carry 2500 lbs more that Columbia, but still far less than the rest of the fleet.It was more that that, It was only 100's less that the other orbiters. 116 & 118 were light payloads.
And why was Columbia originally planned to fly STS-118 to ISS? A lighter payload?
Something totally different and ancient shuttle history.
The attached Image is taken from the infamous 1979 Bond movie "Moonraker". It shows an Orbiter getting lifted around the VAB. It looks rather unfinished to me with no visible markings, no TPS and missing flipper doors on the wings.
Because it was a model. No real shuttles were used.
And that's not the VAB either. I'm pretty familiar with the layout of the VAB High Bays as well as the transfer aisle and that screengrab doesn't match any of them. Also the orbiter sling is wrong. It only has the two side beams and is missing the aft sling structure which would be used to rotate the orbiter to and from vertical.Being rotated from from vertical would be a rarity wouldnt it? Any instances where that occured operationally?
Does anyone know the weight of the various parachutes of the SRB Recovery System (Pilot, drogue and mains)?2180lbs. or 990kg for the mains
I'd be surprised if nobody has asked this question before, but since this is now a 5 part thread with lots of posts, it's not easy to check.
What is the theoretical maximum altitude of the Shuttle? Obviously we have the Hubble's altitude of just over 600 km as an maximum that was actually reached during the STS program, but is there anywhere that details any possibilities higher than that?
Obviously the question marks are how much payload is in the bay to begin with, and how much dV the OMS has for circularisation and deorbit. So, let's go with an empty payload bay, a Hubble-ish weight in the payload bay, and something half way between. Any ideas?
100lb per nautical mile was the rule of thumb for trades.
Thanks Jim. Presumably that only works until the OMS tanks are full. Which would be reached first? A full OMS tank or an empty cargo bay?
I'd be surprised if nobody has asked this question before, but since this is now a 5 part thread with lots of posts, it's not easy to check.
What is the theoretical maximum altitude of the Shuttle? Obviously we have the Hubble's altitude of just over 600 km as an maximum that was actually reached during the STS program, but is there anywhere that details any possibilities higher than that?
Obviously the question marks are how much payload is in the bay to begin with, and how much dV the OMS has for circularisation and deorbit. So, let's go with an empty payload bay, a Hubble-ish weight in the payload bay, and something half way between. Any ideas?
An OMS payload bay kit was planned which would have greatly increased the available delta-v. When I was working on the SMS in the early 80s there were scars in the models related to this kit. It never flew though.
Does somebody happen to be familiar with the XO coordinates of the FWD/aft Orb/ET attachment points?
Thanks. Do you happen to know the length of the nosecap and the NLG doors?Does somebody happen to be familiar with the XO coordinates of the FWD/aft Orb/ET attachment points?
From the SLWT bible drawings:
Forward attachment XO = 338.045
Aft attachments XO = 1317 YO ±96.50
(these are orbiter referenced, i.e. not XT values)
http://forum.nasaspaceflight.com/index.php?topic=14350.msg317169#msg317169 (http://forum.nasaspaceflight.com/index.php?topic=14350.msg317169#msg317169)
I just noticed in video #3 on the Discovery press day L2 videos, that there is a few moments where the Ascent Abort selector is visible.(pause at 14:15 of the video)
L2 video: http://forum.nasaspaceflight.com/downloads/l2/Discovery_Media_Event_Pt3.wmv
The Abort Mode selection order on the dial of Discovery as of 2011 with her glass cockpit is "RTLS/OFF/ATO/TAL".
A picture taken during STS-51F Challenger, where you can se that Abort To Orbit(ATO) is selected. On Challenger the Abort selector's sequence is "OFF/RTLS/TAL-AOA/ATO".
Were these changes made during the "glass cockpit" upgrading?
What was the rational for the order of the Abort Modes on the dials?
One of the calls made to the crew during ascent was something called "droop". What does this mean?If you have L2, there's a great reference for Shuttle ascents/aborts (flight procedures handbook, circa OI-30 / 2005):
Thanks
edit- Also mentioned here- http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940017386.pdf
Was fitting the SRB segments for rail delivery at all a driving force on Shuttle's cargo bay size?
Thanks Jim. +1Was fitting the SRB segments for rail delivery at all a driving force on Shuttle's cargo bay size?
Unrelated. The payload bay size was decided before booster selection.
How much weight could be saved on the orbiter (thus extra weight to be carried in to space) if it had a wingless design and re-entered like apolloYou could save as much or as little as you desired as you would be designing an entirely different system than STS.
What is the name of those really really big gimballed cameras they used to use to track shuttle launches? I can't remember what they're called and it's driving me nuts!DOAMS (Distant Object Attitude Measurement System): http://www2.l-3com.com/ios/products/r_doams.htm
How much weight could be saved on the orbiter (thus extra weight to be carried in to space) if it had a wingless design and re-entered like apolloYou could save as much or as little as you desired as you would be designing an entirely different system than STS.
Yeah, DOAMS was the one I was thinking of. Thanks! Some of those other ones are pretty cool too.
How much weight could be saved on the orbiter (thus extra weight to be carried in to space) if it had a wingless design and re-entered like apolloYou could save as much or as little as you desired as you would be designing an entirely different system than STS.
If you did this but still wanted the same crew cabin size, payload bay size and capabilities and had the engines attached to the orbiter like they were for STS, wouldn't it become enormous if you tried to design that inside of a capsule shape? I would think that it might actually end up heavier than the orbiter.
I'm certainly no expert, but I don't think that a 60 foot long payload bay capable of returning cargo lends itself well to a capsule design. I would guess to eliminate the wings, you'd probably have to go with a powered re-entry system like SpaceX plans for the reusable Falcon 2nd stage since it would be roughly shaped like a fuel tank to be structurally efficient.
How much weight could be saved on the orbiter (thus extra weight to be carried in to space) if it had a wingless design and re-entered like apolloYou could save as much or as little as you desired as you would be designing an entirely different system than STS.
If you did this but still wanted the same crew cabin size, payload bay size and capabilities and had the engines attached to the orbiter like they were for STS, wouldn't it become enormous if you tried to design that inside of a capsule shape? I would think that it might actually end up heavier than the orbiter.
I'm certainly no expert, but I don't think that a 60 foot long payload bay capable of returning cargo lends itself well to a capsule design. I would guess to eliminate the wings, you'd probably have to go with a powered re-entry system like SpaceX plans for the reusable Falcon 2nd stage since it would be roughly shaped like a fuel tank to be structurally efficient.
Just makes me wondering if the Crewcabin was to reenter like a capsule and the rest was to burn up (cargo and engine part). Could this be actually cheaper and carry more to orbit then to carry those costly wings which are only used for landing. And therefore flights be cheaper as there would be much less maintanance?
How much weight could be saved on the orbiter (thus extra weight to be carried in to space) if it had a wingless design and re-entered like apolloYou could save as much or as little as you desired as you would be designing an entirely different system than STS.
If you did this but still wanted the same crew cabin size, payload bay size and capabilities and had the engines attached to the orbiter like they were for STS, wouldn't it become enormous if you tried to design that inside of a capsule shape? I would think that it might actually end up heavier than the orbiter.
I'm certainly no expert, but I don't think that a 60 foot long payload bay capable of returning cargo lends itself well to a capsule design. I would guess to eliminate the wings, you'd probably have to go with a powered re-entry system like SpaceX plans for the reusable Falcon 2nd stage since it would be roughly shaped like a fuel tank to be structurally efficient.
Just makes me wondering if the Crewcabin was to reenter like a capsule and the rest was to burn up (cargo and engine part). Could this be actually cheaper and carry more to orbit then to carry those costly wings which are only used for landing. And therefore flights be cheaper as there would be much less maintanance?
...Then you may as well have just kept flying the Apollo program...
Similar photo and description at https://blogs.nasa.gov/J2X/2014/01/24/inside-the-leo-doghouse-light-my-fire/
I'm studying STS-93 and a question has come up that I can't answer. From Wayne Hale's blog post:
Regarding the hydrogen leak from the nozzle, "Since the chamber pressure dropped slightly due to the loss of fuel for the fire in the main combustion chamber, the SSME controller commanded more oxygen be sent to the MCC. "
What I don't understand is why the chamber pressure dropped. If the engine is running fuel-rich, all the oxygen is being consumed even if there's a slight loss of fuel flow. So, the same chemical reaction should be happening, albeit with a slightly lower mass flow and a slightly lower mixture ratio. So why did the main combustion chamber pressure drop?
What am I missing here?
I'm studying STS-93 and a question has come up that I can't answer. From Wayne Hale's blog post:
Regarding the hydrogen leak from the nozzle, "Since the chamber pressure dropped slightly due to the loss of fuel for the fire in the main combustion chamber, the SSME controller commanded more oxygen be sent to the MCC. "
What I don't understand is why the chamber pressure dropped. If the engine is running fuel-rich, all the oxygen is being consumed even if there's a slight loss of fuel flow. So, the same chemical reaction should be happening, albeit with a slightly lower mass flow and a slightly lower mixture ratio. So why did the main combustion chamber pressure drop?
What am I missing here?
The fuel rich condition means excess hydrogen injected into the chamber doesn't react with the oxygen, but it certainly gets heated and expands against the chamber walls. Take that away means less chamber pressure, doesn't it?
I shouldn't do this, but here is a Wiki article on STS's Thermal Protection System(TPS).
Anyone remember when NASA made the decision to change the back stripe on the edge of the Shuttle wings to white squares?
Was it done after their long maintenance periods? Also, why the transition from black to white? Was it for looks or did it serve a specific function?
MikeEndeavor23
While reading the book "Comm Check..." about STS-107, I read that there was a 1/10 inch gap behind the top of the leading edges of the wings to allow pressure equalization within the wings. I was just curious if anyone could tell me more about that or any other similar open spaces on the vehicle. How did they keep water or insects out? My first thought was maybe it was covered similar to the RCS ports but I couldn't recall seeing covers falling off during launch.
While reading the book "Comm Check..." about STS-107, I read that there was a 1/10 inch gap behind the top of the leading edges of the wings to allow pressure equalization within the wings. I was just curious if anyone could tell me more about that or any other similar open spaces on the vehicle. How did they keep water or insects out? My first thought was maybe it was covered similar to the RCS ports but I couldn't recall seeing covers falling off during launch.
http://spaceflight.nasa.gov/shuttle/reference/shutref/purge/
The Filament Wound Case (FWC) designed for STS/Vandenberg polar flights was roughly 25,000lbs lighter than the 1/2" steel cases for lower inclination KSC launches.
1)Approx. how much extra payload mass would 25,000lbs decrease in booster weight allow for? (not worrying about the effects of inclination in this question-IIRC Jim stating its about 625lb/º and approx. 100lbs/nautical mile for altitude)
1)Approx. how much extra payload mass would 25,000lbs decrease in booster weight allow for?
Was there ever an EVA to the rear of the orbiter? No real reason to asking, just curious if it ever came up and why.
Anyone remember when NASA made the decision to change the back stripe on the edge of the Shuttle wings to white squares?
Was it done after their long maintenance periods? Also, why the transition from black to white? Was it for looks or did it serve a specific function?
MikeEndeavor23
The question was vague...another wild guess that might, possibly, maybe sorta fit "back stripe" and "white squares" is the change to the elevon flipper doors. Screen of a STS-109 FRR slide attached (that being the first flight for Columbia after her last OMDP), which notes the material change and TPS change. I believe this was one of the "orbiter diet" parts of the Performance Enhancement "program" for a 51.6-degree inclined ISS.
Anyone remember when NASA made the decision to change the back stripe on the edge of the Shuttle wings to white squares?
Was it done after their long maintenance periods? Also, why the transition from black to white? Was it for looks or did it serve a specific function?
MikeEndeavor23
Are you asking about the black wing chines seen only on Columbia?
If so, do a search here for "Columbia wing chines". It has been discussed a lot. This is the best answer I remember:
http://forum.nasaspaceflight.com/index.php?topic=17437.msg860524#msg860524
Was there ever an EVA to the rear of the orbiter? No real reason for asking, just curious if it ever came up and why.
When SSMEs were replaced on the launch pad, was there a complete enclosure to protect the process from the elements, or was it open?It was (more or less) open -- similar to the component replacement on one of the engines at the pad during the last launch campaign.
Yes, STS-101: http://spaceflightnow.com/shuttle/sts101/000412repairplan/index.htmlWhen SSMEs were replaced on the launch pad, was there a complete enclosure to protect the process from the elements, or was it open?(For something more extraordinary, there was the time a rudder/speed brake PDU was replaced at the pad.)
Hmmm... I always thought that the Shuttle engines were pulled off an orbiter after a mission (as were the OMS pods), and taken off to be refurbished.That was the norm. Issues would come up occasionally when Shuttle vehicles were out at the pad or in the VAB. (IIRC, the engines were temporarily removed from the STS-117 vehicle in the VAB while the tank was getting all those hail repairs...link (http://forum.nasaspaceflight.com/index.php?topic=6938.msg133290#msg133290).)
That said, when did they ever replace engines while the Shuttle was on the pad?Less and less over the time the program was flying...an obvious one would be STS-6 due to all the issues discovered around the two FRFs (there are some pictures in a historical thread starting around here (http://forum.nasaspaceflight.com/index.php?topic=33194.msg1115447#msg1115447); not sure when the last occurrence was but as an example the engines for the STS-49 vehicle were replaced at the pad after Endeavour's FRF.
Some questions regarding the sims (specifically launch & entry).
Did the sims have the same GPC's and BFS that the orbiters had or were their functions simulated?
Some questions regarding the sims (specifically launch & entry).
Did the sims have the same GPC's and BFS that the orbiters had or were their functions simulated?
SAIL would have had everything the same. Not sure about the motion based simulator.
Can anyone tell me where the ''big hole'' is for? Cables?That's where the star trackers were.
Does anyone have any info/history on ME-2050. It was last flown on STS-120 Discovery along with ME-2048(which flew again on 4 more STS missions #'s 124, 119, 129, 133) and ME-2058 which also flew 4 more missions (124, 119, 129, 133)coupled with ME 2048.
Seeing that ME-2048 and ME-2058 flewout the remainder of the SSP as a pair, what happened to ME-2050 that caused it to be pulled from service back after its last mission of STS-120 in 2007?
Now, is it on display somewhere?
Thank you. Great info.Does anyone have any info/history on ME-2050. It was last flown on STS-120 Discovery along with ME-2048(which flew again on 4 more STS missions #'s 124, 119, 129, 133) and ME-2058 which also flew 4 more missions (124, 119, 129, 133)coupled with ME 2048.
Seeing that ME-2048 and ME-2058 flewout the remainder of the SSP as a pair, what happened to ME-2050 that caused it to be pulled from service back after its last mission of STS-120 in 2007?
There is an SSME Schedule on L2 dated August 31, 2007 that shows Engine Assignments from STS-118 thru' STS-127.
E2050 is allocated to STS-120 (and actually flew as we know) but is marked with an note saying "Last Planned Flight due to DAR Life Limits". DAR stands for Deviation Approval Request - these cover special inspections and part life-limits that are imposed to preclude inflight problems.
Link to schedule [L2 access only] is:
http://forum.nasaspaceflight.com/index.php?topic=9767.0 (http://forum.nasaspaceflight.com/index.php?topic=9767.0)
Interestingly an earlier flight plan for HPOTPs dated March 12, 2007 [also on L2] shows E2050 was previously allocated to STS-119.
http://forum.nasaspaceflight.com/index.php?topic=7081.msg120394#msg120394 (http://forum.nasaspaceflight.com/index.php?topic=7081.msg120394#msg120394)
Okay,
Here is a question. What was with STS 76's External tank?
It looks like they tried to paint the tank white like they did on STS 1 and STS 2 and then forgot to finish.
...
MikeEndeavour23
Okay,
Here is another one. Why did they change the camera targets on SRBs from the glymph design to the simple black strip for the left SRB?
I think the glymphs were more "artistic."
;)
MikeEndeavour23
No, that's silly. People didn't start to paint an ET and then forget to finish it. That would have been noticed. Nor did they suddenly decide to add more weight to one tank in the middle of the program.
I've done some searching but not having much luck. What I'm curious about is the maintenance breakdown of the Space Shuttle system. Just how many man hours of it were required between launches? How much percentage wise did it increase for each shuttle as they got older. Considering they were designed for at least a 100 missions each, they were relatively low on actual flight time hours with Discovery at 39 missions and Endeavor at only 25 missions. Sorry if it's been addressed before.I can't answer, but maybe you'll be interested in this paper I saw on NTRS a few years ago and thankfully it is back on NTRS (because I can't remember which backup hard drive I originally stored it on): "Space Shuttle Operations and Infrastructure: A Systems Analysis of Design Root Causes and Effects" by Carey M. McCleskey (NASA/TP—2005–211519)
I've done some searching but not having much luck. What I'm curious about is the maintenance breakdown of the Space Shuttle system. Just how many man hours of it were required between launches? How much percentage wise did it increase for each shuttle as they got older. Considering they were designed for at least a 100 missions each, they were relatively low on actual flight time hours with Discovery at 39 missions and Endeavor at only 25 missions. Sorry if it's been addressed before.I can't answer, but maybe you'll be interested in this paper I saw on NTRS a few years ago and thankfully it is back on NTRS (because I can't remember which backup hard drive I originally stored it on): "Space Shuttle Operations and Infrastructure: A Systems Analysis of Design Root Causes and Effects" by Carey M. McCleskey (NASA/TP—2005–211519)
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050172128.pdf
There's a lot of interesting data, including some chronological detail on a single ground processing flow (for STS-86, in 1997) in Appendix D.
I'm sure someone will correct me if I'm wrong, but I believe it meant that ASA 1 was being bypassed since it had failed. In fact I believe the next call up was "No action required".
STS-125 launch. ASA 1 failure. CAPCOM calls up, "bypass across the board".
Is that an instruction to do something, if so, what? Or was it informational and if so what did it mean?
Thanks!
I'm sure someone will correct me if I'm wrong, but I believe it meant that ASA 1 was being bypassed since it had failed. In fact I believe the next call up was "No action required".
STS-125 launch. ASA 1 failure. CAPCOM calls up, "bypass across the board".
Is that an instruction to do something, if so, what? Or was it informational and if so what did it mean?
Thanks!
sorry i didn't specify, i want any pumping system and type pump schamatic that is used in shuttle while flying in space, and if it possible to specify the use of it so i could simulate it in detail using the sofware :)Do you mean the pumps on the rocket engines turbopump? The pumps on the heat rejection system? The onboard water supply pumps? The hydraulic actuators' pump? The pneumatic pressurization pump?
can anyone give me the schismatic of the onboard water supply pumps that is used on the shuttle to simulate please? :D
I think the woman on the left is Stephanie Stilson, Discovery's flow director.
How long after MECO are the payload bay doors opened?
After MECO, what composes the various particles/debris that are seen escaping from the Orbiter?
As in water ice from combustion?After MECO, what composes the various particles/debris that are seen escaping from the Orbiter?
A good bit is ice peeling off of the SSMEs.
How long after MECO are the payload bay doors opened?
TIA
Excellent!How long after MECO are the payload bay doors opened?
TIA
I seem to recall that, at least on STS 1, if the PLBD were not opened during the first orbit there would be an immediate abort.
How had the Lockheed ejection seats been tested, which were installed for the OFT missions? I know their envelope was up to Mach 2.7 and 80'000 ft, but how was this tested? Which methods were used?There was sled testing and they used SR-71 suits.
Also: Had the seats actually been tested together with the EES suits? If so, how?
For a school project, I need a list of every shuttle mission's payload weight. Somewhere other than Wikipedia. Does this exist? Where can I find it?
Anything that includes STS-89 through STS-135. That was a nice document Jim.For a school project, I need a list of every shuttle mission's payload weight. Somewhere other than Wikipedia. Does this exist? Where can I find it?
http://www.spaceflight.nasa.gov/shuttle/reference/green/cargsumm.pdf
Anything that includes STS-89 through STS-135. That was a nice document Jim.For a school project, I need a list of every shuttle mission's payload weight. Somewhere other than Wikipedia. Does this exist? Where can I find it?
http://www.spaceflight.nasa.gov/shuttle/reference/green/cargsumm.pdf
Thank you IMOM, I appreciate the link. A "LIKE" for you!Anything that includes STS-89 through STS-135. That was a nice document Jim.For a school project, I need a list of every shuttle mission's payload weight. Somewhere other than Wikipedia. Does this exist? Where can I find it?
http://www.spaceflight.nasa.gov/shuttle/reference/green/cargsumm.pdf
This Space Shuttle Mission Summary book has payload weights for all the program's missions.
http://www.jsc.nasa.gov/history/reference/TM-2011-216142.pdf
Mark
When the Soviets had their own Shuttle program, one of their concerns was a possible negative influence on the piloting skills of the cosmonauts during a mission, i.e. their ability to fly and precisely land Buran after staying in zero-gravity for more than a week. To address this concern and simulate these conditions, both Igor Volk and Anatoliy Levchenko, right after landing of their respective Soyuz missions, had to fly the Tu-154LL Buran training aircraft back to Zhukovsky to perform a Buran style approach and landing. After that, they had to fly right back to Baykonur in a MiG-25 to do some more Buran profile landings there.
Had there been any similar concerns for the US Space Shuttle astronauts? If so, how were these concerns addressed and dealt with?
When the Soviets had their own Shuttle program, one of their concerns was a possible negative influence on the piloting skills of the cosmonauts during a mission, i.e. their ability to fly and precisely land Buran after staying in zero-gravity for more than a week. To address this concern and simulate these conditions, both Igor Volk and Anatoliy Levchenko, right after landing of their respective Soyuz missions, had to fly the Tu-154LL Buran training aircraft back to Zhukovsky to perform a Buran style approach and landing. After that, they had to fly right back to Baykonur in a MiG-25 to do some more Buran profile landings there.
Had there been any similar concerns for the US Space Shuttle astronauts? If so, how were these concerns addressed and dealt with?
How had the Lockheed ejection seats been tested, which were installed for the OFT missions? I know their envelope was up to Mach 2.7 and 80'000 ft, but how was this tested? Which methods were used?The upper limits were educated guesses, there was no certification at Mach 3 or 80,000-100,000ft.
Also: Had the seats actually been tested together with the EES suits? If so, how?
The ejection seats for Buran had been tested together with the Strizh suits during five Progress launches in addition to the usual ground tests on rocket sleds and test aircraft.
Was something similar done with the Shuttle seats?
Actually, all SR71s were two seaters (one pilot, one RSO). However, I think you're referring to the SR71 pilot training aircraft which is a totally bizarre looking variant.Like I wrote "the LEAST rare SR-71 spy plane 2 seater", meaning the most common of the Blackbirds was the 2 seat SR-71(32 built), as there were more 2 seat SR-71s built than 1 seat A-12s(13 built, plus 2 M-21s and 3 YF-12 models being built-the YF-12 has no chines on its nose to allow a radar suite to be installed, this forced designers to include a single fin that is retractable under the fuselage as well as a fin under each engine nancelle)
How much do these things weigh? Specifically the older design before the crossover was added to ensure both sides blew simultaneously.
Anyone know the context for the missing tiles in this photo? Service panel access? Access behind those tiles wasn't a normal part of launch prep, was it?
The Purge, Drain and Servicing panels had their TPS removed in readiness for S0024, Prelaunch Propellant Loading. During rollover and VAB ops, the panels are covered with a green fabric cover. This cover is removed after arrival at the pad. The photo above was most likely taken at a time the RSS had been retracted for Payload Canister ops before S0024.Anyone know the context for the missing tiles in this photo? Service panel access? Access behind those tiles wasn't a normal part of launch prep, was it?
Larger region is a Purge and Drain Access Panel (monomethylhydrazine & helium)
Smaller one is a Service Access Panel (also monomethylhydrazine & helium)
It also looks like a tank relief vent (monomethylhydrazine) has had something taped over it (the white rectangular taped area above top panel)
Not routinely removed during normal pad flow. I'm sure someone will know the reason why they were opened.
The Purge, Drain and Servicing panels had their TPS removed in readiness for S0024, Prelaunch Propellant Loading. During rollover and VAB ops, the panels are covered with a green fabric cover. This cover is removed after arrival at the pad. The photo above was most likely taken at a time the RSS had been retracted for Payload Canister ops before S0024.Anyone know the context for the missing tiles in this photo? Service panel access? Access behind those tiles wasn't a normal part of launch prep, was it?
Larger region is a Purge and Drain Access Panel (monomethylhydrazine & helium)
Smaller one is a Service Access Panel (also monomethylhydrazine & helium)
It also looks like a tank relief vent (monomethylhydrazine) has had something taped over it (the white rectangular taped area above top panel)
Not routinely removed during normal pad flow. I'm sure someone will know the reason why they were opened.
So yes, these panels are routinely removed during the pad flow for servicing of the FRCS propellant tanks (MMH and NTO).
I'm wondering about the nut itself. Goes on a 28 inch long, 3.5 inch diameter bolt. I've seen them on display but not seen any details. It's the biggest frangible nut I know of.
I'm wondering about the nut itself. Goes on a 28 inch long, 3.5 inch diameter bolt. I've seen them on display but not seen any details. It's the biggest frangible nut I know of.
I'm wondering about the nut itself. Goes on a 28 inch long, 3.5 inch diameter bolt. I've seen them on display but not seen any details. It's the biggest frangible nut I know of.
The attached document gives detailed design dimensions of the nut, plus some other info (pre-crossover implementation). It is made of Inconel 718 whose density is around 0.30 lbs/in3 (8.2 g/cm3). So in principle the mass of the nut could be calculated from the drawing!
I wouldn't be suprised to find out that this question has been asked in the past, but as this website doesn't seem to have a search function, I shall ask it here.
STS-107 seems to have flown about 1.5 years later than STS-108. While shuttle launches would often have completely out of synch numbers, that was because the numbers were allocated when the missions were funded? So what happened for the mission to take so long between funding and launch? I would also guess that STS-107 was the last non station/hubble launch planned?
I wouldn't be suprised to find out that this question has been asked in the past, but as this website doesn't seem to have a search function, I shall ask it here.
STS-107 seems to have flown about 1.5 years later than STS-108. While shuttle launches would often have completely out of synch numbers, that was because the numbers were allocated when the missions were funded? So what happened for the mission to take so long between funding and launch? I would also guess that STS-107 was the last non station/hubble launch planned?
I wouldn't be suprised to find out that this question has been asked in the past, but as this website doesn't seem to have a search function, I shall ask it here.
STS-107 seems to have flown about 1.5 years later than STS-108. While shuttle launches would often have completely out of synch numbers, that was because the numbers were allocated when the missions were funded? So what happened for the mission to take so long between funding and launch? I would also guess that STS-107 was the last non station/hubble launch planned?
numbering was as manifested, not as flown. Missions flew out of sequence sometimes according to payload needs/constraints.
1. I was reading STS-115 Orbit Operations checklist and on page 12-89 is DEORBIT Manager Initialization . I see from the checklist it's a software application which I imagine is run on a laptop. I was wondering if the software is the same or the parent to this? https://www.nasa.gov/centers/johnson/techtransfer/technology/MSC-24639-1-tsa-dops.html#.V3QgpvkrJqM
2. I know mission control sorts out the data for deorbit but would the crew use this software routinely or was it simply a back-up?
3. Lastly if there is any other information/screenshots of this software, other than what is on the checklist, could anyone point me in the right direction?
Not sure where I can find this information, so I'll post it for the "experts" here...during the time that MIR was permanently manned by U.S. astronauts (from STS-76 through STS-91) there were 9 other shuttle flights that flew independent missions.
Did each of those (independent) flights (albeit briefly) communicate with the U.S. MIR crew member?
Thank you.
As always, thanks, Jim...are there links available for those flights that did communicate?Not sure where I can find this information, so I'll post it for the "experts" here...during the time that MIR was permanently manned by U.S. astronauts (from STS-76 through STS-91) there were 9 other shuttle flights that flew independent missions.
Did each of those (independent) flights (albeit briefly) communicate with the U.S. MIR crew member?
Thank you.
not each one.
QuoteOrbiter Obvious - 7/11/2006 8:37 PMQuotejcopella - 25/7/2006 1:50 PMQuotepsloss - 25/7/2006 6:20 AMQuotejcopella - 25/7/2006 12:44 AMThanks, John. On the comm loop that was broadcast on NASA Select, SPE says it was PCL sequence 18 (if I'm hearing right). Also sounds like Ms. Pape's voice at the GLS console.
P.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.
Yep. GCL18. That's the PCL sequence for V41K1515XL, the LO2 outboard f/d valve close command (I still have my GLS "brain book" here in the office, which I keep around for sentimental reasons. Never thought I'd have to use it to look up a PCL sequence again! LOL)
How long does it take someone to train up and know all these sequences like this?
The short answer is, years. But you should keep in mind a couple of things. Not everyone in a given system knows every single PCL sequence for that system cold. Usually only the system specialists (very small number of very senior people) had that sort of in-depth knowledge, and even they relied on source code listings and other reference material to supplement their grey matter.
I was a GLS engineer, and we executed a lot of commands on behalf of the subsystems, and we were software weenies anyway, so we were sort of expected to have that sort of knowledge. But even we realied on our "brain books" for this sort of thing, and of course that knowledge is supplemented by messages and displays that we saw in real-time on launch day.
On my first tour thru KSC, I worked with GLS for about 4 years, and at the end of that 4 years I felt like I was just starting to really know what I was doing. At that time (early 90s), we had a training and certification program for new engineers that generally took about a year to complete, depending on what the launch schedule was like -- you had to complete X number of S0044s, X number of S0017s and X number of S0007s (both as early shift support, backup operator, and primary operator). There were also classes you were required to attend, and we had some assignments and tests as well. That was on top of your daily job assignments which would've included software development & maintenance, data review, paperwork, attending meetings (yay!!), etc. After your training was complete, you really needed a few (3 or 4 years) of hard experience before things really settle in and you get confident in the role.
Maybe some of the other Shuttle vets who worked on the hardware can chime in on what sort of training they received and how long it took them to get comfortable with the job. And if they worked console for any length of time, and dealt with high energy systems, I'll be they even remember some of their PCL sequences! LOL
GLS is go for main engine start at T-10 seconds but I note that unlike at other points in the GLS sequence below T-9 minutes this was not marked as auto in S0007. Was an action required by CGLS to allow the RSLS to start the engines?It was a software command, see the chart that Mark posted here:
At this point GLS & RSLS run in parallel, interacting directly only when there's a countdown clock hold/resume (e.g., the T-9m built-in hold), and at T-31 sec and T-10 sec when the two LPS "go" flags (auto sequence start & SSME start, respectively) are sent.
Does anyone know what the upmass used on a Hubble Servicing Mission was?Which one?
Which one?Any generic one (a rough total mass for a generic Hubble servicing), but all if possible. I looked in L2, but the documentation I found is very in depth on the systems carried up while not actually mentioning total mass.
This is all stuff from Wikipedia and isn't consistent in format. Some is detailed payload breakdown, while some is simply launch mass and landing mass of the Orbiter. I think there was some very detailed documentation on payloads earlier on in this very thread. Perhaps a quick read in this thread may reveal some answers. Perhaps this will pique some others input?Which one?Any generic one (a rough total mass for a generic Hubble servicing), but all if possible. I looked in L2, but the documentation I found is very in depth on the systems carried up while not actually mentioning total mass.
Can anyone provide links to audio/video/transcript/articles of instances when an orbiter burn was not responded to with "no trim required"...and needed to be trimmed? Curious as to what instructions were given, what corrections were made to meet the targets, and any other information.
Listening to some old Shuttle audio, before the full TDRSS network was operational. The Orbiter was instructed to "Configure LOS" and "Configure AOS" as its orbital path moved from ground station to ground station...and TDRSS. What did these procedures entail?
Forgive me if this rather simple question was asked and answered already, but...
My understanding is that Discovery was to be assigned to Vandenberg for the polar launches. Would Discovery have stayed there, or been "shuttled" to KSC for other missions?
Which begets another question...or actually five -
1. The tank fill schedule (as I understand it) was low flow to 2% then high flow (5,000 gal/min) til 98% then low flow again to 100%
a. What was the low flow rate?
b. How do it know? No 2% sensor...
Dave
2. The feed lines openings were offset (as I measure it, 10 degrees for LOX and 6 degrees for LH2).
a. I ASSUME that this was to make up for gravity effect, si or no?
b. Why are these not the same? (density delta twix LO2 & LH2?)
c. Was the offset towards or away from the orbiter?
Dave
Thanks again! Excellent response/info.
I'm trying to get my (very) limited grey matter wrapped around the offset CG thing - I realize why the CG was offset, but did the offset cause/require a pitch that in turn caused the feed ports to be "canted"?
Thanks again! Excellent response/info.
I'm trying to get my (very) limited grey matter wrapped around the offset CG thing - I realize why the CG was offset, but did the offset cause/require a pitch that in turn caused the feed ports to be "canted"?
Why didn't the shuttle external tank have LOX/LH2 common bulkhead - unlike Saturn S-II ? they were of similar sizes and volumes.
I thought it could have made the E.T lighter, helping the shuttle performance a little ? by 1979 the Air Force was considering strapping Titan engines or solid rocket motors to improve performance.
Could a common bulkhead external tank have been fitted to shuttles as an upgrade ?
Recently was looking at old mission pictures and the images of Challenger post landing and actually in the preflare on 61a gave me a start! The browned burn from nose cap up to the cabin window was striking. I've never seen the shuttle look like that in that area. Was is a different reentry plan? High inclined orbit?
My other question was regarding I believe sts 8 or maybe 9. I read that there was tile slumping. I don't know what that is and what would cause it?
Yes. What they used pre-Challenger was stock 3M ScotchGuard that was sprayed directly onto the orbiter. It was later found that the ScotchGuard wasn’t working too well with the adhesive used to bond the tiles to the orbiter. This caused alot tiles to debond and was what was really behind the “TPS issues” with Challenger that forced her substitution with Discovery for STS-51C. In fact the problems were so severe that they removed Challenger’s original body flap and used the one intended for Atlantis. The body flaps were never changed back prior to the loss of Challenger so even to this day, Atlantis still have the refurbished body flap from Challenger.Recently was looking at old mission pictures and the images of Challenger post landing and actually in the preflare on 61a gave me a start! The browned burn from nose cap up to the cabin window was striking. I've never seen the shuttle look like that in that area. Was is a different reentry plan? High inclined orbit?
No, just waterproofing material burning off. no different entry
Yes. What they used pre-Challenger was stock 3M ScotchGuard that was sprayed directly onto the orbiter. It was later found that the ScotchGuard wasn’t working too well with the adhesive used to bond the tiles to the orbiter. This caused alot tiles to debond and was what was really behind the “TPS issues” with Challenger that forced her substitution with Discovery for STS-51C. In fact the problems were so severe that they removed Challenger’s original body flap and used the one intended for Atlantis. The body flaps were never changed back prior to the loss of Challenger so even to this day, Atlantis still have the refurbished body flap from Challenger.
DISCUSSION: The forward RCS oxidizer aft Z strut failed in Euler buckling due to the lift-off dynamic response from the SRB overpressure. The forward and
aft Z axis tank struts on both the fuel and the oxidizer tanks were replaced with struts reinforced by plies of boron/epoxy. The rod end diameter of the fuel tank struts was
increased by 1/16 in. to be the same as the diameter of the oxidizer struts.
The base heat shield left and right struts were reinforced and replaced. All other large mass support systems were reassessed for positive margins. CONCLUSION: Z axis
accelerations exceeded design limits due to SRB overpressure which resulted in deformation of the forward RCS oxidizer tank aft Z strut. CORRECTIVE_ACTION:
Forward RCS struts were modified and replaced. Base heat shield left and right struts were reinforced and replaced. All large mass structures were analyzed and found to
have positive margins of safety. CAR ANALYSIS: Descriptions of damage, causes, and corrective actions are defined in the preceding. [not included in original problem
report] EFFECTS_ON_SUBSEQUENT_MISSIONS: None
A theoretical question: What is the maximum payload the Shuttle with Centaur (both versions) could have pushed to a standard GTO (*) or to a trans-Mars trajectory?
(*) I know that most of such missions would had smaller satellites doing direct injection to geostationary, but just let's say that we have the satellite making the circulation burns here. ;)
Also what is the maximum size of the volume that can be allocated to the payload in the Shuttlr Orbiter cargo bay?
Re-posting a question I have from the Shuttle-Centaur thread:A theoretical question: What is the maximum payload the Shuttle with Centaur (both versions) could have pushed to a standard GTO (*) or to a trans-Mars trajectory?
(*) I know that most of such missions would had smaller satellites doing direct injection to geostationary, but just let's say that we have the satellite making the circulation burns here. ;)
Also what is the maximum size of the volume that can be allocated to the payload in the Shuttlr Orbiter cargo bay?
The figures I have seen are only for direct geostationary insertion missions, and they don't give out the payload volume that can be used (which looked rather small).
Sorry to hijack your post, but I am surprised at the potential FOD this tech is wearing. Watch, bracelet, pen in pocket...This photo was taken during Endeavour's T&R processing. Otherwise there would be a mandatory bunny suit requirement for when working inside the crew module and payload bay. This requirement was dropped once the T&R processing began as the orbiter wouldn't fly again, ever.
Maybe in this particular image this was a retired orbiter or otherwise not space-bound.
Good evening all, we have just watched the 2 Mission Control documentaries on YouTube and we wondered whether there were always film crews in Mission Control or where they there because there was a whiff of an issue, this relates particularly to the SLS-107 disaster, which seemed to have been covered by a number of cameras in amongst the controllers at a very critical time, or is it perhaps clever editing is existing footage to provide pictures for the r3corded audio?
I hope I’m mak8ngbsome sense?
Cheers
John
unpacking after moving house, i came accross two old Shuttle manifests. Going through them, i stumbled over an Inmarsat payload manifested for the 4th quarter of 1994.
A late 1991 version of the manifest, has the Inmarsat payload removed and the secondary objective (SFU-RETR) moved to 1995. There is an empty Atlantis for STS-68 manifested for August '94 so maybe that was supposed to be the Inmarsat flight.
Obviously, there was never an Inmarsat that was deployed by Shuttle but i have not yet heared about one of their payloads being switched from Shuttle to an ELV. Was it just an experiment carried aboard (although, it appears to be a primary payload in the manifest)? Can an anyone shed light on that? Thanks!
What is the source and date of the manifest? It isn't a NASA document. It may be an error.
This two-foot by two-foot plate -roughly in the shape of the orbiter itself- had been bonded underneath the orbiter and then covered with tiles.What is its correct designation and its actual function and purpose? Where exactly was it mounted and what is its actual shape? Was this piece unique to Columbia or did every orbiter have it?
What is the source and date of the manifest? It isn't a NASA document. It may be an error.
i received it from NASA as a kid. Among a load of "Information Summaries" brochures.
EDIT: on second thought, i might have gotten these two documents together with the STS press kits i requested before each flight from JSC (mail code AP-4).
As for the date, i must have been in '91 - i remember having them pinned on my wall and editing them as the years unfolded.
Also, as a follow-up question, why does some engines have two or three numbers? Like 2012 | 2107 or 2036 | 2045?
Can someone help me with the SSMEs serial numbers for STS-134 and STS-135? All I have is this chart (http://www.collectspace.com//review/sts133_ssmechart-lg.jpg), but it's not updated for the last two missions. Thank you.Don't forget the 2010 build E-2062 and the 2014 build E-2063.
Also, as a follow-up question, why does some engines have two or three numbers? Like 2012 | 2107 or 2036 | 2045?
Edit: I've found the answer to my first question: 2059, 2061 and 2057 for STS-134 and 2047, 2060, 2045 for STS-135.
One question that popped into my mind last night was, what was the payload weight penalty for having the obss installed? Was the ability to throttle to 104.5% able to claw some of the weight back?Found this reference:
One question that popped into my mind last night was, what was the payload weight penalty for having the obss installed? Was the ability to throttle to 104.5% able to claw some of the weight back?
I don't think any of the astronauts would refuse an assignment. To do so, especially under George Abbey, would be career suicide.So long as it wasn't a Return To Launch Site trial for STS-1.
Were there potential Shuttle crewmembers that refused to fly on proposed Shuttle-Centaur missions (Galileo, Ulysses, Magellan)?
In early January 1986, [STS-61F commander Fred] Hauck recalled, "we were working an issue to do with redundancy in the helium actuation system for the liquid oxygen [and] liquid hydrogen dump valves and it was clear that the [Shuttle management] was willing to compromise on the margins in the propulsive force being provided by the pressurised helium. We were very concerned about it."
"We had discussions about it with the technical people, but we went to a [review] board to argue why this was not a good idea to compromise on this feature. The board turned down the request. I went back to the crew office and said to my crew, in essence, 'NASA is doing business differently from the way it has in the past. Safety is being compromised and, if any of you want to take yourself off this flight, I will support you.'"
One of the reasons for Fabian’s departure was his conviction that NASA prized commercial respectability above operational flight safety. He spent enough time with the 61G crew to see a technician clambering onto the Centaur with an untethered wrench in his back pocket and another smoothing out a weld, then accidentally scarring the booster’s thin skin with a tool. In Fabian’s mind, it was bad enough that the Shuttle was carrying a volatile booster with limited redundancy, without adding new worries about poor quality control oversight and a lax attitude towards safety.
become Director of Space, Deputy Chief of Staff, Plans and Operations, Headquarters USAF.https://www.jsc.nasa.gov/Bios/htmlbios/fabian-jm.html
Colonel Fabian retired from the USAF in June 1987 and joined Analytic Services Inc (ANSER), a non-profit aerospace professional services firm in Arlington, Virginia, where he is now President and Chief Executive Officer.
None? The fixed service structures have been there since the start of the Shuttle program, they're part of the pad not the MLPsThe Fixed Service Structures were created by disassembling the old Saturn V LUTs and trucking them, segment-by-segment to the pads. Pad A's FSS was created from the LUT on ML-2 and the FSS on Pad B was the ML-1 LUT. ML-3's LUT went into the "LUT Bone Yard" in the KSC Industrial Area after it had been removed from ML-3 in order to convert ML-3 into MLP-3 for the shuttle program.
None? The fixed service structures have been there since the start of the Shuttle program, they're part of the pad not the MLPsThe Fixed Service Structures were created by disassembling the old Saturn V LUTs and trucking them, segment-by-segment to the pads. Pad A's FSS was created from the LUT on ML-2 and the FSS on Pad B was the ML-1 LUT. ML-3's LUT went into the "LUT Bone Yard" in the KSC Industrial Area after it had been removed from ML-3 in order to convert ML-3 into MLP-3 for the shuttle program.
Only the Rotating Service Structures were new builds.
None? The fixed service structures have been there since the start of the Shuttle program, they're part of the pad not the MLPsThe Fixed Service Structures were created by disassembling the old Saturn V LUTs and trucking them, segment-by-segment to the pads. Pad A's FSS was created from the LUT on ML-2 and the FSS on Pad B was the ML-1 LUT. ML-3's LUT went into the "LUT Bone Yard" in the KSC Industrial Area after it had been removed from ML-3 in order to convert ML-3 into MLP-3 for the shuttle program.
Only the Rotating Service Structures were new builds.
Wasn't ML-1 renamed MLP-3 since it was the last to be reconfigured for Shuttle? I thought I read ML-1 became MLP-3 and ML-3 became MLP-1, with ML-2 becoming MLP-2.
So, would it be:
ML-1 (MLP-3): LUT disassembled, scrapped in 2004
ML-2 (MLP-2): LUT became 39A FSS
ML-3 (MLP-1): LUT became 39B FSS
Is that right?
Thanks for the help!
What "triggers" the Roll Program? MET? Velocity? Altitude?
-Did the SRB's ignite at T + 3 seconds? I can hear a voice in the nasa feed counting up, "T+1, T+2, T+3".
-When chase is counting down the number of feet to TD where is that altitude coming from? Radar on the chase?
"Roll Program" - What is the crew looking for to cue them to say "Roll Program" and "Roll Program Complete"?
What "triggers" the Roll Program? MET? Velocity? Altitude?
STS-1
-Pre launch I thought I heard the phrase, "up arrow, down arrow"?
-Did the SRB's ignite at T + 3 seconds? I can hear a voice in the nasa feed counting up, "T+1, T+2, T+3".
-What is being called down by the crew at approx. 1:04:00 in the video feed. It is shortly after, "Go at 40". Sounded to me like, "434 max q 48" ???
I'm in a bit of discussion about whether or not the orbiter was at an slight angle when it was mated to the ET. Based on measurements of the separation planes (FWD and aft) it seems like the orbiter would have to be at an angle to be properly mated to both the FWD and aft points (EO-1 through EO-3).
Drawings in the SLWT System Definition Handbook Vol. 2 show that the FWD attachment point is 16.285 inches above the AFT attachment points. The FWD and AFT attachment points are 843.60 inches apart, so ARCTAN(16.285/843.60) = 1.106 degrees.
F=ma
Drawings in the SLWT System Definition Handbook Vol. 2 show that the FWD attachment point is 16.285 inches above the AFT attachment points. The FWD and AFT attachment points are 843.60 inches apart, so ARCTAN(16.285/843.60) = 1.106 degrees.
F=ma
For a dry tank or a fueled tank? The ET shrank something like a foot in the vertical direction when cryo-loaded. So that would rotate the forward bipod a bit.
The meat of the question is now what if any AoA did the orbiter have when mated to the ET?
https://www.aiaa.org/uploadedFiles/About-AIAA/History_and_Heritage/Final_Space_Shuttle_Launches/Why_the_Wings_Stay_On.pdfI meant when while stationary on the MLP, not in-flight. Was the axes of the orbiter and ET/SRB stack different or were they inline with each other?
F=maThe meat of the question is now what if any AoA did the orbiter have when mated to the ET?
https://www.aiaa.org/uploadedFiles/About-AIAA/History_and_Heritage/Final_Space_Shuttle_Launches/Why_the_Wings_Stay_On.pdfI meant when while stationary on the MLP, not in-flight. Was the axes of the orbiter and ET/SRB stack different or were they inline with each other?
F=maThe meat of the question is now what if any AoA did the orbiter have when mated to the ET?
Did the orbiter have a pitch bias (positive or negative) when mated to the ET like it when it was mated to the OTS/SCA? When it was mated to either of those two, it was always pitched up by 3°s(6°s for the ALTs). That is what I am trying find out, if it had a positive or negative pitch angle (AKA Angle of Attack) when mated to the ET like it did for everything else it could be mated to.
https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/ (https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/)The orbiter X-axis which goes through the nose. I have attached a schematic of Discovery at a level attitude. Is that how the how the orbiter would sit on the ET or would it be at an angle relative to the X axis?
Scaling from this drawing of the Orbiter/SCA, its FWD attachment is 4.5 feet above the AFT attachments, so the attachment point plane is inclined +3.4 degrees relative to the SCA reference plane (windows/body stripe), or 2.3 degrees higher than the Orbiter/ET stack (1.1 degrees). The Orbiter reference plane (Payload Bay Door sill) is inclined +1.8 degrees relative to the SCA waterline plane, or 1.8 degrees higher than on the Orbiter/ET stack (zero).
Since this drawing is not CAD or a known scale, these angles are probably not accurate, but if you average them, the Orbiter sits 2 degrees (3 versus 1) more nose-high on the SCA than on the ET. What AOA between the Orbiter and ET are you looking for? The angle of the wings relative to the ET? If so, then at the root? At the chine?
https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/ (https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/)The orbiter X-axis which goes through the nose. I have attached a schematic of Discovery at a level attitude. Is that how the how the orbiter would sit on the ET or would it be at an angle relative to the X axis?
Scaling from this drawing of the Orbiter/SCA, its FWD attachment is 4.5 feet above the AFT attachments, so the attachment point plane is inclined +3.4 degrees relative to the SCA reference plane (windows/body stripe), or 2.3 degrees higher than the Orbiter/ET stack (1.1 degrees). The Orbiter reference plane (Payload Bay Door sill) is inclined +1.8 degrees relative to the SCA waterline plane, or 1.8 degrees higher than on the Orbiter/ET stack (zero).
Since this drawing is not CAD or a known scale, these angles are probably not accurate, but if you average them, the Orbiter sits 2 degrees (3 versus 1) more nose-high on the SCA than on the ET. What AOA between the Orbiter and ET are you looking for? The angle of the wings relative to the ET? If so, then at the root? At the chine?
My assessment is yes. The Orbiter X-axis in your image runs through the centerline of the Orbiter Payload Bay, and is parallel to the centerline of the ET, separated by 336.5 inches (see Reply #3546).So the difference in heights of the attachment points (FWD vs aft) doesn't make the orbiter X-axis have an angle?
F=ma
https://history.nasa.gov/rogersrep/v3o5.htmhttps://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/ (https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/)The orbiter X-axis which goes through the nose. I have attached a schematic of Discovery at a level attitude. Is that how the how the orbiter would sit on the ET or would it be at an angle relative to the X axis?
Scaling from this drawing of the Orbiter/SCA, its FWD attachment is 4.5 feet above the AFT attachments, so the attachment point plane is inclined +3.4 degrees relative to the SCA reference plane (windows/body stripe), or 2.3 degrees higher than the Orbiter/ET stack (1.1 degrees). The Orbiter reference plane (Payload Bay Door sill) is inclined +1.8 degrees relative to the SCA waterline plane, or 1.8 degrees higher than on the Orbiter/ET stack (zero).
Since this drawing is not CAD or a known scale, these angles are probably not accurate, but if you average them, the Orbiter sits 2 degrees (3 versus 1) more nose-high on the SCA than on the ET. What AOA between the Orbiter and ET are you looking for? The angle of the wings relative to the ET? If so, then at the root? At the chine?
My assessment is yes. The Orbiter X-axis in your image runs through the centerline of the Orbiter Payload Bay, and is parallel to the centerline of the ET, separated by 336.5 inches (see Reply #3546).So the difference in heights of the attachment points (FWD vs aft) doesn't make the orbiter X-axis have an angle?
F=ma
https://history.nasa.gov/rogersrep/v3o5.htmhttps://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/ (https://www.the-blueprints.com/blueprints/modernplanes/modern-sa-st/56557/view/space_shuttle_boeing_747/)The orbiter X-axis which goes through the nose. I have attached a schematic of Discovery at a level attitude. Is that how the how the orbiter would sit on the ET or would it be at an angle relative to the X axis?
Scaling from this drawing of the Orbiter/SCA, its FWD attachment is 4.5 feet above the AFT attachments, so the attachment point plane is inclined +3.4 degrees relative to the SCA reference plane (windows/body stripe), or 2.3 degrees higher than the Orbiter/ET stack (1.1 degrees). The Orbiter reference plane (Payload Bay Door sill) is inclined +1.8 degrees relative to the SCA waterline plane, or 1.8 degrees higher than on the Orbiter/ET stack (zero).
Since this drawing is not CAD or a known scale, these angles are probably not accurate, but if you average them, the Orbiter sits 2 degrees (3 versus 1) more nose-high on the SCA than on the ET. What AOA between the Orbiter and ET are you looking for? The angle of the wings relative to the ET? If so, then at the root? At the chine?
Did the orbiter have a pitch bias (positive or negative) when mated to the ET like it when it was mated to the OTS/SCA? When it was mated to either of those two, it was always pitched up by 3°s(6°s for the ALTs). That is what I am trying find out, if it had a positive or negative pitch angle (AKA Angle of Attack) when mated to the ET like it did for everything else it could be mated to.I recall that the attachment angle used for actual transport flights was different than the angle used for the Approach and Landing Test. For ferry flights, the Orbiter was mounted at 3º
Archibald, check out the Orbiter weights starting on page D-81 of:thank you !!
W. Heineman Jr..: “Design Mass Properties II: Mass Estimating and Forecasting for Aerospace Vehicles Based on Historical Data,” Report No. JSC-26098, NASA Johnson Space Center, Houston, TX, November 1994.
http://www.alternatewars.com/BBOW/Space/JSC-26098_Design_Mass_Properties_II.pdf
F=ma
Currently trying to wrap my mind around the orbiter weight breakdown.
First, did I got the basic numbers right
- Orbiter weight without the SSME and no payload: 151 000 pounds.
- With the SSME added: 171 000 pounds.
- Maximum landing weight: 240 000 pounds (does that includes a 60 000 pounds full payload bay ?)
Well, is there, somewhere, a detailed breakdown of those 151 000 pounds of empty weight ? The two OMS pods weight 30 000 pounds by themselves, TPs was also pretty heavy - 20 000 pounds. What else ?
Archibald, check out the Orbiter weights starting on page D-81 of:thank you !!
W. Heineman Jr..: “Design Mass Properties II: Mass Estimating and Forecasting for Aerospace Vehicles Based on Historical Data,” Report No. JSC-26098, NASA Johnson Space Center, Houston, TX, November 1994.
http://www.alternatewars.com/BBOW/Space/JSC-26098_Design_Mass_Properties_II.pdf
F=ma
Yes it did. Never realized before how heavy were the RCS/OMS systems + their propellants. More or less 1/3 of an orbiter mass by themselves.
Yes it did. Never realized before how heavy were the RCS/OMS systems + their propellants. More or less 1/3 of an orbiter mass by themselves.
Note this is why the program adopted burning the OMS engines for about a minute shortly after SRB sep--improve upmass, reduce on-orbit mass and improve down mass.
I'm left wondering, was the OMS/RCS oversized for some reason (safety, something else), or was it the absolute right / minimum size for such a big vehicle ?
(browsed direct insertion) So they found that the SSMEs could do the final push into orbit better than the OMS pods. Interesting.
(browsed direct insertion) So they found that the SSMEs could do the final push into orbit better than the OMS pods. Interesting.
(browsed direct insertion) So they found that the SSMEs could do the final push into orbit better than the OMS pods. Interesting.
I think they always knew that, but the SSMEs on the first flights were at 100% RPL. 104.5% wasn't certified yet. Hence the OMS-1 burn.
Does anyone know the Xo locations of the 16 PLBD C/L latches? I have the locations of latches 3 through 16 but I'm lacking the locations of the two forward-most latches.
DaveS, here are the Xo coordinates that I found. How do they compare with yours?Thanks, your coordinates agrees with the one I have found for latches 3-16. You don't happen to have the Yo coordinates for the inboard edges of the door rib beams? I mean the ones that the latches and passive shear fittings are attached to.
F=ma
602.3, 647.3, 692.3, 737.3
783.6, 828.3, 873.0, 917.7
966.4, 1011.1, 1055.8, 1100.5
1144.2, 1184.2, 1224.2, 1264.2Does anyone know the Xo locations of the 16 PLBD C/L latches? I have the locations of latches 3 through 16 but I'm lacking the locations of the two forward-most latches.
DaveS, here are the Xo coordinates that I found. How do they compare with yours?Thanks, your coordinates agrees with the one I have found for latches 3-16. You don't happen to have the Yo coordinates for the inboard edges of the door rib beams? I mean the ones that the latches and passive shear fittings are attached to.
F=ma
602.3, 647.3, 692.3, 737.3
783.6, 828.3, 873.0, 917.7
966.4, 1011.1, 1055.8, 1100.5
1144.2, 1184.2, 1224.2, 1264.2Does anyone know the Xo locations of the 16 PLBD C/L latches? I have the locations of latches 3 through 16 but I'm lacking the locations of the two forward-most latches.
Yes it did. Never realized before how heavy were the RCS/OMS systems + their propellants. More or less 1/3 of an orbiter mass by themselves.
Note this is why the program adopted burning the OMS engines for about a minute shortly after SRB sep--improve upmass, reduce on-orbit mass and improve down mass.
If they planned on burning the OMS engines to save weight, why not simply load that much less propellant?
How was the velocity scale of MM103 ASCENT TRAJ 2 handled for HST missions? I'm asking because the scale only goes between 25K and 26K, with the MECO velocity for HST missions going slightly beyond the 26K maximum of the scale. Was it pegged OSH for the last few seconds on those missions or was the scale adjusted for those missions only?
Perfect! I think it would be way too much to ask to pressurize the whole bay so I'd think they had units to fit in the bay that were pressurized. Also I've seen the shuttle cockpit and the "locker" room below, so it would be nice to stretch your legs in that sucker.One of our NSF members Jim worked the Spacehab missions 8)
On some missions, two modules were flown together to make a SPACEHAB Logistics Double Module, providing more room for experiments and storage.
Topic, this is hard to explain.
I'm looking for information on the skylab-like units they put in the shuttle bay which they could connect to the hatch and work in a pressurized environment. These units stay in the shuttle bay. Am I thinking incorrectly here and the shuttles launched satellites and/or connected to mir/ISS every mission?
SpaceHAB related question: On which missions was either or both of the XO576 bulkhead CCTV cameras (A/D) moved to the aft bulkhead of the SpaceHAB? Two missions I'm aware of are STS-95 (both cameras relocated) and STS-107 (camera D relocated the left camera platform of the SpaceHAB), but where there any others? And what was the reason for relocating these cameras?
Thanks for the answers. Was there anything special they wanted to keep an eye on during those missions? On a similar tangent: The RMS end effector camera, was it different in any way from the other cameras that were mounted on PTUs? Or was it bog standard, just not mounted on a PTU?SpaceHAB related question: On which missions was either or both of the XO576 bulkhead CCTV cameras (A/D) moved to the aft bulkhead of the SpaceHAB? Two missions I'm aware of are STS-95 (both cameras relocated) and STS-107 (camera D relocated the left camera platform of the SpaceHAB), but where there any others? And what was the reason for relocating these cameras?
STS-57, 60, 63, 77. The module blocked the view of the cameras for items behind the module
Thanks for the answers. Was there anything special they wanted to keep an eye on during those missions?SpaceHAB related question: On which missions was either or both of the XO576 bulkhead CCTV cameras (A/D) moved to the aft bulkhead of the SpaceHAB? Two missions I'm aware of are STS-95 (both cameras relocated) and STS-107 (camera D relocated the left camera platform of the SpaceHAB), but where there any others? And what was the reason for relocating these cameras?
STS-57, 60, 63, 77. The module blocked the view of the cameras for items behind the module
On a similar tangent: The RMS end effector camera, was it different in any way from the other cameras that were mounted on PTUs? Or was it bog standard, just not mounted on a PTU?
Can someone confirm that the forward-most edge of the PLBD forward curvature are located at XO576 and the aft-most edge where they meet the mid-fuselage is at XO582?
I seem to remember soome footage of a Big Wing Canberra that was going to be monitoring Discovery's descent--flying 'chase'. (https://www.viki.com/users/ppornnapa01_632/about/)Anyone have any links?
Question about rcs. I've noticed on the control panel that has a low-z selection. I know that this was used on docking to iss. How exactly does this work?
What would a shuttle mission cost in CRS + CCTCap prices?
;D sorry,What would a shuttle mission cost in CRS + CCTCap prices?
I'm not sure I really understand the question -- it doesn't make a whole lot of sense to me.
Kind of like asking how many calories an apple would have if you made it out of bananas.
;D sorry,What would a shuttle mission cost in CRS + CCTCap prices?
I'm not sure I really understand the question -- it doesn't make a whole lot of sense to me.
Kind of like asking how many calories an apple would have if you made it out of bananas.
Assuming
1. shuttle could carry 20 ton to ISS, AND 7 crew members*
2. CRS prices are about 60-70$ million per ton*
3. CCTCap prices are between 30-50$ million per seat *
So a full shuttle mission would "worth" 1410-1750$ million.
If Shuttle prices were lower than that, does it mean that shuttle was more cost effective than COTS ?!
* My estimates are mostly unsubstantiated. I couldn't find formal prices or capabilities.
So I ask for better opinions
Post STS-51-L, was their contingency plans that would have allowed crews to survive a Challenger type incident?
This is post 51-L so the crew is now in a pressure suit and would have been concious for the rest of the ride up and down.
Were there actual cue cards that would have instructed the crew to blow the hatch and egress a falling crew compartment?
What did the Shuttle GLS user interface look like?
I'm building a simulator for the CCMS. I have a lot very detailed info on the OS and base applications (including the GOAL executor and FEPs) and even a pretty good idea how the GLS works (based on S0007 and the various GLSDD's that are floating around). Surprisingly, there's virtually no information out there about what the actual screens the console operators interacted with look like. I've found a single youtube video that briefly shows half of a barely visible screen here:
https://www.youtube.com/watch?v=R8aByl2fK5I?t=720 (https://www.youtube.com/watch?v=R8aByl2fK5I?t=720) (skip to 12 minutes in)
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
A couple more specific questions:
- It looks to me like the top section with the timers is constant across all GLS displays, and the lower section is replaced depending on the particular GOAL program you're interacting with (SLP07 in this case). Is this right?
- what do the marks under the VFY/MIP/LIP columns signify? I'm assuming the columns correspond to the state of mainline verifies, the mainline interrupt processor and LCC interrupt processors? Does it signify if there's a violation for that milestone?
- what does 'ML REVERIFICATION' do? Is it a user invokable action?
- I'm guessing the 'BFS' and the top center is indicating the current ops? Should there be a matching 'PASS' mode next to it?
- Although it's hard to see in the source image, above 'LAST HOLD' it looks like 'CPERS', which would be 'contingent performs'? Is that indicating whether any CPERS are currently running?
- similar to CPERS, I *think* that's 'TB0' in the lower right box, which would be 'Timebase zero'? is that just a display, or is it indicating something else?
These are pretty obscure details to be worrying about, but I'm basically looking for any info to make this as accurate as possible. Any insight on what this or other GLS screens should look like or how they behave is greatly appreciated.
Thanks!
What did the Shuttle GLS user interface look like?
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
It's very accurate. What's on the right side, if memory serves, are a few additional cursor targets to invoke other GLS tasks. I'd have to go back to my brain book to get the details.
I have some printed copies of the GOAL display skeletons (the static part of the display) that I can dig up if you're still interested in pursuing this project.
(I was a GLS operator during mid-life of the Shuttle program, 1989 thru 1993)
p.s. Kudos to you on reverse engineering the semantics of that display from that grainy video and S0007. If you have access to Vol IV, you might find the GLS subsystem section which might provide some additional detail for not only SLP07, but the other GLS displays. As you've correctly surmised, SLP07 was just one of several.
What did the Shuttle GLS user interface look like?
From this video and a bit of guesswork I've reconstructed the display in the attached image. Does anyone know how accurate this is, and what should be on the right side of the screen?
It's very accurate. What's on the right side, if memory serves, are a few additional cursor targets to invoke other GLS tasks. I'd have to go back to my brain book to get the details.
I have some printed copies of the GOAL display skeletons (the static part of the display) that I can dig up if you're still interested in pursuing this project.
(I was a GLS operator during mid-life of the Shuttle program, 1989 thru 1993)
Sweet! It's great to hear from someone with first hand experience. Some of your previous posts have been invaluable in figuring this stuff out.
I'm definitely still (slowly) working on it, and every bit of information is appreciated. I'm currently putting together a GOAL compiler/executor and using code automatically generated from parts of the GLSDD as my main test case. Of course, I'm entirely unsure that the code I'm generating is correct. I suspect, for example, that the VFY/CVFYs should be in tables rather than separate statements. GOAL is a weird language.
Another high level question I've had: is the GLSDD the input that's used to generate the executable code, or is there a separate input file that generates both the GLSDD and executable code? I ask because there's enough variation that it's not always clear to me how to map entries in the GLSDD to GOAL statements. On the other hand, there are comments like "DELAY 2 SECONDS" that map directly.
Thanks again for your response; this is great!
Can someone explain why are there bellows on the turbine ends of HPFTP and HPOTP (in SSMEs of course)? What exactly are they loading onto the turbine? Is the whole stationary aft section free to shift axially inside the turbine housing, which includes the turbine inlet struts and all the stator blades? Then how is the clearance between this aft section and the turbine disc maintained? Through hydraulic pressure vs seal clearance?
Another quick follow-on, are all the turbines and stators uncooled and thus as hot as the fuel-rich gas? I've heard from non-authoritative sources that all these blades are coated with gold to mitigate hydrogen embrittlement. Is this true?
I don't have design knowledge, but from looking at illustrations, it appears the bellows serves the purpose of strain relief to allow for thermal expansion.
The high pressure turbopump turbines are cooled with GH2, which is discharged into the turbine outlet.
Quick question to settle a discussion I'm having: The forward edges of the orbiter midbody sidewalls are perfectly vertical when seen from the side, is this correct? There's no angle to them? I'm talking about where the midbody joins with the lower forward fuselage half.
Edit:To make the question a bit more clear, is the interpretation of the attached schematic correct? Teal vertical line being the bottom of the Xo576 bulkhead, green horizontal line the PLBD hinge line at Zo420 and the red diagonal line the tilted upper section of the Xo576 bulkhead.
Pretty sure that the entire Xo 576 bulkhead is flat, not angled above Zo 420. See photo of 576 without the insulation liner.It has to be to account the canted upper forward fuselage aft face. Or are you saying that the entire bulkhead is angled in the X-Z plane?
F=ma
Random question, apologies if it's been asked before.
How much control authority do the flight control surfaces (especially the vertical tail) have at high aoa and reentry velocity+altitude? I've read that the shuttle pulls high alpha S-turns in early stages of reentry, but I can't imagine the control surfaces are especially effective in that regime. I was specifically wondering about the vertical tail, as it almost seems like it would be in the "shadow" of the leading edge of the wing+the fuselage, especially if there's flow separation?
Thanks
Was any thought ever given to doing STS as an inline vehicle from scratch, with the SSMEs on the ET?
Now that I think about it, it would have meant losing the SSMEs along with the ET, defeating the purpose/selling point of a near fully reuseable vehicle, so I doubt it was ever considered. Bummer, as it would have given a better system from the beginning.
I need some light on a shuttle GN&C term here. When talking about a certain attitude, in some cases it has the prefix of "Bias". What is this and how was it determined? For example, some of the attitudes flown during STS-107 was "BIAS -ZLV -XVV"? How did this attitude differ from a regular "-ZLV -XVV" attitude?
I seem to remember soome footage of a Big Wing Canberra that was going to be monitoring Discovery' (https://www.triptoday.ir)s descent--flying ' (http://www.rahkarenovin.net)chase' (http://www.rahkarenovin.com).Anyone have any links?
:o ??? ;)
طراحی سایت (http://www.rahkarenovin.com) هاست لینوکس (http://www.rahkarenovin.net/web-hosting/) ثبت دامنه (http://www.rahkarenovin.net/domains/) میزبانی وب (http://www.rahkarenovin.net/) بلیط هواپیما (https://www.triptoday.ir/)
Though the space shuttle accomplished quite a bit, we all know that the Shuttle was a grand fiasco in design, safety, and especially cost.
It was responsible in the end for NASA decisively losing the rocket battle to the private sector.
But given that NASA consists of thousands of people with as much expertise in spaceflight as anyone (and more than anyone else in the 70s), I'm left wondering how it all stacked up like this.
I heard that back in the 70s, they wanted a reusable spacecraft to cheapen the costs of spaceflight. Did not the NASA people realize that the Shuttle might cost more than a low cost expendable system, and/or that for a reusable design the shuttle was an odd and extremely inefficient way to go? Or was this nothing more than a cosmic miscalculation and failure by NASA?(I know it's because in those days there was no KSP)
Hi all — Obscure question about Enterprise from a scale modeller's perspective... were/are her elevon flapper doors made from Inconel? In photos during ALT, they seem much lighter in colour, even a light grey. But in subsequent photos (integration test at KSC, European tour ’83, World’s Fair ’84) they’re the expected black.
Were they originally a different material and then replaced? Or maybe just later painted black? Or are the ALT photos just a trick of the harsh Californian sunlight and they were Inconel all along? (Although I can’t remember photos of the X-15 looking light grey!)
Was avionics bay 3B used in the final Shuttle flights? Is there a diagram that shows which black boxes are located in each bay?
F=ma
Thanks mkirk. What's the source of these images?
F=ma
Good info thanks mkirk. I saw in one of Wayne Hale's posts that the RSB is closed at 15 percent. Do you know why 15 and not 0?
F=ma
I know he said don't ask - but I couldn't help myself! And he answered on the other thread...
Thanks again for your insight mkirk.
F=ma
Been watching close-up/high speed imagery of SSME and SRB launch events on NASA TV. Always wondered why the SSME nozzles pulled toward each other (while at full thrust) just before SRB ignition. Final check of engine controller? Final check of gimbaling? Thanks!
Way upthread, I was making the same discussion about SSME in Position 2 and 3(left and right engine positions). And while having engine 2 and 3's nozzles splayed further apart for the "start" position was perhaps a small part of the reason, primarily the start position was to control thrust vector in an attempt to reduce of center loading of the stack. An effect was a reduced "twang" effect which at the same time reduced that amount of movement in the SRB joints. The SRB joints elusively allow for the "twang" movement as the SRB nozzles are bolted hard-down to the MLP .Been watching close-up/high speed imagery of SSME and SRB launch events on NASA TV. Always wondered why the SSME nozzles pulled toward each other (while at full thrust) just before SRB ignition. Final check of engine controller? Final check of gimbaling? Thanks!
That is the RS-25s moving to actual launch position--they are slightly splayed as they spin up to full thrust to avoid hitting each other during start-up transients. (that is, to keep the nozzles from hitting each other--that would make for a very bad day)
EDIT: not sure which imagery you've been watching, but I've seen super high res/super slo-mo imagery where one can see not just the large-scale transients (engines shaking visibly), but also the harmonics in the nozzles themselves--subtle oscillations much like a ringing bell. Amazing stuff!
Space Shuttle Training Briefings
Throughout this Space Shuttle Q&A Thread/Forum, the subject of shuttle aborts has come up numerous times. Since before STS-1 even flew, there were (and still are) countless myths regarding how the shuttle was actually flown/operated, and how it would have been flown in various nominal, off-nominal, and contingency abort scenarios - particularly with regard to expected survivability.
The links below are to some recently produced Briefing on the topic of Shuttle Ascent / Abort procedures and techniques. They are presented by Andy Foster, a former Space Shuttle Training Instructor in the same group that I would ultimately end up working in for a while. He presents these briefings in essentially the same fashion as we presented the initial academics to Astronauts before beginning their Shuttle Mission Simulator (SMS) training.
Andy is still conducting the remaining briefings every Tuesday night via the Webex Meeting app at 7:00 central time. You can still sign up for free to participate in the remaining briefings by sending an email to: [email protected]
The remaining briefs will cover Contingency Aborts - by far the most complex and “scariest” aspects of shuttle flight operations. Can the space shuttle ditch in the ocean? When and how would the crew bailout? What if all 3 engines fail during first or second stage?
Once those are recorded I will update this post with links to them as well.
Space Shuttle Ascent Aborts - Return to Launch Site (RTLS):
https://m.youtube.com/watch?v=bAEjgvSYi-E
Space Shuttle Ascent Aborts - Transoceanic Abort Landing (TAL):
https://m.youtube.com/watch?v=JoTJvbsKl2k
Space Shuttle Contingency Aborts Part 1:
https://www.youtube.com/watch?v=9Ijf0Yx7OEE
Space Shuttle Contingency Aborts Part 2:
https://www.youtube.com/watch?v=kzKSf60uork
Here is a link to a Space Shuttle Ascent briefing Andy presented to the news media prior to the first flight (STS-26) after the Challenger Accident :
https://m.youtube.com/watch?v=zkAvE2FGeUM
Mark Kirkman
“NASA Space Shuttle Hugger”
Some fellow SMS (Shuttle Mission Simulator) Instructors posted some videos of an Integrated Sim for STS-135 in another group forum. They said I could link those videos here as well.Nice. Thanks, Mark.
This Integrated Simulation was conducted on 6/16/2011 for STS-135.
Thanks for the highlight.
Can we share those videos or is it just for forum members?
Yes, you can share.
Mark Kirkman
Sitting here reading a bit about sts-48. Amazing work, but I was wondering why the need for a 3 person Eva? Would it not have been better to spin Endeavour to match the sat and then just use the rms?
I think you mean STS-49. The 3-crew EVA was done because they were DESPERATE for a solution, as the capture bar approach was a complete non-starter.
Think about what you're proposing to do. Let's just spin up the WHOLE orbiter to # RPM, and then grab Intelsat with the RMS. Probably rip the dam thing right off the Orbiter.
F=maSitting here reading a bit about sts-48. Amazing work, but I was wondering why the need for a 3 person Eva? Would it not have been better to spin Endeavour to match the sat and then just use the rms?
Hey Folks-
Some fellow SMS (Shuttle Mission Simulator) Instructors posted some videos of an Integrated Sim for STS-135 in another group forum. They said I could link those videos here as well.
This Integrated Simulation was conducted on 6/16/2011 for STS-135.
What you will see is a video for each of the 4 runs they conducted this particular day. The video shows 4 cameras that usually monitored the PFD (primary flight display) in the shuttle simulator cockpit, another camera showing a PASS (primary) GPC (general purpose computer) display, a third showing a BFS (backup flight system) display, and a 4th that is usually looking out the commander’s side window. All of the audio is from within the cockpit as Chris Ferguson, Doug Hurley, Sandra Magnus, and Rex Walheim work through the problems and talk to CAPCOM Butch Wilmore.
I will also post a pdf link at the very bottom to the Sim Instructor Script used that day. You will notice that it mentions 5 runs, but iirc, only 4 were done that day.
FYI; the PFD shows, (from left to right), MACH/VELOCITY, ANGLE OF ATTACH (ALPHA), the attitude of the shuttle with regard to the earth horizon, ALTITUDE (in thousands of feet) and rate of climb (H-dot in feet per second).
Unfortunately the cameras used for this cutoff the tops of each display - what you would normally see up on the top would be the GPC Modes, Display Title, and Mission Elapsed Time.
VIDEO 1
Is from Run #1 of the script, a “TAL - Cabin Leak” scenario:
https://m.youtube.com/watch?v=XTJ2pCK5Apw
VIDEO 2
Is from Run #4 of the script; a “ATO - Launch hold, BFS engage for GPC failures” scenario:
https://m.youtube.com/watch?v=nbeAbWzyYDs
VIDEO 3
Is from Run #2 of the script; a “Stuck droop - 1 engine throttle stuck and 1 engine shutdown” scenario:
https://m.youtube.com/watch?v=UBeHeuKmETM
VIDEO 4
Is from Run #3 of the script; a “Systems AOA - loss of 2 H2O loops” scenario:
https://m.youtube.com/watch?v=nIvGBd0SHOQ
Here’s a link to a pdf of the Sim Script
https://ia601400.us.archive.org/16/items/sts-135-ascent-3/STS-135%20Ascent%203.pdf
Mark Kirkman
“NASA Space Shuttle Hugger”
How accurate are the mathematical motion models used in this simulator?
An error occurs when trying to load a display format GPC MEMORY. What to do? What is the reason?
(https://cdn.discordapp.com/attachments/694153756870443059/744773550006861964/unknown.png)
An error occurs when trying to load a display format GPC MEMORY. What to do? What is the reason?
can someone explain to me what it is PREBANK
can someone explain to me what it is PREBANK
It is usually used for underburn during deorbit or during Abort Once Around .
It is associated in general with propellant failure, or limited DeltaV for those burns.
By Banking the Orbiter before the Entry Interface , vertical component of the lift vector will be decreased slighlty.
It will then cause a steeper entry trajectory early on.
Steeper entry angle = increased drag = Delta V dissipated faster, helping to recover from a shallow entry angle.
Prebank value will depend by how far is the current perigee after deorbit burn compared to the forecasted one.
for Mark KirkmanIt's just HDOT or Height Delta Over Time, AKA vertical velocity. In normal aviation terms it would climb rate/sink rate.
very impressive video
what does H-double dot mean?
how astronauts use H-double dot when performing manual control?
for Mark KirkmanIt's just HDOT or Height Delta Over Time, AKA vertical velocity. In normal aviation terms it would climb rate/sink rate.
very impressive video
what does H-double dot mean?
how astronauts use H-double dot when performing manual control?
I wanted to know about H-double-dot :)
It's just HDOT or Height Delta Over Time, AKA vertical velocity. In normal aviation terms it would climb rate/sink rate.
I wanted to know about H-double-dot :)
It's just HDOT or Height Delta Over Time, AKA vertical velocity. In normal aviation terms it would climb rate/sink rate.
for Mark Kirkman
very impressive video
what does H-double dot mean?
how astronauts use H-double dot when performing manual control?
H double dot is altitude acceleration
H dot is altitude rate (analogous to rate of climb or descent in an airplane)
H double dot is a very valuable tool for flying a manual entry.
Background:
For a Space Shuttle entry, range to the landing site is controlled by managing drag. You manage drag by controlling altitude. You control altitude by adjusting roll.
For example; if you are high energy and need to slow down so you don’t go zipping by the runway at the landing site; you obviously want to increase your current drag in order to reduce your high total energy condition.
Where can you find more drag????
Well, right below you in the thicker part of the atmosphere.
If you roll the orbiter, the vertical component of lift is reduced and the orbiter begins to descend (fall) faster into the thicker part of the atmosphere.
This is somewhat counter intuitive from a piloting point of view because in a traditional airplane you manage altitude by pitching up or down. Unfortunately, the shuttle had a very small alpha (angle of attack) envelope during entry of only +/- 3 degrees. If you exceeded that alpha it would result in loss of control and you’d “burn the wings off”.
The amount of roll needed to achieve the desire descent rate (H dot) to get you to the desire drag - was provided by the GPC (general purpose computer) displays. If that wasn’t available or couldn’t be trusted, the astronauts could do a little math in public and use the formula Hdot Desired = Hdot + 20 * (Drag current - Drag desired)......sounds like a great job for the Flight Engineer (MS2).
H double dot provided a means for the pilot to evaluate the amount of roll being used. An H double dot of close to zero meant you had a stable H dot.
All of the above is an overly simplistic explanation, but it hopefully gives you a little insight.
Mark Kirkman
“NASA Space Shuttle Hugger”
for Mark Kirkman
very impressive video
what does H-double dot mean?
how astronauts use H-double dot when performing manual control?
So if you are controlling H dot with roll angle, are you applying counter yaw to keep the ground track "straight" or are you allowing the Orbiter to turn and then counter-rolling later to get back on track?
for Mark Kirkman
very impressive video
what does H-double dot mean?
how astronauts use H-double dot when performing manual control?
If you have a L 2 subscription, you can have a look to the Entry TAEM, Approach Landing Guidance Workbook to have even more informations.
for Mark Kirkman
H double dot is altitude acceleration
H dot is altitude rate (analogous to rate of climb or descent in an airplane)
H double dot is a very valuable tool for flying a manual entry.
Background:
For a Space Shuttle entry, range to the landing site is controlled by managing drag. You manage drag by controlling altitude. You control altitude by adjusting roll.
For example; if you are high energy and need to slow down so you don’t go zipping by the runway at the landing site; you obviously want to increase your current drag in order to reduce your high total energy condition.
Where can you find more drag????
Well, right below you in the thicker part of the atmosphere.
If you roll the orbiter, the vertical component of lift is reduced and the orbiter begins to descend (fall) faster into the thicker part of the atmosphere.
This is somewhat counter intuitive from a piloting point of view because in a traditional airplane you manage altitude by pitching up or down. Unfortunately, the shuttle had a very small alpha (angle of attack) envelope during entry of only +/- 3 degrees. If you exceeded that alpha it would result in loss of control and you’d “burn the wings off”.
The amount of roll needed to achieve the desire descent rate (H dot) to get you to the desire drag - was provided by the GPC (general purpose computer) displays. If that wasn’t available or couldn’t be trusted, the astronauts could do a little math in public and use the formula Hdot Desired = Hdot + 20 * (Drag current - Drag desired)......sounds like a great job for the Flight Engineer (MS2).
H double dot provided a means for the pilot to evaluate the amount of roll being used. An H double dot of close to zero meant you had a stable H dot.
All of the above is an overly simplistic explanation, but it hopefully gives you a little insight.
Mark Kirkman
“NASA Space Shuttle Hugger”
Mark thanks for your answer.
The ENTRY TRAJ has a Phugoid scale.
Is this scale used for manual control?
After the DELAZ gets to those values, you then reverse the orbiter’s bank angle (i.e. a roll reversal) to the opposite direction. Doing this allows the orbiter’s nose to track back in the opposite direction until it again gets to 10.5 to 17.5 degrees of DELAZ. Although you don’t point the orbiter directly at the landing site (DELAZ of zero), you keep it within a manageable tolerance of 17.5 degrees for most of the entry.
This entire process of roll reversals is referred to as cross range control.
Mark Kirkman
“NASA Space Shuttle
Hugger”
After the DELAZ gets to those values, you then reverse the orbiter’s bank angle (i.e. a roll reversal) to the opposite direction. Doing this allows the orbiter’s nose to track back in the opposite direction until it again gets to 10.5 to 17.5 degrees of DELAZ. Although you don’t point the orbiter directly at the landing site (DELAZ of zero), you keep it within a manageable tolerance of 17.5 degrees for most of the entry.
This entire process of roll reversals is referred to as cross range control.
Mark Kirkman
“NASA Space Shuttle
Hugger”
I've heard two versions of what roll reversals look like.
1.This is a roll around the X axis
2. This is yaw turn around the velocity vector.
3. What does it look like in reality?
After the DELAZ gets to those values, you then reverse the orbiter’s bank angle (i.e. a roll reversal) to the opposite direction. Doing this allows the orbiter’s nose to track back in the opposite direction until it again gets to 10.5 to 17.5 degrees of DELAZ. Although you don’t point the orbiter directly at the landing site (DELAZ of zero), you keep it within a manageable tolerance of 17.5 degrees for most of the entry.
This entire process of roll reversals is referred to as cross range control.
Mark Kirkman
“NASA Space Shuttle
Hugger”
The roll reversals are rolls around the velocity vector. Because of the orbiter’s very high angle of attack (40 degrees for most of the entry until below Mach 10), this roll maneuver is actually a body axis yaw.
If viewed externally, it would look like the orbiter is yawing from side to side.
Dumb question: what prevented the Shuttle's SRB's from filling with water and sinking after ocean impact? Were balloons used?No balloons. The SRBs were naturally buoyant. The first task in SRB recovery was to install a Diver Operated Plug (DOP) that would allow the booster to switch from from the vertical splashdown orientation to the horizontal tow orientation by "de-watering" the boosters, IE by pumping out the water from the inside. That caused the boosters to rise until they fell over and were ready for the tow back to Port Canaveral.
So the boosters naturally floated in a vertical, nozzle-down orientation after splashdown?Yes. Their natural orientation the water was vertical as they then were just water-filled steel tubes.
So the boosters naturally floated in a vertical, nozzle-down orientation after splashdown?Yes. Their natural orientation the water was vertical as they then were just water-filled steel tubes.
I've learned that when Entreprise was at Pad 39-A, her External Tank was filled "through Enterprise’s mock Main Propulsion System – with hundreds of thousands of gallons of Liquid Hydrogen and Liquid Oxygen. Source: https://www.nasaspaceflight.com/2012/04/space-shuttle-enterprise-the-orbiter-that-started-it-all/ (https://www.nasaspaceflight.com/2012/04/space-shuttle-enterprise-the-orbiter-that-started-it-all/)There was none. Enterprise only had fake SSME nozzles made from cast iron. The only umbilicals that Enterprise ever had were for interfacing with the SCA during the ALTs. She didn't ever have any T0 umbilical panels on her aft engine compartment where the TSMs on the then unfinished MLP-1 would have interfaced with the orbiter. As far as I know, Enterprise's check out of KSC was all mechanical in nature, very similar to the so called Facility Checkouts she did in the mid-80's of Vandenberg's shuttle facilities.
Does anybody know more about this "mock Main Propulsion System"? Did Enterprise had External Tank umbilicals?
Thanks in advance.
Edit: corrections.
If they could load no cryogens, how/when were the "beanie cap" requirements first noticed?Probably through model testing, not using Enterprise.
Interesting. Hmm.
Thank you all for your answers. Maybe they found a way to fill the ET bypassing Enterprise and TSM.If they could load no cryogens, how/when were the "beanie cap" requirements first noticed?Probably through model testing, not using Enterprise.
Interesting. Hmm.
That would be a no-go as the pad cryo facilities tie into the cryo lines on the exterior of the MLP which enter the MLP on Side 1 (south side when it is at the pad) and is routed up through the TSMs. And the fill/drain of the ET is where the orbiter is mated to it (aft structure), so they're blocked off when the orbiter is mated to it.Thank you all for your answers. Maybe they found a way to fill the ET bypassing Enterprise and TSM.If they could load no cryogens, how/when were the "beanie cap" requirements first noticed?Probably through model testing, not using Enterprise.
Interesting. Hmm.
ET-GVTA was one of the first three external tanks that was manufactured at Michoud. Built to represent a flight article, it was not covered in insulating foam like those that would later launch to space, but was painted white.
"ET-GVTA played a critical role in the early testing for the space shuttle," said Dennis Jenkins, the author of the new book, "Space Shuttle: Developing an Icon, 1972-2013" and a former project manager for the space shuttle program. "It was the subject of several iconic photos."
First used with the prototype orbiter Enterprise for a series of vibration tests at NASA's Marshall Space Flight Center in Alabama, ET-GVTA helped establish the bending modes and nodal crossing points to validate various analyses and locate the rate gyros and accelerometers used by the flight control system.
It was then moved to the Kennedy Space Center in Florida for a series of facility verification tests, culminating with it being paired with two solid rocket boosters and mounted to Enterprise in the Vehicle Assembly Building and moving to Launch Complex 39A for the first time.
ET-GTVA was subsequently shipped back to Louisiana for its possible refurbishment into a flight tank, but that did not happen. Instead, it was disassembled and its liquid oxygen and liquid hydrogen tanks, as well as its interstage, were put into storage, eventually being parked outside Building 103, the facility's main manufacturing building.
There would be opportunities to catch the LOX vent ice issues in real-world tests. Importantly, the Main Propulsion Test Article (MPTA) tests at NSTL (later Stennis). The MPTA had an actual, functioning, insulated external tank that was filled and drained through an actual orbiter aft compartment. Whether or not such an issue was identified in the tests, I don't know, but it was possible.ET-MPTA was delivered to NSTL in September, 1977, and had gone through several initial tanking cycles and firing tests through 1978 while mated with MPTA-098 in the B-2 Test Stand. (Those MPTA tests continued into early 1981.)
If they could load no cryogens, how/when were the "beanie cap" requirements first noticed?
https://www.nasaspaceflight.com/2012/04/space-shuttle-enterprise-the-orbiter-that-started-it-all/ (https://www.nasaspaceflight.com/2012/04/space-shuttle-enterprise-the-orbiter-that-started-it-all/)
"She was then rolled out to launch pad 39A on 1 May 1979. During rollout, Enterprise was driven at various speeds to measure and note the various vibration strains on the fully-mated Shuttle stack. This was used to determine an optimal rollout speed for operational Space Shuttle missions.
Once at the pad, Enterprise helped validate launch pad procedures – with her biggest test and benefit to the ground processing operations coming during the full-up Wet Countdown Dress Rehearsal when she helped simulate External Tank fueling operations for launch.
During the test, Enterprise’s ET was filled – through Enterprise’s mock Main Propulsion System – with hundreds of thousands of gallons of Liquid Hydrogen and Liquid Oxygen.
During this time, the venting capabilities of the gaseous hydrogen vent line/system were tested.
However, something quite disturbing was discovered during this test – ICE was building up at the top of the External Tank where the gaseous oxygen was being allowed to vent directly from the tank.
This posed a significant problem as ice was already understood to be a serious hazard to the Shuttle orbiter’s Thermal Protection System tiles and panels.
With the maiden voyage of the Shuttle just under two years away, NASA needed a solution to this newly-discovered problem."
Interesting. Hmm.
During April 1979, OV-101 was mated to a pair of inert solid rocket boosters and the ET (serial number 2) scheduled to be used on STS-1. The stack was transported atop MLP #1 to Pad 39A on 1 May 1979. During almost three months at the pad, Enterprise would help verify that maintenance platforms mated to the vehicle in the correct locations, and that crew escape procedures worked properly. On 23 July 1979, Enterprise was rolled back to the VAB to be demated from the SRBs and ET.
Once at the pad, Enterprise supported checks of the sound suppression system, as well as loading of the super-cold liquid oxygen and liquid hydrogen propellants. Orbiter mid-body umbilicals were attached to the vehicle. Cryogenic propellants were to flow from storage facilities through the Mobile Launcher Platform into the Tail Service Masts, though these liquefied gases did not go further, for Enterprise lacked the appropriate plumbing.https://forum.nasaspaceflight.com/index.php?topic=35828.msg1272680#msg1272680
Verification tests of the Orbiter Access Arm and Rotating Service Structure were conducted. The payload ground-handling mechanism for transfer of an assembled payload from the Rotating Service Structure into the shuttle’s cargo bay also demonstrated its readiness. A 20,000-pound concrete weight, representing a spacecraft, arrived within a sealed canister. With the RSS well away from the shuttle, workers hoisted the canister into the PCR, removed its dummy payload, then rotated the RSS to lie against the back of Enterprise for payload installation within the cargo bay. All this was done under strict environmental control, to prevent contamination of the “spacecraft.”
From May 1 to July 23, 1979, Enterprise completed extensive mechanical fit checks of Kennedy’s checkout and launch operations before she was rolled back to the VAB. “By using Enterprise, we were able to work out a lot of things on a noninterference basis, making the entire effort worthwhile,” Talone said.
I thought this would be a fairly easy and straightforward question to answer but it's turned into an interesting "deep dive."
The Orbiter Mid-Body Umbilical Unit (OMBUU) was located on the RSS. It was used to fill/drain the Power Reactant Storage and Distribution (PRSD) storage tanks located below the payload bay. The OMBUU had a large umbilical that connected to an umbilical panel on the orbiter (large green rectangle in photo 2). It was mated during the S0009 Pad Validation operations that took place following rollout. It was demated from the orbiter once servicing of the PRSD had been completed during the launch countdown. Photo 3 shows the midbody umbilical panel on orbiter with the cover removed in the OPF.
User Ares67 wrote on a post about Enterprise that they load the LH2 and LOX, but up to the Tail Service Master, since Enterprise didn't have a Main Propulsion System, it couldn't flow the propellant to the External Tank.NASA KSC did a similar test at Pad 39B late last year to get ready to load propellants on their new vehicle and NASA Stennis did the same in 2018 using turnaround tools as stand-ins.
So we can assume that's probably what happened when Enterprise was at the pad 39A, right?It's plausible, but I'd rather see documentation that's more definitive.
Twelve weeks of ground tests on the lockup orbiter Enterprise ended.
test series was deemed a complete success. Although the ground tests were
successful, a new problem was discovered with the vehicle--there was a
possibility of ice forming on the outside of the fuel tanks, which could
falloff during launch and damage other parts of the ship.
I found this great paper on lessons learned in external tank development. If you are a fan of the External Tank, it's one of the best resources I've ever seen on the ET.
https://case.edu/cps/sites/case.edu.cps/files/2019-05/2241main_shuttle_et_lesson_021030.pdf (https://case.edu/cps/sites/case.edu.cps/files/2019-05/2241main_shuttle_et_lesson_021030.pdf)
Page 18 mentions the GOX vent ice problem, and specifically ties it to the MPTA tests, as I suspected. Another technical paper I came across gives the background to the GOX vent program arising from a problem identified in the "summer of 1979."
I still strongly suspect a true all-up tanking test at the pad never happened until Columbia arrived out there for STS-1, and that the story of Enterprise being tanked and somehow heroically finding this hitherto unknown ice issue is an apocryphal one.
Fagets original concept for the fully reusable Shuttle had it entering fully stalled in a near 90 degree angle of attack.
This allowed it to slow down higher in the atmosphere for a lower heat load. This was at the cost of lower cross range.
Was the shuttle as designed capable of entering using this profile and was it considered when the cross range requirement was no longer particularly useful?
That's the Tunnel Adapter Assembly (TAA) that was used to link the orbiter airlock with either Spacelab or SpaceHAB when either of those were flown. Those are some rare photos of the interior of the TAA. Most photos only show the exterior.
Thanks DaveS. But where is the part that is in the photos that I posted?What part? The only photos I see is the ones in the pdf file.
F=ma
This photo of the TAA being installed into the PLB of Endeavour for STS-89 shows the interior somewhat. The External Airlock with the ODS on it can be seen to the extreme right in the photo.Another point of view I believe for one of those units; this is in between STS-83 and STS-94.
Does anyone have handy any pictures or diagram of what a Shuttle stack would look like with 5 segment boosters being used instead of the typical 4 segment boosters?
Figure 23 in https://www.aiaa.org/docs/default-source/uploadedfiles/about-aiaa/history-and-heritage/shuttlevariationsfinalaiaa.pdf?sfvrsn=b8875e90_0Wow, thank you very much! There's a couple gems there that I will need to study. 96"/8 feet=2.44m is the difference in height, to the tips of the SRBs and to the tip of the External Tank. That's is closer to the same elevation than I was guessing.
https://ntrs.nasa.gov/api/citations/20020023401/downloads/20020023401.pdf
F=maDoes anyone have handy any pictures or diagram of what a Shuttle stack would look like with 5 segment boosters being used instead of the typical 4 segment boosters?
Also leads me to realize why the road from reusable to expendable for the SLS 5 segment SRB was an easy one. To retain reusability in the 5 segment configuration would have required a new parachute system. The parachute systems designed for the 4 segment RSRM(Redesigned Solid Rocket Motor) nor the FWC(Filament Wound Case) SRB for Polar launches out of Vandenberg would not suffice. Also launch cadence of 1 per year doesn't help the economics of reusability in this particular case.
Thanks again, I really appreciate it!
Only four segments had live propellant in them. The fifth segment was inert, a mass simulator for launch just like the upper stage and Orion/LAS. So what was launched was essentially a regular STS RSRM. So the chutes had to deal with the extra mass of not only the fifth segment but also its inert propellant that was still in the case. Only the lower four segments were empty at the time. I think the splashdown would have been successful if the fifth segment had been empty and not carrying a couple of hundreds of thousands pounds of inert propellant.
Also leads me to realize why the road from reusable to expendable for the SLS 5 segment SRB was an easy one. To retain reusability in the 5 segment configuration would have required a new parachute system. The parachute systems designed for the 4 segment RSRM(Redesigned Solid Rocket Motor) nor the FWC(Filament Wound Case) SRB for Polar launches out of Vandenberg would not suffice. Also launch cadence of 1 per year doesn't help the economics of reusability in this particular case.
Thanks again, I really appreciate it!
Indeed, as evidenced by the parachute "failure" on the Ares 1 test flight, it demonstrated in real terms that much more robust 'chutes would be required, adding so much mass as to eat in to the performance gained by 5-seg boosters in the first place. I put failure in quotes due to the fact the 'chutes didn't fail so much as being asked to do way more than that for which they were designed. Even empty segments are incredibly heavy...
If the Shuttle landed SLF RWY33, how did it get turned around to head back to the VAB? Or were all the landings RWY15?They just turned around on the runway and headed down the runway.
In Kathy Sullivan podcast recently, during her first mission, STS 41-G (Challenger), after MECO, the commander, Bob Crippen made a routine radio call to MCC. But, it turned out it not MCC who reply, but an RAF pilot somewhere in GB (Challenger was over GB at the moment). So, they needed to change radio frequency on the Shuttle very often? or they had a fixed radio frequency for entire duration?
In Kathy Sullivan podcast recently, during her first mission, STS 41-G (Challenger), after MECO, the commander, Bob Crippen made a routine radio call to MCC. But, it turned out it not MCC who reply, but an RAF pilot somewhere in GB (Challenger was over GB at the moment). So, they needed to change radio frequency on the Shuttle very often? or they had a fixed radio frequency for entire duration?
The mid deck was stripped after every flight.Thanks for the confirmation, I thought I'd read that but was having trouble finding specific documentation.
It looked like that most of time.
Where were the two-digit relay addresses assigned for the APC (Autonomous Payload Controller)*?
*Worked with GAS payloads, the IMAX and certain "secondary" PLB payloads (SSBUV).
On the APS's display the center two digits were the relay number the two digits to either side were alpha-numeric. ("A" "E" "L" Etc. What did these codes mean?
Were there other or backup off-nominal functions an APC could perform? There seemed to be a "generic" list of commands imprinted on the controllers that changed throughout the program.
Good day, I have just been challenged as to my reasoning of exactly why the Shuttle's main engines ignition was staggered by 120 milliseconds
I've always understood that it was to reduce loads throughout the Main Propulsion System(MPS).
or
Was the 120 millisecond staggered ignition to reduce the shockwave leaving the aft section in an effort to reduce the wear/tear on the SSME exhaust tunnel(to keep the fire bricks from flying around)?
or some combination of both or neither?
Do any of our Shuttle-minded members have any memories of Flight Termination System(FTS) batteries being changed at the pad?No, what you most likely saw was recorded KSC PAO footage of the HST battery removal and recharge and subsequent re-installation following the first scrub of STS-31. The HST batteries required a 120 hr recharging period following any launch scrubs and they had to it in the VAB Battery Lab which batteries like this are stored in a special refrigerator which chills the batteries which allows them to take on a stronger charge. This was all done in tandem with the APU R&R that caused the launch scrub.
I remember a video showing a man/men pushing a cart with a battery or batteries loaded on it. The very careful manner in which these people were pushing the cart led me to think that they were very important and/or delicate and had some weight to them.. The commentators were talking about battery temperatures and battery life.
I was watching the video online, so that precludes any of the missions Return To Flight#1 (RTF#1) STS-26 that I was watching live via NASA-Select(now NASA-TV) via C band satellite. Unless it was recorded and then I watched it later, online.
If this indeed was a FTS battery change event, was it common?
Excellent and thank you, that was great to watch another shuttle video. That was exactly the video I was asking about.Do any of our Shuttle-minded members have any memories of Flight Termination System(FTS) batteries being changed at the pad?No, what you most likely saw was recorded KSC PAO footage of the HST battery removal and recharge and subsequent re-installation following the first scrub of STS-31. The HST batteries required a 120 hr recharging period following any launch scrubs and they had to it in the VAB Battery Lab which batteries like this are stored in a special refrigerator which chills the batteries which allows them to take on a stronger charge. This was all done in tandem with the APU R&R that caused the launch scrub.
I remember a video showing a man/men pushing a cart with a battery or batteries loaded on it. The very careful manner in which these people were pushing the cart led me to think that they were very important and/or delicate and had some weight to them.. The commentators were talking about battery temperatures and battery life.
I was watching the video online, so that precludes any of the missions Return To Flight#1 (RTF#1) STS-26 that I was watching live via NASA-Select(now NASA-TV) via C band satellite. Unless it was recorded and then I watched it later, online.
If this indeed was a FTS battery change event, was it common?
In the earlier days, of many Edwards AFB landings- why were some fights landed on the lakebed and others on the concrete runway??
For example: STS-36 landed on lakebed runway 23. Why?? The previous flight landed on concrete runway 22..
I understand in the very early days they wanted the extra margin the lakebed runways allowed for, but in the above example it was 1990..
Question on the post-MECO ET Sep translation maneuver that was done by the CDR: On the early missions it seems like it wasn't a a +X maneuver but rather a -Y maneuver given the PAO's comments on STS-1 that the orbiter was "moving to north of the External Tank" and that Young should have been "able to see it out of his window". Is this correct and when wasn't it changed to the +X maneuver that was used through the rest of the program?
Mark: thanks for the answer. It was something that had been on my mind on and off again for a few years. In my mind up until now was that the "north" that the MCC PAO stated was in relation to the orbiter coordinate system where "north" was +X.
Another DPS question: Did MM104 OMS-1 MNVR EXEC take in account the additional dV of the MPS propellant dump when calculating the dV targets?
I'm curious about one aspect of the radiators inside the payload bay doors. When the orbiter was flying on its own (i.e. not docked to Mir or ISS), was the payload bay oriented away from the Sun as often as possible to minimize Solar heating of the radiators? When the bay was facing the Sun, did the radiators lose some of their cooling efficiency? I'm not well versed in the underlying physics of the radiators.
Thx
I’ve tried searching but to no avail; I recall somewhere on here, there was a dramatic photo of the forward fire team “caught” outside their bunker during launch.. I think the story was that a hold was called for T-31 so they went outside.. then the hold was cancelled and they didn’t have time to get back inside.. there was talk on here of which launch it was but idk if it was ever determined ?
I'm not sure if it was ever identified as to which mission it was, but here is the photo...
https://www.thedrive.com/content-b/message-editor%2F1642726676274-lzajden.jpeg?auto=webp&optimize=high&quality=70&width=1440
Yes, the carrier vehicle is outside the pad's perimeter fence. This was M-113/Hard Top One's astronaut rescue vehicle and team (I think Unit #HE-704-080) on station at A/B 4, just under a mile from the shuttle on Pad B, during the launch of STS-26/Discovery in Sept. 1988. I think the photo seen is one that had been autographed by one of the 12-member astronaut pad rescue teams that Bob had gotten from me long ago.