Post by: Skinny on 01/14/2007 12:42 am
To keep everything at readable proportions, this is part 4 of the highly informative thread. Below are the links to previous parts. Please use the search (http://forum.nasaspaceflight.com/index.php?action=search") function to see if your question has been answered before. Have Fun!
Shuttle Q&A Part 1 (http://forum.nasaspaceflight.com/index.php?topic=625)
Shuttle Q&A Part 2 (http://forum.nasaspaceflight.com/index.php?topic=2030)
Shuttle Q&A Part 3 (http://forum.nasaspaceflight.com/index.php?topic=6156)
Shuttle Q&A Part 4 (http://forum.nasaspaceflight.com/index.php?topic=10600.0)
Shuttle Q&A Part 5 (http://forum.nasaspaceflight.com/index.php?topic=17437.0)
Post by: trebloc on 01/14/2007 10:46 pm
1. After the SSME ignition the stack moves towards the ET. I understand this because the SSME's are offset from the CoG of the stack. This is called the "twang" effect I think?? SRB ignition happens when the stack is back in the upright again...makes sense..my question however is how does the stack get back to the upright, if the SSME's are still running at full trottle, should the stack not be left pointing away from the Orbiter?
2. How is the roll manouver controlled? Is it by the SSME's or by the Orbiter aero surfaces?
Thanks in advance
Post by: Jim on 01/14/2007 10:46 pm
2. SRB's and SSME's
Post by: Austin on 01/14/2007 10:46 pm
As Jim stated, the SRB's and SSME's control the roll and pitch of the vehicle. Both the main engine and SRB nozzles gimble, in effect steering the vehicle and positioning it in the proper launch plane. These patterns are preprogrammed and controlled by the computers, of course.
During the next countdown, watch for the main engine gimble check at the T minus 3 minutes, 55 second mark and you will see them moving through their ascent flight profile.
The final gimble check of the SRB nozzles occurs at T minus 21 seconds, but this will not be visible.
Post by: Jim on 01/14/2007 10:46 pm
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Austin - 14/1/2007 3:18 PM
There is also a connection extending from the launch gantry to the rear of the ET that is blown away at T-O.
There is no connection at the aft of the ET. The only T-0 connection is at the intertank and it is not structural
Post by: spaceflight101 on 01/14/2007 10:46 pm
If you want to have some fun during a liftoff, and landing, try this:
Get a copy of Boy Meets Girl's "Waiting For a Star To Fall", and begin playing it at T-16 seconds. Play it all the way through, and listen for the major "events" in the song which correspond to main engine ignition, and SRB separation. When I pointed this out to George and Shannon, they sent me a copy of their unreleased album "New Dream", and asked me to listen to "Flying The Cosmos" and tell them what I thought of it.
Any song that begins and ends with an SR-71 flyby is a big hit with me.
On the way home, I cue up Kavin Hoo's "On The Wings of an Angel" from his "Above the Clouds" instrumental album. There is a pause at 4:50 that just coincides with that special point when the rear wheels first touch down.
At that point, they have made it home...on the wings of an angel.
Post by: Austin on 01/14/2007 10:46 pm
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Jim - 14/1/2007 12:40 PMQuoteAustin - 14/1/2007 3:18 PM
There is also a connection extending from the launch gantry to the rear of the ET that is blown away at T-O.
There is no connection at the aft of the ET. The only T-0 connection is at the intertank and it is not structural
I know that it is not structural (as in fixed) but it is connected to the ET. The 51I launch video (www.insideksc.com) provides a good view of it being released as it falls away at T-0. Also, in pictures from behind the ET it is clearly visible.
Post by: spaceshuttle on 01/14/2007 11:21 pm
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Austin - 14/1/2007 5:29 PM
There is also a connection extending from the launch gantry to the rear of the ET that is blown away at T-O.
As Jim stated, the SRB's and SSME's control the roll and pitch of the vehicle. Both the main engine and SRB nozzles gimble, in effect steering the vehicle and positioning it in the proper launch plane. These patterns are preprogrammed and controlled by the computers, of course.
During the next countdown, watch for the main engine gimble check at the T minus 3 minutes, 55 second mark and you will see them moving through their ascent flight profile.
The final gimble check of the SRB nozzles occurs at T minus 21 seconds, but this will not be visible.
Looking at some daytime VAB Roof launch replays, it looked like the SRB exhaust criss-crossed, so (I if my observation is correct) you can see how the roll actualy happens from that view. The flame also spreads out.
Post by: Austin on 01/15/2007 12:42 am
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spaceshuttle - 14/1/2007 4:04 PM
Looking at some daytime VAB Roof launch replays, it looked like the SRB exhaust criss-crossed, so (I if my observation is correct) you can see how the roll actualy happens from that view. The flame also spreads out.
The VAB roof launch view has always been my favorite. Very nice perspective of a launch.
Post by: elmarko on 01/15/2007 10:53 am
Post by: Skinny on 01/15/2007 12:34 pm
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elmarko - 15/1/2007 5:36 AM Skinny, you have your links the wrong way round in your first post :)
Thanks for pointing that out ! :-)
Post by: Radioheaded on 01/15/2007 02:31 pm
Post by: mkirk on 01/15/2007 03:26 pm
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Radioheaded - 15/1/2007 9:14 AM
After watching the excellent Diary of Discovery posted by Gordo, I noticed that in one part of that program they very quickly showed the crew working an RTLS scenario in the simulator. I was curious (considering how quickly they moved to a different scene) how often are the RTLS performed successfully in the simulator? It's my understanding that were this abort to actually occur that it might take some good fortune (perhaps even divine intervention) to pull it off. It just made me wonder how crews handle it during their simulator time, and what would be the % of successfull landings versus not.
That is really a loaded question. The problem with giving an easy answer is there are too many variables. For instance is the RTLS being performed because of a Systems problem such as with the APUs, Fuel Cells & Electrical Power Busses, Cabin Leaks, OMS/RCS Propellant Leak, or was the Abort called because of a Performance Problem such as the loss of an engine? Then you have to consider what if anything happens during the Abort Profile. Did additional engines fail, are there flight control system issues, is Guidance and Nav good or degraded?
During flight specific training a crew will receive plenty of exposure to RTLS aborts with varying levels of complexity. In fact just about every 4 hour training session of Ascent/Abort procedures will have at least one run that results in an RTLS (a typical session has 4 to 5 ascent runs).
Despite the best effort of the training team to “kill” their crew, it is not something that happens very often. Believe me the instructors work very hard to come up with creative ways to make life hard for the Crew in training, however, if the crew dies during a training session it is a very big deal within the Mission Operations Community. Many folks will look over every detail of what happened to determine if the reason for the simulated “loss of the crew” was related to a real world problem with the shuttle and its flight regime, a flaw in the simulator hardware or software, a mistake by the training team, or a mistake by the crew (or mission control team for integrated simulations).
My point is the intent of training is to work the crew very hard by giving them multiple problems to deal with in an effort to increase the stress levels. However, it is counter productive to train them with situations they can not get out of. If crews are dying in the sim then something is wrong somewhere and it needs to be addressed.
Back to your specific question; RTLS is a certified abort profile and is expected to be survivable. It ws not invented to give the crew something to occupy their time until they hit the dirt. Being a "certified abort" means that it has been studied to a high level of confidence and with much more rigor than other less likely aborts such as contingency cases. For the loss of a single engine or many of the potential system failures I personally see no reason RTLS will not work as advertised. This is not to say that it is not an ambitious profile and that it does not “push the performance envelope”. There are points in the profile where the vehicle is flying backwards thru its own exhaust plume at high mach numbers (~ Mach 5 – 7) and relatively high alpha (angle of attack), the vehicle has to perform an aggressive pitch around maneuver (while mated to the ET), there is a point where the mated stack is falling vertically at around Mach 1 as it zeros out its downrange velocity and begins to head back to the Cape, the orbiter has to get off the external fuel tank (ET), the ET doors have to get closed, and the entry flight software has to get loaded – these are just some of the reasons RTLS is ambitious.
In the simplest of RTLS scenarios, I would have to say my biggest concern would be at ET SEP. You have to make sure the orbiter is at the right alpha (angle of attack) of -2 degrees, and with minimal remaining propellant (i.e. less than 2%) to ensure the tank does not re-contact the orbiter…at least that is what the models say.
Survival both in the sim and real world will depend on just how bad a day the crew is having and how many things are going wrong. I really cant give you the answer in a percentage…
Personally I thought flying RTLS in the simulator was a hell of a lot of fun and the more complicated the scenario the better. In fact in order for me (or anyone) to be certified in the simulator as a so called “motion pilot” – meaning you are allowed to use the simulator on your own (without a safety instructor) with full motion on – I had to fly the entire RTLS profile manually without the use of the HUD (heads up display) while an instructor evaluates you and asks lots of questions so you can’t concentrate. Compared to the more complex RTLS scenarios this was actually pretty easy.
The reason they make you do this for the certification is because it demonstrates your ability to maneuver the shuttle (simulator) in a manner that will not damage the sim or its occupants. The motion based simulator can move aggressively and they don’t want you hurting people or damaging expensive equipment. They also don’t want you hurting some VIP (such as the President, Congressman, movie star, or Journalist) that has managed to get a sim ride.
Mark Kirkman
P.S.
Last year Craig Covault of Aviation Week and Space Technology sat in on a suited Ascent/Abort sim with the STS-115 crew. He wrote an aritcle about it last fall which gives a good overview of the RTLS profile and a narative of a typical TAL Abort. If you have access to the magazine this will give you some good insight into what a training session is like. He is much better at translating the technical stuff than I am.
Post by: DMeader on 01/15/2007 03:56 pm
Briefly on another topic, the Shuttle image used in the headline of the "Shuttle fleet on schedule ahead of NASA summit" article is one of the most stunning launch photographs I have ever seen. Can someone point me to a full-size high-quality copy somewhere I can download, perhaps on L2? I'm not an L2 member yet, but I believe I would join on the spot for that image.
Thank you!
Post by: jabe on 01/15/2007 07:03 pm
how much mass is the shuttle losing each second at the start of the launch? Can do some rough estimates on the masses before and after but curious the actual values. I under stand it is several tonnes per second..
is the there a "chart" that discusses it .. I can find the thrust profile discussed but never the mass loss.. those numbers seem to imprsee kids more than the thrust. Mass loss seems to be a better "visual" for them than thrust
Post by: mkirk on 01/15/2007 07:28 pm
Quote
jabe - 15/1/2007 1:46 PM
slightly off topic..can't seem to find the info..I teach physics and do lessons on rocketry. my search skills seem to be lacking today .. :)
how much mass is the shuttle losing each second at the start of the launch? Can do some rough estimates on the masses before and after but curious the actual values. I under stand it is several tonnes per second..
is the there a "chart" that discusses it .. I can find the thrust profile discussed but never the mass loss.. those numbers seem to imprsee kids more than the thrust. Mass loss seems to be a better "visual" for them than thrust
Well of course it does vary with power setting for the SSME’s (space shuttle main engines) and the burn pattern for the SRB (solid rocket booster).
The SSME’s consume about 1,084 pounds of propellant per engine (3 engines total) per second at the mission throttle setting of 104.5%. I will have to look up the burn rate for the SRB and get back to you if someone else doesn't provide it sooner.
Mark Kirkman
Post by: psloss on 01/15/2007 08:23 pm
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mkirk - 15/1/2007 11:09 AMThanks for the heads up. I believe it was Mr. Covault who wrote one of the first published articles on shuttle abort scenarios for AW&ST back in 1979 (something I didn't find until several years later). Sounds like an interesting read.
P.S.
Last year Craig Covault of Aviation Week and Space Technology sat in on a suited Ascent/Abort sim with the STS-115 crew. He wrote an aritcle about it last fall which gives a good overview of the RTLS profile and a narative of a typical TAL Abort. If you have access to the magazine this will give you some good insight into what a training session is like. He is much better at translating the technical stuff than I am.
Post by: Radioheaded on 01/15/2007 09:12 pm
Post by: mkirk on 01/16/2007 12:59 am
Quote
jabe - 15/1/2007 1:46 PM
slightly off topic..can't seem to find the info..I teach physics and do lessons on rocketry. my search skills seem to be lacking today .. :)
how much mass is the shuttle losing each second at the start of the launch? Can do some rough estimates on the masses before and after but curious the actual values. I under stand it is several tonnes per second..
is the there a "chart" that discusses it .. I can find the thrust profile discussed but never the mass loss.. those numbers seem to imprsee kids more than the thrust. Mass loss seems to be a better "visual" for them than thrust
I haven’t had a chance to look up the SRB burn rates as I promised in my previous post, but I just realized for your purposes it would be much easier to look at this chart compiled by Bill Harwood. It is from the Ascent Flight Design Package for STS-121. It gives you the total vehicle mass (l2nd to last column) in one second intervals from liftoff to MECO (main engine cutoff – zero thrust). MECO mass includes the still attached ET (external fuel tank).
Mark Kirkman
Post by: Chris Bergin on 01/16/2007 01:58 am
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DMeader - 15/1/2007 4:39 PM
Somewhere I think I saw a quote from a crewmember referring to the RTLS abort as "two miracles followed by an act of God".
Briefly on another topic, the Shuttle image used in the headline of the "Shuttle fleet on schedule ahead of NASA summit" article is one of the most stunning launch photographs I have ever seen. Can someone point me to a full-size high-quality copy somewhere I can download, perhaps on L2? I'm not an L2 member yet, but I believe I would join on the spot for that image.
Thank you!
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6171&posts=8&start=1 for different options. I took the image I used from one of the StarScapes presentations on L2, which usually have some stunning images in them. Although L2 is not about images, that's usually a side bonus if that.
Post by: jabe on 01/16/2007 02:04 am
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mkirk - 15/1/2007 7:42 PMseems perfect..I'm assuming the weight means it is in lbs? the amount that the SRB's have over liquid would be interesting too..
It gives you the total vehicle mass (l2nd to last column) in one second intervals from liftoff to MECO (main engine cutoff – zero thrust). MECO mass includes the still attached ET (external fuel tank).
http://spaceflightnow.com/shuttle/sts121/fdf/121ascentdata.html
Mark Kirkman
love to get that in a excel file :)
cheers
jb
Post by: mkirk on 01/17/2007 03:24 pm
I said I believed it was 140,000 feet. I happened to run across my copy of the STS-1 Ascent Checklist yesterday and it turns out the “Negative Seats” call was to be made at 120,000 feet at 1 minute 54 seconds.
In reality (for STS-1) the call was made slightly sooner than that. This was because the SRBs were burning hotter than expected which resulted in a lofted trajectory for 1st stage.
I also noticed that for Entry the preferred ejection altitude (assuming a controlled bailout) was 10,000-15,000 feet.
Mark Kirkman
Post by: TheMadCap on 01/18/2007 01:30 pm
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DMeader - 15/1/2007 10:56 AM
Somewhere I think I saw a quote from a crewmember referring to the RTLS abort as "two miracles followed by an act of God".
Briefly on another topic, the Shuttle image used in the headline of the "Shuttle fleet on schedule ahead of NASA summit" article is one of the most stunning launch photographs I have ever seen. Can someone point me to a full-size high-quality copy somewhere I can download, perhaps on L2? I'm not an L2 member yet, but I believe I would join on the spot for that image.
Thank you!
I had the same question! PM Chris and I am sure he can provide it to you.
BTW, which launch is that photo from?
Post by: DMeader on 01/18/2007 06:46 pm
Quote
Chris Bergin - 15/1/2007 9:58 PM
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6171&posts=8&start=1 for different options. I took the image I used from one of the StarScapes presentations on L2, which usually have some stunning images in them. Although L2 is not about images, that's usually a side bonus if that.
Thanks very much to Chris and everyone who pointed out other versions. I'm using the rotated and "massaged" version on my desktop right now and I'm going to experiment with all of them to get the best print.
Thanks again! :)
Post by: nathan.moeller on 01/18/2007 07:26 pm
Post by: Jorge on 01/18/2007 07:29 pm
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nathan.moeller - 18/1/2007 2:26 PM
Probably an odd question but here goes. During launch, when CAPCOM calls to the CDR "Single Engine (TAL Site) 104" or "Single Engine Press 104," what does he/she mean by "104?"
The SSME power level (104%). In other words, max throttles not required.
--
JRF
Post by: jarthur on 01/18/2007 09:39 pm
I have a bunch of random questions about the external tank. Basically I was hoping to get a general feel for their processing flows, so I was wintering how many tanks are being worked on at any given moment. How many of these are in Michoud, how many are in the VAB, how long does it take to build a tank from beginning to launch.
Also, which specific tanks are in the flow now? Why are we launching tank 124 next? what happened to 123, 122 etc.
Thanks for your answers, any info is appreciated!
Post by: nathan.moeller on 01/18/2007 09:48 pm
Quote
jarthur - 18/1/2007 4:39 PM
Hello,
I have a bunch of random questions about the external tank. Basically I was hoping to get a general feel for their processing flows, so I was wintering how many tanks are being worked on at any given moment. How many of these are in Michoud, how many are in the VAB, how long does it take to build a tank from beginning to launch.
Also, which specific tanks are in the flow now? Why are we launching tank 124 next? what happened to 123, 122 etc.
Thanks for your answers, any info is appreciated!
Tanks are processed at the Michoud Assembly Facility (MAF) in New Orleans, LA. Almost all processing work is completed there. They are then shipped via barge to KSC in Florida and transported to the VAB for a final checkout and overview and any leftover work is completed in the vertical checkout cell. Afterwards it is lifted from the checkout cell and moved to one of two high bays (HB1 or HB3) and mated to the waiting SRBs.
As far as tanks in the flow and recent tanks, ET-123 flew with STS-116, ET-118 with STS-115, ET-119 with STS-121, ET-121 with STS-114 and ET-94 with STS-107. ET-117 is set to fly with STS-118. Of course, the tank numbers don't usually match the STS designation. That's all I know off the top of my head. A full version of the tank-flow is on L2. Hope this helps.
Post by: spaceshuttle on 01/18/2007 11:10 pm
Post by: nathan.moeller on 01/18/2007 11:47 pm
Post by: jarthur on 01/19/2007 06:02 pm
And out of curiosity, how many tanks are actively being constructed right now?
Post by: nathan.moeller on 01/19/2007 06:12 pm
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And out of curiosity, how many tanks are actively being constructed right now?
Enough :) I believe about eight to ten tanks are in active construction at this point but don't quote me on that.
But that's what I've gathered as well. ET-124 will fly with STS-117 (shuttle flight 118), ET-117 with STS-118/LON-318 (shuttle flight 119) and ET-125 will fly with STS-120/LON-320 (shuttle flight 120). I believe ET-120 will be ready to fly with STS-122/LON-322. I had not heard about ET-122 but it's definitely possible. I have heard, however of ET-95 but no specifics. PM Jim about it, as I'm willing to bet he knows. He's pretty much our Mr. Phone-a-Friend here and gives great and accurate information on just about everything.
Post by: spaceshuttle on 01/19/2007 08:03 pm
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jarthur - 19/1/2007 1:02 PM
...and one other tank, possibly left over from the switch from original tanks to LWT's. And out of curiosity, how many tanks are actively being constructed right now?
I'm assuming they're keeping that one as an artifact? :) Just kidding.
Post by: nathan.moeller on 01/19/2007 09:33 pm
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spaceshuttle - 19/1/2007 3:03 PM
I'm assuming they're keeping that one as an artifact? :) Just kidding.
Most likely a test article for foam improving operations and other safety modifications like ET-120 was post-STS-114. I don't expect any of these to wind up in museums or go on display at a NASA center like the orbiters.
Post by: astrobrian on 01/20/2007 03:36 pm
Post by: TJL on 01/20/2007 06:46 pm
What was the reason for the LWT being used on "99"...also am I correct in that was the only use of that type of tank since mid-1998?
Post by: Rocket Guy on 01/20/2007 06:58 pm
Post by: Argosy on 01/20/2007 07:40 pm
What is the maximum achievable delta-v of the shuttle if all the fuel would be burnt out during it's climb, and the shuttle would be empty(no cargo whatsoever, just the skeleton crew)?
Post by: Jorge on 01/20/2007 07:54 pm
Quote
Argosy - 20/1/2007 2:40 PM
Here a question I've been interested in for some time...
What is the maximum achievable delta-v of the shuttle if all the fuel would be burnt out during it's climb, and the shuttle would be empty(no cargo whatsoever, just the skeleton crew)?
Only about 500 fps more than a nominal HST launch. The resulting orbital altitude would be around 600 n.mi.
--
JRF
Post by: mkirk on 01/21/2007 12:33 am
Quote
Jorge - 20/1/2007 2:54 PMQuoteArgosy - 20/1/2007 2:40 PM
Here a question I've been interested in for some time...
What is the maximum achievable delta-v of the shuttle if all the fuel would be burnt out during it's climb, and the shuttle would be empty(no cargo whatsoever, just the skeleton crew)?
Only about 500 fps more than a nominal HST launch. The resulting orbital altitude would be around 600 n.mi.
--
JRF
Yeah, but your use of the word "skeleton crew" may be a poor- although very acurate - choice of words in this case.
Don't let that pesky little desire to come back home get in the way of a maximum performance altitude record. Heck lets really go for broke and use up all the gas in the RCS by using the +x and -x jets as well. Of course we can save just enough propellant for one more attitude change to a right wing forward orientation (i.e. along the velocity vector) which would allow us to blow the hatch and get just one more burst of Delta V as the cabin vents every ounce of remaining O2 and N2 in the ECLSS (environmental control and life support system) out through the open hatch...that would be cool ;) :)
Mark Kirkman
Post by: nathan.moeller on 01/21/2007 04:55 am
Post by: elmarko on 01/21/2007 12:38 pm
To clarify the rules, are we going for the highest circularised orbit, or can we just shoot upwards at 90deg pitch and burn out every propellant available? :p
Post by: Argosy on 01/21/2007 12:40 pm
Post by: Jim on 01/21/2007 01:19 pm
Quote
Argosy - 21/1/2007 8:40 AM
How about storing some extra fuel in the cargo bay(that would be burned also)?
Now you are including things that don't exist. How about adding two more SRB's or a 4th SSME?
I know want you are getting at, there is now way the shuttle can leave LEO
Post by: nathan.moeller on 01/21/2007 01:43 pm
Post by: Jim on 01/21/2007 01:48 pm
Quote
nathan.moeller - 21/1/2007 9:43 AM
Hey Jim. That reminds me of another question. Including those currently installed on the orbiters, how many useable SSMEs are currently in existence?
there is a list on L2
Post by: mainengine on 01/21/2007 01:59 pm
Newest one is SSME 2059 flying on STS-117 in March.
A stock of 15 engines was originally planned.
You may have a look at http://www.mainengine.gratis-webspace.de/ssme_gen2.html
Post by: mainengine on 01/21/2007 02:01 pm
Quote
Jim - 21/1/2007 8:48 AMQuotenathan.moeller - 21/1/2007 9:43 AM
Hey Jim. That reminds me of another question. Including those currently installed on the orbiters, how many useable SSMEs are currently in existence?
there is a list on L2
A list ? Where is it ?
Post by: Jorge on 01/21/2007 04:16 pm
Quote
mkirk - 20/1/2007 7:33 PMQuoteJorge - 20/1/2007 2:54 PMQuoteArgosy - 20/1/2007 2:40 PM
Here a question I've been interested in for some time...
What is the maximum achievable delta-v of the shuttle if all the fuel would be burnt out during it's climb, and the shuttle would be empty(no cargo whatsoever, just the skeleton crew)?
Only about 500 fps more than a nominal HST launch. The resulting orbital altitude would be around 600 n.mi.
--
JRF
Yeah, but your use of the word "skeleton crew" may be a poor- although very acurate - choice of words in this case.
Strictly speaking, it was Argosy's use, not mine...
Quote
Don't let that pesky little desire to come back home get in the way of a maximum performance altitude record. Heck lets really go for broke and use up all the gas in the RCS by using the +x and -x jets as well. Of course we can save just enough propellant for one more attitude change to a right wing forward orientation (i.e. along the velocity vector) which would allow us to blow the hatch and get just one more burst of Delta V as the cabin vents every ounce of remaining O2 and N2 in the ECLSS (environmental control and life support system) out through the open hatch...that would be cool ;) :)
Mark Kirkman
OK, call it another 100 fps from each pod, for a total of 800 fps. The cabin vent, as cool as it sounds, will probably produce negligible delta-V (though it will spin the orbiter quite spectacularly...). From a nominal 300 nmi HST orbit that will get us to a max apogee around 820 nmi, or a circular orbit around 550 nmi.
Alternatively, let's say we never circularized our 300 nmi HST orbit, buying back that amount of OMS. Now we're starting at 300x100 nmi with around 1150 fps to burn at perigee. That could yield a max apogee of almost 1100 nmi.
--
JRF
Post by: Jorge on 01/21/2007 04:17 pm
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elmarko - 21/1/2007 7:38 AM
I would be interested in that! I'm also tempted to run a sim in Orbiter too :P
To clarify the rules, are we going for the highest circularised orbit, or can we just shoot upwards at 90deg pitch and burn out every propellant available? :p
You'll get max altitude burning along the velocity vector, not upwards... :p
--
JRF
Post by: TJL on 01/21/2007 05:51 pm
With super light weight tanks already flying why did STS-99 (which had a relatively heavy payload) and STS-107 use the older type tanks?
I guess the same can be asked of STS-7 and 8. STS 7 used a heavy weight tank (STS-6 flew with the first LWT) and flew a heavier payload than STS-8 which used a LWT.
Thank you.
Post by: Jim on 01/21/2007 07:48 pm
Post by: Fred Clausen on 01/22/2007 06:09 am
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mainengine - 21/1/2007 8:01 AM
A list ? Where is it ?
It is on the pay portion of this site, also known as "L2". It is very much worth the money to join.
Post by: joebacsi on 01/22/2007 02:34 pm
Post by: Jorge on 01/22/2007 04:02 pm
Quote
joebacsi - 22/1/2007 9:34 AM
What was the highest orbit the Shuttle was ever sent up to?
STS-82 in 1997. Semimajor axis 3,781 n.mi., average orbital height 337 n.mi.
All of the highest shuttle orbits were on HST servicing missions, except for STS-95, which was flying a "simulated" HST orbit for one of its payloads, the HST Orbiting Systems Test (HOST).
--
JRF
Post by: elmarko on 01/22/2007 04:41 pm
Ground speed coming through the atmosphere was a slightly toasty 8,000 m/s.
I know this has no bearing on real world applications, but it was brought up, and Mark gave me the idea with his post :)
Edit: Fixed dodgy unit of measurement
Post by: Jorge on 01/22/2007 05:57 pm
Quote
elmarko - 22/1/2007 11:41 AM
For the record I just sent up a shuttle in Orbiter at 90deg pitch and burned out every single propellant there is and attained a maximum altitude of about 7,500m/s (I forget the exact figure). That was with errors in the path though, sometimes my flight path wasn't pointing straight up. Also the shuttle in Orbiter does seem to be a bit more powerful in the first stage than the real life one.
Ground speed coming through the atmosphere was a slightly toasty 8,000 m/s.
I know this has no bearing on real world applications, but it was brought up, and Mark gave me the idea with his post :)
7,500 m/s is a speed, not an altitude... you sure you were looking at the right gauge? :)
--
JRF
Post by: elmarko on 01/22/2007 06:21 pm
And then i did mean m/s for the second measurement :)
Post by: TJL on 02/02/2007 02:05 am
Any talk of increasing the thrust before the program ends for one of the heavier payload missions?
For the 50,000 + pound payload on Columbia's STS-93 mission, was the thrust level 104.5%?
Thanks!
Post by: nathan.moeller on 02/02/2007 03:15 am
Quote
TJL - 1/2/2007 9:05 PM]
What was the first shuttle mission to use 104.5% thrust on the SSME's?
Any talk of increasing the thrust before the program ends for one of the heavier payload missions?
For the 50,000 + pound payload on Columbia's STS-93 mission, was the thrust level 104.5%?
Thanks!
Thrust level will not increase for heavier payloads. Heaviest ISS payloads were about 18 tons (P6, P3/P4, S3/S4, S6) and didn't require extra thrust. I'm sure it wasn't increased for the STS-93 launch. That was the heaviest payload ever hauled into orbit by a shuttle (25 tons). So if it didn't require extra thrust, the ISS payloads don't and will not. In any case, I think the highest possible thrust level is 107%. They had the option of using it for a while in the early days should an ATO case be ordered. They wouldn't use it in the dense lower/middle atmosphere due to aerodynamic loading on the vehicle.
Post by: Jim on 02/02/2007 11:47 am
Post by: mkirk on 02/02/2007 03:27 pm
Quote
pad rat - 2/2/2007 8:40 AM
Isn't the "old" 109% today's 104% due to pump upgrades?
There has been a lot of work done to certify higher thrust levels to help gain some performance and to close black zones (points in the ascent trajectory where certain abort options are not expected to be survivable). 106, 109 and even 115 have all had serious attention – depending I guess on how you define serious.
106 was kind of going to be the new 104.5 but much of the certification work and testing was halted after Columbia. There were initial concerns about 106 for use in first stage with regard to excessive loading - I believe that had been mostly worked out.
When Parsons was still the Shuttle Program Manager I asked him about the SSME power settings and he said it just didn’t make sense for the program to spend the money given the reduced manifest and the fact that the remaining flights didn’t need the additional performance.
There were some changes in the flight software (around OI-26 or 27 I believe) that would have allowed the 106 setting in place of 104.5 for “performance critical” missions.
Mark Kirkman
Post by: gordo on 02/02/2007 08:18 pm
Post by: mkirk on 02/02/2007 09:13 pm
Quote
gordo - 2/2/2007 3:18 PM
Is there a contigency thrust level avail for abort situations?
Yes MAX THROTTLES are available for thrust deficient abort scenarios. The crew types in an "ITEM 4" into the SPEC 51 OVERRIDE display for the GPCs (General purpose computers) and that changes the maximum throttle setting from 104.5% to 109%. This also applys for manual throttling, if the Pilot (left seater) pushes the lever full forward it will now be set for 109%.
The risk of using the higher uncertified power level is outweighed by the risks of not completing the abort successfully.
Mark Kirkman
Post by: nathan.moeller on 02/02/2007 09:19 pm
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5906&posts=22&start=1
Post by: stefan1138 on 02/02/2007 11:26 pm
Stefan :)
Post by: Jim on 02/02/2007 11:26 pm
Post by: stefan1138 on 02/02/2007 11:26 pm
Stefan :)
Post by: nathan.moeller on 02/03/2007 01:20 am
Post by: MKremer on 02/03/2007 03:23 am
Quote
stefan1138 - 2/2/2007 6:26 PM
I hope this has not been discussed before. Following I post a direct view of OV-103. I have marked the odd tile(s) directly under the pilot´s window. This seems to be there since Discovery came out of Palmdale in 1983. Why is it there? Is there something underneath which needs special protection?
Stefan :)
Good question. Columbia had none on either side, and Challenger, Endeavour and Atlantis didn't had that extra 'special' black tile placed in that location:
http://mediaarchive.ksc.nasa.gov/imageviewer.cfm?mediaid=21583&mr=l&w=0&h=0&fn=04pd0011&sn=KSC-04pd-0011 (2004)
http://mediaarchive.ksc.nasa.gov/imageviewer.cfm?mediaid=30144&mr=l&w=0&h=0&fn=06pd2210&sn=KSC-06pd-2210 (2006)
Sure would be interesting to find out why only '-103' has the extra black thermal tile there.
Post by: Flightstar on 02/03/2007 03:56 am
Quote
nathan.moeller - 2/2/2007 8:20 PM
Wow that's strange. I've never noticed that before. Flightstar might know. He works pretty close with the orbiters if I'm not mistaken :)
I'm aft electrical.
Post by: nathan.moeller on 02/03/2007 06:59 pm
Post by: kanathan on 02/03/2007 08:30 pm
Post by: nathan.moeller on 02/03/2007 09:04 pm
Quote
kanathan - 3/2/2007 3:30 PM
I know that the shuttle crews train extensively for the normal abort modes that they might encounter, such as RTLS or ATO, but do they do any training for the contingency aborts such as "fast sep"?
I don't believe there is any fast separation abort. Once the solids light, there is no way to shut them off. If I'm not mistaken, separating the orbiter from the rest of the stack could (and probably would) be catastrophic. Once the SRBs are lit, you're committed to two minutes flight. Once they're gone, you can abort RTLS, TAL or ATO.
Post by: mkirk on 02/03/2007 11:03 pm
Quote
nathan.moeller - 3/2/2007 4:04 PMQuotekanathan - 3/2/2007 3:30 PM
I know that the shuttle crews train extensively for the normal abort modes that they might encounter, such as RTLS or ATO, but do they do any training for the contingency aborts such as "fast sep"?
I don't believe there is any fast separation abort. Once the solids light, there is no way to shut them off. If I'm not mistaken, separating the orbiter from the rest of the stack could (and probably would) be catastrophic. Once the SRBs are lit, you're committed to two minutes flight. Once they're gone, you can abort RTLS, TAL or ATO.
Crews are trained in Contingency Aborts as part of their early shuttle training (i.e. when they are ASCANS – Astronaut Candidates) and later as part of the mission specific training. So yes they get plenty of exposure to them.
It is a pretty specialized part of shuttle training mostly because of the numerous variables that come into play and the sensitive nature of the Contingency Aborts themselves. There are only a couple of training instructors for this particular type of training called "Ascent Procedures Specialists" who sit in on the sims when contingency cases are being trained and who provide the contingency training classes and briefings.
FAST SEP is a real procedure used in some of the Contingency cases for getting off of the tank very quickly – in about 5 seconds. There are situations that can result in very high sink rates which means a rapid buildup in dynamic pressure and thermal stress – both of which affect the ability to safely get off the tank and into an Entry configuration.
There are 7 methods for performing the FAST SEP procedure which are dependent on attitude and altitude.
One of the FAST SEP options is intended for getting off the entire stack (ET and SRBs) during first stage. This is done by separating the orbiter from the ET right at SRB thrust tail off (i.e. prior to SRB SEP).
Mark Kirkman
Post by: shuttlefan on 02/03/2007 11:33 pm
Quote
mkirk - 3/2/2007 6:03 PMQuotenathan.moeller - 3/2/2007 4:04 PMQuotekanathan - 3/2/2007 3:30 PM
I know that the shuttle crews train extensively for the normal abort modes that they might encounter, such as RTLS or ATO, but do they do any training for the contingency aborts such as "fast sep"?
I don't believe there is any fast separation abort. Once the solids light, there is no way to shut them off. If I'm not mistaken, separating the orbiter from the rest of the stack could (and probably would) be catastrophic. Once the SRBs are lit, you're committed to two minutes flight. Once they're gone, you can abort RTLS, TAL or ATO.
Crews are trained in Contingency Aborts as part of their early shuttle training (i.e. when they are ASCANS – Astronaut Candidates) and later as part of the mission specific training. So yes they get plenty of exposure to them.
It is a pretty specialized part of shuttle training mostly because of the numerous variables that come into play and the sensitive nature of the Contingency Aborts themselves. There are only a couple of training instructors for this particular type of training called "Ascent Procedures Specialists" who sit in on the sims when contingency cases are being trained and who provide the contingency training classes and briefings.
FAST SEP is a real procedure used in some of the Contingency cases for getting off of the tank very quickly – in about 5 seconds. There are situations that can result in very high sink rates which means a rapid buildup in dynamic pressure and thermal stress – both of which affect the ability to safely get off the tank and into an Entry configuration.
There are 7 methods for performing the FAST SEP procedure which are dependent on attitude and altitude.
One of the FAST SEP options is intended for getting off the entire stack (ET and SRBs) during first stage. This is done by separating the orbiter from the ET right at SRB thrust tail off (i.e. prior to SRB SEP).
Mark Kirkman
Mark, would it be pretty safe to separate from the stack if the SRB thrust were starting to tail off? ;)
Post by: nathan.moeller on 02/03/2007 11:49 pm
Post by: C5C6 on 02/04/2007 02:48 am
Post by: nathan.moeller on 02/04/2007 02:01 pm
Quote
C5C6 - 3/2/2007 9:48 PM
silly yet interesting question: when is the big countown clock at KSC turned off? it doesn't have day count or hundreds of hours so it can't remain on during the whole mission
It runs through the countdown and the first few hours after launch.
Post by: TJL on 02/04/2007 02:51 pm
I see that STS-118 which is carrying a similar ISS payload, does not show Spacehab...thank you.
Post by: mkirk on 02/04/2007 03:58 pm
Quote
shuttlefan - 3/2/2007 6:33 PM
Mark, would it be pretty safe to separate from the stack if the SRB thrust were starting to tail off? ;)
“Safe” is certainly a relative term. If you are in a contingency abort situation then you are already having a really bad day.
The real concern for the 1st Stage FAST SEP option is the potential for re-contact with the External Tank and the potential for the ET & Orbiter to “hang up” on the aft attachment points.
For all of the FAST SEP cases the intent is to get off of the tank before the dynamic pressure builds up too much to prevent a safe separation – generally anything above 10 psf (pounds per square foot) is too high. Safe separation is a function of dynamic pressure and angle of attack (alpha), the ideal alpha is -2 degrees.
Mark Kirkman
Post by: mkirk on 02/04/2007 04:00 pm
Quote
nathan.moeller - 3/2/2007 6:49 PM
Would that mean that the orbiter would have to go through a short re-entry scenario after the separtaion?
Well it’s not an Entry in the way you are used to thinking about it at the end of a normal shuttle mission.
In the case of a 1st Stage Separation - which occurs very late in 1st sage from the entire stack (ET & SRBs) - the SEP occurs at a relatively low airspeed/velocity. The orbiter will develop a high sink rate and will be trying to achieve an optimum angle of attack (alpha) as the dynamic pressure increases, this will likely result in relatively high g loads as the pullout occurs.
The whole point of all of this is to get the orbiter in stable flight to allow for a bail out of the crew. The KSC runway is not an option here...
Mark Kirkman
Post by: TJL on 02/04/2007 04:14 pm
Post by: rdale on 02/04/2007 04:59 pm
Post by: Jorge on 02/04/2007 05:03 pm
Quote
TJL - 4/2/2007 9:51 AM
Was STS-116 the last planned mission to include the Spacehab module?
I see that STS-118 which is carrying a similar ISS payload, does not show Spacehab...thank you.
118 is the last Spacehab flight.
--
JRF
Post by: Jorge on 02/04/2007 05:05 pm
Quote
TJL - 4/2/2007 11:14 AM
I'm watching the EVA on NASA TV and I don't seem to remember ever seeing someone other than an astronaut acting as CAPCOM. Is that a new policy of having the Lead EVA Engineer also act as CAPCOM?
The policy of using ISS flight controllers as CAPCOM on weekends and sleep shifts is not new - it's been going on for several years. This may be the first time a non-astronaut has been CAPCOM for a "complex phase" like EVA.
--
JRF
Post by: spacemuppet on 02/05/2007 02:28 am
Post by: nathan.moeller on 02/05/2007 02:30 am
Quote
spacemuppet - 4/2/2007 9:28 PM
Is it really necessary for human intervention during the landing of the shuttle? Could the a/p take the shuttle to wheels stop? Somehow I would think that in this day and age it easily could. Why it is hand flown near the airfield?
They had a/p on it in the early 80s. It nearly resulted in the end-over-end crash of Columbia on STS-3. It wasn't fully automated but it still posed problems. Plus, the CDR and PLT can make necessary adjustments to the flight path if they feel that they're needed.
Post by: Antares on 02/05/2007 02:44 am
Post by: spacemuppet on 02/05/2007 02:53 am
Post by: Paul Howard on 02/05/2007 02:55 am
Post by: nathan.moeller on 02/05/2007 02:57 am
Quote
Antares - 4/2/2007 9:44 PM
Huh? I request a source for that assertion about STS-3. I thought the pitch-up was attributed to the PIC. The conventional wisdom on autopilots has been that the astronauts are too proud to let the computers land it. Allegedly there was 1 that landed totally on autopilot. I don't think it was STS-3. There was another one (under human control) at Edwards that went wide around the HAC. I was told by Shuttle greybeards that it would have ended up in the swamp had it been at KSC.
My bad. The pitch-up was CDR error I believe. Lousma said he thought the nose was coming down too quickly so when he tried to slow it down, he over corrected and just about rooster-tailed the poor bird. The pitch was pretty severe. The close call, it seemed, was the late deploy of the landing gear. They came down just seconds before the orbiter touched down. I never heard about the wide-around-HAC landing. I'll try to find some info on it. Didn't hear about the all-a/p landing either. I'm sure there's someone who knows. Here's to 1300. :)
Post by: Chris Bergin on 02/05/2007 03:15 am
http://www.nasaspaceflight.com/forum/forums/thread-view.asp?tid=3017&start=1
Post by: mkirk on 02/05/2007 07:59 pm
The auto land stuff has been covered extensively in the Shuttle Q & A threads and in the dedicated RCO/AORP thread.
Please let me clear up one point here – the shuttle has never landed (i.e. all the way to touchdown in auto) in auto. Every entry & landing is flown with some degree of auto. The standard is to fly auto until MACH < 1 and then to fly manually around the HAC to Touchdown.
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
Post by: TJL on 02/05/2007 08:24 pm
Thanks!
Post by: DMeader on 02/05/2007 11:02 pm
Quote
Paul Howard - 4/2/2007 10:55 PM
Another subject already covered on here. Please do a search before starting new threads.
What is the purpose of a "Shuttle Questions Q & A" thread if the answer is always "search the forum" or "it is on L2"?
A brief answer is no more a waste of space than is a pithy admonition to search the forum.
Post by: Jim on 02/05/2007 11:13 pm
Quote
DMeader - 5/2/2007 7:02 PMQuotePaul Howard - 4/2/2007 10:55 PM
Another subject already covered on here. Please do a search before starting new threads.
What is the purpose of a "Shuttle Questions Q & A" thread if the answer is always "search the forum" or "it is on L2"?
A brief answer is no more a waste of space than is a pithy admonition to search the forum.
Incorrect
One should search before posting questions.
Also one should read all of the Q&A thread before posting a question. That is the point of the Q&A thread. It is a repository of answers. Most of the answers are not brief and person who originally posted the answer doesn't want to repost it.
As
Post by: C5C6 on 02/06/2007 12:20 am
yes, it would be hard work, but the results would be worth the effort, since from the moment you finish to load the existing Q&A you can continue loading new single Q&A fast.....
Post by: elmarko on 02/06/2007 08:38 am
The problems are:
1) How detailed do you go?
2) Do you put special L2-style info on there (kind of related to 1) )
3) Who will edit it? Public editing, like Wikipedia? As long as we're all sensible, it would police itself, as Wikipedia does.
Post by: STS-500Cmdr on 02/06/2007 04:20 pm
Post by: Tahii on 02/06/2007 05:25 pm
Quote
elmarko - 6/2/2007 8:38 PMFor me:
1) How detailed do you go?
2) Do you put special L2-style info on there (kind of related to 1) )
3) Who will edit it? Public editing, like Wikipedia? As long as we're all sensible, it would police itself, as Wikipedia does.
1). as detailed as possible - that to me is the general idea - have it very detailed, but such that someone new to spaceflight can understand it
2). L2 stuff could go in after a set timeframe, say, after whatever the information is about has passed
3). I believe that you can password Wiki's. When you sign up to NSF, or become a L2 member, part of the email that you get could contain a generic password for editing the site. That would mean only those from here could edit it, but it could be available to everyone to view. I think we have enough knowledge around here that editing it could just be restricted even to a few people.
Post by: elmarko on 02/06/2007 05:51 pm
Good start, though. :)
Post by: Tahii on 02/07/2007 04:00 am
I must admit, I really like the idea of something like a Wiki run by this site.
Post by: TJL on 02/08/2007 07:57 pm
Does anyone have, or know where I can get that info? (Was unable to find anything in "Q & A" section)
Thank you very much!
Post by: Jim on 02/08/2007 08:00 pm
Post by: Chris Bergin on 02/08/2007 08:04 pm
Post by: nathan.moeller on 02/08/2007 08:11 pm
http://www.nasa.gov/mission_pages/station/structure/index.html
It's not a heck of a lot, much less everything but there is some good information concerning weight of shuttle-delivered payloads.
Post by: mkirk on 02/08/2007 08:14 pm
http://www.boeing.com/defense-space/space_exploration/kits/STS-116%20Spaceflight%20Notepad.pdf
Mark Kirkman
Post by: TJL on 02/08/2007 08:56 pm
Post by: shuttlefan on 02/10/2007 12:10 am
Post by: nathan.moeller on 02/11/2007 01:05 am
Post by: shuttlefan on 02/11/2007 01:39 am
Quote
nathan.moeller - 10/2/2007 8:05 PM
The lightning tower took a hit before launch of STS-106 Atlantis back in 2000. Here's a question pertaining to launch spectators. I've seen quite a few launch videos taken by the public who attend the events, especially from the press site. In many of those videos, about between T+60 seconds and T+70 seconds, people let up a huge cheer. Why is that? I understand liftoff and SRB sep, but this happens right before the 'Go at Throttle Up' call.
Don't know, but perhaps because they know the throttle up call is just about to ocurr?
Post by: TJL on 02/11/2007 02:16 am
I believe it's because the sound of launch has decreased enough for the cheering sound of the viewers to be heard.
Post by: nathan.moeller on 02/11/2007 02:32 am
Quote
TJL - 10/2/2007 9:16 PM
QUOTE...In many of those videos, about between T+60 seconds and T+70 seconds, people let up a huge cheer. Why is that?
I believe it's because the sound of launch has decreased enough for the cheering sound of the viewers to be heard.
No. You can hear people talking throughout the lfitoff. They start cheering very suddenly and loudly. They don't cheer like mad throughout the whole launch.
Post by: rolly on 02/13/2007 05:44 pm
Post by: nathan.moeller on 02/13/2007 05:58 pm
Quote
rolly - 13/2/2007 12:44 PM
I wonder what is the colour of the plasma glow that envelopes the space shuttle during reentry. How bright is the glow during the peak heating pharase altitude 250,000-150,000 feet.
Welcome to the site Rolly. The plasma glow is basically like fire. The view out the forward windows shows bright orange, yellow, red, etc. The view out the overheads shows a flashing light and the white plasma trail behind. And it is very bright ;) Starts slow, builds up to an extreme level of brightness and intensity and then dissipates rather quickly. Check out the STS-115 re-entry video on L2 sometime. Well worth the price. It shows the crew on the flight deck from the de-orbit burn until sunrise on the runway. Dazzling stuff!
Post by: Joffan on 02/13/2007 06:33 pm
Quote
nathan.moeller - 10/2/2007 7:05 PM
I've seen quite a few launch videos taken by the public who attend the events, especially from the press site. In many of those videos, about between T+60 seconds and T+70 seconds, people let up a huge cheer. Why is that? I understand liftoff and SRB sep, but this happens right before the 'Go at Throttle Up' call.
I'm not sure how far away the spectators are - could this be when the sound of the launch reaches them? That would make them about 12-13 miles from the launch pad, which sounds a lot further than I would have guessed. From Google maps I'd guess that the spectators are around 3-5 miles from the launch.
The other sound it could be - I don't know if this happens - when the Shuttle breaks the sound barrier, does a sonic boom go back from there?
Post by: nathan.moeller on 02/13/2007 06:52 pm
Quote
Joffan - 13/2/2007 1:33 PM
I'm not sure how far away the spectators are - could this be when the sound of the launch reaches them? That would make them about 12-13 miles from the launch pad, which sounds a lot further than I would have guessed. From Google maps I'd guess that the spectators are around 3-5 miles from the launch.
The other sound it could be - I don't know if this happens - when the Shuttle breaks the sound barrier, does a sonic boom go back from there?
No. The press site is about 3.5-4 miles from the pad and it takes approximately 6-7 seconds for the sound of the boosters to reach the spectators there. It could be breaking the sound barrier, but I've never heard a sonic boom on any video, whether it comes from NASA TV or a spectator. That's possible though and I hadn't thought of that.
Post by: Jim on 02/13/2007 07:11 pm
Post by: STS-500Cmdr on 02/14/2007 03:00 am
Post by: Austin on 02/14/2007 04:31 am
Post by: joema on 02/14/2007 11:19 am
Quote
Austin - 13/2/2007 11:31 PMActually the number sounds about right. Vehicle liftoff mass is about 4.5 million lbs (2.041 million kg), total liftoff thrust is about 6.781 million lbf (3.076 million kgf), so liftoff thrust:weight ratio is about 1.5-to-1. Therefore liftoff and initial acceleration would be about 1.5 g. From v = a*t, this would give 32.2 ft/sec/sec * 1.5 * 26 = 1256 ft/sec (857 mph) @ T+26 sec.
Did anyone notice that during the launch of sts 116, about 26 seconds into flight, the launch commentator reported Discovery's speed at 1000 mph? Obviously a mistake (closer to 400 mph at that point). The shuttle gets out in a hurry, but not that fast!
SRB sea level thrust increases from about 2.8 million lbf/each at liftoff to about 3.0 million lbf/each at T+10 sec, then to about 3.1 million lbf/each at T+25 sec. Don't know exact combined SRB+SSME mass flow rate, but a rough estimate would be about 11,400 kg/sec for the SRBs and 1,400 kg/sec for the SSMEs, for a total of 12,800 kg/sec.
So at T+10 sec vehicle is about 128,000 kg (282,200 lbs) lighter, combined with increasing SRB thrust giving a thrust:weight ratio of 1.7. At T+26 sec it's about 332,800 kg (734,000 lbs) lighter, giving a thrust:weight ratio of 1.96.
Just crudely approximating by taking the thrust:weight ratio at T+10 sec gives 32.2 ft/sec/sec * 1.7 * 26 = 1423 ft/sec or 972 mph @ T+26 sec, very close to what the announcer said.
Post by: elmarko on 02/14/2007 01:28 pm
Post by: nathan.moeller on 02/14/2007 02:25 pm
Quote
Austin - 13/2/2007 11:31 PM
Did anyone notice that during the launch of sts 116, about 26 seconds into flight, the launch commentator reported Discovery's speed at 1000 mph? Obviously a mistake (closer to 400 mph at that point). The shuttle gets out in a hurry, but not that fast!
I noticed that too. He also said it was one mile high (correct) but four and a half miles downrange (wrong). I think he just got a little excited :) Speed at T+26 seconds is in the neighborhood of 350-400 mph. The shuttle doesn't hit 1000 mph until after 1 minute into the flight. And downrange distance isn't greater than altitude until after they even out around 25 miles altitude/25 miles drd. But yeah...even the commentators make mistakes but oh well.
Post by: Austin on 02/14/2007 02:39 pm
Quote
joema - 14/2/2007 4:19 AMQuoteAustin - 13/2/2007 11:31 PMActually the number sounds about right. Vehicle liftoff mass is about 4.5 million lbs (2.041 million kg), total liftoff thrust is about 6.781 million lbf (3.076 million kgf), so liftoff thrust:weight ratio is about 1.5-to-1. Therefore liftoff and initial acceleration would be about 1.5 g. From v = a*t, this would give 32.2 ft/sec/sec * 1.5 * 26 = 1256 ft/sec (857 mph) @ T+26 sec.
Did anyone notice that during the launch of sts 116, about 26 seconds into flight, the launch commentator reported Discovery's speed at 1000 mph? Obviously a mistake (closer to 400 mph at that point). The shuttle gets out in a hurry, but not that fast!
SRB sea level thrust increases from about 2.8 million lbf/each at liftoff to about 3.0 million lbf/each at T+10 sec, then to about 3.1 million lbf/each at T+25 sec. Don't know exact combined SRB+SSME mass flow rate, but a rough estimate would be about 11,400 kg/sec for the SRBs and 1,400 kg/sec for the SSMEs, for a total of 12,800 kg/sec.
So at T+10 sec vehicle is about 128,000 kg (282,200 lbs) lighter, combined with increasing SRB thrust giving a thrust:weight ratio of 1.7. At T+26 sec it's about 332,800 kg (734,000 lbs) lighter, giving a thrust:weight ratio of 1.96.
Just crudely approximating by taking the thrust:weight ratio at T+10 sec gives 32.2 ft/sec/sec * 1.7 * 26 = 1423 ft/sec or 972 mph @ T+26 sec, very close to what the announcer said.
Joe -- thanks for your response but that's not correct. Take a look/listen to the launch of sts 114, for example...
http://www.youtube.com/watch?v=ixwzRNH_l0g
In this video of Discovery's Return to Flight mission, Discovery's speed at 26 seconds is 400 mph at an altitude of 12,000 feet. At the 60 second mark, the vehicle is travelling at 900 mph.
So unless Discovery had an added set of SRBs strapped to the ET on sts 116 that were not visible (after all, it was a night launch : ), the report from the commentator was incorrect. I've seen every shuttle launch (without exception) and I remember that this one struck me when I heard that report. Clearly a mistake.
Post by: Austin on 02/14/2007 02:44 pm
Quote
nathan.moeller - 14/2/2007 7:25 AMQuoteAustin - 13/2/2007 11:31 PM
Did anyone notice that during the launch of sts 116, about 26 seconds into flight, the launch commentator reported Discovery's speed at 1000 mph? Obviously a mistake (closer to 400 mph at that point). The shuttle gets out in a hurry, but not that fast!
I noticed that too. He also said it was one mile high (correct) but four and a half miles downrange (wrong). I think he just got a little excited :) Speed at T+26 seconds is in the neighborhood of 350-400 mph. The shuttle doesn't hit 1000 mph until after 1 minute into the flight. And downrange distance isn't greater than altitude until after they even out around 25 miles altitude/25 miles drd. But yeah...even the commentators make mistakes but oh well.
Nathan -- yepper. If memory serves me correct, that was his first time as launch commentator, and I think you're right. I didn't mean to rag on the guy, it just caught my attention.
Post by: mkirk on 02/14/2007 03:01 pm
Quote
Austin - 13/2/2007 11:31 PM
Did anyone notice that during the launch of sts 116, about 26 seconds into flight, the launch commentator reported Discovery's speed at 1000 mph? Obviously a mistake (closer to 400 mph at that point). The shuttle gets out in a hurry, but not that fast!
Here is the link (that I posted on page 2 of this thread) to a breakdown of the Ascent Events that Bill Harwood posted from the Ascent Data Package for 121.
http://spaceflightnow.com/shuttle/sts121/fdf/121ascentdata.html
In defense of the commentator there are two velocities that are used by the shuttle, Relative and Inertial. These are the reference frames with Relative – in simple terms – being the velocity of the vehicle along the ground track from the pad. In other words this is the more intuitive velocity you are used to because it tells you how fast the vehicle is going compared to a stationary point on the ground.
The inertial reference frame takes into account that the earth is rotating and therefore when the shuttle is sitting on the Pad it is traveling at almost 1000 feet per second.
In the cockpit the velocity tapes display relative velocity until SRB SEP and then they transition to Inertial – this causes an almost instantaneous jump in velocity of about 1 MACH number or 1000 feet per second on the airspeed/velocity indicator.
So PAO may have read out the inertial velocity rather than the relative on his console display in the Mission Control Center.
Mark Kirkman
Post by: STS-500Cmdr on 02/14/2007 03:11 pm
Post by: nathan.moeller on 02/14/2007 04:49 pm
Quote
STS-500Cmdr - 14/2/2007 10:11 AM
Yeah i think Kelly Humphries-who was the commentator for the STS-116 launch/ascent-he was new to doing ascent commentary--yeah i noticed him calling 1000 mph and 4 1/2 miles downrange prematurely--i get the feeling hes reading a script and maybe jumping to that part of the script- -do the PAO's read a script of some sort?? I notice Humphries sounded alot like James Hartsfield--sounded like he was borrowing from him.
Yeah I think he just got excited - it being his first launch commentary and all. Yeah I think they read from scripts and follow timelines during commentaries. If so, he probably just got ahead of himself. As for sounding like James Hartsfield, I know exactly what you mean. Listen to Hartsfield's STS-114 launch commentary then take a listen to Humphries' STS-116 commentary. A lot of similarities in the wording quickly become apparent.
Hartsfield at Roll Program: 'Houston now controlling. CDR Eileen Collins confirming Discovery's rolling on course for a rendezvous with the International Space Station.'
Humphries at Roll Program: 'Houston now controlling. CDR Mark Polansky confirming Discovery's rolling on course to the International Space Station.'
:)
In my opinion, he did an excellent job. Just got ahead of himself that's all. He got back on track pretty quick. Trust me...public announcing/commenting is difficult. I had a hard time talking over the store intercom at Target the first time I made the closing announcements. But I nailed it anyway ;) It takes practice.
Post by: spaceshuttle on 02/14/2007 05:13 pm
Quote
nathan.moeller - 14/2/2007 11:49 AMQuoteSTS-500Cmdr - 14/2/2007 10:11 AM
Yeah i think Kelly Humphries-who was the commentator for the STS-116 launch/ascent-he was new to doing ascent commentary--yeah i noticed him calling 1000 mph and 4 1/2 miles downrange prematurely--i get the feeling hes reading a script and maybe jumping to that part of the script- -do the PAO's read a script of some sort?? I notice Humphries sounded alot like James Hartsfield--sounded like he was borrowing from him.
Yeah I think he just got excited - it being his first launch commentary and all. Yeah I think they read from scripts and follow timelines during commentaries. If so, he probably just got ahead of himself. As for sounding like James Hartsfield, I know exactly what you mean. Listen to Hartsfield's STS-114 launch commentary then take a listen to Humphries' STS-116 commentary. A lot of similarities in the wording quickly become apparent.
Hartsfield at Roll Program: 'Houston now controlling. CDR Eileen Collins confirming Discovery's rolling on course for a rendezvous with the International Space Station.'
Humphries at Roll Program: 'Houston now controlling. CDR Mark Polansky confirming Discovery's rolling on course to the International Space Station.'
:)
In my opinion, he did an excellent job. Just got ahead of himself that's all. He got back on track pretty quick. Trust me...public announcing/commenting is difficult. I had a hard time talking over the store intercom at Target the first time I made the closing announcements. But I nailed it anyway ;) It takes practice.
LOL, I like the Target comment. I wonder if Rob Navias plans to do anymore launches?
Post by: nathan.moeller on 02/14/2007 07:10 pm
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spaceshuttle - 14/2/2007 12:13 PM
LOL, I like the Target comment. I wonder if Rob Navias plans to do anymore launches?
I don't know. I bet he will. He did four in a row from 2002-2003 (STS 111-107). In my opinion, Navias is the best at covering launches and landings. He's very precise and detailed and gets you riled up about what's going on. Don't get me wrong, the others do great as well, but Navias is a personal favorite. Hopefully he'll be back before too long.
Post by: joema on 02/14/2007 09:48 pm
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Austin - 14/2/2007 9:39 AMTake a look at the attached Mach profile as a function of time, taken from actual STS-107 flight data. It indicates at about T+30 sec, the vehicle is at about Mach 2. It seems to show the velocity at T+26 sec would be pretty fast, at least 1000 mph. I don't understand the discrepancy. Would appreciate any further comments from anybody on this.
Joe -- thanks for your response but that's not correct. Take a look/listen to the launch of sts 114, for example...
Post by: Jim on 02/14/2007 09:56 pm
Post by: Austin on 02/14/2007 10:17 pm
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mkirk - 14/2/2007 8:01 AM
Here is the link (that I posted on page 2 of this thread) to a breakdown of the Ascent Events that Bill Harwood posted from the Ascent Data Package for 121.
http://spaceflightnow.com/shuttle/sts121/fdf/121ascentdata.html
In defense of the commentator there are two velocities that are used by the shuttle, Relative and Inertial. These are the reference frames with Relative – in simple terms – being the velocity of the vehicle along the ground track from the pad. In other words this is the more intuitive velocity you are used to because it tells you how fast the vehicle is going compared to a stationary point on the ground.
The inertial reference frame takes into account that the earth is rotating and therefore when the shuttle is sitting on the Pad it is traveling at almost 1000 feet per second.
In the cockpit the velocity tapes display relative velocity until SRB SEP and then they transition to Inertial – this causes an almost instantaneous jump in velocity of about 1 MACH number or 1000 feet per second on the airspeed/velocity indicator.
So PAO may have read out the inertial velocity rather than the relative on his console display in the Mission Control Center.
Mark Kirkman
Thanks Mark for the info. I've always wondered to what extent NASA provided technical training to Public Affairs Officers. Although many have journalism degrees, they obviously must have thorough knowledge of the shuttle's systems in order to field reporters' questions in an informed and intelligent manner.
Joe -- not sure where you got the "mach profile," but I can assure you that the shuttle is not traveling at mach 2 thirty seconds into flight.
Post by: joema on 02/15/2007 01:36 am
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Antares - 14/2/2007 5:26 PMYou're right, thanks for the correction. I mistakenly looked at the qbar line instead of the Mach line.
...Joema, you read that graph backwards. STS is not supersonic until T+~45s, Mach 2 at T+~72s...
Post by: rolly on 02/15/2007 06:07 pm
Post by: Jamie Young on 02/15/2007 06:14 pm
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rolly - 15/2/2007 1:07 PM
At what altitude is sts-115 during reentry when the plasma is at its brightest, how bright would it look like in a bedroom if there was an arc lamp that bright
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=4813&start=1 That'll help on what it looks like!
Post by: Mark Dave on 02/15/2007 06:26 pm
Post by: Jim on 02/15/2007 06:29 pm
move to shuttle Q&A
Post by: SCE2Aux on 02/15/2007 06:31 pm
Post by: spaceshuttle on 02/16/2007 01:52 am
Experts, PLEASE correct me if i'm wrong.
Post by: TJL on 02/16/2007 02:02 am
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SCE2Aux - 15/2/2007 2:31 PM
I've noticed changes in the TPS on the wings of the orbiters. Could anyone tell me why it's different?
Those changes began on Discovery for the STS-82 HST repair mission.
Post by: Mark Dave on 02/16/2007 04:52 pm
Post by: gordo on 02/16/2007 08:36 pm
Found a great NASA doco about them included on a 99p DVD from the local supermarket. I'm sure it will find its way onto the video collection pages
Post by: Mark Nguyen on 02/16/2007 09:40 pm
Mark
Post by: Mark Dave on 02/16/2007 10:47 pm
Post by: DaveS on 02/17/2007 10:58 am
Post by: Jim on 02/17/2007 04:35 pm
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Mark Nguyen - 16/2/2007 5:40 PM
Are there any videos, diagrams, etc. that show how the payload is stransferred from the transfer vehicle at the pad, to rest in the payload bay itself? I understand that the canister is hoisted up into the RSS, which is then rotated into place, but what happens after that? I've always wanted to know how the payload is physically placed into the shuttle's bay, but have never been able to figure it out...
Mark
The payload is removed from the canister by the PGHM (payload ground handling mechanism) which is in the PCR (payload changeout room) of the RSS.
After the payload is removed from the canister, the canister is lowered. The RSS rotates around the orbiter and the payload bay doors are opened to the PCR. The PGHM inserts the payload into the orbiter
Post by: nathan.moeller on 02/19/2007 01:20 am
Post by: Jim on 02/19/2007 01:54 am
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nathan.moeller - 18/2/2007 9:20 PM
Can anyone tell me why the forward areas of Columbia's wings were black, while the same areas on the other four orbiters were white? I want to say it's some kind of TPS that was discovered to be unnecessary and changed on later vehicles, but please let me know.
correct. It is the same black tiles as the rest of the vehicle. AFRSI was incorporated on OV-099
Post by: nathan.moeller on 02/19/2007 02:04 am
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Jim - 18/2/2007 8:54 PMQuotenathan.moeller - 18/2/2007 9:20 PM
Can anyone tell me why the forward areas of Columbia's wings were black, while the same areas on the other four orbiters were white? I want to say it's some kind of TPS that was discovered to be unnecessary and changed on later vehicles, but please let me know.
correct. It is the same black tiles as the rest of the vehicle. AFRSI was incorporated on OV-099
Thanks for the quick response Jim. Can you clarify what AFRSI stands for? I couldn't find it in the site acronyms.
Post by: Jorge on 02/19/2007 02:08 am
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nathan.moeller - 18/2/2007 9:04 PMQuoteJim - 18/2/2007 8:54 PMQuotenathan.moeller - 18/2/2007 9:20 PM
Can anyone tell me why the forward areas of Columbia's wings were black, while the same areas on the other four orbiters were white? I want to say it's some kind of TPS that was discovered to be unnecessary and changed on later vehicles, but please let me know.
correct. It is the same black tiles as the rest of the vehicle. AFRSI was incorporated on OV-099
Thanks for the quick response Jim. Can you clarify what AFRSI stands for? I couldn't find it in the site acronyms.
Advanced Flexible Reusable Surface Insulation.
--
JRF
Post by: Zpoxy on 02/19/2007 03:03 am
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Jim - 18/2/2007 9:54 PMQuotenathan.moeller - 18/2/2007 9:20 PM
Can anyone tell me why the forward areas of Columbia's wings were black, while the same areas on the other four orbiters were white? I want to say it's some kind of TPS that was discovered to be unnecessary and changed on later vehicles, but please let me know.
correct. It is the same black tiles as the rest of the vehicle. AFRSI was incorporated on OV-099
Sorry, not completely correct. Columbia's wing gloves were covered with a combination of LRSI (white tiles) and FRSI. The area Nathan asked about was painted with a black high-temp paint just before rollout from the OPF for STS-1 due to thermal concerns from the engineers. Over the years there were some HRSI (black tiles) added there but the majority of the area was still the black painted TPS.
Post by: rfoshaug on 02/19/2007 12:25 pm
At about T-12 seconds you can hear several high-pitched sounds, like something spooling up to speed, just before the spark-throwers start. What makes this sound? Is it the spark igniters we hear or could it be the turbopumps?
A good example of this sound is heard in this video:
http://youtube.com/watch?v=TH8Oq0PuIU8
Thanks.
Post by: Jim on 02/19/2007 12:41 pm
Post by: shuttlefan on 02/19/2007 12:51 pm
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Jim - 19/2/2007 7:41 AMJim, what are the ROFIs? ;)
It is not the turbopumps, they don't start untill T-6.6. It is the ROFI's
Post by: rfoshaug on 02/19/2007 12:52 pm
:)
Post by: Jim on 02/19/2007 01:01 pm
Quote
shuttlefan - 19/2/2007 8:51 AMQuoteJim - 19/2/2007 7:41 AMJim, what are the ROFIs? ;)
It is not the turbopumps, they don't start untill T-6.6. It is the ROFI's
Radially Outward Firing Inititors
Post by: Mark Dave on 02/19/2007 05:23 pm
Post by: Jim on 02/19/2007 05:41 pm
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MarkD - 19/2/2007 1:23 PM
How come Columbia's forward fuselage was never modified with the AFRSI to replace the white tiles as o nthe other orbiters? I mean given how dirty the tiles looked, it seems like they'd have to be replaced.
Why? If it works, don't change it and waste money. Dirty? Only cosmetic and doesn't affect them. Just the effects of reentry on the waterproofing.
Post by: TJL on 02/19/2007 07:45 pm
Atlantis: http://www-pao.ksc.nasa.gov/kscpao/images//large/07pd0401.jpg
Discovery: http://www-pao.ksc.nasa.gov/kscpao/images//large/06pd2481.jpg
Post by: Mark Dave on 02/19/2007 11:33 pm
Post by: hyper_snyper on 02/20/2007 02:36 pm
Post by: Jim on 02/20/2007 03:08 pm
Post by: joema on 02/20/2007 03:21 pm
Since the SSME is designed for reuse it has a very long maximum total firing time. Normally the engine is inspected after each flight, so while the engine is certified for 20 or 50 flights, that assumes it's inspected and possibly refurbished after each 8.5 min firing.
In the hypothetical case of a ground test with unlimited propellant, the block II SSME enhancements would probably translate to a longer continuous firing time before ultimate failure (vs earlier SSME versions).
If run continuously to failure, it seems unlikely thermal or erosion problems in the engine itself would be the cause. Rather the turbopumps might fail in some way, as they normally require inspection and possibly some refurbishing (but not overhauling) after each flight. The turbopumps are highly stressed rotating turbomachinery spinning at 36,000 rpm, and producing about 75,000 shaft horsepower in the space of a trash can. My guess is a turbine blade would crack or a bearing fail before the engine combustion chamber, nozzle or associated plumbing would fail.
It's an interesting hypothetical exercise -- what if you took an F-1, RS-68, and SSME and ran them continuously to failure in a ground test. Which one would run the longest, and how long would that be? The SSME has the advantage of longest certified total running time, but it's not designed to run that long continuously, plus the chamber pressure and turbopumps are highly stressed relative to the other engines. While you're at it, may as well run a simple pressure-fed hypergolic engine like the OMS. Since it has no turbopumps, maybe it would win the "run 'till you blow" test.
Post by: Antares on 02/22/2007 04:57 am
Post by: MKremer on 02/22/2007 06:10 am
Quote
joema - 20/2/2007 10:21 AM
...-- what if you took an F-1, RS-68, and SSME and ran them continuously to failure in a ground test. Which one would run the longest, and how long would that be? The SSME has the advantage of longest certified total running time, but it's not designed to run that long continuously, plus the chamber pressure and turbopumps are highly stressed relative to the other engines. While you're at it, may as well run a simple pressure-fed hypergolic engine like the OMS. Since it has no turbopumps, maybe it would win the "run 'till you blow" test.
Sorry, but you can't make any firm conclusions that way - you'd have to run at least a dozen of each for their entire burn in your scenario to just get some baseline data - since each engine is more-or-less hand-built with dozens of sub-contractor parts, there's more than too-many factors to evaluate to even begin to disrespect one engine design/constrution over another.
Post by: C5C6 on 02/23/2007 12:00 pm
Post by: geminy007 on 02/23/2007 12:10 pm
And timing: Depends, but asap might be a good idea, there are more than 2000t of propellant ready to explode,... so I would hurry;-)
Post by: Jim on 02/23/2007 12:16 pm
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Antares - 22/2/2007 12:57 AM
When the STA is out flying around as it was tonight, are controllers on console in Houston simming as well?
Not for the STA flights
Post by: STS-500Cmdr on 02/23/2007 03:58 pm
Post by: Jim on 02/23/2007 04:12 pm
Quote
STS-500Cmdr - 23/2/2007 11:58 AM
Somewhat in the vein of C5C6's Q--and about the White Room--i see when the closeout crew breaks down the White Room and pulls back that retaining section with the dock seal and tie it down--i wonder why they do that?? I assume its to protect that seal thing from the blast. The other thing is when they pull that section back and tie it down--theres a gap between the White Room and the hatch and the closeout guys hook up to the harnesses so they dont fall down thru that gap. Hows the crew suppose to get out of the vehicle in a hurry without falling through that gap between the WR and the ship's hatch and falling to their death on the MLP??
The gap is not that big.
Two things get folded away: 1. the "back" wall with opening to the orbiter with the dock seal. 2. Part of the "left" wall is folded back. The reason is for if there was a emergency egress after the OAA is retracted. The OAA would swing back to the service position. If the astronauts were a little jumpy, they might have the hatch open before the OAA is in place. If it weren't for these walls folded away, the whiteroom would slam into the hatch and the crew couldn't get out. The reason for the harness is the opening on the left side once the walls are folded. For a crew egressing, the open hatch blocks the opening, protecting the crew
Post by: TJL on 02/24/2007 07:49 pm
Any reason why all 4 crew members did not sit on the flight deck for launch and landing, as did the STS-6 crew?
Thank you.
Post by: Jim on 02/24/2007 08:14 pm
Quote
TJL - 24/2/2007 3:49 PM
I have a question related to STS-5.
Any reason why all 4 crew members did not sit on the flight deck for launch and landing, as did the STS-6 crew?
Thank you.
With the ejection seats on Columbia (which were taken out later), there wasn't enough room
Post by: shuttlefan on 02/26/2007 12:33 pm
Post by: DaveS on 02/26/2007 12:38 pm
Quote
shuttlefan - 26/2/2007 2:33 PMYes, except for the amount that has boiled off during the countdown prior to the scrub and start of draining activties.
When NASA tanks and then has to go into a 24-hour scrub turnaround for whatever reason, is it the same fuel that is loaded into the ET the next day?
Also please note that both fuel(LH2) and oxidizer(LOX) is loaded into the ET and both are drained from the ET and reused on subsequent launch attempts.
So to be really technically correct, you want to use the term "propellents".
Post by: nathan.moeller on 02/26/2007 12:38 pm
Quote
Jim - 24/2/2007 3:14 PMQuoteTJL - 24/2/2007 3:49 PM
I have a question related to STS-5.
Any reason why all 4 crew members did not sit on the flight deck for launch and landing, as did the STS-6 crew?
Thank you.
With the ejection seats on Columbia (which were taken out later), there wasn't enough room
Jim, could you elaborate on the ejection seats and how they would have worked. I've always been very curious about this.
Post by: Jim on 02/26/2007 12:47 pm
Quote
nathan.moeller - 26/2/2007 8:38 AMQuoteJim - 24/2/2007 3:14 PMQuoteTJL - 24/2/2007 3:49 PM
I have a question related to STS-5.
Any reason why all 4 crew members did not sit on the flight deck for launch and landing, as did the STS-6 crew?
Thank you.
With the ejection seats on Columbia (which were taken out later), there wasn't enough room
Jim, could you elaborate on the ejection seats and how they would have worked. I've always been very curious about this.
They were similar to "standard" ejection seats for high speed aircraft. They were 'usable" on ascent until 140K ft (mkirk knows the number) and also on descent. There was debate whether the seats could have cleared the SRB plumes
Post by: joema on 02/26/2007 01:15 pm
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nathan.moeller - 26/2/2007 7:38 AMColumbia was equipped with modified SR-71 ejection seats http://www.ejectionsite.com/sr1seat.htm for the first four missions. The astronauts wore pressure suits, I believe also derived from the SR-71 suits.
...could you elaborate on the ejection seats and how they would have worked. I've always been very curious about this...
The theoretical ejection envelope extended from on the pad to (very roughly) about 120,000-140,000 ft and Mach 3.5, which occurred at about T+110 seconds. The "negative seats" call which indicated they were above the ejection envelope happened at about 120k ft.
On ascent the seats would be used similar to those in fighter planes or the Gemini spacecraft -- pull the handle and go. On descent the seats would be usable below about 120k ft, or roughly the same envelope.
Doubt has been expressed concerning how effective the seats would have been. However essentially the same seats and pressure suits have been proven in several successful SR-71 ejections, some from high Mach numbers and altitudes.
A potential problem is clearing the hot SRB plume. This is a function of several factors, including atmospheric drag on the ejected astronaut at altitude, seat ejection G force and time, acceleration/orientation of the vehicle stack, and whether a forward component exists in the rocket catapult. In general the ejected astronaut would be moving laterally at high acceleration, probably about 12 Gs, decelerating longitudinally based on atmospheric drag at given altitude & speed, while the vehicle continued accelerating upward. This gives a time period over which the seat trajectory must clear the cone-shaped SRB exhaust. There are many unknowns but simple calculations show it's possible to clear the plume, at least for some conditions.
The problem with seats is they take a lot of space, aren't really feasible for the entire crew, plus cover only a small fraction of the vehicle operating envelope. They're also full of explosives, so there's a small but finite risk of uncommanded operation, fire or other hazards while on orbit.
Post by: Austin on 02/26/2007 02:05 pm
Quote
joema - 26/2/2007 6:15 AM
The problem with seats is they take a lot of space, aren't really feasible for the entire crew
Indeed...as Henry Hartsfield once said, how would it make you feel if the captain and copilot on your next airline flight were wearing parachutes?! If it isn't possible to include ejection seats for the entire crew -- you don't include them for anyone.
Post by: nathan.moeller on 02/26/2007 10:12 pm
Post by: kanathan on 02/26/2007 10:26 pm
Post by: Mark Dave on 03/04/2007 06:11 pm
Post by: Jim on 03/04/2007 06:40 pm
Quote
MarkD - 4/3/2007 2:11 PM
I was curious on why the hatches look difernt on each mission. For example if you compare the Orbiter Access hatch of Columbia on STS-107 to Discovery's on STS-114 there is some extra dark tiles around the porthole. Why is that? Some missions have it pure white around the porthole, and sometimes not.
different orbiters have different TPS patterns based the lessons learned from OV-102, OV-099, etc as the other orbiters were built later
Post by: Mark Dave on 03/04/2007 09:55 pm
Thanks for clearing that up. :)
Post by: mkirk on 03/05/2007 11:27 pm
Quote
kneecaps - 5/3/2007 5:27 AMQuotemkirk - 5/3/2007 1:08 AM
This is a hefty set of questions, all of which have complex answers made up of lots of ifs, ands, ors and buts.
I can't wait, as much as I absorb myself, nothing beats hearing from a professional on the subject!
Pete
Here is what I can tell you about Command Path Failures, I will try and answer at least one of the other questions each day...time permitting.
Command Path Failures:
The main engine controller operates by comparing the commands within its 3 command channels, if at least 2 of those incoming commands are identical then the command is executed (refer to the diagram I attached below). If all 3 commands are different, a Command Path Failure is declared and the controller informs the GPCs (general purpose computers) which annunciate the failure for that engine.
The training philosophy is to pound into crew members heads two important points concerning Command Path Failures; 1) the affected engine MUST be shutdown manually and 2) the engine MUST be shutdown using what is called the AC/PB method.
When an engine is experiencing a Command Path Failure it will not accept any incoming commands, including the command to shutdown - the engine should remain at its last valid commanded setting.
The crew can not use the Main Engine Shutdown Pushbuttons (PBs), located on the center console, to initiate a shutdown because the buttons only send out a GPC shutdown command. That shutdown command will be rejected by the engine controller because of the Command Path Failure.
The crew has to shutdown the engine by taking the respective engine power switches known as the “ACs” to off. These switches which are located to the right of the Pilot (on panel R2) will remove all electrical power from that engine’s main engine controller – with a complete loss of the controller the engine will perform a pneumatic shutdown using the helium supply as a safety feature to ensure an uncontrolled engine is not allowed to keep running.
A pneumatic shutdown uses helium to close the 5 main SSME valves, these are normally closed hydraulically.
Since the engines were shutdown using the power switches (rather than the pushbuttons) the GPCs do not know what has happened. From the perspective of the GPCs, data is no longer coming in from the engine and they therefore assume a Data Path Failure (I will cover those in my next post) has occurred. In order to let the GPCs know that the engine has been shutdown the pushbutton for that engine is pressed.
Pressing the PB is referred to as “moding guidance”. This is important because you want the guidance system to know it doesn’t have the engine running any more, otherwise it will assume the engine is running and fly accordingly.
The timing of the manual shutdown is dictated by the type of ascent being flown (i.e. Nominal, ATO, RTLS, or TAL) and the number of engines operating. For a nominal uphill ascent with all 3 engines running, the one with a Command Path Failure will be shutdown at Mach 23. This allows the engine to run as long as possible but shuts it down with enough time for guidance to compensate for the lost engine prior to MECO. The engine needs to be shutdown in this manner to protect it from possible fuel starvation and to protect against LO2 NPSP (net positive suction pressure) violations caused by a rapid loss of acceleration at MECO.
Mark Kirkman
Post by: hmh33 on 03/06/2007 01:08 am
Post by: Jim on 03/06/2007 01:19 am
Quote
hmh33 - 5/3/2007 9:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The engine exploding is what could take out the stack
Post by: rfoshaug on 03/06/2007 02:36 pm
As the shuttle lifts off the pad, it translates a bit in the direction of the tank (north). I'm not talking abot the "twang" but the first few seconds after liftoff.
It can be seen here: http://youtube.com/watch?v=2Ok3-_K3XUU (28-31 seconds into the video).
What is the reason for this translation, and does it happen on every shuttle launch?
Post by: kneecaps on 03/06/2007 03:48 pm
Quote
Jim - 6/3/2007 2:19 AMQuotehmh33 - 5/3/2007 9:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The engine exploding is what could take out the stack
My understanding is this situation causes the tubopumps to overspeed and fly apart (which is obviously very bad).
Post by: Jorge on 03/06/2007 04:12 pm
Quote
rfoshaug - 6/3/2007 9:36 AM
A quick question that comes from a discussion on another forum:
As the shuttle lifts off the pad, it translates a bit in the direction of the tank (north). I'm not talking abot the "twang" but the first few seconds after liftoff.
It can be seen here: http://youtube.com/watch?v=2Ok3-_K3XUU (28-31 seconds into the video).
What is the reason for this translation,
The SSMEs are on the orbiter, which is on the side of the stack, and are gimballed to point through the stack c.g. This results in a component of thrust toward the ET.
Quote
and does it happen on every shuttle launch?
Yes.
--
JRF
Post by: rfoshaug on 03/06/2007 04:26 pm
Post by: edkyle99 on 03/06/2007 04:45 pm
Quote
Jorge - 6/3/2007 11:12 AMQuoterfoshaug - 6/3/2007 9:36 AM
A quick question that comes from a discussion on another forum:
As the shuttle lifts off the pad, it translates a bit in the direction of the tank (north). I'm not talking abot the "twang" but the first few seconds after liftoff.
It can be seen here: http://youtube.com/watch?v=2Ok3-_K3XUU (28-31 seconds into the video).
What is the reason for this translation,
The SSMEs are on the orbiter, which is on the side of the stack, and are gimballed to point through the stack c.g. This results in a component of thrust toward the ET.Quoteand does it happen on every shuttle launch?
Yes.
--
JRF
Isn't this a momentary effect, in that the SSMEs and SRBs gimbal to offset each other's non-X-axis (vertical at liftoff) force components shortly after liftoff?
- Ed Kyle
Post by: nathan.moeller on 03/06/2007 05:07 pm
Post by: Jim on 03/06/2007 05:39 pm
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edkyle99 - 6/3/2007 12:45 PMQuoteJorge - 6/3/2007 11:12 AMQuoterfoshaug - 6/3/2007 9:36 AM
A quick question that comes from a discussion on another forum:
As the shuttle lifts off the pad, it translates a bit in the direction of the tank (north). I'm not talking abot the "twang" but the first few seconds after liftoff.
It can be seen here: http://youtube.com/watch?v=2Ok3-_K3XUU (28-31 seconds into the video).
What is the reason for this translation,
The SSMEs are on the orbiter, which is on the side of the stack, and are gimballed to point through the stack c.g. This results in a component of thrust toward the ET.Quoteand does it happen on every shuttle launch?
Yes.
--
JRF
Isn't this a momentary effect, in that the SSMEs and SRBs gimbal to offset each other's non-X-axis (vertical at liftoff) force components shortly after liftoff?
- Ed Kyle
Correct. Also the stack flies at an angle of attack, so it isn't completely zeroed out.
the translation is sometimes referred to a "walk".
Post by: astrobrian on 03/06/2007 09:45 pm
Post by: Jim on 03/06/2007 09:51 pm
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astrobrian - 6/3/2007 5:45 PM
The SSME thrust goes through the CG of the orbiter I thought, not the entire stack.
It goes through the stack. The CG of the orbiter would cause a rotation of the whole stack
Post by: aftercolumbia on 03/06/2007 09:54 pm
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hmh33 - 5/3/2007 7:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The HPFT spins at about 35,000RPM, and the chamber pressure is 2900psia...trust me, it can take out the whole stack!
Post by: joema on 03/06/2007 10:37 pm
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aftercolumbia - 6/3/2007 4:54 PMQuotehmh33 - 5/3/2007 7:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The HPFT spins at about 35,000RPM, and the chamber pressure is 2900psia...trust me, it can take out the whole stack!
A little more on this, the HPFT produces about 85,000 shaft horsepower, in the space of a large trash can. The pump discharge pressure is 8,000 psi (!!!), about 4x a SCUBA tank: http://www.nasa.gov/offices/oce/llis/0750.html
http://history.nasa.gov/SP-4221/ch6.htm
Post by: Antares on 03/07/2007 12:34 am
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kneecaps - 6/3/2007 11:48 AMI don't have the amount here at home, but the LOX pump can ingest a rather large amount of vapor and still survive. Watch this space for an edit if you're curious.QuoteJim - 6/3/2007 2:19 AMQuotehmh33 - 5/3/2007 9:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The engine exploding is what could take out the stack
My understanding is this situation causes the tubopumps to overspeed and fly apart (which is obviously very bad).
Post by: shuttlefan on 03/07/2007 01:18 am
Post by: Jim on 03/07/2007 01:24 am
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shuttlefan - 6/3/2007 9:18 PM
I've noticed sometimes, that during the count, if the GLS has to insert a hold at T-5min or T-4min, for example, the clock will countdown 1 second past 5:00, to 4:59, and then count back up to 5:00 and hold there. Does anyone know why it goes back and then up one second and holds? :laugh:
That is just a display clock and not the actual
Post by: Shadow Spork on 03/07/2007 02:05 am
Now here's my question. I don't know if this has been asked already, and I apologize if it already has, but after the Apollo program, I understand that they reused the towers as the FSS for the Space Shuttle program. I wonder, how did they manage to take those towers of the launch platforms and install it onto the pad? Did it take a lot of cranes just to install onto the pad, or did they had to go through the trouble of partially or fully dismantling the tower, and then put back together again onto the pad?
Post by: BenB5150 on 03/07/2007 02:25 pm
Thanks!
Ben
Post by: kneecaps on 03/07/2007 02:26 pm
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Antares - 7/3/2007 1:34 AMQuotekneecaps - 6/3/2007 11:48 AMI don't have the amount here at home, but the LOX pump can ingest a rather large amount of vapor and still survive. Watch this space for an edit if you're curious.QuoteJim - 6/3/2007 2:19 AMQuotehmh33 - 5/3/2007 9:08 PM
I have heard in a couple of places that if an SSME ingests vapours the turbopumps will fail catastrophically and cause loss of vehicle. Is this really true? Can see it damaging/destroying the engine but is it really violent enough to take out the whole stack?
The engine exploding is what could take out the stack
My understanding is this situation causes the tubopumps to overspeed and fly apart (which is obviously very bad).
I came across this while looking for some other info:
http://www.spaceref.com/news/viewsr.html?pid=10520
The HPFTP first stage turbine blades failed, unbalancing the turbine, yet the engine was still shutdown without a catastrophe.
Post by: Jim on 03/07/2007 03:54 pm
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BenB5150 - 7/3/2007 10:25 AM
I have a question about the shuttle tiles. Do they still have problems with tiles falling off during flight like the earlier flights or was the bonding problem solved long ago?
Thanks!
Ben
The adhesion problem was solved before Challenger. Debris hits are the real issue
Post by: nathan.moeller on 03/07/2007 04:12 pm
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Shadow Spork - 6/3/2007 9:05 PM
Hi. This is my first time here, and I've read most of the questions and answers to my questions that I had.
Now here's my question. I don't know if this has been asked already, and I apologize if it already has, but after the Apollo program, I understand that they reused the towers as the FSS for the Space Shuttle program. I wonder, how did they manage to take those towers of the launch platforms and install it onto the pad? Did it take a lot of cranes just to install onto the pad, or did they had to go through the trouble of partially or fully dismantling the tower, and then put back together again onto the pad?
Welcome to the site Shadow Spork! They were dismantled and re-assembled if memory serves me right. If you look at the Saturn SUTs (service umbilical towers) and the shuttle FSS (fixed service structure), you can see they are quite different. I imagine the same will be done for the transition from shuttle to Ares I and Ares V.
Post by: Jim on 03/07/2007 04:14 pm
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nathan.moeller - 7/3/2007 12:12 PMQuoteShadow Spork - 6/3/2007 9:05 PM
Hi. This is my first time here, and I've read most of the questions and answers to my questions that I had.
Now here's my question. I don't know if this has been asked already, and I apologize if it already has, but after the Apollo program, I understand that they reused the towers as the FSS for the Space Shuttle program. I wonder, how did they manage to take those towers of the launch platforms and install it onto the pad? Did it take a lot of cranes just to install onto the pad, or did they had to go through the trouble of partially or fully dismantling the tower, and then put back together again onto the pad?
Welcome to the site Shadow Spork! They were dismantled and re-assembled if memory serves me right. If you look at the Saturn SUTs (service umbilical towers) and the shuttle FSS (fixed service structure), you can see they are quite different. I imagine the same will be done for the transition from shuttle to Ares I and Ares V.
The LUTs became the FSS. Ares will not use the same towers
Post by: nathan.moeller on 03/07/2007 04:33 pm
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Jim - 7/3/2007 11:14 AM
Ares will not use the same towers
What will be done with the components of the FSS and RSS? Will they end up in the same metal graveyard as the Saturn LUT components that were discarded after Apollo?
Post by: BenB5150 on 03/07/2007 05:50 pm
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Jim - 7/3/2007 10:54 AMQuoteBenB5150 - 7/3/2007 10:25 AM
I have a question about the shuttle tiles. Do they still have problems with tiles falling off during flight like the earlier flights or was the bonding problem solved long ago?
Thanks!
Ben
The adhesion problem was solved before Challenger. Debris hits are the real issue
I thought they had fixed the bonding issue just wasn't sure. Thanks for the Reply!
Ben
Post by: edkyle99 on 03/07/2007 06:01 pm
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Shadow Spork - 6/3/2007 9:05 PM
Hi. This is my first time here, and I've read most of the questions and answers to my questions that I had.
Now here's my question. I don't know if this has been asked already, and I apologize if it already has, but after the Apollo program, I understand that they reused the towers as the FSS for the Space Shuttle program. I wonder, how did they manage to take those towers of the launch platforms and install it onto the pad? Did it take a lot of cranes just to install onto the pad, or did they had to go through the trouble of partially or fully dismantling the tower, and then put back together again onto the pad?
Contractors essentially disassembled the Saturn V towers into "chunks", and used big cranes and specially-built moving equipment to relocate these pieces to either be reassembled as shuttle fixed towers or to be scrapped. Here is an image of part of the process.
http://www.capcomespace.net/dossiers/espace_US/shuttle/ksc/LC%2039%20construction%20mars%201976%20KSC-76C-0715.jpg
Note that a big derrick (I think this type is called a "breast derrick), attached to the Apollo tower, was used for this lift, rather than a standard crane.
This image is from the following web page that describes the process with more images. If you don't read French, it is worth running through a translater like Alta Vista Babel Fish. ( http://babelfish.altavista.com )
http://www.capcomespace.net/dossiers/espace_US/shuttle/ksc/LC39_chrono.htm
- Ed Kyle
Post by: Mark Dave on 03/07/2007 06:44 pm
Post by: astrobrian on 03/07/2007 08:05 pm
If kept as a display, it would not be an easy move for sure.
Post by: nathan.moeller on 03/07/2007 10:59 pm
Post by: Shadow Spork on 03/09/2007 02:45 am
Post by: nathan.moeller on 03/09/2007 03:46 am
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Shadow Spork - 8/3/2007 9:45 PM
Wow, thanks! More than what I needed to know. :)
That's usually what you get here my friend :) Welcome to the greatest NASA website on the world-wide web.
Post by: MKremer on 03/10/2007 06:17 am
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nathan.moeller - 7/3/2007 11:33 AMQuoteJim - 7/3/2007 11:14 AM
Ares will not use the same towers
What will be done with the components of the FSS and RSS? Will they end up in the same metal graveyard as the Saturn LUT components that were discarded after Apollo?
Frankly, unless folks can get their Congressperson to sponsor/pass enough appropriations (ie $$$$$$) to 'save' those structures via NASA itself, they're likely going to be scrapped.
Of course, there's the Private financing way, but that's a long haul - choosing (or creating from scratch) a responsible rescue/preservation Organization to manage/finance everything; creating/financing enough PR to raise lots of money; lobbying NASA to save the hardware (and proving you have the resources/financing to do it); creating/bidding contracts for relocation/preservation; and most importantly (assuming everything before this is done) being able to raise the money to pay for everything.
Post by: Austin on 03/10/2007 07:55 pm
Post by: Jim on 03/10/2007 08:42 pm
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Austin - 10/3/2007 3:55 PM
Why does the crew only need their O2 on during the first two minutes or so of launch? (until the SRBs separate) I noticed that the CDR gives the okay for his/her crew to turn off the 02 after SRB sep, and open the visors on their helmets. Maximum g-loads (3) occur closer to the 8 minute mark. If anything, I would think that would be the time when additionaly oxygen would be needed, as it is harder to breath at that time.
There is another post on this else. It isn't for the "extra" oxygen, it is for safety. Search on mkirk as the author
Post by: ANDY_WALLACEGROVE on 03/18/2007 06:58 pm
My question is, can anyone direct me to some in-depth technical detail about the operation of the GPC's? The kind of thing i'm interested in is how the units combine to operate during critical phases, and the kind of redundancy/resilience is employed to deliver fault-tolerance.
Andy
Post by: Jim on 03/18/2007 09:42 pm
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ANDY_WALLACEGROVE - 18/3/2007 3:58 AM
First, can I say what a great site! The depth of members knowledge and the availability of info is just astonishing, thanks and congratulations.
My question is, can anyone direct me to some in-depth technical detail about the operation of the GPC's? The kind of thing i'm interested in is how the units combine to operate during critical phases, and the kind of redundancy/resilience is employed to deliver fault-tolerance.
Andy
It can be found on L2.
I know I will be corrected if I am wrong.
But basically 4 GPC's combine to provide a redundant set with the GPC's voting the oddball out. The 5th is running backup software (BFS) which has different coding than what is used (PASS) in the others
Post by: mkirk on 03/18/2007 09:42 pm
http://www.shuttlepresskit.com/scom/26.pdf
If you have specific questions feel free to ask, someone out there will likely know the answer.
Mark Kirkman
Post by: Jim on 03/18/2007 09:56 pm
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mkirk - 18/3/2007 6:42 AM
If you have specific questions feel free to ask, someone out there will likely know the answer.
Mark Kirkman
That would be you, Mark.
I forgot about the older version of the SCOM online. L2 has a newer version
Post by: joema on 03/19/2007 11:11 am
In particular, this article from "Communications of the ACM", Sept. 1984, is a good overview of the original GPC hardware/software design issues. It's presented in question and answer format, from interviews with the original developers and program managers (5.3MB .pdf): http://klabs.org/DEI/Processor/shuttle/shuttle_primary_computer_system.pdf
Post by: ANDY_WALLACEGROVE on 03/19/2007 05:25 pm
Post by: shuttlepilot on 03/28/2007 06:31 pm
Post by: Jim on 03/28/2007 06:43 pm
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shuttlepilot - 28/3/2007 2:31 PM
I have small question. Many times on many videos of shuttle launch aborts I heard call, probably from CGLS "GLS safing is in progress, BFS is 101, PAS is 101 and LBD is 1"... But what BFS, PAS and LBD mean? I know that for many people from here it's stupid question, but I'm newbie so I don't know many things ;)
There is an acronym list somewhere on the site
BFS - Backup Flight Software
PASS - Primary Avionics Software System
Post by: mkirk on 03/28/2007 06:58 pm
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shuttlepilot - 28/3/2007 1:31 PM
I have small question. Many times on many videos of shuttle launch aborts I heard call, probably from CGLS "GLS safing is in progress, BFS is 101, PAS is 101 and LBD is 1"... But what BFS, PAS and LBD mean? I know that for many people from here it's stupid question, but I'm newbie so I don't know many things ;)
Jim go the first two as for the third I think you mean LDB not LBD which is Launch Data Bus.
LDB 1 refers to the data source in the Launch Control Center Firing Room.
Mark Kirkman
Post by: shuttlepilot on 03/28/2007 07:39 pm
Greetings.
Post by: Jorge on 03/28/2007 08:49 pm
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Jim - 28/3/2007 1:43 PMQuoteshuttlepilot - 28/3/2007 2:31 PM
I have small question. Many times on many videos of shuttle launch aborts I heard call, probably from CGLS "GLS safing is in progress, BFS is 101, PAS is 101 and LBD is 1"... But what BFS, PAS and LBD mean? I know that for many people from here it's stupid question, but I'm newbie so I don't know many things ;)
There is an acronym list somewhere on the site
BFS - Backup Flight Software
PASS - Primary Avionics Software System
And just to tidy up, the "101" is the software major mode. The hundreds digit is the Operational Sequence or OPS. OPS 1 is ascent, OPS 2 is orbit, and OPS 3 is entry. (There are others for RTLS, on-orbit checkout, ground checkout, etc). Within OPS 1, major mode 101 is prelaunch, 102 is first stage (SRB+SSME) powered ascent, 103 is second stage, etc. So the call is simply to confirm that both PASS and BFS are in the correct major mode.
--
JRF
Post by: Gary on 03/29/2007 12:24 am
Thanks.
Post by: mjp25 on 04/06/2007 11:41 pm
Post by: shuttlefan on 04/12/2007 01:34 pm
Thank-you!
Post by: Firehawk153 on 04/16/2007 05:04 am
1.) The OMS engines produce relatively little thrust compared to the monster SSME's (what, about 12,000 lbs. of thrust for both as opposed to 1.2 million lbs of thrust for the SSME.) Why do they even need them? That's like a leaf blower next to a Trent 900 jet engine.
2.) Why wouldn't they wait until after ET seperation to burn the engines instead of burning the engines while the ET (and its remaining propellants) are still attached to the orbiter?
Post by: Space101 on 04/16/2007 05:09 am
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Firehawk153 - 15/4/2007 12:04 AM
I've noticed on some launches that the shuttle's OMS will fire after SRB seperation to aid the shuttle's ascent to orbit. Two questions about this:
1.) The OMS engines produce relatively little thrust compared to the monster SSME's (what, about 12,000 lbs. of thrust for both as opposed to 1.2 million lbs of thrust for the SSME.) Why do they even need them? That's like a leaf blower next to a Trent 900 jet engine.
2.) Why wouldn't they wait until after ET seperation to burn the engines instead of burning the engines while the ET (and its remaining propellants) are still attached to the orbiter?
Good one. Put me down for wanting to know too!
Post by: privateer on 04/16/2007 05:53 am
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Firehawk153 - 15/4/2007 12:04 AM
I've noticed on some launches that the shuttle's OMS will fire after SRB seperation to aid the shuttle's ascent to orbit. Two questions about this:
1.) The OMS engines produce relatively little thrust compared to the monster SSME's (what, about 12,000 lbs. of thrust for both as opposed to 1.2 million lbs of thrust for the SSME.) Why do they even need them? That's like a leaf blower next to a Trent 900 jet engine.
I think SSMEs are not used for the last push because SSMEs run on fuel supplied by ET -> if you use SSMEs for orbital insertion you end up *orbiting ET* too! Which is going to be quite a piece of space debris then...
Quote
2.) Why wouldn't they wait until after ET seperation to burn the engines instead of burning the engines while the ET (and its remaining propellants) are still attached to the orbiter?
I think OMW can be used a bit for attitude control while tank is still attached.
Post by: Jim on 04/16/2007 11:47 am
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Firehawk153 - 16/4/2007 1:04 AM
I've noticed on some launches that the shuttle's OMS will fire after SRB seperation to aid the shuttle's ascent to orbit. Two questions about this:
1.) The OMS engines produce relatively little thrust compared to the monster SSME's (what, about 12,000 lbs. of thrust for both as opposed to 1.2 million lbs of thrust for the SSME.) Why do they even need them? That's like a leaf blower next to a Trent 900 jet engine.
2.) Why wouldn't they wait until after ET seperation to burn the engines instead of burning the engines while the ET (and its remaining propellants) are still attached to the orbiter?
It is in Q&A part 2
Post by: Firehawk153 on 04/16/2007 06:49 pm
Post by: Jim on 04/16/2007 06:52 pm
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Firehawk153 - 16/4/2007 2:49 PM
I found the answer in part 2 of the Q&A; interesting...does the RCS/OMS propellant make up that significant of a portion of the orbiter's mass?
Full load of OMS is 25k lb, which is near 10% of the orbiter weight
Post by: ANDY_WALLACEGROVE on 04/19/2007 12:16 pm
"Young and Crippen will land Columbia manually on this first test flight. A microwave landing system on the ground will be the primary landing aid in subsequent flights, with optional manual takeover"
Post by: Jim on 04/19/2007 12:19 pm
Post by: spaceshuttle on 04/19/2007 04:02 pm
Post by: Jorge on 04/19/2007 04:45 pm
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ANDY_WALLACEGROVE - 19/4/2007 7:16 AM
Can someone enlighten me as to whether the microwave landing system noted in the presskit of STS1 (see below) is used for guidance (radar) or control (autopilot).
Strictly speaking, neither. MLS data is processed solely by the navigation software, not guidance or control. NAV uses MLS inputs to a Kalman filter to estimate the Orbiter’s position and velocity state vector relative to the runway. However, the guidance and control software do use the NAV state vector as input, so it could be said that they use MLS data indirectly.
The distinction matters only because there are some sensors that do provide direct inputs to guidance and/or control. For example, the air data probes provide data to all three: corrected pressure altitude to NAV, equivalent airspeed to Guidance, and alpha, Mach, dynamic pressure, and true airspeed to both Guidance and Control (G&C). (Strictly speaking, the probes themselves only provide pressures and temperatures, and the air data Subsystem Operating Program (SOP) derives the above parameters from that and provides them to GNC).
--
JRF
Post by: j2_ on 04/19/2007 06:02 pm
Does anyone know what Young's rationale was for being opposed to what seems so routine today?
Post by: edkyle99 on 04/19/2007 06:41 pm
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j2_ - 19/4/2007 1:02 PM
I read in Mike Mullane's book that John Young was vehemently opposed to using the OMS Assist maneuver for safety reasons.
Does anyone know what Young's rationale was for being opposed to what seems so routine today?
Anytime an engine start/stop event takes place, the slight odds of a failure are present. Starting the OMS engines in the midst of the SSME burn complicates the equation, adding a little more risk and creating new abort issues, etc.. My guess is that Mr. Young was simply opposed to the addition of risk during ascent, however small, for the small benefit provided by the burn.
- Ed Kyle
Post by: psloss on 04/29/2007 08:46 pm
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mkirk - 15/1/2007 11:26 AMFinally got time to find this; the two pieces were in the 21 August 2006 issue and I agree they are very good. Being greedy, I wish Mr. Covault had gotten the print space to do narratives for all four sim cases he sat in on; however, the L2 documentation is a fine substitute.
P.S.
Last year Craig Covault of Aviation Week and Space Technology sat in on a suited Ascent/Abort sim with the STS-115 crew. He wrote an aritcle about it last fall which gives a good overview of the RTLS profile and a narative of a typical TAL Abort. If you have access to the magazine this will give you some good insight into what a training session is like. He is much better at translating the technical stuff than I am.
Post by: ANDY_WALLACEGROVE on 05/04/2007 03:50 pm
Question 2: My second question (may be worth a differenth thread, ed?), relates to the incident/crisis management practices and procedures used by NASA. Whilst we have based our response on a mode used by the UK Civil Contigencies Secretariat, it would be interesting to know how crisis are managed in other spheres.
Thanks
A
Post by: Jim on 05/04/2007 03:59 pm
Post by: ANDY_WALLACEGROVE on 05/04/2007 04:12 pm
If you suggest ISS, then i'd be glad to take those examples.
Post by: ANDY_WALLACEGROVE on 05/09/2007 10:12 pm
Post by: Marsman on 05/09/2007 10:23 pm
Post by: Jim on 05/09/2007 11:12 pm
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ANDY_WALLACEGROVE - 9/5/2007 6:12 PM
Which draws me to my conclusion, in light of technological developments on the horizon, be it composites, quantum computing or scramjet, how long will it be before we're back with a beautiful bird?
When there is a requirement for it. Maybe never
Post by: MKremer on 05/09/2007 11:43 pm
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ANDY_WALLACEGROVE - 9/5/2007 6:12 PM
Which draws me to my conclusion, in light of technological developments on the horizon, be it composites, quantum computing or scramjet, how long will it be before we're back with a beautiful bird?
From NASA? Probably not for a long, long time, if ever.
Sometime in the future from the private sector (or some other national space program) would be your only hope. (But again, quite a long time until that may happen.)
Post by: spaceshuttle on 05/17/2007 05:23 pm
Post by: DaveS on 05/17/2007 05:30 pm
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spaceshuttle - 17/5/2007 7:23 PMWhat wind tunnel test are referring to? The pre-STS-121 PAL ramp tests? in that case, no ET was used for the tests. All of the tests were with subscale models.
Lord, could someone PLEASE tell me which external tank was sent through the windtunnel, and which mission it was originally set to fly on?
Attached to this post a screen cap from a NASA TV videofile showing the wind tunnel model they used at Ames Research Center in California.
Post by: spaceshuttle on 05/17/2007 06:39 pm
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DaveS - 17/5/2007 12:30 PMQuotespaceshuttle - 17/5/2007 7:23 PMWhat wind tunnel test are referring to? The pre-STS-121 PAL ramp tests? in that case, no ET was used for the tests. All of the tests were with subscale models.
Lord, could someone PLEASE tell me which external tank was sent through the windtunnel, and which mission it was originally set to fly on?
Attached to this post a screen cap from a NASA TV videofile showing the wind tunnel model they used at Ames Research Center in California.
Oh. Whoops! I thought that STS-114's original tank (I believe that one ended up being ATLANTIS sts-121's tank) was sent somewhere for those test. Clumsy nistake...
Post by: programmer78 on 05/17/2007 07:52 pm
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Question 1: In their seminal (as far a IT geeks are concerned) publication "Transaction Processing Concepts and Techniques", Jim Grey and Andreas Reuter quote "a rule of thumb is that business software costs $10 to $100 per line of code, against $5000 per line of code for the shuttle, the cost differential coming from much more careful design and testing". My question therefore is can anyone direct me to other such statements which highligh the casm between NASA and commercial systems develop is stated. Whilst I am responsible for a "mission critical" system, in my world a major system loss could cost Ł600billion, whereas in this world it's flesh and bone.
Nasa's system is unlike any commercial software process. Have a read of "They Write the Right Stuff."
http://www.fastcompany.com/online/06/writestuff.html
Dave
Post by: joema on 05/18/2007 03:45 am
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programmer78 - 17/5/2007 2:52 PMThat's exactly right -- the shuttle Primary Avionics Software System (PASS) is an example of a Real Time Control System. It's very different from commerical software such as PC operating systems, databases, etc. It's more akin to the flight control software on fly-by-wire airliners and fighter planes.
...Nasa's system is unlike any commercial software process. Have a read of "They Write the Right Stuff."
http://www.fastcompany.com/online/06/writestuff.html...
Real time control systems have a limited number of code lines and global states to deal with. E.g, the PASS system is about 420,000 lines of code, produced by about 260 developers. By contrast, Windows XP (for example) has 40 million lines of code.
The Fastcompany.com article is interesting, but it perpetuates the myth that developers of real time control systems have discovered a secret which allows them to write code with few errors. In reality there is no secret. Real time control systems have few lines of code (relative to much commerical software), and typically 10x or 100x the ratio of developers to lines of code.
The shuttle PASS system is impressive, but so is the software running the fly-by-wire flight controls on the Airbus A380. Both have no manual reversion, and simply must work perfectly.
Post by: brahmanknight on 05/18/2007 08:30 pm
Post by: anik on 05/18/2007 10:26 pm
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brahmanknight - 19/5/2007 12:30 AM
When will this happen?
OBSS will be left on ISS during STS-123 (1J/A) and returned to Earth aboard STS-124 (1J)...
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brahmanknight - 19/5/2007 12:30 AM
How will it be stored on the ISS?
OBSS will be stored on the Orbital Support Equipment (OSE), which will be installed onto S1 truss during STS-118 (13A.1)...
Post by: DaveS on 05/18/2007 10:39 pm
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anik - 19/5/2007 12:26 AMAny images of the OSE?
OBSS will be stored on the Orbital Support Equipment (OSE), which will be installed onto S1 truss during STS-118 (13A.1)...
Post by: DaveS on 05/19/2007 08:39 pm
Post by: shuttlefan on 05/21/2007 10:24 pm
Post by: MKremer on 05/21/2007 10:33 pm
Post by: DaveS on 05/21/2007 11:16 pm
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MKremer - 22/5/2007 12:33 AMHave actually happened. Remember 51L? Ice everywhere. Foot long icicles on the FSS and RSS.
Snowfall, no. It'd be more likely to be freezing rain or sleet (either of which would be much worse because of lots more ice buildup over both the Shuttle and pad structures).
The Shuttle has heaters. Also gets pretty hot during ascent.
Post by: Paul Howard on 05/23/2007 11:29 pm
Post by: MKremer on 05/25/2007 12:23 am
Post by: brahmanknight on 05/26/2007 12:18 am
Post by: mkirk on 05/26/2007 02:59 pm
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brahmanknight - 25/5/2007 7:18 PM
Does anyone know what kind of temperatures are experienced on the launchpad during a shuttle launch?
Well the exhaust temperature of the solid rocket boosters is about 5,600 degrees Fahrenheit and the temperature of the space shuttle main engine exhaust is around 6,000 degrees Fahrenheit.
Yes the SSMEs burn hotter than the SRBs.
Mark Kirkman
Post by: Mark Dave on 05/26/2007 04:12 pm
Post by: shuttlefan on 05/26/2007 06:06 pm
Post by: rdale on 05/26/2007 09:43 pm
Post by: Jim on 05/26/2007 11:00 pm
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shuttlefan - 26/5/2007 2:06 PM
Why don't we see air views of the shuttle launches and landings, like in the early days of the program?
Chase planes aren't used anymore
Post by: astrobrian on 05/27/2007 05:42 am
Post by: Austin on 05/27/2007 06:50 am
Post by: psloss on 05/27/2007 11:36 am
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astrobrian - 27/5/2007 1:42 AMThey probably could -- a camera operator would be a good thing to include, also -- but based on what has been said in the past, cameras don't tend to be used solely to get good pictures. If there aren't any programmatic requirements for it, then it probably looks like a "cost" to the program without any direct or tangible benefits. They stopped flying chase planes very early -- first Spacelab landing, first KSC landing.
The chase planes are not, but why then couldn't the STA be equipped with cameras?
The orbiter doesn't have any running lights, so low-light footage would require special equipment.
As Rob noted, though, the WB-57 has been up there in the RTF timeframe and I don't think the entry footage from STS-121 has been publicly released.
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Austin - 27/5/2007 2:50 AMThe camera on the STS-112 tank was mounted in a different location than the current LO2 feedline fairing (LO2 cable tray cover / STA 718):
Although unrelated to planes, I still love the view of the Florida coastline dropping away courtesy of the liquid oxygen feed line camera. We had a particularly nice view of this on STS 112, which I believe was the first launch during which this was used.
http://www.spaceref.com/news/viewsr.html?pid=6516
It had a broader view of the vehicle and surroundings during first stage, but the view was mostly fouled by the right SRB sep motor firing. (I believe that was part of the motivation for relocating the camera for RTF.)
Note that in the STS-112 case, it would be interesting to see what programmatic plans there were for reflight, but the press asked about that at the time and I believe Mr. Dittemore responded that there were no definite plans on when the ET camera would fly again.
Personally, I think the rocket cam views from past Delta launches were more spectacular views of Florida -- the Mars Odyssey launch was on a really clear day in the spring of 2001 and that view from the Delta second stage was spectacular. (I believe someone copied that video over to YouTube -- without asking, of course. But in case anyone wants to see it, it's there.)
Ecliptic Enterprises has excerpts of all of these:
http://www.eclipticenterprises.com/gallery_rocketcam.php
Post by: Austin on 05/27/2007 04:01 pm
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psloss - 27/5/2007 4:36 AM
The camera on the STS-112 tank was mounted in a different location than the current LO2 feedline fairing (LO2 cable tray cover / STA 718):
http://www.spaceref.com/news/viewsr.html?pid=6516
It had a broader view of the vehicle and surroundings during first stage, but the view was mostly fouled by the right SRB sep motor firing. (I believe that was part of the motivation for relocating the camera for RTF.)
I remember this. There was a great deal of anticipation of what the SRB staging would look like from that camera, only to have the view obscured as the SRBs separated.
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Personally, I think the rocket cam views from past Delta launches were more spectacular views of Florida -- the Mars Odyssey launch was on a really clear day in the spring of 2001 and that view from the Delta second stage was spectacular. (I believe someone copied that video over to YouTube -- without asking, of course. But in case anyone wants to see it, it's there.)
Ecliptic Enterprises has excerpts of all of these:
http://www.eclipticenterprises.com/gallery_rocketcam.php
Thanks for the link -- I'll check it out!
Post by: psloss on 05/27/2007 04:51 pm
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Austin - 27/5/2007 12:01 PMYeah -- NTV ran some b-roll after the camera was tested on the pad on rollout day; since you could see at least one of the sep motors in the view, it was something I remember that was a question before launch.
I remember this. There was a great deal of anticipation of what the SRB staging would look like from that camera, only to have the view obscured as the SRBs separated.
(Attached a cap from a test done the night before launch.)
Post by: DaveS on 05/27/2007 05:05 pm
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psloss - 27/5/2007 6:51 PMThat's not one of the BSMs. It's one of the pitot tubes. The upper BSMs have a grey appearance, the pitot tubes are black.
Yeah -- NTV ran some b-roll after the camera was tested on the pad on rollout day; since you could see at least one of the sep motors in the view
Post by: psloss on 05/27/2007 05:14 pm
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DaveS - 27/5/2007 1:05 PMI stand corrected -- you're right, the motors are out of the field of view.
That's not one of the BSMs. It's one of the pitot tubes. The upper BSMs have a grey appearance, the pitot tubes are black.
(We were curious about fogging from the sep motors at the time, though, and I remember wondering about it after the post-rollout test video was shown on NTV.)
Post by: madmardy on 05/28/2007 08:19 am
Where they keep the recovery convoy purge and cooling trucks when they are not being used?
Well actually all the main convoy trucks
Post by: Jim on 05/28/2007 01:45 pm
Post by: madmardy on 05/28/2007 06:46 pm
Post by: Endeavour118 on 05/29/2007 02:21 pm
Post by: MKremer on 05/29/2007 03:25 pm
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Endeavour118 - 29/5/2007 9:21 AMSee the third message on this page: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=625&start=391
What Is Clear Caution and Warning Memory?
(mkirk's answer)
Post by: Jorge on 05/29/2007 03:39 pm
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Endeavour118 - 29/5/2007 9:21 AM
What Is Clear Caution and Warning Memory?
Caution and Warning is the system that alerts the crew (using fault messages, alarms, etc) when there's a problem (parameters out-of-limits, hardware failure, etc). During launch countdown, there are certain events that "normally" trip a C&W alarm. For troubleshooting purposes later on during the flight, you don't want those events cluttering up C&W memory. So at T-2:30, the crew clears all messages from the FAULT SUMM display (first making sure that all the errors were the expected ones), and clears C&W memory by flipping a switch on the center panel between the CDR and PLT.
Post by: mkirk on 05/29/2007 03:41 pm
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Endeavour118 - 29/5/2007 9:21 AM
What Is Clear Caution and Warning Memory?
This would be a good question for one of those DPS (data processing system) weenies to answer but I take a shot at it for now. ;)
All of the caution & warning messages that have been annunciated during the countdown are cleared at T-2 minute 30 seconds by the flight crew. This prevents the old messages that are still stored in the buffer from being confused with new warnings that may occur during the final minutes of the count and ascent.
Specifically the pilot (seated in the right seat) will call up the fault summary pages for the PASS (primary) general purpose computers (GPC) and BFS (backup) GPC to ensure that all of the displayed warnings were the ones everyone expected to see – things like cabin pressure messages that occurred during the cabin leak check. Once that is done the pilot will type in “SPEC 99 PRO” on the keyboard for both the PASS and BFS GPCs – this clears the software memory buffer. The pilot will then move the caution and warning switch, located on the center console, to the clear position – this clears the hardware caution and warning memory.
Mark Kirkman
Post by: mkirk on 05/29/2007 03:44 pm
It looks like Jorge did beat me to the answer on that.
See like I said it was a good topic for one of those DPS pukes. ;)
Mark Kirkman
Post by: mkirk on 05/29/2007 05:42 pm
I went back and fixed it.
Mark Kirkman
Post by: joncz on 05/31/2007 01:05 am
I can think of two things and immediately dismiss them:
-- Humidity: On the coast in Florida?!? Besides, 21% is unhealthy low for electronics.
-- O2: Why would they need hundredths of a percent of O2 percent?
The number has been right at 21.32% for as long as I've seen white room shots since the rollout.
Post by: Lee Jay on 05/31/2007 01:13 am
Post by: MKremer on 05/31/2007 01:18 am
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Lee Jay - 30/5/2007 8:13 PMYeah, it's O2 percentage. The interesting thing about watching that gauge is noting how the # of people and activies in the white room cause it to vary - I've seen it down into the mid-19's with the room full of people doing prep's and 19's/low 20's during crew entry for launches.
I don't actually know the answer, but I'd guess it's O2, and needed because a purge gas like Nitrogen is available there and could dilute the O2 right out of the air in there if there was a leak or other failure of some sort.
Post by: Jim on 05/31/2007 12:11 pm
Post by: STS-500Cmdr on 05/31/2007 04:50 pm
Post by: Jim on 05/31/2007 05:09 pm
Post by: gordo on 06/02/2007 07:17 pm
Post by: Jim on 06/02/2007 07:27 pm
Post by: madmardy on 06/02/2007 09:23 pm
but whats the difference between the roles of booster and main engines in MCC?
as in the STS-93 video they seem to be doing very similar things
Post by: Mark Dave on 06/02/2007 09:29 pm
Post by: Jim on 06/02/2007 09:36 pm
Post by: psloss on 06/02/2007 09:38 pm
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madmardy - 2/6/2007 5:23 PM
I'm not sure whether this has been covered before
but whats the difference between the roles of booster and main engines in MCC?
as in the STS-93 video they seem to be doing very similar things
Sort of covered, I guess:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=442&start=61&posts=73&mid=137684#M137684
Post by: gordo on 06/02/2007 10:35 pm
Post by: Jim on 06/02/2007 10:36 pm
Post by: Danny Dot on 06/03/2007 05:28 pm
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madmardy - 2/6/2007 4:23 PM
I'm not sure whether this has been covered before
but whats the difference between the roles of booster and main engines in MCC?
as in the STS-93 video they seem to be doing very similar things
Main Engines works for Booster. Booster is in the main flight control room and Main Engines is in a back room. Most if not all people in the flight control room have about 4 people in the backrooms that talk to them.
Danny Deger
Post by: Mark Dave on 06/03/2007 06:32 pm
Post by: DaveS on 06/03/2007 06:40 pm
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MarkD - 3/6/2007 8:32 PMYou never heard of the "Twang"? The "Twang" is caused by the SSMEs being offset from the cg of the stack. When the SSMEs fire they cause the stack to bend as much as 6 ft and then the stack "twangs" back and when the stack is pure vertical again, the SRBs are ignited.
Does the stack sway a lot before launch? I saw a clip of the new simulator ride on NASA TV and it showed the stack sway a bit. What causes this to happen?
Post by: ShuttleDiscovery on 06/03/2007 07:55 pm
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DaveS - 3/6/2007 7:40 PMQuoteMarkD - 3/6/2007 8:32 PMYou never heard of the "Twang"? The "Twang" is caused by the SSMEs being offset from the cg of the stack. When the SSMEs fire they cause the stack to bend as much as 6 ft and then the stack "twangs" back and when the stack is pure vertical again, the SRBs are ignited.
Does the stack sway a lot before launch? I saw a clip of the new simulator ride on NASA TV and it showed the stack sway a bit. What causes this to happen?
That's why the SSMEs ignite at T-6.6 seconds, as it gives enough time for the twang to occur so that at T-0, the stack is pure vertical. :)
Post by: Jim on 06/03/2007 08:06 pm
Post by: Mark Dave on 06/03/2007 09:25 pm
Post by: Jim on 06/04/2007 02:06 am
Post by: spaceshuttle on 06/04/2007 03:40 am
Post by: rdale on 06/04/2007 03:53 am
Post by: spaceshuttle on 06/04/2007 03:57 am
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rdale - 3/6/2007 10:53 PM
Winds aren't normally that excessive, what leads you to believe they regularly get hammered by strong gusts?
Somebody said that wind nudges the stack while on the launch pad, but considering how heavy the thing is, I was 'caught off guard'. I didn't think that the stack would move that easily.
Post by: Mark Dave on 06/04/2007 01:18 pm
Wouldn't the swaying affect the LOX vent arm? I was just wondering given how winds can affect the stack.
Post by: Jim on 06/04/2007 07:28 pm
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MarkD - 4/6/2007 9:18 AM
Well, considering the two TSMs that support the orbiter, and the arms to hold the orbiter are designed to move during the "twang". I've read it feels like you're sitting ontop of a tree on a windy day and you feel yourself swaying.
TSM's do not physically support the orbiter. They only house the umbilicals to the orbiter. The orbiter weight is totally supported by the ET.
Post by: brahmanknight on 06/05/2007 09:25 pm
Post by: Jim on 06/05/2007 09:34 pm
Post by: brahmanknight on 06/05/2007 09:47 pm
Post by: Ford Mustang on 06/06/2007 01:58 am
2: Things in space are in micro gravity. Couldn't astronauts just push the truss/whatever they're adding around themselves? I know it's safer using the OBSS.. Just a question. :)
Post by: Jim on 06/06/2007 02:24 am
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Ford Mustang - 5/6/2007 9:58 PM
1: Why don't they show the PLB Doors opening? The KU band is within reach (all over the Earth).. Just askin', simply because it's cool to see.
2: Things in space are in micro gravity. Couldn't astronauts just push the truss/whatever they're adding around themselves? I know it's safer using the OBSS.. Just a question. :)
1. The Ku-band antenna is in the payload bay and it is stowed
2. OBSS is only used for surveying the orbiter TPS, not for handling payloads, that is the RMS's job.
Even though the truss has no weight, it still has mass and inertia. The crew can't handle that large of a structure by hand and still maintain adequate control
Post by: Ford Mustang on 06/06/2007 03:20 am
As to 1, I was told by another person that the KU, even stowed, could reach JSC for television coverage.
EDIT: Still, why can't they downlink the video, because they DO have a DV camera..
Post by: MKremer on 06/06/2007 03:28 am
Post by: Ford Mustang on 06/06/2007 03:38 am
That's just me.
Post by: MKremer on 06/06/2007 03:59 am
Post by: Jim on 06/06/2007 05:23 am
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Ford Mustang - 5/6/2007 11:20 PM
Got the OBSS and the RMS mixed up.. Sorry bout that.
As to 1, I was told by another person that the KU, even stowed, could reach JSC for television coverage.
EDIT: Still, why can't they downlink the video, because they DO have a DV camera..
No TV, It can't transmit while stowed
Post by: psloss on 06/06/2007 10:48 am
But that was also prior to the Columbia disaster. (Don't know if the attitudes they fly now are good for downlink to MILA.)
Post by: DaveS on 06/06/2007 10:59 am
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psloss - 6/6/2007 12:48 PMThey did show live payload bay door opening video on STS-112, when Atlantis flew over JSC. It's still pretty common that orbiter overflies JSC at about 90 minutes into the mission which is when door opening is usually scheduled for.
Payload bay opening has very occasionally been shown something close to live, but IIRC only on low-inclination flights, since sometimes the timeline sync-ed up with the orbiter being in range of MILA...that was also prior to the Columbia disaster. (Don't know if the attitudes they fly now are good for downlink to MILA.)
The most likely reason for not showing the payload bay doors opening is because that the post-launch press-conference happens at the same.
Post by: psloss on 06/06/2007 11:20 am
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DaveS - 6/6/2007 6:59 AMThere you go, I stand corrected. Seems like in the past when they got downlink they've also replayed it, too, after the post-launch press conference (but that was still all prior to the Columbia disaster).
They did show live payload bay door opening video on STS-112, when Atlantis flew over JSC. It's still pretty common that orbiter overflies JSC at about 90 minutes into the mission which is when door opening is usually scheduled for.
Post by: Danny Dot on 06/06/2007 03:49 pm
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mkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
Post by: brahmanknight on 06/06/2007 08:54 pm
Post by: mkirk on 06/07/2007 12:12 am
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Danny Dot - 6/6/2007 10:49 AMQuotemkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
Thanks Danny-
That was obviously long before my time. I will go look it up. I am surprised I never heard about it during my time in training - that is a big deal, I can only imagine the fallout from that within MOD/FCOD at the time.
Mark Kirkman
Post by: mkirk on 06/07/2007 12:52 am
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brahmanknight - 6/6/2007 3:54 PM
Could anyone elaborate more on "High Energy" and "Low Energy" landings? Is it just a computer miscalculation that happens?
Well, here is a quick and overly simplistic pass at this topic:
Energy – as it is used in this case – is a way of quantifying the orbiter’s ability to make it to the runway. For the most part energy is a function of the orbiter’s altitude and velocity. There are many variables that can affect the orbiter’s energy state. If you are very “LOW ENERGY” that means you are probably not gonna make it to the runway and you could fall on the “mouse’s house” over in Orlando (i.e. Disney World). If you are really “HIGH ENERGY” that means you are going to zip right on past the runway which at KSC means you are going for a swim.
Some of the many variables that can affect your energy state include, drag, atmospheric density, trim (i.e. flight control positions and gains), orbiter attitude, bad/degraded Guidance & NAV, flight control problems, late runway changes, winds, and many more…
The orbiter’s entry trajectory is optimized to allow for some margin both high and low. So for instance if the orbiter is low energy approaching the terminal area you can possibly down mode to a straight in approach rather than flying around the HAC – that results in an instant reduction in the distance the orbiter has to fly to get to the runway.
Mark Kirkman
Post by: MKremer on 06/07/2007 01:14 am
Just to add..."energy" means kinetic energy - the mass/velocity energy you have at any particular time.
As an example, say you're in an unpowered glider - if you dive, you're gaining energy; if you climb, you're losing energy.
Gravity has a large effect on kinetic energy, and managing that energy (via climb/dive/banks/turns) in an atmospheric craft (especially an unpowered one!) is very important.
It's even more important with the Shuttle orbiter, which has been (probably accurately) described as "a brick with wings".
Energy management (mass/velocity) when approaching the runway site - turning into the final alignment at the correct location and time, and the approach to the runway itself - all require managing energy correctly to finally touch down at the necessary point on the runway.
Post by: Danny Dot on 06/07/2007 02:11 am
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mkirk - 6/6/2007 7:12 PMQuoteDanny Dot - 6/6/2007 10:49 AMQuotemkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
Thanks Danny-
That was obviously long before my time. I will go look it up. I am surprised I never heard about it during my time in training - that is a big deal, I can only imagine the fallout from that within MOD/FCOD at the time.
Mark Kirkman
For a detailed write-up see:
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1?lnk=st&q=&rnum=1#5c6efd21ae4f32a1
Danny Deger
Post by: mkirk on 06/07/2007 02:47 am
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Danny Dot - 6/6/2007 9:11 PM
For a detailed write-up see:
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1?lnk=st&q=&rnum=1#5c6efd21ae4f32a1
Danny Deger
Thanks for that write up, that told me a lot...and yes with the rules in place right now I could not imagine how this could have happend. I think that is why I didn't beleive the original post on this subject and just assumed they had heard the space program's version of an urban myth.
I still don't recall ever hearing about this specific flight during my training. Of course they may have discussed it and I just didn't pick it up - part of that whole drinking from a fire hose mentality.
After reading that all I can do is shake my head, I can't believe the program ever let itself get into that kind of corner.
Mark Kirkman
P.S.
I thought I recognized your name when you first started posting on this site but I couldn't figure out why. Now I think it is becuase I must have read some of your training stuff when I was an instructor.
Post by: Jorge on 06/07/2007 04:12 am
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MKremer - 6/6/2007 8:14 PM
mkirk's descriptions are excellent.
Just to add..."energy" means kinetic energy - the mass/velocity energy you have at any particular time.
That's actually oversimplifying a bit. "Energy" means total energy - the sum of kinetic and potential energy. Kinetic energy is proportional to velocity squared, potential energy to height.
Quote
As an example, say you're in an unpowered glider - if you dive, you're gaining energy; if you climb, you're losing energy.
In an unpowered glider, your total energy is always decreasing, due to drag. If you dive, you're trading potential energy for kinetic energy; if you climb, you're trading potential for kinetic. But the sum of potential and kinetic is always getting smaller.
Quote
Gravity has a large effect on kinetic energy, and managing that energy (via climb/dive/banks/turns) in an atmospheric craft (especially an unpowered one!) is very important.
It's even more important with the Shuttle orbiter, which has been (probably accurately) described as "a brick with wings".
Compared to other winged aircraft, yes. The orbiter has a subsonic L/D around 4, compared to around 20 for most subsonic aircraft. But that's still a lot better than any lifting body or capsule.
Post by: sketterer on 06/07/2007 04:56 am
Post by: MKremer on 06/07/2007 06:13 am
Post by: mkirk on 06/07/2007 06:38 pm
Commander – Red (A)
Pilot –Yellow (B)
MS1 – Blue (C)
MS2 – Green (D)
MS3 – Orange (E)
MS4/PS1 – Brown (F)
MS5/PS2 – Purple (G)
MS6/PS3 – Beige (H)
MS7/PS4 – Black (I)
MS8/PS5 – Light Gray (J)
Mark Kirkman
Post by: elmarko on 06/07/2007 06:50 pm
Edit 2: OK, i clicked on the "last post" in the General Discussion thread, but the thread had changed between me loading the page and me clicking. Ignore/prune the post please :)
Post by: dawei on 06/08/2007 03:30 pm
Post by: mkirk on 06/08/2007 05:04 pm
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dawei - 8/6/2007 10:30 AM
Could someone help me know the difference between "droop Zaragoza (109%) " and "1E OPS-3 Zaragoza (109%)? I am guessing ops-3 means an intact abort to the runway and "droop" means a bailout scenario? Thanks in advance for the help.
Well here is the definition straight from the Flight Rules...more than you wanted to know...If this doesn' help any I will try and provide a less criptic version after launch.
e. SINGLE ENGINE (PRIME TAL - 109) (E.G., SINGLE ENGINE
BEN GUERIR - 109):
THIS BOUNDARY REPRESENTS THE EARLIEST TIME AFTER
WHICH AUTO GUIDANCE WILL ACHIEVE THE RANGE-VELOCITY
TARGETS AT MECO FOR THE PRIME SITE. ASSUMPTIONS:
PROTECTS 2-SIGMA MPS FPR, PROTECTS AT LEAST ZEROSIGMA
ENTRY DISPERSIONS, AND MAX THROTTLE. ®[120894-1741 ]
This boundary is different from the single engine TAL boundaries for the in-plane cases because it assumes max throttles versus nominal throttles. Using max throttles allows the earliest opportunity to continue to the prime TAL site and not have to risk possible control problems caused by a large yaw maneuver required to head to the ACLS. Reference Flight Rule {A2-52C}, ASCENT MODE PRIORITIES FOR PERFORMANCE CASES, for more details on using max throttles for this case. If this boundary has not been reached yet and the NEGATIVE ACLS boundary has been crossed, this call will be made on 0 sigma MPS to close the gap. These cases, by definition, reach the range-velocity (R-V) target line; however, they do so at a lower velocity than the design point. For this reason, entry dispersions are not explicitly protected, although for any given mission, the protection level for these constraints (first roll reversal velocity, constant drag phase length, and equilibrium glide boundary margin) may vary from less than 1-sigma to more than 3-sigma (reference 5/18/94 Abort Panel splinter meeting).
**************************************************
a. DROOP (PRIME TAL OR ACLS - 109):
THE DROOP BOUNDARY REPRESENTS THE EARLIEST TIME AFTER
WHICH A TWO-SSME-OUT TRAJECTORY WILL NOT FALL BELOW
265,000 FEET AND TAL GUIDANCE WILL CONVERGE TO THE
SELECTED/REDESIGNATED SITE’S MECO TARGETS PRIOR TO
THE DESIRED MECO TIME. THIS BOUNDARY ASSUMES TWO
SSME’S OUT, MAX THROTTLE, AND 15-SECOND ABORT
DECISION DELAY. THE WEATHER AT THE SITE WILL NOT BE
A CONSIDERATION WHEN ASSESSING THIS BOUNDARY.
This boundary is the earliest time that TAL guidance can be used on a two-engine-out trajectory. It ensures that the minimum droop altitude will not be violated. Analysis has shown that trajectories that droop below 265,000 feet could result in ET rupture due to aerodynamic heating. If, upon TAL droop declaration, guidance is unconverged, the crew’s procedures call for flying manually until guidance does converge. (The likelihood of unconverged guidance in this region was significantly reduced by incorporation of the OI-21 low-thrust-to-weight guidance CR.) This boundary does not ensure the capability to reach a runway. Therefore, the weather at the targeted site is not considered when evaluating this boundary.
Mark Kirkman
Post by: elmarko on 06/08/2007 05:48 pm
"After all these activities are complete, one of the ASPs remains in the shuttle overnight to "babysit," so that there is no chance of anybody else entering the vehicle and changing anything."
Can anyone give anymore information on this? Does the ASP climb into one of the seats and sleep there or what? This is one thing I hadn't previously heard of before.
Post by: mkirk on 06/08/2007 09:04 pm
Quote
elmarko - 8/6/2007 12:48 PM
A quick question based on something that I just googled, from the Canadian Space Agency website:
"After all these activities are complete, one of the ASPs remains in the shuttle overnight to "babysit," so that there is no chance of anybody else entering the vehicle and changing anything."
Can anyone give anymore information on this? Does the ASP climb into one of the seats and sleep there or what? This is one thing I hadn't previously heard of before.
I just had a conversation with Alan Poindexter - a former ASP – on this very topic as I was getting some background for a project.
Once the Ascent Switch List is performed by the ASP during the T-11 hour hold the astronaut office “owns the crew module”. With the exception of tanking there is always a member of the ASP office in the vehicle. They are doing other tasks such as stowing equipment, configuring cables, and helping with tasks such as fuel cell activation.
Mark Kirkman
Post by: Mark Dave on 06/08/2007 09:32 pm
Post by: brahmanknight on 06/08/2007 10:38 pm
Post by: Danny Dot on 06/08/2007 11:52 pm
Quote
brahmanknight - 8/6/2007 5:38 PM
In an emergency, how do the astronauts get over the gap between the space shuttle and the White Room? Looking at the view on the camera, I can't tell how big the gap is.
Very, very carefully :-)
Danny Deger
Post by: MKremer on 06/09/2007 12:33 am
Post by: spaceshuttle on 06/09/2007 12:45 am
Post by: sketterer on 06/09/2007 02:24 am
Post by: spaceshuttle on 06/09/2007 07:24 am
Post by: MKremer on 06/09/2007 07:37 am
Quote
spaceshuttle - 9/6/2007 2:24 AMBeing very, very sure the water volume was at the max level prior to T-0? (just a guess)
Why was water pouring from the water tower before the launch?
Post by: kally1 on 06/09/2007 08:02 am
I am no expert, but hopefully I've got this right.... I heard on TV today just prior to the launch, that the big water tower
near the shuttle launch pad delivers its entire water supply to the launch pad just moments before launch in order to suppress sound vibrations from the engines that can damage/fatigue the tower structure.
Post by: MKremer on 06/09/2007 08:34 am
Post by: psloss on 06/09/2007 10:35 am
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=653&posts=28&start=1
Post by: joncz on 06/09/2007 11:46 am
Post by: DaveS on 06/09/2007 11:48 am
Quote
joncz - 9/6/2007 1:46 PMSSME TVC.
Is the roll to heads-up effected by gimballing the mains or by RCS?
Post by: MKremer on 06/09/2007 11:51 am
RCS is probably backup (in case of single engine MECO).
Post by: spaceshuttle on 06/09/2007 06:45 pm
Quote
MKremer - 9/6/2007 3:34 AM
Well, partially - prior to ignition water starts spraying down through outlets lining the main engine pad opening and within the bottom of the SRB openings - then starts spraying/spouting big-time through the pad spouts right after liftoff to protect the pad surface/structure from heat damage.
I was talking about something that happened a couple hours before launch. Water was rushing out of the top of the water tower...
Post by: Jim on 06/09/2007 06:54 pm
Post by: blazotron on 06/10/2007 05:45 am
What are the radial grooves in the area around some of the RCS nozzles? The grooves look like they are in HRSI, but I dont think they actually are (they look to be in a bolted-on plate of some kind, maybe columbium like the nozzles themselves?). Up till a few minutes ago, I had been thinking that the grooves were some sort of aerothermal device to improve the heating or aerodynamics around the jets upon reentry. But after getting a good close look at them, I am now thinking that they might be stiffeners in the plate that seems to cover the the area around the nozzle and chamber of the inclined RCS engines (ie not the ones that point normal to the surface).
Here is an example image showing some of the grooves:
link
Can anyone confirm the real porpose?
While I'm at it, what are the other holes visible in this image: two elongated holes in the upper right quadrant of the image, near the white/black boundary, a large hole at the very top of the image on the right side, and a small hole about 2/3 of the way from the center of the image to the nosecap.
Thanks for the help!
Post by: dawei on 06/10/2007 11:37 am
Post by: Jorge on 06/10/2007 12:33 pm
Quote
dawei - 10/6/2007 6:37 AM
I believe the elongated slot by the white/black boundry is for the Air Date Probe used during the landing phase. The bigger, rounder area above that is a star tracker. That is all the help I can give you.
The air data probe "door" is actually a lot further down in the image, below the bottom of the seam separating the forward RCS pod from the rest of the forward fuselage.
The elongated slot is a vent door.
Post by: mkirk on 06/10/2007 02:28 pm
Quote
Jorge - 10/6/2007 7:33 AMQuotedawei - 10/6/2007 6:37 AM
I believe the elongated slot by the white/black boundry is for the Air Date Probe used during the landing phase. The bigger, rounder area above that is a star tracker. That is all the help I can give you.
The air data probe "door" is actually a lot further down in the image, below the bottom of the seam separating the forward RCS pod from the rest of the forward fuselage.
The elongated slot is a vent door.
Yes, and the two elongated slots are Vent Doors 1 and 2. There are identical doors on the other side of the nose. Vent Door 1 is for the forward RCS cavity and Vent Door 2 is for the forward fuselage and also includes the nose wheel well.
Mark Kirkman
Post by: dawei on 06/10/2007 03:10 pm
Thanks Mark and Jorge!
Post by: j2_ on 06/11/2007 12:57 am
Post by: Jim on 06/11/2007 01:22 am
Post by: Zoomer30 on 06/11/2007 02:00 am
Is it just so they stay out of the SRB plume recirculation?
Post by: MKremer on 06/11/2007 02:22 am
Post by: kneecaps on 06/11/2007 03:49 pm
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
Post by: j2_ on 06/11/2007 07:11 pm
Quote
kneecaps - 11/6/2007 8:49 AM
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
I believe OOP refers to "Out of plane". That means burning the engine orbit normal or anti-normal (perpendicular to the velocity vector), which is an effective way to use up the leaking fuel, because plane change maneuvers are very expensive in terms of delta-v, and burning the OMS engines out of plane won't affect the shuttle trajectory much.
Post by: Danny Dot on 06/11/2007 10:22 pm
Quote
kneecaps - 11/6/2007 10:49 AM
The daily execute packages always give information on 'OMS TANK FAIL CAPABILITY'...is this the capability to complete the mission if both tanks in a pod were rendered unusable?
Also the same document also mentions for 'LEAKING OMS PRPLT BURN' to 'ALWAYS RETROGRADE' (makes sense) but I have seen it say 'OOP' in the past. I'm wondering what OOP is and in what situations would you continue to use an OMS engine with leaking tanks.
Thanks!
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
Post by: kneecaps on 06/12/2007 07:59 pm
Quote
Danny Dot - 11/6/2007 11:22 PM
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
Thanks for that makes it very clear, does the 'OMS TANK FAIL' also refer to the same thing but not in case of a leak? Maybe a He failure, which presumably you wouldn't burn off the fuel?
Post by: Danny Dot on 06/12/2007 10:37 pm
Quote
kneecaps - 12/6/2007 2:59 PMQuoteDanny Dot - 11/6/2007 11:22 PM
I used to teach this subject to the astronauts, but it has been a while. The idea is an OMS burn will be accomplished after the leak is detected, but before all the propellant leaks out. Always retro grade means the current orbit's perigee must be lowered some by the leaking system, or the shuttle will not be able to come home with the non-leaking pod. The problem with Alway Retrograde is the perigee may be lowered in the Southern Hemisphere, which would force the shuttle to do the second OMS burn such that a landing in the Southern Hemisphere is the only option. Obviously, landing in Australia , would be a pain in the rear -- the 747 would have to go down and pick the shuttle up. But a landing in Australia would be better than being stuck in orbit "forever". If the leaking OMS tank is burned Out Of Plane, this means there is enough prop in the other tank to allow it to do a deorbit burn (along with RCS prop) from the current orbit.
This is a simplification, there are other things to consider such as shallow entry, but I hope this helps somewhat.
Danny Deger
Thanks for that makes it very clear, does the 'OMS TANK FAIL' also refer to the same thing but not in case of a leak? Maybe a He failure, which presumably you wouldn't burn off the fuel?
Sorry, I don't remember. I stopped training astronauts in 1995.
Danny Deger
Post by: kneecaps on 06/12/2007 10:54 pm
Quote
Sorry, I don't remember. I stopped training astronauts in 1995.
Danny Deger
Thanks still! What you did remember was great :)
Always love to hear from the pros!
Post by: Wolverine on 06/13/2007 12:58 am
1. Can the shuttle do a skip glide re-entry?
2. Of the STS budget, how much $$$ is actually for orbiter vehicle prep/upkeep and how much is for the boosters and ET? I'm looking for a rough percentage.
Post by: hyper_snyper on 06/13/2007 01:56 am
In this photo: http://www.nasa.gov/images/content/179249main_iss015e11463.jpg
What are two holes on the port side of the nose forward of the cockpit windows? Before the RCS ..one is facing to the side and the other right at the camera.
Post by: j2_ on 06/13/2007 02:01 am
Quote
hyper_snyper - 12/6/2007 6:56 PM
Quick question:
In this photo: http://www.nasa.gov/images/content/179249main_iss015e11463.jpg
What are two holes on the port side of the nose forward of the cockpit windows? Before the RCS ..one is facing to the side and the other right at the camera.
Star tracker windows
Post by: Danny Dot on 06/13/2007 02:13 am
Quote
Wolverine - 12/6/2007 7:58 PM
I have 2 questions.
1. Can the shuttle do a skip glide re-entry?
snip
When I first started training astronauts in 1990, I was told if the shuttle skipped the second entry would be too seviour to survive. In about 1992, I tried one in the high fedility simulator and it worked OK. The second entry was very mild.
Danny Deger
Post by: kneecaps on 06/13/2007 09:46 pm
Thanks in advance!
Post by: Jorge on 06/13/2007 10:57 pm
Quote
kneecaps - 13/6/2007 4:46 PM
Just a quickie. What is an OI TFL...I know the OI bit..but whats a TFL?
Thanks in advance!
Telemetry Format Load. It defines what parameters get included in the downlist.
These are all defined in the Orbit Ops C/L Flight Supplement, which for STS-117 can be downloaded here:
http://www.nasa.gov/centers/johnson/pdf/174660main_orb_ops_117_f.pdf
(it is linked from this page:)
http://www.nasa.gov/centers/johnson/news/flightdatafiles/index.html
The format definitions are in the COMM/INST section, starting on p. 15 of the PDF.
The Flight Plan contains the callouts for changing the TFL. Nominally INCO commands this from the ground, but the crew can also do it.
The current TFL is 199, the prime docked format, which supports the Orbiter Interface Unit (OIU) and Sequential Still Video (SSV).
Post by: kneecaps on 06/13/2007 11:24 pm
Quote
Jorge - 13/6/2007 11:57 PMQuotekneecaps - 13/6/2007 4:46 PM
Just a quickie. What is an OI TFL...I know the OI bit..but whats a TFL?
Thanks in advance!
Telemetry Format Load. It defines what parameters get included in the downlist.
These are all defined in the Orbit Ops C/L Flight Supplement, which for STS-117 can be downloaded here:
http://www.nasa.gov/centers/johnson/pdf/174660main_orb_ops_117_f.pdf
(it is linked from this page:)
http://www.nasa.gov/centers/johnson/news/flightdatafiles/index.html
The format definitions are in the COMM/INST section, starting on p. 15 of the PDF.
The Flight Plan contains the callouts for changing the TFL. Nominally INCO commands this from the ground, but the crew can also do it.
The current TFL is 199, the prime docked format, which supports the Orbiter Interface Unit (OIU) and Sequential Still Video (SSV).
Again thanks for the information! I'm going to digest the info in the orbit ops C/L :)
Post by: ZeeNL on 06/13/2007 11:25 pm
Post by: Ankle-bone12 on 06/14/2007 12:26 am
I know its not about the shuttle directly but i couldn't find anywhere else to ask and I didn't want to start a thread.
Post by: DaveS on 06/14/2007 12:43 am
Quote
Ankle-bone12 - 14/6/2007 2:26 AMWith Centaur, it would have been a direct flight(IE, no slingshots) so around 2 years.
How long would it have taken for the Galileo space probe to reach Jupiter were it not for the saftey revisions restricting fuel for payloads after Callenger?
I know its not about the shuttle directly but i couldn't find anywhere else to ask and I didn't want to start a thread.
Post by: psloss on 06/14/2007 01:23 am
Quote
DaveS - 13/6/2007 8:43 PMFWIW, this JPL press release (http://www.jpl.nasa.gov/releases/80s/release_1987_1126.html) says 30 months.QuoteAnkle-bone12 - 14/6/2007 2:26 AMWith Centaur, it would have been a direct flight(IE, no slingshots) so around 2 years.
How long would it have taken for the Galileo space probe to reach Jupiter were it not for the saftey revisions restricting fuel for payloads after Callenger?
I know its not about the shuttle directly but i couldn't find anywhere else to ask and I didn't want to start a thread.
Post by: Do Shuttles Dream on 06/15/2007 04:42 pm
When Atlantis uses her thrusters to help the ISS attitude, then the force must be translated through the docking port? What sort of stresses does that put on that small area?
Post by: brahmanknight on 06/15/2007 04:48 pm
Post by: mjp25 on 06/16/2007 12:24 am
Post by: brahmanknight on 06/16/2007 12:38 am
Post by: ichilton on 06/16/2007 09:30 pm
I'm interested in how the ground communicates with the shuttle and the ISS. I've heard mention about Ku-band, S-band, Air to Ground 2 etc.
What are these, what are the difference between them and what is the full list of what's available?
Is communication available all the time?
How do they downlink photos & video's? What about the NASA TV coverage?
How much bandwidth is available and when?
Do they have internet & email access up there?
Any explanation, information or links to more info would be appreciated.
Thanks
Ian
Post by: Danny Dot on 06/17/2007 12:53 am
(I am not talking about the throttle back early for max-q. I am talking about the later one)
Danny Deger
Post by: yinzer on 06/17/2007 01:25 am
Post by: Danny Dot on 06/17/2007 02:06 am
Quote
Danny Dot - 16/6/2007 7:53 PM
Just before MECO, the main engines on the shuttle throttle back to maintain 3Gs. Why?
(I am not talking about the throttle back early for max-q. I am talking about the later one)
Danny Deger
The answer is a joke I used to tell the Navy Test Pilot class, "So Navy Fighter Pilots can fly the shuttle" :-)
Danny Deger
P.S. I flew F-4Es for the Air Force.
Post by: vt_hokie on 06/17/2007 03:14 am
Quote
Danny Dot - 16/6/2007 10:06 PM
P.S. I flew F-4Es for the Air Force.
I'm jealous! :) The F-4's always been one of my favorite aircraft!
Post by: MKremer on 06/17/2007 04:18 am
Quote
Do Shuttles Dream - 15/6/2007 11:42 AMNot a lot - the small vernier thrusters are used, and just a few short pulses are needed.
Sorry if this has been answered, but I didn't see it.
When Atlantis uses her thrusters to help the ISS attitude, then the force must be translated through the docking port? What sort of stresses does that put on that small area?
Attitude control movements can generally be described as very slow and ponderous - 20 minutes or more per 180 degree rotation.
Not much difference than the force the Russian side's docking ports experience when using that side's thrusters for attitude control.
(Plus, the docking ports on both sides are pretty beefy constructions in their own right - thick steel rings, heavy clamps and support structures.)
Post by: MKremer on 06/17/2007 04:19 am
Quote
brahmanknight - 15/6/2007 11:48 AMI still can't figure out what "notch" you see - got any pic links to better describe what you're asking about?
I noticed a "notch" in the back of the payload bay. Most of the bay is curved, except that part. Why is it there?
Post by: MKremer on 06/17/2007 04:34 am
Quote
ichilton - 16/6/2007 4:30 PMUm, not to sound insulting, but much of that info is already available through internet searches (Google, etc.) - lots of NASA and industry pages, pdf documents and reports that describe and detail the various comm channels, bandwidths, and what and how data is radiated back and forth.
Hi,
I'm interested in how the ground communicates with the shuttle and the ISS. I've heard mention about Ku-band, S-band, Air to Ground 2 etc.
What are these, what are the difference between them and what is the full list of what's available?
Is communication available all the time?
How do they downlink photos & video's? What about the NASA TV coverage?
How much bandwidth is available and when?
Do they have internet & email access up there?
Any explanation, information or links to more info would be appreciated.
Thanks
Ian
Searching this site will find some of the same and additional details, plus there are some of the official manuals available through L2 here that include further technical and operational descriptions.
There is no *one* overall document/manual/report that lists absolutely every detail available. You'll have to do the overall research and reading on your own, but I can guarantee that folks here will be glad to answer any *specific*, detailed operational or technical questions that haven't already been covered or answered previously.
Post by: brahmanknight on 06/18/2007 03:47 am
Post by: Jim on 06/18/2007 04:29 pm
Post by: spacemuppet on 06/18/2007 09:19 pm
What is the max the ISS will ever hold?
Post by: Jim on 06/18/2007 09:54 pm
Post by: Andrewwski on 06/18/2007 09:59 pm
Post by: Jim on 06/18/2007 10:02 pm
Post by: ichilton on 06/18/2007 10:56 pm
Quote
Um, not to sound insulting, but much of that info is already available through internet searches (Google, etc.) - lots of NASA and industry pages, pdf documents and reports that describe and detail the various comm channels, bandwidths, and what and how data is radiated back and forthI've done quite a bit of searching but have not been able to find much useful information.
Don't suppose you have any links as a starting point?
Thanks
Ian
Post by: Jorge on 06/18/2007 11:04 pm
Quote
ichilton - 18/6/2007 5:56 PMQuoteUm, not to sound insulting, but much of that info is already available through internet searches (Google, etc.) - lots of NASA and industry pages, pdf documents and reports that describe and detail the various comm channels, bandwidths, and what and how data is radiated back and forthI've done quite a bit of searching but have not been able to find much useful information.
Don't suppose you have any links as a starting point?
Thanks
Ian
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/comm/
http://www.vision-play.com/products/game1/ISS_Manual.pdf (pp. 89-117)
Post by: Ikelos on 06/19/2007 08:11 pm
Either way, why is there a max wind and not just a crosswind component limit. When the shuttle is coming in at 180+ knots, is there a negative effect between 25 knots of pure headwind vs 35 knots of pure headwind. Where did this 25 number come from. As a pilot, we want as much headwind as possible because it makes the touch down ground speed lower, and when you have a lakebed to land on, you can make it so there is a 0 knot crosswind component.
With bad weather forcasted in KSC and possible wind gusts up to 30 knots at EDW, is the difference in 5 knots of headwind worth making the shuttle land at White sands or over seas?
Post by: mkirk on 06/19/2007 11:35 pm
Quote
Ikelos - 19/6/2007 3:11 PM
Is this correct, that the shuttle has a limit for crosswind components for landing and also a max wind of 25 knots. Or is it a crosswind of 15 and headwind of 25 meaning the total wind would be a max of 40? Which is it?
Either way, why is there a max wind and not just a crosswind component limit. When the shuttle is coming in at 180+ knots, is there a negative effect between 25 knots of pure headwind vs 35 knots of pure headwind. Where did this 25 number come from. As a pilot, we want as much headwind as possible because it makes the touch down ground speed lower, and when you have a lakebed to land on, you can make it so there is a 0 knot crosswind component.
With bad weather forcasted in KSC and possible wind gusts up to 30 knots at EDW, is the difference in 5 knots of headwind worth making the shuttle land at White sands or over seas?
Crosswind: The crosswind flight rule limits are based primarily on factors such as main landing gear side loads, controllability and handling qualities, pilot workload, and HUD (heads up display) symbol availability – with large crab angles the HUD symbols can move off the combining glass.
For a nominal end of mission the crosswind limit is 15 knots for daytime and 12 for night. On launch day this limit can be increased to 17 knots (daytime only) based on realtime evaluation by the STA (shuttle training aircraft) pilot.
Headwind: The headwind component limitation factors in orbiter performance and predicted touchdown energy. To answer your question - yes there is a negative affect of 35 on the head verses 25. In simple terms this is about the orbiter's ability to make it to the runway - remember the orbiter is a high speed glider at this point and pushing up the power is not really an option.
The peak head component is 25 knots (day or night).
Mark Kirkman
Post by: hyper_snyper on 06/19/2007 11:49 pm
If the above is true and also true that the cross range capability was never needed, how much smaller could the wings be and by how much would the payload be increased?
I thought I read somewhere about this once and I'm curious about it. I could be mistaken.
Post by: Andrewwski on 06/20/2007 12:00 am
Post by: joncz on 06/20/2007 12:19 am
Post by: Ikelos on 06/20/2007 01:16 am
Yes but you can account for a 25 knot headwind just the same as a 35. Where do you draw the line and should it a definitive line? especially when the backup landing site is a lake bed that is over 10 miles long? It seems stupid to me that they would call off a landing at EDW for 26 knot winds.
Post by: Namechange User on 06/20/2007 02:13 am
Quote
hyper_snyper - 19/6/2007 6:49 PM
I have a question. Is it true or false that the Air Force imposed certain cross range requirements on the Shuttle during development? This resulted in larger than necessary wings.
If the above is true and also true that the cross range capability was never needed, how much smaller could the wings be and by how much would the payload be increased?
I thought I read somewhere about this once and I'm curious about it. I could be mistaken.
It's true. Also the size of the payload bay and up/down mass was heavily influenced by the USAF and the percieved requirements of the time based on the hopeful and assumed flight rate. If these requirements were not there it's anyone's guess what the shuttle would have looked like.
Post by: Jorge on 06/20/2007 06:07 am
Quote
hyper_snyper - 19/6/2007 6:49 PM
I have a question. Is it true or false that the Air Force imposed certain cross range requirements on the Shuttle during development? This resulted in larger than necessary wings.
If the above is true and also true that the cross range capability was never needed, how much smaller could the wings be and by how much would the payload be increased?
I thought I read somewhere about this once and I'm curious about it. I could be mistaken.
Partially. The USAF did impose the crossrange requirement, and it did drive NASA toward the delta-winged orbiter, but whether that's "larger than necessary" depends on how you define "necessary". The USAF wanted the high crossrange in order to perform single-orbit polar missions from Vandenberg. The crossrange enabled the orbiter to land back at Vandenberg even though the Earth would have rotated far enough to move Vandenberg a thousand miles east of the orbiter's groundtrack.
But that's not the only thing that crossrange is useful for. The crossrange can be used during ascent aborts, enabling an "Abort Once Around" mode and allowing NASA to need fewer TAL sites than would otherwise be required (with lower crossrange, you'd need one under every inclination the shuttle flies). The crossrange is also used nominally to increase landing opportunities - the standard is to provide two landing opportunities per day to each of the three CONUS primary landing sites. That simply wouldn't be possible with a low-crossrange orbiter. And it isn't true that the capability has never been used - take a look at the actual crossranges for the first 93 flights:
http://spaceflight.nasa.gov/shuttle/reference/green/entare.pdf
The crossranges are pretty much uniformly distributed within the orbiter's ~800 n.mi. crossrange limit.
For these reasons, Robert Thompson (shuttle program manager during the 70's) has said that NASA might well have ended up going with the high crossrange design anyway, even if the USAF wasn't a partner.
http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html
The leading alternative to the high crossrange design was Max Faget's straight wing design. It had a crossrange capability of about 300 n.mi. But it would not necessarily have had a larger payload than the high-crossrange orbiter, since it used internal fuel tanks. OV-106 is right; you really can't make too many assumptions about what the orbiter would have looked like if the high crossrange design hadn't won the day. Faget's design had some other shortcomings which Thompson discusses in his CAIB testimony.
Post by: gispa on 06/20/2007 07:46 am
Post by: rfoshaug on 06/20/2007 09:58 am
After undocking, the shuttle first went to a point about 600 feet in front of the station. Then it slowly (and beautifully) did a complete 360° "loop" around the station, keeping its distance at about 600 feet, and keeping the top of the shuttle constantly pointing toward the station. This allowed the crew of Atlantis to photograph the station from all angles and document how it looks, help search for any damages etc.
After the flyaround, when the shuttle was back in its position in front of the docking port, it continued for another 90° to the "top" of the station and then flew away from it.
Post by: rsp1202 on 06/20/2007 01:19 pm
Post by: iphitus on 06/20/2007 01:19 pm
Post by: psloss on 06/20/2007 01:33 pm
Quote
iphitus - 20/6/2007 9:19 AMIt cannot go around -- if they miss the SLF runway, you're talking about a really bad day.
What would happen if the shuttle happened to just miss a landing attempt, say arrive off the side of the SLF? Has it got enough energy to go-around? Or is the SLF long enough that it'd be able to correct itself?
This was noted earlier in the thread -- read through this exchange about coming up short of the runway on STS-37 and Danny Dot's Usenet post that he links to:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6156&start=331#M143930
Post by: pkspx on 06/20/2007 03:11 pm
Post by: mkirk on 06/20/2007 05:01 pm
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Ikelos - 19/6/2007 8:16 PM
Yes but you can account for a 25 knot headwind just the same as a 35. Where do you draw the line and should it a definitive line? especially when the backup landing site is a lake bed that is over 10 miles long? It seems stupid to me that they would call off a landing at EDW for 26 knot winds.
Well I am not really sure how to respond to this, however, I DO know what the heck I am talking about here.
I was trying to keep my initial response short and to the point, if you need a better explanation then give me and some of the others in the forum some time and we can formulate more detailed responses.
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It seems stupid to me that they would call off a landing at EDW for 26 knot winds.
Well generally that is exactly what would happen if the winds are out of limits – there would be a wave-off. What would be stupid is to ignore a well reasoned flight rule.
While the flight rules are not written in stone, working outside of the operational framework that they provide is not a decision that is made lightly.
The flight rules were developed to “outline preplanned decisions designed to minimize the amount of real-time rationalization required when non-nominal situations occur” during a mission. A lot of study and analysis went into the landing weather criteria, so when real world conditions are outside of what is considered to be the well understood limits of the orbiter the correct response is to step back.
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Where do you draw the line and should it a definitive line?
Well for the headwind the line is less than or equal to 25 knots.
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Yes but you can account for a 25 knot headwind just the same as a 35.
How? Not without changing the landing geometry (i.e. outer 20/18 degree and inner 1.5 degree glideslopes).
I will try and find some material that explains the rationale and assumptions used in flying the TAEM (terminal area energy management) approach in the shuttle.
Mark Kirkman
Post by: Ikelos on 06/20/2007 05:08 pm
I fully understand the need for limits and waving off if they are borken to reduce the decision making time, but I am interested in seeing what makes that limit exactly 25 knots and not 26 knots or 27 knots...
Post by: mkirk on 06/20/2007 05:15 pm
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Ikelos - 20/6/2007 12:08 PM
Thanks for the response.
I fully understand the need for limits and waving off if they are borken to reduce the decision making time, but I am interested in seeing what makes that limit exactly 25 knots and not 26 knots or 27 knots...
For the headwind it is all about managing energy.
I will see if I can dig out my notes on this and come up with a good overview. It may not be until after landing day due to my schedule.
Mark Kirkman
Post by: JWag on 06/20/2007 07:20 pm
I've read these three Q&A threads fairly carefully, and own two editions of Dennis Jenkins' Space Shuttle book.
However, I haven't seen anywhere that describes how the aft compartment access doors between the OMS pods and the wing upper surface got their name. From a thread elsewhere I learned (correctly?) that the left door is the "50-1" door, and the right side door is called "50-2". How'd they get their names?
I don't clearly remember anyone saying them aloud, and I pronounce "50-1" as "fifty-to-one" in my head. The word "dash" seems to have gone out of favor in aerospace circles. :)
Post by: Jim on 06/20/2007 08:44 pm
Post by: Namechange User on 06/20/2007 10:06 pm
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MondoMor - 20/6/2007 2:20 PMI've read these three Q&A threads fairly carefully, and own two editions of Dennis Jenkins' Space Shuttle book.
However, I haven't seen anywhere that describes how the aft compartment access doors between the OMS pods and the wing upper surface got their name. From a thread elsewhere I learned (correctly?) that the left door is the "50-1" door, and the right side door is called "50-2". How'd they get their names?
I don't clearly remember anyone saying them aloud, and I pronounce "50-1" as "fifty-to-one" in my head. The word "dash" seems to have gone out of favor in aerospace circles. :)
The orbiter is devided into zones so that things can be easily referenced. The aft compartment is zone 50. Hence, the way to get in the aft is via the two doors, 50-1 and 50-2.
Post by: Namechange User on 06/20/2007 10:10 pm
Post by: Ikelos on 06/20/2007 11:51 pm
Post by: brahmanknight on 06/20/2007 11:54 pm
And what about ISS? Would it have to be abandoned in the same scenario, or would Moscow take over?
Post by: DaveS on 06/21/2007 12:00 am
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brahmanknight - 21/6/2007 1:54 AMShuttle: Would be an early ticket home no matter what. The Firing Rooms in the Launch Control Center at KSC can handle a shuttle mission from the de-orbit point without any MCC assistance, but they cannot handle a full shuttle mission.
I have heard it mentioned that if a hurricane were to threaten Houston ( such as Hurricane Rita a few years ago ), that MCC would have to be evacuated. And if this were to occur, that a shuttle in orbit would have to come back to earth no matter what. Is this true? Is there really not back up plan in that respect?
And what about ISS? Would it have to be abandoned in the same scenario, or would Moscow take over?
ISS: Yes, Moscow is then in charge and the US solar arrays are feathered.
Go through the STS-115 prelaunch threads for more info when hurricane Ernesto looked like it was heading directly for the Houston-area.
Post by: Namechange User on 06/21/2007 12:16 am
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DaveS - 20/6/2007 7:00 PMQuotebrahmanknight - 21/6/2007 1:54 AMShuttle: Would be an early ticket home no matter what. The Firing Rooms in the Launch Control Center at KSC can handle a shuttle mission from the de-orbit point without any MCC assistance, but they cannot handle a full shuttle mission.
I have heard it mentioned that if a hurricane were to threaten Houston ( such as Hurricane Rita a few years ago ), that MCC would have to be evacuated. And if this were to occur, that a shuttle in orbit would have to come back to earth no matter what. Is this true? Is there really not back up plan in that respect?
And what about ISS? Would it have to be abandoned in the same scenario, or would Moscow take over?
ISS: Yes, Moscow is then in charge and the US solar arrays are feathered.
Go through the STS-115 prelaunch threads for more info when hurricane Ernesto looked like it was heading directly for the Houston-area.
Actually the firing rooms at KSC can handle it. It's the exact same data feed. In the event of a hurricane, we would not say come home now. Take this mission, what if the crew was right in the middle of installing the array? We wouldn't say stop and we'll come back and finish later.
Post by: gispa on 06/21/2007 08:20 am
Post by: Rocket Ronnie on 06/21/2007 08:24 am
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gispa - 21/6/2007 3:20 AM
I have a question about reentry procedure: in the normal operations the pilots in the space shuttle performes te reentry automaticly? and which is the point where they take the manual control of the spacecraft? thank you.
There's only one pilot, but the orbiter does all the flying herself. The pilot does some flying in the final minute or so and they drop the gear etc. but it's mainly the orbiter all the time.
Post by: rfoshaug on 06/21/2007 09:17 am
Post by: whitewatcher on 06/21/2007 09:32 am
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rfoshaug - 21/6/2007 11:17 AM
Why do all shuttle landings from ISS inclination always approach the Cape from the south? I mean, it's probably a desire to avoid flying over land as much as possible (especially after STS-107), but for Edwards it shouldn't make much of a difference if they came in from southwest or northwest? And it would give them twice as many landing opportunities every day.
I guess that the TACAN (similar to VOR/DME) guidance system is only installed on one end of the runway.
It's not easy to land with the shuttle delta wings because you have no flaps and your angle of attack is pretty high, so you can't see to much of the runway. So you rely on a radio landing aids.
Post by: psloss on 06/21/2007 09:49 am
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rfoshaug - 21/6/2007 5:17 AMBecause they pretty much re-enter on ascending node orbits -- discussed a little bit in the current mission's FD8/9 thread:
Why do all shuttle landings from ISS inclination always approach the Cape from the south? I mean, it's probably a desire to avoid flying over land as much as possible (especially after STS-107), but for Edwards it shouldn't make much of a difference if they came in from southwest or northwest? And it would give them twice as many landing opportunities every day.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=8406&posts=85&mid=151127&highlight=descending+node&highlightmode=2&action=search#M151127
(Earlier in the program, even some high-inclination missions re-entered on descending nodes.)
Post by: rfoshaug on 06/21/2007 10:47 am
whitewatcher,
It is true that they rely on landing aids, but this is installed on both ends of the runway (often they make the final decision on which runway to use during the reentry based on wind directions). Once the orbiter is directly above the runway, it doesn't really matter if you turn about 270° left or about 270° right to align with the runway of choice, no matter if the reentry sees the shuttle approaching from northwest or southwest.
Post by: psloss on 06/21/2007 11:07 am
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rfoshaug - 21/6/2007 6:47 AMAs an example, the STS-117 approaches for orbits 202 and 203 are from the south, but the final approaches shown in the ground tracks on NASA's website show touchdown from the north (Runway 15 end of SLF). Attached is orbit 202 / Runway 15 (which can be redesignated to 33, of course)...
Thanks. Especially that bit about noctilucent clouds and ice crystals was interesting.
whitewatcher,
It is true that they rely on landing aids, but this is installed on both ends of the runway (often they make the final decision on which runway to use during the reentry based on wind directions). Once the orbiter is directly above the runway, it doesn't really matter if you turn about 270° left or about 270° right to align with the runway of choice, no matter if the reentry sees the shuttle approaching from northwest or southwest.
Post by: mkirk on 06/21/2007 12:22 pm
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gispa - 21/6/2007 3:20 AM
I have a question about reentry procedure: in the normal operations the pilots in the space shuttle performes te reentry automaticly? and which is the point where they take the manual control of the spacecraft? thank you.
Typically the commander will take CSS (control stick steering - i.e. manual control) for Roll, Pitch, and Yaw after the orbiter goes subsonic at MACH .9 - this usually occurs at about 4 minutes to go before tocuhdown.
Mark Kirkman
Post by: rfoshaug on 06/21/2007 01:05 pm
Post by: mkirk on 06/21/2007 01:10 pm
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Gary - 21/6/2007 7:27 AMQuotemkirk - 21/6/2007 1:22 PM
Typically the commander will take CSS (control stick steering - i.e. manual control) for Roll, Pitch, and Yaw after the orbiter goes subsonic at MACH .9 - this usually occurs at about 4 minutes to go before tocuhdown.
Mark Kirkman
ohhh, I always wondered what CSS meant when it flashed up on the HUD!
Yeah I should also point out that in some mission phases you can take CSS in just a single axis if you want. For example you can take manual control of the pitch axis and allow auto guidance to fly roll and yaw.
Mark Kirkman
Post by: Danny Dot on 06/21/2007 03:17 pm
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whitewatcher - 21/6/2007 4:32 AMQuoterfoshaug - 21/6/2007 11:17 AM
Why do all shuttle landings from ISS inclination always approach the Cape from the south? I mean, it's probably a desire to avoid flying over land as much as possible (especially after STS-107), but for Edwards it shouldn't make much of a difference if they came in from southwest or northwest? And it would give them twice as many landing opportunities every day.
I guess that the TACAN (similar to VOR/DME) guidance system is only installed on one end of the runway.
It's not easy to land with the shuttle delta wings because you have no flaps and your angle of attack is pretty high, so you can't see to much of the runway. So you rely on a radio landing aids.
TACAN is wide area and not on any end of the runway. I think you are thinking about the Microwave Landing System, MLS. This is on the ends of the runway, but it is on both ends. The direction of approach has little to do with the direction of landing. The shuttle can, and does, approach from the north, but land to the north (from the south). Landing direction is based mainly on the surface winds.
Danny Deger
Post by: Kel on 06/21/2007 04:06 pm
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rfoshaug - 21/6/2007 8:05 AM
Also, the pilot usually (always?) flies part of the HAC to get some experience piloting the shuttle. The commander then takes control again for landing.
I wondered why they passed control of the shuttle back and forth between PLT and CDR - seems like introducing more opportunity for error (as opposed to having one person in control the whole time).
Post by: elmarko on 06/21/2007 04:09 pm
What model are those egg timers used on the flight deck? My friend wanted to know and I said I'd check.
Edit: FOUND IT! Thanks anyway :)
Post by: mkirk on 06/21/2007 04:13 pm
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Kel - 21/6/2007 11:06 AMQuoterfoshaug - 21/6/2007 8:05 AM
Also, the pilot usually (always?) flies part of the HAC to get some experience piloting the shuttle. The commander then takes control again for landing.
I wondered why they passed control of the shuttle back and forth between PLT and CDR - seems like introducing more opportunity for error (as opposed to having one person in control the whole time).
This has been covered somewhere in theses threads, but basically the idea is to give the PLT some stick time. Just a little bit of time to evaluate the handling qualities of the orbiter verses the shuttle mission simulator and the STA (shuttle training aircraft). Rember the PLT will eventually be flying the orbiter for the entire approach as a CDR so even a few seconds of stick time can be of value.
Mark Kirkman
Post by: Jorge on 06/21/2007 06:46 pm
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psloss - 21/6/2007 4:49 AMQuoterfoshaug - 21/6/2007 5:17 AMBecause they pretty much re-enter on ascending node orbits -- discussed a little bit in the current mission's FD8/9 thread:
Why do all shuttle landings from ISS inclination always approach the Cape from the south? I mean, it's probably a desire to avoid flying over land as much as possible (especially after STS-107), but for Edwards it shouldn't make much of a difference if they came in from southwest or northwest? And it would give them twice as many landing opportunities every day.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=8406&posts=85&mid=151127&highlight=descending+node&highlightmode=2&action=search#M151127
(Earlier in the program, even some high-inclination missions re-entered on descending nodes.)
Update to that - noctilucent clouds aren't the only reason (only applicable during summer). The descending opportunities are generally several hours different from the ascending ones and would typically require sleep-shifting the crew drastically, which is to be avoided.
Post by: jackyg on 06/21/2007 09:24 pm
Post by: DaveS on 06/21/2007 09:31 pm
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jackyg - 21/6/2007 11:24 PMThe earlier OA burn was to bring in the first Edwards AFB landing opportunity earlier so it overlaps the second KSC opportunity. This is to land earlier before the winds at Edwards are scheduled to pick-up and go out of limits.
Question about the change of altitude, do I understand it correctly that they are flying higher now? And why do they do that.
And please, do read the update thread as the info you're looking for is in there.
Post by: Chris Bergin on 06/21/2007 09:32 pm
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jackyg - 21/6/2007 10:24 PM
Question about the change of altitude, do I understand it correctly that they are flying higher now? And why do they do that.
That is correct. They've raised the orbit by a few miles and have increased velocity by 15 feet per second extra.
This is to gain earlier landing opportunities at Edwards Air Force base tomorrow.
See live STS-117 FD14 thread, as this info is there and explained.
Post by: jackyg on 06/21/2007 09:41 pm
Post by: Danny Dot on 06/22/2007 12:18 am
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jackyg - 21/6/2007 4:41 PM
I understand and did reed the threat of FD 14, I read all of the FD threats by the way, but my question is why do they have to fligh higher. So I know it's for an extra oppertunity to land on Edwards, but I don't know why they have to fligh higher.
Raising the orbit makes the time to go around the earth longer. This way Edwards is further east than it would have been, thus closer to the path of the orbiter.
Danny Deger
Post by: C5C6 on 06/22/2007 12:39 am
Post by: hyper_snyper on 06/22/2007 01:04 am
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C5C6 - 21/6/2007 8:39 PM
a friend asked me and didn't know what to answer: does the SRBs, RCSs and OMSs contaminate the air/atmosphere/water(SRB splashdown) in a significant way? and when the ET deintegrates in the atmosphere???
SSME exhaust is water vapor so that's environmentally friendly. SRBs exhaust isn't. RCS/OMS exhaust isn't either (i think) but that's outside the atmosphere.
Some info on SRB effects on the ozone layer:
http://nai.arc.nasa.gov/astrobio/astrobio_detail.cfm?ID=373
Even more:
http://www.globalsecurity.org/org/news/2005/050808-shuttle-green.htm
Post by: rfoshaug on 06/22/2007 08:03 am
Viewing the ground track for the first landing opportunity at Edwards for STS-117 today, it seems to come in a directly northernly heading towards Edwards.
Of course, being a lifting reentry, the Shuttle has quite a bit of crossrange capability. But my question is:
Can the shuttle do a reentry in, say, one long left turn, or does it have to do the roll reversals? For the orbiter itself and heat loads, it shouldn't be a problem (as far as I know it does not sideslip during those turns, so the airflow relative to the orbiter is the same during left and right turns)?
Post by: MKremer on 06/22/2007 08:30 am
Let's put it this way - even with close to 100 flights and re-entries, and even before Columbia, don't you think they would have already have done something like that to get an orbiter landed more quickly if it were desired and possible?
And, if not by then, why would they even consider something like that now with the extra emphasis on re-entry safety and other optional emergency landing sites available?
Isn't all this common sense?
Post by: jackyg on 06/22/2007 08:34 am
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Danny Dot - 22/6/2007 2:18 AMQuotejackyg - 21/6/2007 4:41 PM
I understand and did reed the threat of FD 14, I read all of the FD threats by the way, but my question is why do they have to fligh higher. So I know it's for an extra oppertunity to land on Edwards, but I don't know why they have to fligh higher.
Raising the orbit makes the time to go around the earth longer. This way Edwards is further east than it would have been, thus closer to the path of the orbiter.
Danny Deger
Thank you Danny , this is the answer i was looking for.
Post by: Jim on 06/22/2007 11:14 am
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rfoshaug - 22/6/2007 4:03 AM
Can the shuttle do a reentry in, say, one long left turn, or does it have to do the roll reversals? For the orbiter itself and heat loads, it shouldn't be a problem (as far as I know it does not sideslip during those turns, so the airflow relative to the orbiter is the same during left and right turns)?
The air flow is different whether it is a left or right turn
roll reversals are part of the energy management
Post by: mkirk on 06/22/2007 03:33 pm
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rfoshaug - 22/6/2007 3:03 AM
Sorry if this has been asked before.
Viewing the ground track for the first landing opportunity at Edwards for STS-117 today, it seems to come in a directly northernly heading towards Edwards.
Of course, being a lifting reentry, the Shuttle has quite a bit of crossrange capability. But my question is:
Can the shuttle do a reentry in, say, one long left turn, or does it have to do the roll reversals? For the orbiter itself and heat loads, it shouldn't be a problem (as far as I know it does not sideslip during those turns, so the airflow relative to the orbiter is the same during left and right turns)?
The shuttle does roll reversals in order to keep delta azimuth (DELAZ) small, not to bleed off energy as in s-turns.
So what do I mean by that?
First off the shuttle has a small alpha envelope of 3 degrees during entry which means that it can NOT use pitch to control descent rate and drag. Instead the orbiter has to use bank angle. By changing bank angle the descent rate can be increased (because the vertical component of lift is decreased) which means the orbiter falls faster into the denser atmosphere which in turn increases drag.
Since the orbiter is banked this means the nose will begin to track (steer) away from the intended landing site which means DELAZ will increase.
So what is DELAZ?
DELAZ or delta azimuth is the way cross range is displayed to the crew in the cockpit. It is the angle between the orbiters velocity vector (direction of flight) and the landing sight. DELAZ is displayed in the upper right corner of the Trajectory display and by the HSI bearing pointer.
In order to keep DELAZ from getting to big the orbiter reverses the direction of the bank angle – this is called a roll reversal. For example if the orbiter is banked left 45 degrees it will roll to the right until it gets to the new desired roll angle.
For entry the DELAZ is never allowed to become greater than 17.5 Since the nose never steers away from the landing site by very much this means there is no appreciable increase in range to the runway as there would be in an s-turn.
So to summarize the shuttle does roll reversals to keep the runway in front of the nose not to bleed off energy by increasing the range/distance to go to the runway.
Mark Kirkman
Post by: mkirk on 06/22/2007 03:44 pm
I just came across one of my training workbooks on this subject – which was coincidentally authored by one of the members of this forum “Dany Dot” – and I thought I would quote him verbatim here since his explanation is better than mine.
“In a conventional aircraft cross range (DELAZ) is controlled by turning until the landing site is on the nose then rolling wings level. Pitch is then used to control altitude.
You can’t do this at high Mach in the shuttle. You can’t use pitch to control altitude – remember the small (+/-3 degree) angle of attack envelope. You use bank to control altitude.
Since you always have a little bank (or maybe a lot of bank) to control altitude, the orbiter will always be turning. So, you let the nose of the orbiter fly past the site a little bit – then turn back toward the site. This is called a roll reversal. Cross range control is so easy!
The decision to do a roll reversal is based on DELAZ. Guidance always does the first roll reversal at 10.5 degrees. Guidance does subsequent reversals at 17.5 degrees until below Mach 4. From Mach 4 to 3 guidance ramps the value down from 17.5 to 10.
There is a common misconception that we use roll reversals to bleed off energy; i.e. S-turn. We use drag to bleed off energy. To bleed off energy by turning, we would need to delay turning until DELAZ became large; thus, the range flown would be increased. The small DELAZ that guidance uses does not increase the range flown any significant amount.”
“The concept of using turns to increase the range flown is called S-turns.”
These will be used by the shuttle below Mach 2.5 if the shuttle is high energy.
Mark Kirkman
Post by: mdmcgrory on 06/22/2007 04:12 pm
Post by: Danny Dot on 06/22/2007 04:27 pm
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rfoshaug - 22/6/2007 3:03 AM
Sorry if this has been asked before.
Viewing the ground track for the first landing opportunity at Edwards for STS-117 today, it seems to come in a directly northernly heading towards Edwards.
Of course, being a lifting reentry, the Shuttle has quite a bit of crossrange capability. But my question is:
Can the shuttle do a reentry in, say, one long left turn, or does it have to do the roll reversals? For the orbiter itself and heat loads, it shouldn't be a problem (as far as I know it does not sideslip during those turns, so the airflow relative to the orbiter is the same during left and right turns)?
The shuttle could do an entry without a roll reversal, but the flight rules do not allow for it. If the cross range is so high a roll reversal is not performed by Mach 6 (I think it is Mach 6), in the prelanding simulation, the profile is No Go. Not allowing a no reversal entry is a way to make sure there is margin in cross range control. It is equivalent to an airplane to have a reserve in the fuel needed to make an airfield.
Danny Deger
Post by: Danny Dot on 06/22/2007 04:37 pm
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mkirk - 22/6/2007 10:44 AM
Keeping DELAZ small...
I just came across one of my training workbooks on this subject – which was coincidentally authored by one of the members of this forum “Dany Dot” – and I thought I would quote him verbatim here since his explanation is better than mine.
snip
I think your way of saying it is just as good as mine. I am glad to see NASA has not reverted back to the phrase: "The shuttle does roll reversals to bleed off energy". Most shuttle pilots were at one time a fighter pilot. In fighter combat, turning was done to increase range flown and not over shoot a adversary going slower than you. Roll reversals in the shuttle were "assumed" to be the same, but they are not. Keep up the good work!!!
Danny Deger
Post by: Danny Dot on 06/22/2007 04:43 pm
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mdmcgrory - 22/6/2007 11:12 AM
Someone asked this on another thread and I think it's an intersting question. What's the maximum duration a space shuttle could achieve in orbit, docked to the ISS or not, with a Spacehab or not. I know that every Shuttle has been retrofitted to draw power from the Station (except Atlantis.) Which allows for about an 18 day flight. But what about the shuttles that had an extended duration orbiter pallet installed? I always heard that could keep them up for 30 days. And I also noticed on an old ISS construction manifest, that an EDO was supposed to be shipped to the ISS. Anybody know what that's about?
Are you talking normal operations or an emergency powerdown for something like waiting for a rescue mission to come up and save a crew in a crippled orbiter. I think I read that if the leading edge damage on Columbia had been found early, they could have stayed up for a month. The limiting factor was the CO2 removal canisters. Take this with a grain of salt, I am going from memory here.
Danny Deger
Post by: Danny Dot on 06/22/2007 04:45 pm
Danny Deger
Post by: mdmcgrory on 06/22/2007 04:53 pm
QUOTE] Are you talking normal operations or an emergency powerdown for something like waiting for a rescue mission to come up and save a crew in a crippled orbiter. I think I read that if the leading edge damage on Columbia had been found early, they could have stayed up for a month. The limiting factor was the CO2 removal canisters. Take this with a grain of salt, I am going from memory here. Danny Deger[/QUOTE]
I was thinking of a long duration science mission. The shuttle was supposed to be everythng to everybody, and I guess the EDO kit filled the limited time on orbit space station role. I know STS-50 flew with one. I don't know off-hand how long they stayed up.
Post by: mdmcgrory on 06/22/2007 04:55 pm
Post by: mdmcgrory on 06/22/2007 05:01 pm
Post by: mkirk on 06/22/2007 05:08 pm
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Danny Dot - 22/6/2007 11:45 AM
Does anyone know how short STS-37 landed? I thought it was 1,600 feet, but have been told on sci.space.shuttle it was 600 feet. The difference is enough to say if the landing had been at KSC the crew would have lived or not.
Danny Deger
I just looked it up in the SODB and the number in there is 623 feet.
The public link is here;
http://www.spaceflight.nasa.gov/shuttle/reference/green/
Select "landing deceleration" to get the touchdown distance from the threshold. There should be a big fat negative sign in front of that number...
In all my time at JSC I don't recall ever hearing about the landing short of the runway story. After reading your post on that I asked around and looked it up for myself.
Even if it was 623 feet instead of 1623 feet that is still unacceptable as hell and I can't believe that the program let themselves get cornered like that.
Also as you know we target 2500 feet down the runway as the touchdown point...that means the error was over 3100 feet...
Not cool!
Mark Kirkman
Post by: hawkeye9797 on 06/22/2007 05:17 pm
Post by: psloss on 06/22/2007 05:37 pm
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mdmcgrory - 22/6/2007 1:01 PMFYI, some more data:
Ok, Endeavour & Columbia had the EDO kits installed. I don't know if Endeavour's was yanked during it's OMP. But it looks like they were gunning for 16-day Spacelab missions. Not quite 30 days like I thought.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1892&posts=6#M25964
http://www.nasa.gov/mission_pages/shuttle/launch/extend_duration.html
Post by: mkirk on 06/22/2007 05:39 pm
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hawkeye9797 - 22/6/2007 12:17 PM
I was just wondering if one oms engine were to fail for some reason would one engine be enough for deorbit? Could it just be burned longer?
Yes they can "downmode" to a single engine burn and if both OMS engines were not available then they can downmode to RCS jets.
Mark Kirkman
Post by: dawei on 06/22/2007 07:01 pm
Post by: Jim on 06/22/2007 07:10 pm
Post by: Antares on 06/22/2007 07:25 pm
Post by: psloss on 06/22/2007 07:31 pm
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Danny Dot - 22/6/2007 12:37 PMPAO didn't get the memo in time for this entry...
I think your way of saying it is just as good as mine. I am glad to see NASA has not reverted back to the phrase: "The shuttle does roll reversals to bleed off energy". Most shuttle pilots were at one time a fighter pilot. In fighter combat, turning was done to increase range flown and not over shoot a adversary going slower than you. Roll reversals in the shuttle were "assumed" to be the same, but they are not. Keep up the good work!!!
Danny Deger
Post by: triddirt on 06/22/2007 07:33 pm
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mkirk - 22/6/2007 11:44 AMWell PAO for STS-117 just said that roll-reversal were used to slow down the shuttle... So we certainly can understand how the misconceptions come around... So It seems like the problem is S-turn does not equal Roll Reversal... To the layman they sound similar but aren't really.
Keeping DELAZ small...
I just came across one of my training workbooks on this subject – which was coincidentally authored by one of the members of this forum “Dany Dot” – and I thought I would quote him verbatim here since his explanation is better than mine.
“In a conventional aircraft cross range (DELAZ) is controlled by turning until the landing site is on the nose then rolling wings level. Pitch is then used to control altitude.
...There is a common misconception that we use roll reversals to bleed off energy; i.e. S-turn. We use drag to bleed off energy. To bleed off energy by turning, we would need to delay turning until DELAZ became large; thus, the range flown would be increased. The small DELAZ that guidance uses does not increase the range flown any significant amount.”
“The concept of using turns to increase the range flown is called S-turns.”
These will be used by the shuttle below Mach 2.5 if the shuttle is high energy.
Mark Kirkman
Post by: Danny Dot on 06/22/2007 08:16 pm
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psloss - 22/6/2007 2:31 PMQuoteDanny Dot - 22/6/2007 12:37 PMPAO didn't get the memo in time for this entry...
I think your way of saying it is just as good as mine. I am glad to see NASA has not reverted back to the phrase: "The shuttle does roll reversals to bleed off energy". Most shuttle pilots were at one time a fighter pilot. In fighter combat, turning was done to increase range flown and not over shoot a adversary going slower than you. Roll reversals in the shuttle were "assumed" to be the same, but they are not. Keep up the good work!!!
Danny Deger
When I was the Entry Training Flow Supervisor from 1993 to 1995, I didn't make any effort to "fix" the PAO. It was hard enough to fix the astronauts and the flight controllers :)
About the time I was changing the Entry class to remove the words, "The shuttle S-turns to bleed off energy", I saw Hoot Gibson on the Discovery channel saying, "The shuttle S-turns to bleed off energy".
Speaking of PAO, NASA PAO should spend more time explaining what we are seeing in the landing video on NASA TV. I don't work there any more, but maybe the entry PAO people should take the Entry Guidance class and the TAEM class. These two classes would really help PAO explain what is happening to the shuttle on the video. My guess is the PAO people would LOVE to take the class. Flying entry, TAEM, and landing is not that hard. Most people over flare the first couple of times, but make a landing on the second or third try. You really don't need high level flying skills to do it. More details from PAO during TAEM and landing would add a lot to NASA TV.
Danny Deger
Post by: dawei on 06/22/2007 08:18 pm
Post by: Danny Dot on 06/22/2007 08:19 pm
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mkirk - 22/6/2007 12:08 PMQuoteDanny Dot - 22/6/2007 11:45 AM
Does anyone know how short STS-37 landed? I thought it was 1,600 feet, but have been told on sci.space.shuttle it was 600 feet. The difference is enough to say if the landing had been at KSC the crew would have lived or not.
Danny Deger
I just looked it up in the SODB and the number in there is 623 feet.
The public link is here;
http://www.spaceflight.nasa.gov/shuttle/reference/green/
Select "landing deceleration" to get the touchdown distance from the threshold. There should be a big fat negative sign in front of that number...
In all my time at JSC I don't recall ever hearing about the landing short of the runway story. After reading your post on that I asked around and looked it up for myself.
Even if it was 623 feet instead of 1623 feet that is still unacceptable as hell and I can't believe that the program let themselves get cornered like that.
Also as you know we target 2500 feet down the runway as the touchdown point...that means the error was over 3100 feet...
Not cool!
Mark Kirkman
The error was more than 3100 feet. The touchdown at 630 feet short was at 165 knots. If he had touched down on air speed, he would have been even shorter than 630 feet.
Danny Deger
Post by: Danny Dot on 06/22/2007 08:24 pm
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triddirt - 22/6/2007 2:33 PMQuotemkirk - 22/6/2007 11:44 AMWell PAO for STS-117 just said that roll-reversal were used to slow down the shuttle... So we certainly can understand how the misconceptions come around... So It seems like the problem is S-turn does not equal Roll Reversal... To the layman they sound similar but aren't really.
Keeping DELAZ small...
I just came across one of my training workbooks on this subject – which was coincidentally authored by one of the members of this forum “Dany Dot” – and I thought I would quote him verbatim here since his explanation is better than mine.
“In a conventional aircraft cross range (DELAZ) is controlled by turning until the landing site is on the nose then rolling wings level. Pitch is then used to control altitude.
...There is a common misconception that we use roll reversals to bleed off energy; i.e. S-turn. We use drag to bleed off energy. To bleed off energy by turning, we would need to delay turning until DELAZ became large; thus, the range flown would be increased. The small DELAZ that guidance uses does not increase the range flown any significant amount.”
“The concept of using turns to increase the range flown is called S-turns.”
These will be used by the shuttle below Mach 2.5 if the shuttle is high energy.
Mark Kirkman
Well put. The shuttle does roll reversals, but does not (normally) do S-turns.
Danny Deger
Post by: Danny Dot on 06/22/2007 08:33 pm
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Antares - 22/6/2007 2:25 PM
I've heard it said that the STS-37 landing miss was due to the CDR "taking it wide around the HAC." Can anyone confirm?
It was a combination of "errors". Flying wide around the HAC was one of the many problems. See my write-up at the following link.
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1
I have since been told by reliable sources the landing was about 600 feet short and not 1,600 feet short. I recall the belief by "all" at the time that if we had been landing at KSC, we would have been short of the underrun. I would not put it past NASA to fudge the official number from 1,600 to 600 feet. For example the Shuttle Operations Data Base lists the touch down point as 623 feet instead of negative 623 feet. I have an excellent memory of such things and 1,600 is leathal (at KSC) and 600 is not. The word on the street at the time was STS-37 would have been loss of crew if we had been landing at KSC.
Danny Deger
Post by: dawei on 06/23/2007 03:01 pm
Post by: Jim on 06/23/2007 04:51 pm
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dawei - 23/6/2007 11:01 AM
When are the O2, N2, He, N2 and hydrazine tanks depressurized after the space shuttle lands? Do they need to be depressurized before the ground crew is allowed to be close to the shuttle in light of concerns about pressure vessel failure?
At the OPF
Post by: psloss on 06/24/2007 04:44 pm
Quote
me - 8/9/2006 7:43 AMThanks.QuoteChris Bergin - 8/9/2006 7:27 AM
"The ECOs are normally armed when the ET 5% sensors go dry during flight (typically around 8 minutes 0 seconds)" - thanks to the source who saw the question and passed on the answer *waves* :)
My thanks, too -- since that sensor also failed on the STS-121 tank, what's the condition to arm the sensors without the 5% sensor?
Edit: I'm assuming with the system biased to the LOX side, the 5% sensor on the LOX tank would be uncovered first and that sensor didn't fail on the STS-121 tank, but I'm curious if there's another indicator or whether it would be "computationally-based."
Post by: mkirk on 06/25/2007 02:18 am
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psloss - 24/6/2007 11:44 AM
OK, going back a-ways to a question (http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=4244&start=151#M65296) I had during the STS-115 launch campaign, which I'll repost here:Quoteme - 8/9/2006 7:43 AMThanks.QuoteChris Bergin - 8/9/2006 7:27 AM
"The ECOs are normally armed when the ET 5% sensors go dry during flight (typically around 8 minutes 0 seconds)" - thanks to the source who saw the question and passed on the answer *waves* :)
My thanks, too -- since that sensor also failed on the STS-121 tank, what's the condition to arm the sensors without the 5% sensor?
Edit: I'm assuming with the system biased to the LOX side, the 5% sensor on the LOX tank would be uncovered first and that sensor didn't fail on the STS-121 tank, but I'm curious if there's another indicator or whether it would be "computationally-based."
I hope I understand what you are asking.
The 5% sensors are not what arms the ECO sensors. They are armed when the vehicle reaches a specific flight mass or if two engines have been shutdown. This mass is currently set at about 2% total propellant remaining in the tank.
Propellant quantity, which is available to the crew on the Trajectory display as a percentage of total quantity, is a guidance derived calculation based on SSME flow rate. Since the sensors in the tank are all fixed level sensors this calculation is the best way to determine ET propellant quantity.
Mark Kirkman
Post by: texas_space on 06/25/2007 03:30 am
Post by: simonbp on 06/25/2007 05:13 am
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texas_space - 24/6/2007 8:30 PM
Does anyone know what the system for the astronaut flight badges is (if there is one)? I noticed some folks have a gold badge, silver badge, or a silver military-style badge (e.g. for rated aviators and pilots).
I believe the silver badge is an unflown astronaut, while gold denotes one that has...
Simon ;)
Post by: Jim on 06/25/2007 11:38 am
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simonbp - 25/6/2007 1:13 AMQuotetexas_space - 24/6/2007 8:30 PM
Does anyone know what the system for the astronaut flight badges is (if there is one)? I noticed some folks have a gold badge, silver badge, or a silver military-style badge (e.g. for rated aviators and pilots).
I believe the silver badge is an unflown astronaut, while gold denotes one that has...
Simon ;)
Depends on the branch of military the astronaut belongs to. Gold is Navy and NASA and silver is USAF
Post by: texas_space on 06/25/2007 02:35 pm
Post by: Antares on 06/25/2007 03:16 pm
Post by: Almurray1958 on 06/25/2007 03:37 pm
* N944NA
* N945NA
* N946NA
* N947NA
source wikipedia, copied from NASA sources
of course these are tail numbers, not necessarily call signs...
Post by: psloss on 06/25/2007 03:43 pm
Post by: fcmadrid on 06/25/2007 07:51 pm
I wonder how do they put space shuttle on boeing 747, when they drive him home to nasa?
Thanks
Post by: DaveS on 06/25/2007 07:58 pm
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fcmadrid - 25/6/2007 9:51 PMThey're already at NASA. More specifically at the Dryden Flight Research Center(DFRC) at Edwards AFB.
Hello!
I wonder how do they put space shuttle on boeing 747, when they drive him home to nasa?
Thanks
And for how they do it, see this QuickTime movie: http://www1.dfrc.nasa.gov/Gallery/Movie/STS/HTML/EM-0084-17.html
It shows the ferry flight processing Discovery underwent when she landed at DFRC in August 2005 following her RTF mission STS-114.
Post by: Andrewwski on 06/26/2007 03:24 am
Even something like this page may help you visualize the mate-demate device.
Also, shuttles are "her" and "she".
http://www.nasa.gov/centers/dryden/news/FactSheets/FS-014-DFRC.html
Post by: missinglink on 06/27/2007 06:45 pm
Speaking of which, is there a spinoff from the ISS and other space projects in the area of "handling of complexity"? What I mean is, are lessons learned from managing the mind-boggling complexity of these machines transferable to other projects down on earth, and are they published somewhere we can learn from them?
One more question about the ISS. Every pic I've seen of the insides shows an environment of astounding ugliness. Access panels, racks, cables, struts, HVAC lines... wasn't there any money in the budget for a quiet nook someplace with unbroken surfaces in soothing colors where people can go to chill? It's no problem for short-time visits, but for someone staying aboard for months on end, don't they go bonkers just from the visual clutter?
Post by: Andrewwski on 06/27/2007 07:42 pm
First, everything is carefully planned. Nothing's "cluttered" like it was on Mir. Everything has it's proper place.
Second, and only an astronaut could answer this, but it would seem to me that it would be more organized when you're actually in zero-g. You can use all of the surfaces, and don't have to worry about walking on them or anything. You can concentrate on any area in a comfortable position.
Post by: Thorny on 06/27/2007 07:53 pm
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missinglink - 27/6/2007 1:45 PM
One more question about the ISS. Every pic I've seen of the insides shows an environment of astounding ugliness. Access panels, racks, cables, struts, HVAC lines... wasn't there any money in the budget for a quiet nook someplace with unbroken surfaces in soothing colors where people can go to chill?
Nope, the Habitation Module was cancelled in 2001 due to ISS cost overruns.
Post by: whitewatcher on 06/27/2007 08:21 pm
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missinglink - 27/6/2007 8:45 PM
Speaking of which, is there a spinoff from the ISS and other space projects in the area of "handling of complexity"? What I mean is, are lessons learned from managing the mind-boggling complexity of these machines transferable to other projects down on earth, and are they published somewhere we can learn from them?
Yes. Aerospace Engineers can easily find a job in different areas of business. It's their ability to see ideas in a context and to detect connections between things and concepts.
Example: Thermodynamics and aerodynamics have many points of contact. It's hard to understand hypersonic aerodynamics without understanding basic thermodynamics. (Both are highly complex fieds of research!)
I know many former fellow students working in different industries now. They design cars, drilling machines, clothes, ....
W.L. Gore & Associates produces the famous Gore-Tex clothing. At the same time, many cables used in the ATV and european ISS modules are produced by this company. As far as I know, they started with making wires and then looked for different possible applications to sell their PTFE.
Post by: missinglink on 06/27/2007 08:46 pm
whitewatcher, that's good to hear. I was looking for spinoffs of a more abstract nature, in the field of operations research.
Such as, "Here is what we've learned in decades of working on one of the most complicated engineering projects ever, with the added difficulty of operating in an extremely unforgiving environment. After numerous setbacks and failures caused by our inadequate grasp of the cross-links and inter-relations between different parts of the system, we developed a set of rules that reduced the incidence of unforeseen consequences. This paper gives a high level overview of the ruleset and we believe that the insights gained by us are to some extent transferable across a broad range of industries in which large-scale projects are conducted. Specifically..."
Post by: Jim on 06/27/2007 09:11 pm
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missinglink - 27/6/2007 4:46 PM
Thank you all for replies.
whitewatcher, that's good to hear. I was looking for spinoffs of a more abstract nature, in the field of operations research.
ISS didn't develop any new processes, it used an existing one, system engineering which was developed by the USAF and JPL to manage large projects, ICBM's and their bases. ISS is not that more complicated
Post by: Danny Dot on 06/27/2007 09:47 pm
Quote
Andrewwski - 27/6/2007 2:42 PM
I think it seems a lot less cluttered if you're there.
First, everything is carefully planned. Nothing's "cluttered" like it was on Mir. Everything has it's proper place.
snip
.
While at NASA, I heard Mir stowage was complete chaos. Nobody knew where anything was. One story I heard is they didn't know what a piece of equipment was, so they tossed it -- only to find out later it was needed for a later experiment.
Post by: swhitt on 06/27/2007 09:57 pm
As a rocket, it combines 4 rocket technologies (SRB, SME, OMS, RCS) and 3 propellents (solid, O2/H2, Hydrazine) into 1 system.
As a spacecraft, it is a hauler, experiment platform, habitat, etc...
As an aircraft, it sinks like a rock and only has to control the last 20 minutes of flight. Yet, it has some very unique areodynamic aspects to it.
Aircraft Carriers are complicated, agreed, but only 1 propulsion system with 1 fuel. Mind you it is nuclear, but still only 1. Reading the Navy's manuals on the nuclear reactor shows that it is a fairly easy system to operate and maintain. A carrier runs in only 1 medium, water. Shuttle in 2 (air and vacuum). If you include all the aircraft, then you would have a point, but on a single system versus single system, then the shuttle beats it. (Only an opinion.)
As to the Shuttle vs ISS, the ISS is again designed for 1 environment, and was specifically designed to be less complicated than the shuttle. Read some of the ISS design docs, and you will see that their target was a much simplier system than the shuttle.
I am not trying to spout the party line, but the shuttle is a very complicated machine. It is a tribute to NASA and her contractors that she has flown so well.
Post by: swhitt on 06/27/2007 10:04 pm
ISS storage was originally planned as enough for the present ISS crew and 6 months.
Now they have storage for that AND 45 days supplies for a STS crew of 8 incase a crew has to abandon the vehicle.
All stored in places that were not designed to be that big.
As for a get away and chill place, by all the video tours of the station, most ISS crew go to the Russian air lock and chill. It seems to have windows to the outstanding view and is isolated.
Post by: Rufus on 06/28/2007 06:17 am
I was wondering how the SSMEs are able to be throttled through, what I consider to be, a wide range of power levels. It seems that if you modify P, mdot, or T by too much you would encounter problems since the nozzle geometry is fixed. Also does anyone know the rough dimensions of the MCC and fluid properties (i.e. P, T, mdot, V, etc...) in the MCC at the various power levels.
Thanks
Post by: whitewatcher on 06/28/2007 07:29 am
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missinglink - 27/6/2007 10:46 PM
whitewatcher, that's good to hear. I was looking for spinoffs of a more abstract nature, in the field of operations research.
Don't want to go offtopic, but maybe you find the Concurrent Design Process interesting:
http://www.esa.int/SPECIALS/CDF/
This is a way of designing systems (Spacecrafts, Probes, Satellites, Landers, ...) down to a very detailed level in a very short time with high accuracy. With this process, Astrium has been able to shrink Phase A and B from 8 months to 8 weeks or so.
Post by: Jim on 06/28/2007 10:56 am
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Rufus - 28/6/2007 2:17 AM
This might have already been addressed; I'm still reading through the posts and have not found an answer yet.
I was wondering how the SSMEs are able to be throttled through, what I consider to be, a wide range of power levels. It seems that if you modify P, mdot, or T by too much you would encounter problems since the nozzle geometry is fixed. Also does anyone know the rough dimensions of the MCC and fluid properties (i.e. P, T, mdot, V, etc...) in the MCC at the various power levels.
Thanks
It is in the SSME handbook on L2.
Post by: mkirk on 06/28/2007 03:28 pm
Quote
Rufus - 28/6/2007 1:17 AM
This might have already been addressed; I'm still reading through the posts and have not found an answer yet.
I was wondering how the SSMEs are able to be throttled through, what I consider to be, a wide range of power levels. It seems that if you modify P, mdot, or T by too much you would encounter problems since the nozzle geometry is fixed. Also does anyone know the rough dimensions of the MCC and fluid properties (i.e. P, T, mdot, V, etc...) in the MCC at the various power levels.
Thanks
Use this thread as a starting point...in message post #23463 I gave a high level discription of throttle control and a link to pdf (public domain) about the SSME.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1781&posts=29&mid=23463&highlight=OPOV+throttle&highlightmode=1&action=search#M23463
Like Jim said there is an SSME Handbook in L2 that also describes most of what you are looking for.
Mark Kirkman
Post by: Rufus on 06/28/2007 07:50 pm
Post by: Jim on 06/28/2007 07:55 pm
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Rufus - 28/6/2007 3:50 PM
T It really didn't go deep enough into the engineering and physics. Maybe if I could get the fluid parameters in the MCC at the various power levels and the dimension of the MCC,
Now you are talking ITAR stuff
Post by: mkirk on 06/29/2007 02:15 am
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Rufus - 28/6/2007 2:50 PM
Thanks for the link, but it really only restated what I have in the MPS 2102 Training Manual, the SCOM, and the Shuttle news reference. It really didn't go deep enough into the engineering and physics. Maybe if I could get the fluid parameters in the MCC at the various power levels and the dimension of the MCC, I could run the nozzle flow calculations and figure it out myself. I don’t have an L2 membership, does the SSME handbook in L2 go into more detail about the engineering, or is it just an overview like the MPS 2102 Training Manual?
Well I was trained to operate the engines, not build them – actually I was trained to train others to operate them (i.e. astronauts and flight controllers).
I might be able to find some rough numbers for chamber pressure and temperatures but for the most part what you are asking about is not much use in the cockpit which is where my alleged expertise is.
If you really need that kind of detail you would be better off talking to Rocketdyne or the folks at Stennis or Marshal. They will ask “what the hell do you need to know that for?”
If you are a aerospace professor or something along those lines who is teaching this stuff at a college or university they will likely be able to work with you. Other than that I don’t know what to tell you.
For now here is what I do have;
MCC Throat Diameter – 10.8 inches for the new Block II engines
65% power level:
Pc - 1785.55 psia
Total Flow Rate - 678.01 lbs/sec
ISP - 451.99
Thrust (vacuum) - 305,711lbs
100% power level:
Pc – 2747.00 psia
Total Flow Rate – 1039.85 lbs/sec
ISP - 451.99
Thrust (vacuum) – 469,804 lbs
104.5% power level:
Pc – 2870.61 psia
Total Flow Rate – 1086.14 lbs/sec
ISP - 451.99
Thrust (vacuum) – 490,884 lbs
Mark Kirkman
Post by: Rufus on 06/29/2007 07:10 am
I appreciate all of the help.
Post by: mcdavis941 on 06/30/2007 10:22 pm
Post by: brahmanknight on 06/30/2007 10:26 pm
Post by: Jim on 06/30/2007 11:30 pm
Quote
mcdavis941 - 30/6/2007 6:22 PM
What is the white sheeting that covers most things in the shuttle payload bay, and what are the black dots all over it?
MLI and the black dots are buttons to keep it from billowing.
Post by: mcdavis941 on 07/01/2007 12:48 am
Quote
Jim - 30/6/2007 6:30 PMQuotemcdavis941 - 30/6/2007 6:22 PM
What is the white sheeting that covers most things in the shuttle payload bay, and what are the black dots all over it?
MLI and the black dots are buttons to keep it from billowing.
Thanks Jim.
I didn't see MLI in the acronym list. Is that "Mylar Multilayer Insulation"?
Post by: Jim on 07/01/2007 12:51 am
Post by: blazotron on 07/01/2007 02:46 am
Quote
missinglink - 27/6/2007 11:45 AM
I have seen the Space Shuttle called the world's most complex machine. Surely this is incorrect? A nuclear submarine is bigger and has more moving parts, not to mention having a nuclear reactor inside... all the more so for an aircraft carrier? And what about the International Space Station?
This depends on how you define "most complex" of course. Simply by parts count, the shuttle is beaten by some modern airliners (mostly because of the enormous numbers of fasteners needed, though). By unique parts count, I'm not sure what takes the prize. By moving parts count, a nuclear aircraft carrier probably also beats the shuttle because it has lots of doors, valves, etc. But does having a lot of (mostly identical) doors really make a complex machine? In my opinion, the complexity of design of each part is also important in evaluating the complexity of the system.
[Sorry this turned out to be very long, but I am trying to give a flavor of the difficulties of design for space that may not be obvious to many people]
Every single part of the shuttle system is planned, calculated, modeled, tested, retested, prototyped, etc. in excruciating detail. Why is this necessary on the shuttle, and not, say, an aircraft carrier?
First, the shuttle has to lift itself into space, so everything has to be absolutely as light as possible, but still strong enough to complete its mission, even under worst case scenarios. Engineers use what is called a factor of safety in designing parts, which means that the part is designed to be a certain amount stronger (the factor of safety) than the maximum anticipated load in the worst case expected scenario in order to account for unknowns or flaws in construction. In the shuttle program (as in other space and some aviation systems) the minimum FOS is 1.4. So many shuttle parts will break at only 1.4 times the maximum loading they are expected to have to endure in order to make them as light as possible while maintaining a adequate safety margin. But because the margin is so small, you obviously have to have very high confidence that there aren't any unknowns left that are greater than your remaining margin, and your confidence that your parts are actually as strong as you think they are must also be very high.
So the flight environment must be studied very thoroughly to bound the unknowns, and parts must be thoroughly tested. Just as an example, it is standard practice for parts like screws to make them in carefully controlled batches. Afterwards, some percent of the batch is tested to make sure the chemical structure is correct, the strength is correct, etc. As another example, virtually all critical welds are X-rayed to make sure that they don't contain hidden flaws that would make the part weaker than its design implies. If you make the FOS higher, you increase the safety of the system (to a point) but you also make it heavier and less efficient, with the end result of being able to carry less payload to orbit. If you make it heavy enough, it won't get off the ground at all. This parallels the old saying: "Anyone can build a bridge that stands up, but it takes an engineer to build a bridge so economically that it just barely stands up."
Take, as a counterexample, a regular elevator (lift for those across the pond). You would think that the unknowns in elevator design are pretty well nailed down (there's no sudden turbulence in elevator shafts, for example), but as it turns out, the factor of safety used in elevator design is usually about 10. This is partly because elevators need to be safe no matter how stupid their operators are--people frequently push heavy carts into elevators or pack them with way more than the rated number of people, so this is covered by the factor of safety. On the other hand, the shuttle is always operated by highly trained ground crew and astronauts. But the other reason is because excess strength in elevator parts really doesn't hurt anything. The dry mass of the elevator is balanced by its counterweight, so there isn’t much of a performance penalty for hauling around a little extra metal. And, by being able to use standard parts with little design (for instance, using standard steel extruded I-beams for structural beams under the floor) you save a great deal in design costs and fabrication costs. In an elevator, all the floor beams are likely the same standard size (one that is sufficiently strong for all locations) whereas if you build a similar "space grade" elevator, each of the beams would likely be different. They would be just barely stronger than they needed to be and probably machined out individually from large blanks of hi-performance aluminum alloys. They would be designed in a way that they are strong enough at each location to give your 1.4 FOS for the loads at that particular location. Of course I am generalizing here, but hopefully you get the point.
As another example, take the aircraft carrier. If you want to put in a wall in an aircraft carrier, you simply have the shipbuilders weld in some quarter inch steel plate in the appropriate location. End of story. No need for computer models of the structural strength, no need for wind tunnel tests, no need to make some prototypes to test them to failure, etc. It's way stronger than it needs to be, but it doesn't matter, because the boat only has to float, which isn’t that difficult to do. There are certainly parts of a carrier that are as thoroughly studied as shuttle parts (especially in the reactors) but many aren't. The thing that makes the space shuttle so complex is that nearly ALL its parts are subject to this kind of design and scrutiny. Every single part matters in the end. In a carrier, if you want a chair for the pilot, you just add a (probably off the shelf) chair. In the space shuttle, it has to be carefully designed, tested, and built from scratch to prescribed standards.
The second thing that distinguishes the shuttle is the consequences of part failure. Because the operating conditions are so unforgiving (enormous energies expended on liftoff along with high forces, high temperatures and forces on reentry, not to mention the thermal issues and vacuum in space, etc.) failure of many parts or systems would be catastrophic. If one of the propeller drive motors on a carrier fails, it certainly isn't a good thing, especially during combat, but it isn't the end of the world either--it still floats. Either the mechanics on board can deal with it or they can airlift in parts or bring the carrier back to port for repairs. If a main engine on the shuttle fails, the consequences are much more serious. In some regimes of flight, the vehicle and crew will not survive, and in others, a risky abort is required. But even simple things can have large consequences. On a carrier, if the pilot's chair breaks, it might be annoying, but he can still stand there and get his job done, or even replace it with a folding chair from the mess hall. If the commander's chair breaks during shuttle reentry, there may be no way for him to fly the shuttle as needed. Thus, many of the parts and systems simply MUST work, and so they are multiply redundant or designed to fail-safe or fail-operational. It is instructive to take a look at a reference such as this one:
http://spaceflight.nasa.gov/shuttle/reference/shutref/verboseindex....
(or the much, much more thorough information on L2) and see how much redundancy is built into every system, and how much thought has gone into what all the possible failure modes are and how to make them redundant. There are then also systems necessary to manage all the redundancy. All this makes the shuttle more complicated.
Finally, how does the shuttle compare to the ISS? The ISS is certainly complicated, with many parts and interfaces, but in the end, it's more like airliner type complexity. The ISS is only ever exposed to the space environment--no need to design for reentry, and it doesn't have to get itself to space, which is done by the launch vehicle (mostly the shuttle), although there is much work done here to deal with the forces and vibrations of launch. As it turns out, the space environment is not TOO harsh, and pretty predictable if nothing else. Because ISS parts aren't taken up and down over and over (like parts on the shuttle), they don't need to be as weight efficient, so the design can be somewhat simpler, in some cases (obviously there are limits). It doesn't need different types of cooling systems for different stages of flight like the shuttle, it gets by with solar panels for energy so it doesn’t need cryogenic storage and energy generation, it doesn't need control surfaces for flying so it doesn’t need hydraulic systems, and on and on. And, since it doesn’t have all these systems, it doesn’t need redundancies and redundancy management for them.
Most people would admit that all this complexity is what makes the shuttle both an amazing machine, and in the end, too expansive to do what it was meant to do. However, I think it does have a pretty fair shot at being the "most complex machine."
Post by: Namechange User on 07/01/2007 02:54 am
Quote
brahmanknight - 30/6/2007 5:26 PM
How much electricity does the orbiter produce? In terms of kWs?
It depends on the need of the vehicle but each fuel cell is capable of producing up to 16KW if necessary.
Post by: treynolds37 on 07/01/2007 03:03 am
Tim
Post by: Orbiter Obvious on 07/01/2007 03:23 am
Quote
treynolds37 - 30/6/2007 10:03 PM
Hey guys and gals, I was part of the Flat Gorby story. We (friends and family) did it because we know Suni and Gorby and it was just a good story not a NASA thing. You guy's are good on your flight analysis, good job!
Tim
Not sure what this is doing on Shuttle Q&A, but are you saying you're a friend of Suni Williams? http://www.nasaspaceflight.com/content/?cid=5140
Post by: Andy L on 07/01/2007 03:29 am
Quote
treynolds37 - 30/6/2007 10:03 PM
You guy's are good on your flight analysis, good job!
Tim
Welcome, this is site packed with NASA, USA and so on engineers and managers and the followers of shuttle and space flight. No gimicks required :)
Post by: mkirk on 07/01/2007 03:53 pm
Quote
OV-106 - 30/6/2007 9:54 PMQuotebrahmanknight - 30/6/2007 5:26 PM
How much electricity does the orbiter produce? In terms of kWs?
It depends on the need of the vehicle but each fuel cell is capable of producing up to 16KW if necessary.
For planning purposes power is generally assumed to be 18 kw (total orbiter power) per mission day. A mission extension day is assumed to be about 15 kw.
Actual mission power useage is much lower especially with docked operations, and priority power downs.
The Group B power down aims for about 12-13 kw and the Group C aims for around 11 kw. There are other contingency power downs which take the loads much lower.
Here is a basic rundown from the SCOM (shuttle crew operations manual) about Fuel Cell output:
“The nominal voltage and current range of each fuel cell is 2 kW at 32.5 volts dc, 61.5 amps to 12kW at 27.5 volts dc, 436 amps. Each is capable of supplying up to 10 kW maximum continuous power in nominal situations, 12 kW continuously in off-nominal situations (with one
or more fuel cells failed), and up to 16 kW for 10 minutes. The average on-orbit power consumption of the orbiter is approximately 14 kW, leaving additional capability available for
payloads. Each fuel cell is serviced between flights and reused until it has accumulated 2,000
hours of on-line service.”
Mark Kirkman
Post by: Danny Dot on 07/01/2007 05:14 pm
Quote
mkirk - 1/7/2007 10:53 AM
snip
For planning purposes power is generally assumed to be 18 kw/hr (total orbiter power) per mission day. A mission extension day is assumed to be about 15 kw/hr.
snip
Did you mean kw-hr?
Danny Deger
Post by: mkirk on 07/01/2007 05:20 pm
Quote
Danny Dot - 1/7/2007 12:14 PMQuotemkirk - 1/7/2007 10:53 AM
snip
For planning purposes power is generally assumed to be 18 kw/hr (total orbiter power) per mission day. A mission extension day is assumed to be about 15 kw/hr.
snip
Did you mean kw-hr?
Danny Deger
Hell, I don't know...did I?
I don't speak Electrical... ;)
I changed the previous posts to kw.
Mark Kirkman
Post by: RedSky on 07/01/2007 06:59 pm
1) Its much wider than a 747 fuselage, so I assume either some very large cargo aircraft has to transport it back from KSC to the west coast.... or else it is separable into pieces. Anyone know if it breaks down into smaller sections?
2) Is the "cost" of its transport back west included in what is always quoted in the extra cost of the shuttle landing in the west instead of KSC ($1.5 million).
3) How many of these exist? Is there one at White Sands in case a shuttle landed there, or is the one at Edwards flown there before flying back to KSC.
Post by: blazotron on 07/01/2007 07:09 pm
Quote
mkirk - 1/7/2007 10:20 AMQuoteDanny Dot - 1/7/2007 12:14 PMQuotemkirk - 1/7/2007 10:53 AM
snip
For planning purposes power is generally assumed to be 18 kw/hr (total orbiter power) per mission day. A mission extension day is assumed to be about 15 kw/hr.
snip
Did you mean kw-hr?
Danny Deger
Hell, I don't know...did I?
I don't speak Electrical... ;)
I changed the previous posts to kw.
It's got to be kW, which is electrical power, rather than kWh (kw-hr). At the quoted nominal 14 kW average production, the orbiter produces 14 kW * 24 hours/day = 336 kWh per day = 336 kWh per day * 3600 sec/hr = 1.21 GJ per day. For comparison, the average US house uses about 1 kW (averaged over the day), which is 24 kWh per day. Thus, the shuttle uses about 15 times the electricity used by an average house. The unit kW/hr doesn't make sense in this context (it would be the rate of change of electrical load).
Post by: DaveS on 07/01/2007 07:10 pm
2)Probably.
3)Two. One for each SCA.
Post by: mkirk on 07/01/2007 10:35 pm
Quote
blazotron - 1/7/2007 2:09 PMQuotemkirk - 1/7/2007 10:20 AMQuoteDanny Dot - 1/7/2007 12:14 PMQuotemkirk - 1/7/2007 10:53 AM
snip
For planning purposes power is generally assumed to be 18 kw/hr (total orbiter power) per mission day. A mission extension day is assumed to be about 15 kw/hr.
snip
Did you mean kw-hr?
Danny Deger
Hell, I don't know...did I?
I don't speak Electrical... ;)
I changed the previous posts to kw.
It's got to be kW, which is electrical power, rather than kWh (kw-hr). At the quoted nominal 14 kW average production, the orbiter produces 14 kW * 24 hours/day = 336 kWh per day = 336 kWh per day * 3600 sec/hr = 1.21 GJ per day. For comparison, the average US house uses about 1 kW (averaged over the day), which is 24 kWh per day. Thus, the shuttle uses about 15 times the electricity used by an average house. The unit kW/hr doesn't make sense in this context (it would be the rate of change of electrical load).
Yeah I know, I was just kidding around and reflecting my lack of electrical expertise (not related to shuttles and airplane) by not catching the mistake prior to someone pointing it out.
Also I really don't speak electrical or EE...even though many of my friends are EE (electrical engineers) I try not to hold it against them... ;)
Mark Kirkman
p.s.
I should also point out that the shuttle's electrical system was the first system I was certified as an instructor in when I worked in the Shuttle Training Division.
Post by: brahmanknight on 07/02/2007 12:41 am
Post by: DaveS on 07/02/2007 12:43 am
Quote
brahmanknight - 2/7/2007 2:41 AMThere's a dedicated S-Band antenna located on the ET that downlinks the ET cam video.
How does the oribiter transmit TV signals during liftoff since it doesn't have it's KU antenna deployed?
Post by: MKremer on 07/02/2007 01:12 am
Quote
brahmanknight - 1/7/2007 7:41 PMThis might help (info about the RocketCam hardware):
How does the oribiter transmit TV signals during liftoff since it doesn't have it's KU antenna deployed?
http://www.eclipticenterprises.com/products_overview.php
Post by: parham55 on 07/02/2007 02:21 am
Post by: blazotron on 07/02/2007 08:17 am
Quote
mkirk - 1/7/2007 3:35 PM
Yeah I know, I was just kidding around and reflecting my lack of electrical expertise (not related to shuttles and airplane) by not catching the mistake prior to someone pointing it out.
Oops--wish I had picked up on the joke, although I thought it did seem a little out of character for you to be having trouble with those units...
Post by: Jim on 07/02/2007 11:24 am
Quote
parham55 - 1/7/2007 10:21 PM
Any photos of the salad bowls we've been hearing about? I checked out some of the hi-res images of the orbiters hanging in the VAB prior to ET mating. Are any closer photos available? Also, what are some of the details on how the SCA/ET attachment points connect to the salad bowls? Is there some type of bolt that holds the two sections together? Thanks.
Post by: missinglink on 07/02/2007 07:33 pm
This forum is truly a remarkable place, I don't know of any other place on the Net where so many knowledgeable people go out of their way to be so forthcoming with useful information and where amateurs like me can ask questions without fear of being ridiculed.
Post by: ShuttleDiscovery on 07/02/2007 07:50 pm
Quote
Danny Dot - 22/6/2007 9:33 PMQuoteAntares - 22/6/2007 2:25 PM
I've heard it said that the STS-37 landing miss was due to the CDR "taking it wide around the HAC." Can anyone confirm?
It was a combination of "errors". Flying wide around the HAC was one of the many problems. See my write-up at the following link.
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1
I have since been told by reliable sources the landing was about 600 feet short and not 1,600 feet short. I recall the belief by "all" at the time that if we had been landing at KSC, we would have been short of the underrun. I would not put it past NASA to fudge the official number from 1,600 to 600 feet. For example the Shuttle Operations Data Base lists the touch down point as 623 feet instead of negative 623 feet. I have an excellent memory of such things and 1,600 is leathal (at KSC) and 600 is not. The word on the street at the time was STS-37 would have been loss of crew if we had been landing at KSC.
Danny Deger
Are there any videos of this landing? I can't find any on YouTube...
Post by: parham55 on 07/03/2007 02:27 am
Thank you.
Rob
Post by: Danny Dot on 07/06/2007 12:37 am
Quote
ShuttleDiscovery - 2/7/2007 2:50 PMQuoteDanny Dot - 22/6/2007 9:33 PMQuoteAntares - 22/6/2007 2:25 PM
I've heard it said that the STS-37 landing miss was due to the CDR "taking it wide around the HAC." Can anyone confirm?
It was a combination of "errors". Flying wide around the HAC was one of the many problems. See my write-up at the following link.
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1
I have since been told by reliable sources the landing was about 600 feet short and not 1,600 feet short. I recall the belief by "all" at the time that if we had been landing at KSC, we would have been short of the underrun. I would not put it past NASA to fudge the official number from 1,600 to 600 feet. For example the Shuttle Operations Data Base lists the touch down point as 623 feet instead of negative 623 feet. I have an excellent memory of such things and 1,600 is leathal (at KSC) and 600 is not. The word on the street at the time was STS-37 would have been loss of crew if we had been landing at KSC.
Danny Deger
Are there any videos of this landing? I can't find any on YouTube...
No video made. There was a last minute change to a lakebed runway that is rarely used. No MLS and no cameras.
Danny Deger
http://www.dannydeger.net
Post by: psloss on 07/06/2007 01:20 am
Quote
Danny Dot - 5/7/2007 8:37 PMI coulda swore that I watched that on CNN live, but I don't have the tape in front of me to verify. Next time I'm home I'll look for it. IIRC, no mention of it was made by the press at the time.
No video made. There was a last minute change to a lakebed runway that is rarely used. No MLS and no cameras.
Post by: ChrisGebhardt on 07/06/2007 02:02 am
Post by: jarthur on 07/06/2007 03:11 pm
I am curious why the shuttle brought up the docking module to MIR for Shuttle-Mir dockings? I don't think it served as an adapter between US and Russian docking systems because the shuttle was able to dock directly to Kristal on the first docking mission (STS-71 I think), nor was it a clearance issue for the same reason. So what purpose did the module serve?
And since the Russians already had a docking system that was compatible with the shuttle, why not switch all their docking ports to to this system? Sure they would have to switch over their Progress and Soyuz spacecraft, but it would add a lot of flexibility to the ISS. Then their wouldn't be "sides" so to speak. US vehicles could dock on the Russian side and vice versa assuming proper clearances and what not. For instance the little used PMA-3 could be used to dock an extra Progress or something.
Thanks!
Post by: psloss on 07/06/2007 03:17 pm
Quote
jarthur - 6/7/2007 11:11 AMWell, here's a starter from the STS-74 press kit (http://www.jsc.nasa.gov/history/shuttle_pk/pk/Flight_073_STS-074_Press_Kit.pdf):
I am curious why the shuttle brought up the docking module to MIR for Shuttle-Mir dockings? I don't think it served as an adapter between US and Russian docking systems because the shuttle was able to dock directly to Kristal on the first docking mission (STS-71 I think), nor was it a clearance issue for the same reason. So what purpose did the module serve?
Quote
The Russian-built Docking Module (DM), to be carried aloft by Atlantis and left attached to the Kristall module of the Mir Space Station, is designed to allow Shuttle-Mir dockings with the Kristall module located at the Mir radial port.
Without the DM, Kristall would have to be moved to the longitudinal axis of Mir to provide clearance for each Shuttle docking. The longitudinal axis location is undesirable for Kristall because the longitudinal port is normally a location for Progress resupply modules and Soyuz spacecraft. In addition, it is not desirable to continually move the Kristall from port to port in preparation for a Shuttle docking.
The 15.4-foot long DM will allow clearance for the Shuttle to dock with Kristall located at the radial axis of Mir. The module will not be moved from that location once STS-74 is complete. All further Shuttle dockings will take place using the DM. It may also be used for future Soyuz dockings.
Post by: Jim on 07/06/2007 03:28 pm
Quote
jarthur - 6/7/2007 11:11 AM
And since the Russians already had a docking system that was compatible with the shuttle, why not switch all their docking ports to to this system? Sure they would have to switch over their Progress and Soyuz spacecraft, but it would add a lot of flexibility to the ISS. Then their wouldn't be "sides" so to speak. US vehicles could dock on the Russian side and vice versa assuming proper clearances and what not. For instance the little used PMA-3 could be used to dock an extra Progress or something.
The only US vehicle to use the APAS is the shuttle. HTV and COTS will use the CBM's. The shuttle can't use the other ports anyways due to clearance issues. Progress, Soyuz and ATV use the Russia probe and drogue. Switching the Progress, Soyuz and ATV is not the issue, it is the ISS which would be harder to adapt. PMA-3 couldn't be used for progress since it doesn't have a KURS system associated with it. CEV will place a LIDS adapter on the APAS to convert them
Post by: jarthur on 07/06/2007 03:42 pm
Quote
The Russian-built Docking Module (DM), to be carried aloft by Atlantis and left attached to the Kristall module of the Mir Space Station, is designed to allow Shuttle-Mir dockings with the Kristall module located at the Mir radial port.
Without the DM, Kristall would have to be moved to the longitudinal axis of Mir to provide clearance for each Shuttle docking. The longitudinal axis location is undesirable for Kristall because the longitudinal port is normally a location for Progress resupply modules and Soyuz spacecraft. In addition, it is not desirable to continually move the Kristall from port to port in preparation for a Shuttle docking.
The 15.4-foot long DM will allow clearance for the Shuttle to dock with Kristall located at the radial axis of Mir. The module will not be moved from that location once STS-74 is complete. All further Shuttle dockings will take place using the DM. It may also be used for future Soyuz dockings.
So was some form of the DM always planned, as I assume the different docking ports on Kristal were originally intended for dockings with Buran?
Post by: brahmanknight on 07/06/2007 04:23 pm
Post by: Jim on 07/06/2007 04:49 pm
Quote
brahmanknight - 6/7/2007 12:23 PM
I believe the DM was meant to be used for Buran.
No, there was an existing port for Buran. DM was just for the shuttle
Post by: jarthur on 07/06/2007 05:11 pm
Quote
Jim - 6/7/2007 10:49 AMQuotebrahmanknight - 6/7/2007 12:23 PM
I believe the DM was meant to be used for Buran.
No, there was an existing port for Buran. DM was just for the shuttle
Which port was intended for Buran, and why could it not be used for Shuttle?
Post by: parham55 on 07/06/2007 05:43 pm
Post by: Jim on 07/06/2007 06:49 pm
Quote
jarthur - 6/7/2007 1:11 PMQuoteJim - 6/7/2007 10:49 AMQuotebrahmanknight - 6/7/2007 12:23 PM
I believe the DM was meant to be used for Buran.
No, there was an existing port for Buran. DM was just for the shuttle
Which port was intended for Buran, and why could it not be used for Shuttle?
Kristall. as stated there were clearance problems
Post by: jarthur on 07/06/2007 07:14 pm
Quote
Jim - 6/7/2007 12:49 PM
Kristall. as stated there were clearance problems
So there are clearance problems for the Shuttle, but not Buran?
Post by: Jorge on 07/06/2007 08:15 pm
Quote
jarthur - 6/7/2007 2:14 PMQuoteJim - 6/7/2007 12:49 PM
Kristall. as stated there were clearance problems
So there are clearance problems for the Shuttle, but not Buran?
Mir would have been in a different config for the planned Buran/Mir dockings, with no clearance concerns.
If Buran/Mir had gotten further in planning, the Russians would eventually have had to solve the same problem as with Shuttle/Mir. The "permanent" Mir config would have had the same clearance problem for Buran.
Post by: Jackson on 07/06/2007 11:25 pm
Quote
pad rat - 5/7/2007 3:25 PM
It's the green bowl-shaped area. Close enough for ya?
That's a great picture. Sure would get a lot of salad in that bowl! :laugh:
Post by: blazotron on 07/07/2007 12:53 am
Quote
missinglink - 2/7/2007 12:33 PM
blazotron, sorry for not replying sooner to your outstanding post about the complexity of the Shuttle. Thank you, that gives me a good idea of the level of planning involved.
This forum is truly a remarkable place, I don't know of any other place on the Net where so many knowledgeable people go out of their way to be so forthcoming with useful information and where amateurs like me can ask questions without fear of being ridiculed.
I'm glad it was helpful. I appreciate the interest of you and others in these topics (which I of course find interesting and important myself), and am happy to help when I can.
Post by: spacemuppet on 07/08/2007 01:41 am
Post by: DaveS on 07/08/2007 01:47 am
Quote
spacemuppet - 8/7/2007 3:41 AMThe reason is that it would get entangled and snagged by the SSME nozzles and create one big mess to clear out in the OPF or in MDD.
What is the purpose of jettosining the landing drogue chute during rollout? I see no purpose for this other than looking cool and giving the pilot something else to do. Is there a good reason?
Post by: ZANL188 on 07/08/2007 01:50 am
Post by: APG85 on 07/08/2007 11:59 pm
Post by: DaveS on 07/09/2007 12:10 am
Quote
APG85 - 9/7/2007 1:59 AM1: 2
How many aerodynamic tailcones does NASA have for transporting the shuttles on the 747's and are any of them the original one used for the Enterprise drop tests? Thanks...
2: Yes. They had to manufacture a new tail cone for Endeavour as the old one didn't fit here as she had a modified vertical stabilizer for the drag chute.
As she was the first one equipped with the new drag chute, the rest of the fleet still had the old vertical stabilizer and needed to use the old tail cone.
Once the rest of the fleet had been equipped with the modified vertical stabilizers, the old tail cone was modified to support the modified vertical stabilizers.
Post by: spacemuppet on 07/09/2007 01:54 am
Post by: Thorny on 07/09/2007 02:12 am
16 days between STS-71 Atlantis and STS-70 Discovery in June-July 1995.
17 days between 51D Discovery and 51B Challenger in April 1985.
17 days between STS-38 Atlantis and STS-35 Columbia in November 1990.
18 days between STS-56 Discovery and STS-55 Columbia in April 1993.
Post by: spacemuppet on 07/09/2007 02:47 am
Post by: rdale on 07/09/2007 02:56 am
Post by: missinglink on 07/09/2007 03:57 pm
Could a near-lightspeed spacecraft of the future be "cushioned" against encounters with microparticles in deep space by a kilometer or two of C60?
Post by: Jim on 07/09/2007 04:04 pm
Post by: Jorge on 07/09/2007 04:50 pm
Quote
missinglink - 9/7/2007 10:57 AM
Are those micrometeorite shields on the ISS made of aluminum? Whatever happened to Carbon 60 a.k.a. "buckminsterfullerene". Wasn't that material supposed to offer awesome compressibility, its hardness under pressure increasing to twice that of diamond? And why aren't the surfaces of the Shuttle covered with C60?
C60 is not yet a practical engineering material. There were never any plans to use it on the shuttle or ISS.
Post by: nathan.moeller on 07/09/2007 05:02 pm
Quote
spacemuppet - 8/7/2007 8:54 PM
What was the shortest time gap between shuttle launches ever? I assume it happened sometime before 1986?
Something I find even more interesting (and frightening with today's processing timelines) is the turnaround time for Atlantis between her first and second missions. I believe she was only on the ground for 47 days between the landing of STS-51J and the launch of STS-61B (both in 1985).
But there are at least two instances of shuttle's flying ten days apart (landing-launch). STS-61C Columbia landed on January 18, 1986 and was followed by STS-51L Challenger on January 28. The same thing happened between STS-64 Discovery and STS-68 Endeavour in 1994.
Post by: C5C6 on 07/09/2007 05:33 pm
Post by: bobthemonkey on 07/09/2007 05:51 pm
Permenant presence was intended for the station, not the shuttle.
Post by: psloss on 07/09/2007 06:07 pm
Quote
nathan.moeller - 9/7/2007 1:02 PMI believe that's been discussed here before...in all the cited cases, delays were a contributing factor...looking at Thorny's list:
But there are at least two instances of shuttle's flying ten days apart (landing-launch). STS-61C Columbia landed on January 18, 1986 and was followed by STS-51L Challenger on January 28. The same thing happened between STS-64 Discovery and STS-68 Endeavour in 1994.
Quote
Thorny - 8/7/2007 10:12 PM61-C was delayed several times mostly in January, but also in December 1985. The STS-70 ET was used as a woodpecker nest, requiring rollback for repairs. Challenger was remanifested to 51-B from 51-E after rollback in early March, 1985. The STS-38 and STS-35 stacks both went through MPS hydrogen leak issues in the summer of 1990. And STS-55 had a RSLS abort. (As did STS-68.)
16 days between 61C Columbia and 51L Challenger in January 1986.
16 days between STS-71 Atlantis and STS-70 Discovery in June-July 1995.
17 days between 51D Discovery and 51B Challenger in April 1985.
17 days between STS-38 Atlantis and STS-35 Columbia in November 1990.
18 days between STS-56 Discovery and STS-55 Columbia in April 1993.
Post by: Thorny on 07/09/2007 08:39 pm
Quote
nathan.moeller - 9/7/2007 12:02 PM
But there are at least two instances of shuttle's flying ten days apart (landing-launch). STS-61C Columbia landed on January 18, 1986 and was followed by STS-51L Challenger on January 28. The same thing happened between STS-64 Discovery and STS-68 Endeavour in 1994.
Even better: only six days seperated the landing of STS-71 Atlantis and the launch of STS-70 Discovery in the summer of 1995.
Post by: John2375 on 07/10/2007 02:10 pm
STS-37 is there - during the narration, CDR Nagel admits he got low on the HAC and there were some "rather unusual high altitude winds" that resulted in a "low-energy but safe touchdown"
From watching the video.. you can't really see anything as far as if it's short and by how much because as stated here, because of the late-change to the lakebed runway, the camera angle doesn't really tell you much - lakebed touchdowns kick up a ton of dust anyway so you can't really tell.
I see that despite this near disaster, the commander, Steve Nagel, was given another command, STS-55, so it couldn't have been completely considered his fault.
Have there been any other "close calls" on return? I seem to remember watching the landing of STS-69 and it not appearing to be as 'normal' as some.. seemed to flatten out and glide sideways somewhat, but maybe all was under control, I don't know.
Post by: Analyst on 07/10/2007 02:19 pm
Quote
nathan.moeller - 9/7/2007 7:02 PM
Something I find even more interesting (and frightening with today's processing timelines) is the turnaround time for Atlantis between her first and second missions. I believe she was only on the ground for 47 days between the landing of STS-51J and the launch of STS-61B (both in 1985).
And the STS-51J landing was in California, this gives you an OPF time of a month maximum (I have to look it up in Jenkings book.) Today (STS-121 or STS-117) we are worried by a west coast landing even if the next mission is almost half a year away.
Analyst
Post by: psloss on 07/10/2007 02:31 pm
Quote
Analyst - 10/7/2007 10:19 AMDoes that mean faster is better? If so, why?
And the STS-51J landing was in California, this gives you an OPF time of a month maximum (I have to look it up in Jenkings book.) Today (STS-121 or STS-117) we are worried by a west coast landing even if the next mission is almost half a year away.
Post by: Analyst on 07/10/2007 02:49 pm
Quote
psloss - 10/7/2007 4:31 PM
Does that mean faster is better? If so, why?
Everything else equal, faster is better. Why? Because you are more efficient. If everything else is not equal, we are talking about trade offs: risk vs. cost, risk vs. speed, etc. If faster is still better depends on how you weight all these factors. I am pretty sure different people will come to different conclusions now. What are your preferences?
Analyst
Post by: psloss on 07/10/2007 03:04 pm
Quote
Analyst - 10/7/2007 10:49 AMSee, that's not polite -- you're supposed to answer my question first. If you weren't implying that that faster (pre-51L processing) was better, then I withdraw my question. Otherwise, I'll follow your answer. :bleh:
Everything else equal, faster is better. Why? Because you are more efficient. If everything else is not equal, we are talking about trade offs: risk vs. cost, risk vs. speed, etc. If faster is still better depends on how you weight all these factors. I am pretty sure different people will come to different conclusions now. What are your preferences?
Post by: Danny Dot on 07/10/2007 03:09 pm
Quote
John2375 - 10/7/2007 9:10 AM
snip
Have there been any other "close calls" on return? I seem to remember watching the landing of STS-69 and it not appearing to be as 'normal' as some.. seemed to flatten out and glide sideways somewhat, but maybe all was under control, I don't know.
I don't remember the flight numbers, but do remember the CDR names and will not post them here. One flight got very low in the HAC as the result of letting the PLT get a little stick time. They ended up flying wings level on the HAC for a while during the crew handover. They got so low as to have maximum HAC shrink, but got back all the energy for a good landing.
Another crew had a significant yaw on tough down because of using too much rudder command.
I would not call these "close calls". There was no real risk of loosing the orbiter and crew. I will send by personal message the names of the CRDs to anyone that asks.
Danny Deger
www.dannydeger.net
Post by: brahmanknight on 07/11/2007 01:25 pm
Post by: Jorge on 07/11/2007 02:02 pm
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brahmanknight - 11/7/2007 8:25 AM
Exactly how will the orbiter inspection be handled with the OBSS at the station? Will the SSRMS be used to do it? Will the late inspection be done before leaving the station? Will flight day two for the orbiter revert back to the old, pre-Columbia days?
Hmm? OBSS will only be left at ISS for one flight. STS-124 is incapable of launching with it so it will be left at the station by STS-123 and returned to Earth by STS-124. STS-123's Late Inspection will be performed while docked, exact combination of arms TBD. STS-124 will be limited to non-OBSS inspections with the RMS on FD2.
Post by: Thorny on 07/11/2007 02:56 pm
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Jorge - 11/7/2007 9:02 AM
Hmm? OBSS will only be left at ISS for one flight. STS-124 is incapable of launching with it so it will be left at the station by STS-123 and returned to Earth by STS-124. STS-123's Late Inspection will be performed while docked, exact combination of arms TBD. STS-124 will be limited to non-OBSS inspections with the RMS on FD2.
Where will the OBSS be parked while at the Station?
Post by: psloss on 07/11/2007 03:58 pm
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Thorny - 11/7/2007 10:56 AMI believe they mentioned yesterday that the posts/brackets were going to be put on S1. But that probably is only the boom itself. I believe there was documentation on L2 about bringing the sensor package inside, but don't know what the plan is right now...
Where will the OBSS be parked while at the Station?
Post by: brahmanknight on 07/11/2007 04:06 pm
Post by: DaveS on 07/11/2007 04:17 pm
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brahmanknight - 11/7/2007 6:06 PMYes. The OBSS is now installed where the second starboard SRMS would have been installed. All the SRMS controls on the aft flight deck were built with this in mind, but it never happened.
Purely hypothetical here, but were they ever any ideas to carry two Canadarms up on a single shuttle flight?
Only one SRMS at the time could have been controlled.
Post by: Ford Mustang on 07/11/2007 07:25 pm
It's seems to be raining at KSC right now. If it rains, would it have any effect on the shuttle? I know, that might sound a bit wacky, but.. I've gotta ask.. Just curious.
Post by: madmardy on 07/11/2007 07:40 pm
at anygiven time using the overview timeline
Post by: Jim on 07/11/2007 08:06 pm
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Ford Mustang - 11/7/2007 3:25 PM
Since Endeavour is at the pad..
It's seems to be raining at KSC right now. If it rains, would it have any effect on the shuttle? I know, that might sound a bit wacky, but.. I've gotta ask.. Just curious.
The orbiter is mostly covered by the pad and the TPS is waterproofing.
Rain is only an issue after landing since the waterproofing burns off
Post by: Jim on 07/11/2007 08:22 pm
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madmardy - 11/7/2007 3:40 PM
could anyone decipher the orbit attitude bias so its possible to work out what attitude the orbiter is in
at anygiven time using the overview timeline
??? Bias?
LV - Local Vertical
VV- Velocity Vector
SI - Sun Inertial
Post by: Thorny on 07/11/2007 08:49 pm
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DaveS - 11/7/2007 11:17 AM
Yes. The OBSS is now installed where the second starboard SRMS would have been installed. All the SRMS controls on the aft flight deck were built with this in mind, but it never happened.
Only one SRMS at the time could have been controlled.
And they wouldn't have been able to use the Ku, if memory serves, because RMS-2 would have taken its circuitry.
Post by: madmardy on 07/11/2007 10:21 pm
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Jim - 11/7/2007 9:22 PMQuotemadmardy - 11/7/2007 3:40 PM
could anyone decipher the orbit attitude bias so its possible to work out what attitude the orbiter is in
at anygiven time using the overview timeline
??? Bias?
LV - Local Vertical
VV- Velocity Vector
SI - Sun Inertial
Cheers that was what i was after
Post by: JayP on 07/12/2007 01:11 am
This may be a dumb question, but how do they get the tailcone back to Dryden? Obviously thay can't take it on the SCA. Does it break down into smaller pieces? Do they ship it by truck or air freighter?
Please read all tail cone related Q&As in the Shuttle Q&A thread in the General Discussion section. These questions have been answered over and over since Atlantis arrived back at KSC.
Edited by DaveS 11/7/2007 7:51 AM
I did review view this entire thread as well as do a search on the entire section. If the info is here, it is hidden very well. Does anyone else have anything?
Post by: madmardy on 07/12/2007 07:37 am
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I did review view this entire thread as well as do a search on the entire section. If the info is here, it is hidden very well. Does anyone else have anything?
Page 37 of this thread second post from the top
Post by: APG85 on 07/12/2007 10:50 am
Post by: DaveS on 07/12/2007 11:01 am
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APG85 - 12/7/2007 12:50 PMThey are already on the orbiter when she rolls to the pad. They're installed in the OPF. On the pad they're simply removed shortly prior to RSS retract.
How are the external window covers attached to the orbiter when it is on the pad? Thanks...
Post by: brahmanknight on 07/12/2007 09:24 pm
Post by: DaveS on 07/12/2007 09:29 pm
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brahmanknight - 12/7/2007 11:24 PMIt probably died when the OBSS had proven itself as a very viable TPS inspection tool and repair platform.
What ever happened to development of the AEROsprint cam mini sat? I know it was considered for use with on orbit inspection.
Post by: APG85 on 07/12/2007 09:46 pm
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DaveS - 12/7/2007 7:01 AMQuoteAPG85 - 12/7/2007 12:50 PMThey are already on the orbiter when she rolls to the pad. They're installed in the OPF. On the pad they're simply removed shortly prior to RSS retract.
How are the external window covers attached to the orbiter when it is on the pad? Thanks...
I'm curious as to how they attach - are they screwed on?
Post by: Jorge on 07/13/2007 02:25 am
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DaveS - 12/7/2007 4:29 PMQuotebrahmanknight - 12/7/2007 11:24 PMIt probably died when the OBSS had proven itself as a very viable TPS inspection tool and repair platform.
What ever happened to development of the AEROsprint cam mini sat? I know it was considered for use with on orbit inspection.
Mini-AERCam (not AEROsprint, there is no such name) actually died twice. First during the initial post-accident downselect of TPS inspection options. It lost to OBSS because OBSS was cheaper to develop and offered a growth option as a standalone TPS repair platform. It was revived when NASA realized that a number of flights could not carry the OBSS and started looking for alternatives again. It died again when the number of such flights was whittled down to one (124/1J) by a variety of get-well measures, then the decision to temporarily stow OBSS on ISS as the get-well for 124.
Post by: spaceshuttle on 07/14/2007 06:57 am
Post by: anik on 07/14/2007 07:10 am
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spaceshuttle - 14/7/2007 10:57 AM
Whatever happened to et-120 (STS-114's original tank)? When is it scheduled to be used?
ET-120 tank has been modified and will be used for STS-120 mission...
More information about it on http://www.nasaspaceflight.com/content/?cid=5112
Post by: Rufus on 07/14/2007 11:48 am
DaveS - 12/7/2007 7:01 AM
They are already on the orbiter when she rolls to the pad. They're installed in the OPF. On the pad they're simply removed shortly prior to RSS retract.
APG85 - 12/7/2007 12:50 PM
How are the external window covers attached to the orbiter when it is on the pad? Thanks...
How are the external window covers attached to the orbiter when it is on the pad? Thanks...
They are already on the orbiter when she rolls to the pad. They're installed in the OPF. On the pad they're simply removed shortly prior to RSS retract.
I'm curious as to how they attach - are they screwed on?
-----
Scott
According to the news reports from the STS-114 incident, they are held on with tape. Maybe someone can confirm that.
http://www.msnbc.msn.com/id/11549018/
Post by: APG85 on 07/15/2007 08:43 pm
Post by: Thorny on 07/15/2007 09:13 pm
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APG85 - 15/7/2007 3:43 PM
Where can I find pictures of Space Shuttle Challenger undergoing processing, Lifting in the VAB, etc.? I've googled it but all that turns up are the typical 51L images. Thanks.
http://images.jsc.nasa.gov/luceneweb/browse.jsp
Browse each of Challenger's flights...
STS-6, STS-7, STS-8, STS-41B, STS-41C, STS-41G, STS-51B, STS-51F, STS-61A, STS-51L
These are ancient, poorly-scanned 640x480 images, alas. Probably haven't been updated since the first Bush presidency... But they're better than nothing.
At least this search system works. The Great NASA Images and NASA Image Exchange search features are useless (type STS-6 and you also get all the missions in the STS 60's plus whole lot of other things that have no discernible link to STS-6.)
Post by: tesheiner on 07/20/2007 07:18 am
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Jim - 20/7/2007 3:20 AMQuoteC5C6 - 19/7/2007 9:15 PM
http://www-pao.ksc.nasa.gov/kscpao/images//small/07pd1873-s.jpg
looking at that picture, that worker is inside a SRB segment? that black thick ring is propellant? and the purple ring? i'm clueless.......
yes, yes and insulation
Q: What happens to that insulation layer?
1. Removed during stacking?
2. Burned at launch?
3. Others?
Post by: GLS on 07/20/2007 09:55 am
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tesheiner - 20/7/2007 8:18 AM
This is from the STS-122 (LON-322) Processing Latest thread:QuoteJim - 20/7/2007 3:20 AMQuoteC5C6 - 19/7/2007 9:15 PM
http://www-pao.ksc.nasa.gov/kscpao/images//small/07pd1873-s.jpg
looking at that picture, that worker is inside a SRB segment? that black thick ring is propellant? and the purple ring? i'm clueless.......
yes, yes and insulation
Q: What happens to that insulation layer?
1. Removed during stacking?
2. Burned at launch?
3. Others?
I think that's called inhibitor. If you ask me, that thing is there to hold the propelant inside the case....
The insulation is between the propelant and the case.
Post by: Jim on 07/20/2007 11:24 am
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GLS - 20/7/2007 5:55 AMIt is inhibitor and it is used to control the burn rate vs holding the propellantQuotetesheiner - 20/7/2007 8:18 AM
This is from the STS-122 (LON-322) Processing Latest thread:QuoteJim - 20/7/2007 3:20 AMQuoteC5C6 - 19/7/2007 9:15 PM
http://www-pao.ksc.nasa.gov/kscpao/images//small/07pd1873-s.jpg
looking at that picture, that worker is inside a SRB segment? that black thick ring is propellant? and the purple ring? i'm clueless.......
yes, yes and insulation
Q: What happens to that insulation layer?
1. Removed during stacking?
2. Burned at launch?
3. Others?
I think that's called inhibitor. If you ask me, that thing is there to hold the propelant inside the case....
The insulation is between the propelant and the case.
Post by: brahmanknight on 07/20/2007 05:39 pm
Is this true? I thought the shuttle could not be manually flown during entry?
Post by: Jorge on 07/20/2007 05:59 pm
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brahmanknight - 20/7/2007 12:39 PM
John2375 said "...STS-2, which I was reading he flew the entry profile manually, first and only time it's ever been done..."
Is this true? I thought the shuttle could not be manually flown during entry?
It is true. The orbiter can be flown manually, and Joe Engle did it. Mind you, the stick inputs still go through the computers.
Post by: psloss on 07/20/2007 06:31 pm
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Jorge - 20/7/2007 1:59 PMHere's a link to one of Mary Shafer Iliff's Usenet posts on this -- discussing with Jorge :) :
It is true. The orbiter can be flown manually, and Joe Engle did it. Mind you, the stick inputs still go through the computers.
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/e4d8d161cf7df5d2/e4dd1f7adcfe65b6?#e4dd1f7adcfe65b6
Edit: actually, here's another one from a couple years earlier, that's also quite good:
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/fa20b9938ef79c3a/953f9cd84f56ac5c?#953f9cd84f56ac5c
Post by: Danny Dot on 07/20/2007 07:07 pm
Quote
brahmanknight - 20/7/2007 12:39 PM
John2375 said "...STS-2, which I was reading he flew the entry profile manually, first and only time it's ever been done..."
Is this true? I thought the shuttle could not be manually flown during entry?
While the stick inputs go through a rate commanded Digital Autopilot, the shuttle handles very well throughout an entire entry. Download my Deger Dots simulation at http://www.dannydeger.net and see for yourself.
I never heard of STS-2 flying the entry manually. I would be surprised if it was, but then STS-2 was well before my time.
Danny Deger
Post by: psloss on 07/20/2007 07:26 pm
http://www.nasa.gov/centers/dryden/pdf/88294main_H-1912.pdf
Post by: APG85 on 07/21/2007 10:06 pm
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Thorny - 15/7/2007 5:13 PMQuoteAPG85 - 15/7/2007 3:43 PM
Where can I find pictures of Space Shuttle Challenger undergoing processing, Lifting in the VAB, etc.? I've googled it but all that turns up are the typical 51L images. Thanks.
http://images.jsc.nasa.gov/luceneweb/browse.jsp
Browse each of Challenger's flights...
STS-6, STS-7, STS-8, STS-41B, STS-41C, STS-41G, STS-51B, STS-51F, STS-61A, STS-51L
These are ancient, poorly-scanned 640x480 images, alas. Probably haven't been updated since the first Bush presidency... But they're better than nothing.
At least this search system works. The Great NASA Images and NASA Image Exchange search features are useless (type STS-6 and you also get all the missions in the STS 60's plus whole lot of other things that have no discernible link to STS-6.)
Thanks. I looked through that and found almost nothing (one picture of her entering the OPF). It seems strange that no pictures exist of Challenger in the OPF or VAB - at least none that I can find on-line...
Post by: Thorny on 07/22/2007 04:23 pm
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APG85 - 21/7/2007 5:06 PM
Thanks. I looked through that and found almost nothing (one picture of her entering the OPF). It seems strange that no pictures exist of Challenger in the OPF or VAB - at least none that I can find on-line...
Here are a few...
STS-8 (note: date should be 07.26.1983)
http://nix.ksc.nasa.gov/info;jsessionid=20r9da9xy6ng0?id=S83-39144&orgid=8
http://www.capcomespace.net/dossiers/espace_US/shuttle/1981-85/1983%20STS8%20payload%20PCR.jpg
STS-41B
http://images.jsc.nasa.gov/lores/S84-25872.jpg
STS-51F
http://nix.ksc.nasa.gov/info;jsessionid=20r9da9xy6ng0?id=S85-28697&orgid=8
STS-61A
http://nix.ksc.nasa.gov/info;jsessionid=20r9da9xy6ng0?id=S85-43138&orgid=8
Remember that in the OPF, the Orbiter is enshrouded in work platforms and even when it isn't, the OPFs aren't large enough to easily get shots of the entire Orbiter without fisheye lenses. So good photos are hard to come by and what is available is more of a close-up technical nature., not something the PAO thinks the general public is interested in.
Post by: APG85 on 07/23/2007 11:04 am
Post by: psloss on 07/23/2007 11:26 am
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APG85 - 23/7/2007 7:04 AMThe 41-B image that Thorny posted the link for is in the VAB.
Thanks! Thats more than I've been able to find. Have you seen any of Challenger in the VAB?
Post by: APG85 on 07/23/2007 10:03 pm
Quote
psloss - 23/7/2007 7:26 AMQuoteAPG85 - 23/7/2007 7:04 AMThe 41-B image that Thorny posted the link for is in the VAB.
Thanks! Thats more than I've been able to find. Have you seen any of Challenger in the VAB?
Oops, you are correct. I still would hope there are many more images out there...
Post by: psloss on 07/23/2007 10:16 pm
Quote
APG85 - 23/7/2007 6:03 PMProbably a bigger issue is both what is still available in their archives and also, importantly, what kind of human resources are available to re-publish photos.
Oops, you are correct. I still would hope there are many more images out there...
Post by: khdrummer on 07/24/2007 12:20 am
Post by: DaveS on 07/24/2007 12:27 am
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khdrummer - 24/7/2007 2:20 AMAround 40-50 minutes, depending on trajectory.
Does anyone know about how long after ET Sep does the ET re-enter?
Post by: brahmanknight on 07/25/2007 02:31 pm
Post by: Jim on 07/25/2007 02:52 pm
Post by: STS-500Cmdr on 07/26/2007 02:19 am
Post by: Endeavour118 on 07/26/2007 02:33 am
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STS-500Cmdr - 25/7/2007 10:19 PMThe hydrogen burn ignitors that ignite at t-10 seconds
What is firing chain that George Diller always refers to??
Post by: shuttlelegs on 07/26/2007 01:54 pm
Post by: John2375 on 07/26/2007 08:19 pm
Post by: psloss on 07/26/2007 08:28 pm
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John2375 - 26/7/2007 4:19 PMFirst flight only.
I noticed watching the launch of STS-1, that the LOX vent arm was retracted during the T-9 min. hold.. was that just the first flight or did that continue for a while??
Post by: Andy_Small on 07/26/2007 08:28 pm
Post by: John2375 on 07/26/2007 08:30 pm
I can't find video of STS-2 or 3 so wasn't able to see for myself....
Post by: psloss on 07/26/2007 08:32 pm
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John2375 - 26/7/2007 4:30 PMThe vent wasn't working during parts of the first launch campaign and was fixed prior to the second launch.
so what was the reason for changing the process?
I can't find video of STS-2 or 3 so wasn't able to see for myself....
STS-2 launch clip is on ShuttleSource:
http://www.shuttlesource.com/library_clips.html
Post by: Ford Mustang on 07/26/2007 09:15 pm
Or, is that if the SSPTS works? (Station to Shuttle Power Transfer System)
EDIT: Thanks, DaveS. I'm not too good with the acronyms
Post by: Jim on 07/26/2007 09:19 pm
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Andy_Small - 26/7/2007 4:28 PM
How does the RMS attach to the payloads in order to hand them off the CA2?
CA2? You mean SSRMS? The RMS attaches to the payloads the same way as the SSRMS does.
Post by: DaveS on 07/26/2007 09:20 pm
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Ford Mustang - 26/7/2007 11:15 PMIt's SSPTS(Station to Shuttle Power Transfer System).
Isn't Endeavour's mission supposed to be 14 days? Just thought I'd ask, because I keep seeing 11 days.
Or, is that if the STSPS works? (Shuttle to station power system)
Post by: Andy_Small on 07/26/2007 09:24 pm
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Jim - 26/7/2007 4:19 PMQuoteAndy_Small - 26/7/2007 4:28 PM
How does the RMS attach to the payloads in order to hand them off the CA2?
CA2? You mean SSRMS? The RMS attaches to the payloads the same way as the SSRMS does.
Candada Arm 2. Yeah I'm not real good with the Lingo yet. But the robtic arms on both station and the orbiter how do they attach to structures in order to move them around?
Post by: Jim on 07/26/2007 09:33 pm
Quote
Andy_Small - 26/7/2007 5:24 PMQuoteJim - 26/7/2007 4:19 PMQuoteAndy_Small - 26/7/2007 4:28 PM
How does the RMS attach to the payloads in order to hand them off the CA2?
CA2? You mean SSRMS? The RMS attaches to the payloads the same way as the SSRMS does.
Candada Arm 2. Yeah I'm not real good with the Lingo yet. But the robtic arms on both station and the orbiter how do they attach to structures in order to move them around?
See attached
Post by: Andy_Small on 07/26/2007 09:36 pm
Post by: Endeavour118 on 07/27/2007 08:27 am
Post by: SpaceNutz SA on 07/27/2007 09:20 am
1. Is the current procedure to try an unmanned landing of the orbiter from ground control regardless of damage? If it is obvious that the orbiter will not re-enter (damaged RCC) do they still attempt a landing anyway or do they do a destrutive de-orbit?
2. I understand that the damaged orbiter is de-orbited a day or 2 after LON call-up. If the LON vehicle has a launch failure or in flight abort - wouldn't it be wise to keep the damaged orbiter near the ISS as a 'better than nothing' backup if the LON mission fails? Or are there Soyuz options in addition to the LON?
3. How does the LON vehicle seat the 7 + 4 crew members?
4. If the mission orbiter has an ATO abort and cannot reach the ISS - I understand that the ISS can drop down, collect the orbiter crew and re-boost. How does this procedure impact on ISS resources during the 'waiting period' for the LON mission? I understand the ISS can support the orbiter crew and ISS crew for 80 days normally. If this rescue is done by the ISS is it still 80 days?
Post by: Endeavour118 on 07/27/2007 10:41 am
Quote
SpaceNutz SA - 27/7/2007 5:20 AM
A few questions on LON procedure:
1. Is the current procedure to try an unmanned landing of the orbiter from ground control regardless of damage? If it is obvious that the orbiter will not re-enter (damaged RCC) do they still attempt a landing anyway or do they do a destrutive de-orbit?
2. I understand that the damaged orbiter is de-orbited a day or 2 after LON call-up. If the LON vehicle has a launch failure or in flight abort - wouldn't it be wise to keep the damaged orbiter near the ISS as a 'better than nothing' backup if the LON mission fails? Or are there Soyuz options in addition to the LON?
3. How does the LON vehicle seat the 7 + 4 crew members?
4. If the mission orbiter has an ATO abort and cannot reach the ISS - I understand that the ISS can drop down, collect the orbiter crew and re-boost. How does this procedure impact on ISS resources during the 'waiting period' for the LON mission? I understand the ISS can support the orbiter crew and ISS crew for 80 days normally. If this rescue is done by the ISS is it still 80 days?
I can answer# 3
!["How]("http://upload.wikimedia.org/wikipedia/en/9/97/Sts-300.recumbent-seats.png" "\"How")
Post by: Jim on 07/27/2007 12:24 pm
Quote
SpaceNutz SA - 27/7/2007 5:20 AM
4. If the mission orbiter has an ATO abort and cannot reach the ISS - I understand that the ISS can drop down, collect the orbiter crew and re-boost. How does this procedure impact on ISS resources during the 'waiting period' for the LON mission? I understand the ISS can support the orbiter crew and ISS crew for 80 days normally. If this rescue is done by the ISS is it still 80 days?
The ISS can't do that
Post by: SpaceNutz SA on 07/27/2007 01:54 pm
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Jim - 27/7/2007 2:24 PMQuoteSpaceNutz SA - 27/7/2007 5:20 AM 4. If the mission orbiter has an ATO abort and cannot reach the ISS - I understand that the ISS can drop down, collect the orbiter crew and re-boost. How does this procedure impact on ISS resources during the 'waiting period' for the LON mission? I understand the ISS can support the orbiter crew and ISS crew for 80 days normally. If this rescue is done by the ISS is it still 80 days?The ISS can't do that
The orbiter and four of the crew which were due to fly the next planned mission would be retasked to the rescue mission. The planning and training processes for a rescue flight would allow NASA to launch the mission within a period of 40 days of it being called up. During that time the damaged (or disabled) shuttle's crew would have to take refuge on the International Space Station (ISS). The ISS is able to support both crews for around 80 days, with oxygen supply being the limiting factor[1]. Within NASA, this plan for maintaining the shuttle crew at the ISS is known as Contingency Shuttle Crew Support (CSCS) operations.[2] Up to STS-121 all rescue missions were to be designated STS-300.
In the case of an abort to orbit, where the shuttle doesn't reach the ISS orbit and the thermal protection system inspections suggest the shuttle could not return to earth safely, the ISS could be brought down to meet the shuttle. Such a procedure is known as joint underspeed recovery [3].
http://en.wikipedia.org/wiki/STS-3xx
This is where I read that but the reference article is not available.
Post by: Thorny on 07/27/2007 02:10 pm
Quote
SpaceNutz SA - 27/7/2007 4:20 AM
2. I understand that the damaged orbiter is de-orbited a day or 2 after LON call-up. If the LON vehicle has a launch failure or in flight abort - wouldn't it be wise to keep the damaged orbiter near the ISS as a 'better than nothing' backup if the LON mission fails? Or are there Soyuz options in addition to the LON?
The disabled Orbiter would be left at the ISS until close to depletion... a lot longer than 2 days. Probably 2-3 weeks. It would leave with just enough juice for the destructive de-orbit or maybe attempted autoland at White Sands. If they wait until the Orbiter has run dry, then it wouldn't be able to undock and get out of the way of the LON shuttle, and if it died in orbit after undocking, it would eventually come down at random somewhere on Earth, and NASA is obligated to try to avoid that.
Post by: DaveS on 07/27/2007 02:16 pm
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Thorny - 27/7/2007 4:10 PMPrime landing site for RCO is Vandenberg AFB, not White Sands.
The disabled Orbiter would be left at the ISS until close to depletion... a lot longer than 2 days. Probably 2-3 weeks. It would leave with just enough juice for the destructive de-orbit or maybe attempted autoland at White Sands.
Post by: Thorny on 07/27/2007 02:21 pm
Quote
Endeavour118 - 27/7/2007 3:27 AM
HAs the shuttle ever launched on any holidays besides the 4th of july and has it launched on friday the 13th
STS-5 launched on Veterans Day.
No Friday the 13th launches.
Post by: Thorny on 07/27/2007 02:23 pm
Quote
DaveS - 27/7/2007 9:16 AMQuoteThorny - 27/7/2007 4:10 PMPrime landing site for RCO is Vandenberg AFB, not White Sands.
The disabled Orbiter would be left at the ISS until close to depletion... a lot longer than 2 days. Probably 2-3 weeks. It would leave with just enough juice for the destructive de-orbit or maybe attempted autoland at White Sands.
Thanks for the correction. When did that change? I'd think WS has a lot more open area to handle landing rollout if it comes in a little long or short.
Post by: DaveS on 07/27/2007 02:29 pm
Quote
Thorny - 27/7/2007 4:23 PMThey can handle the landing rollout. It's the the debris during entry that prompted the change from Edwards to Vandenberg. By landing at Vandenberg they can minimize the amount of land that the orbiter flies over during entry as to compared with either Edwards or White Sands.QuoteDaveS - 27/7/2007 9:16 AMQuoteThorny - 27/7/2007 4:10 PMPrime landing site for RCO is Vandenberg AFB, not White Sands.
The disabled Orbiter would be left at the ISS until close to depletion... a lot longer than 2 days. Probably 2-3 weeks. It would leave with just enough juice for the destructive de-orbit or maybe attempted autoland at White Sands.
Thanks for the correction. When did that change? I'd think WS has a lot more open area to handle landing rollout if it comes in a little long or short.
Post by: AstroRJY on 07/27/2007 02:45 pm
Quote
Endeavour118 - 27/7/2007 4:27 AM HAs the shuttle ever launched on any holidays besides the 4th of july and has it launched on friday the 13th
Great question so I researched it...
No Friday the 13ths, only 3 launches on the 13th of any month- STS,-29, STS-54, STS-70 but no Fridays. Came close a couple times launching on the 12th of a month though. For example if STS-104 had been dealyed 24 hours, might have had a Friday the 13th launch in 2001.
Holidays: STS-1 launched on Palm Sunday 4/12/81.
STS-5 launched on Veteran's Day, 11/11/82.
STS-33 launched 11/22/89 on Thanksgiving Eve, the night before Thanksgiving which actually was Thanksgiving Day in European time zones it was 7 in the evening; eastern time of the US.
And of course as you said STS-121 launched on the 4th of July 2006.
I even checked to see about Columbus Day, Memorial Day, Labor Day-- nope.
edited some typos.
Post by: shuttlefan on 07/27/2007 02:55 pm
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AstroRJY - 27/7/2007 9:45 AMQuoteEndeavour118 - 27/7/2007 4:27 AM HAs the shuttle ever launched on any holidays besides the 4th of july and has it launched on friday the 13th
Great question so I researched it...
No Friday the 13ths, only 3 launches on the 13th of any month- STS,-29, STS-54, STS-70 but no Fridays. Came close a couple times launching on the 12th of a month though. For example if STS-104 had been dealyed 24 hours, might have had a Friday the 13th launch in 2001.
Holidays: STS-1 launched on Palm Sunday 4/12/81.
STS-5 launched on Veteran's Day, 11/11/82.
STS-33 launched 11/22/89 on Thanksgiving Eve, the night before Thanksgiving which actually was Thanksgiving Day in European time zones it was 7 in the evening; eastern time of the US.
And of course as you said STS-121 launched on the 4th of July 2006.
I even checked to see about Columbus Day, Memorial Day, Labor Day-- nope.
edited some typos.
I know you're asking about launches, but just for the record, STS-103 was the first shuttle to be up over Christmas, 1999. ;)
Post by: AstroRJY on 07/27/2007 03:12 pm
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shuttlefan - 27/7/2007 10:55 AMQuoteAstroRJY - 27/7/2007 9:45 AMI know you're asking about launches, but just for the record, STS-103 was the first shuttle to be up over Christmas, 1999. ;)QuoteEndeavour118 - 27/7/2007 4:27 AM HAs the shuttle ever launched on any holidays besides the 4th of july and has it launched on friday the 13th
Great question so I researched it...
No Friday the 13ths, only 3 launches on the 13th of any month- STS,-29, STS-54, STS-70 but no Fridays. Came close a couple times launching on the 12th of a month though. For example if STS-104 had been dealyed 24 hours, might have had a Friday the 13th launch in 2001.
Holidays: STS-1 launched on Palm Sunday 4/12/81.
STS-5 launched on Veteran's Day, 11/11/82.
STS-33 launched 11/22/89 on Thanksgiving Eve, the night before Thanksgiving which actually was Thanksgiving Day in European time zones it was 7 in the evening; eastern time of the US.
And of course as you said STS-121 launched on the 4th of July 2006.
I even checked to see about Columbus Day, Memorial Day, Labor Day-- nope.
edited some typos.
Good point. Also there have been a couple flights during Thanksgiving such as STS-61B in 1985 and STS-113 in 2002
Post by: Jim on 07/27/2007 03:32 pm
Quote
SpaceNutz SA - 27/7/2007 9:54 AM
In the case of an abort to orbit, where the shuttle doesn't reach the ISS orbit and the thermal protection system inspections suggest the shuttle could not return to earth safely, the ISS could be brought down to meet the shuttle. Such a procedure is known as joint underspeed recovery [3].http://en.wikipedia.org/wiki/STS-3xx
This is where I read that but the reference article is not available.
Don't use wikipedia
Post by: joncz on 07/27/2007 04:12 pm
Quote
Jim - 27/7/2007 11:32 AM
Don't use wikipedia
How about AAS and AIAA?
From the 1999 AAS/AIAA Astrodynamics Specialist Conference
http://www.space-flight.org/AAS_meetings/1999_astro/1999_astro.html
is this presentation:
99-394 Contingency ISS Rendezvous Recovery Planning by Houston and Moscow Control
0410pm Centers – D.R. Adamo
During launch to International Space Station (ISS), contingencies compromising Space Shuttle
Orbiter (SSO) propulsive capability may preclude nominal rendezvous. In some of these
contingency scenarios, ISS translation maneuvers to a lower orbit height, planned in real time,
can resurrect SSO rendezvous capability. Expending some ISS propellant in such scenarios can
thereby avoid a costly and disruptive delay to SSO cargo delivery. A cooperative response to
these contingencies, called Joint Underspeed Recovery (JURe), has been negotiated by flight
mechanics specialists from Houston and Moscow Control Centers. Constraints, strategies,
procedures, and a dedicated spreadsheet associated with JURe operations are presented. An
example "paper simulation" is also provided.
Post by: John2375 on 07/27/2007 10:04 pm
STS-80 was also up over Thanksgiving.. and STS-87 too I believe
Post by: AstroRJY on 07/27/2007 10:24 pm
Quote
John2375 - 27/7/2007 6:04 PM . Also there have been a couple flights during Thanksgiving such as STS-61B in 1985 and STS-113 in 2002 STS-80 was also up over Thanksgiving.. and STS-87 too I believe
You are correct both of those launched on Novemebr 19th one year apart ('96 and '97) and were 2 week missions. Also STS-50 was up during the 4th of July 1992 which was a first at that time.
Post by: Endeavour118 on 07/28/2007 03:59 am
Post by: Jorge on 07/28/2007 05:16 am
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DaveS - 27/7/2007 9:29 AMQuoteThorny - 27/7/2007 4:23 PMQuoteDaveS - 27/7/2007 9:16 AMQuoteThorny - 27/7/2007 4:10 PMPrime landing site for RCO is Vandenberg AFB, not White Sands.
The disabled Orbiter would be left at the ISS until close to depletion... a lot longer than 2 days. Probably 2-3 weeks. It would leave with just enough juice for the destructive de-orbit or maybe attempted autoland at White Sands.
Thanks for the correction. When did that change? I'd think WS has a lot more open area to handle landing rollout if it comes in a little long or short.
They can handle the landing rollout. It's the the debris during entry that prompted the change from Edwards to Vandenberg. By landing at Vandenberg they can minimize the amount of land that the orbiter flies over during entry as to compared with either Edwards or White Sands.
Yes, Vandenberg has the lower public overflight risk. But last I heard, White Sands was still prime for RCO landings because WSSH has a lakebed runway with full MLS while VAFB has a concrete runway with only MSBLS Jr. VAFB required upgrade to full MLS to become the prime RCO landing site and last I heard not only was this not completed, it was not funded. If you have any updates that would be appreciated.
Post by: SpaceNutz SA on 07/28/2007 09:02 am
Quote
joncz - 27/7/2007 6:12 PMQuoteJim - 27/7/2007 11:32 AM Don't use wikipediaHow about AAS and AIAA? From the 1999 AAS/AIAA Astrodynamics Specialist Conference http://www.space-flight.org/AAS_meetings/1999_astro/1999_astro.html is this presentation: 99-394 Contingency ISS Rendezvous Recovery Planning by Houston and Moscow Control 0410pm Centers – D.R. Adamo During launch to International Space Station (ISS), contingencies compromising Space Shuttle Orbiter (SSO) propulsive capability may preclude nominal rendezvous. In some of these contingency scenarios, ISS translation maneuvers to a lower orbit height, planned in real time, can resurrect SSO rendezvous capability. Expending some ISS propellant in such scenarios can thereby avoid a costly and disruptive delay to SSO cargo delivery. A cooperative response to these contingencies, called Joint Underspeed Recovery (JURe), has been negotiated by flight mechanics specialists from Houston and Moscow Control Centers. Constraints, strategies, procedures, and a dedicated spreadsheet associated with JURe operations are presented. An example "paper simulation" is also provided.
Can anyone clear this one up? I'm very interested to know. If what Jim say's is true then it seemingly implies that if an ATO situation unfolded where the TPS was damaged on launch it would be game-over for the crew?
Post by: spacemuppet on 07/28/2007 05:03 pm
Post by: Jim on 07/28/2007 05:17 pm
Post by: spacemuppet on 07/28/2007 05:29 pm
Post by: Danny Dot on 07/28/2007 05:33 pm
Quote
spacemuppet - 28/7/2007 12:03 PM
What would happen if say before the shuttle even cleared the tower the entire autopilot system went down and the CDR had to assume manual control all the way to orbit? Is this theoretically possible and would he have anything to reference, anything to "aim for"? What about the roll? Is there an actual throttle lever in the cockpit? I assume that even if this is all possible the chances of living through it are slim and the chances of reaching a mission orbit are probably close to zero...(?)
As Jim said, the computers fly the shuttle -- always. But on ascent there is the capability of flying with the stick and with the throttles. This mode is called "Control Stick Steering -- CSS". While in the atmosphere, chances are a manually flown shuttle would result in the airloads ripping the stack apart. After getting out of the atmosphere, the shuttle handles well and it is simple to fly to an orbit that is safe. Much harder (impossible?) to fly to an orbit that something like a station rendezvous could be made from.
Danny Deger
Post by: Jorge on 07/28/2007 05:35 pm
Quote
SpaceNutz SA - 28/7/2007 4:02 AMQuotejoncz - 27/7/2007 6:12 PMQuoteJim - 27/7/2007 11:32 AM Don't use wikipediaHow about AAS and AIAA? From the 1999 AAS/AIAA Astrodynamics Specialist Conference http://www.space-flight.org/AAS_meetings/1999_astro/1999_astro.html is this presentation: 99-394 Contingency ISS Rendezvous Recovery Planning by Houston and Moscow Control 0410pm Centers – D.R. Adamo During launch to International Space Station (ISS), contingencies compromising Space Shuttle Orbiter (SSO) propulsive capability may preclude nominal rendezvous. In some of these contingency scenarios, ISS translation maneuvers to a lower orbit height, planned in real time, can resurrect SSO rendezvous capability. Expending some ISS propellant in such scenarios can thereby avoid a costly and disruptive delay to SSO cargo delivery. A cooperative response to these contingencies, called Joint Underspeed Recovery (JURe), has been negotiated by flight mechanics specialists from Houston and Moscow Control Centers. Constraints, strategies, procedures, and a dedicated spreadsheet associated with JURe operations are presented. An example "paper simulation" is also provided.Can anyone clear this one up? I'm very interested to know. If what Jim say's is true then it seemingly implies that if an ATO situation unfolded where the TPS was damaged on launch it would be game-over for the crew?
Jim is partially right and partially wrong. JURe is a real capability and there are flight rules and procedures governing it. However, whether it will be used (and whether it can save the crew) depends on circumstances. There is an internationally agreed-to minimum survivable altitude for ISS (150 n.mi., or 278 km), and under no circumstances would ISS be deboosted below that altitude in order to complete a JURe. So the answer to the survivability question depends on just how bad the shuttle's underperformance was (in other words, how early during the ascent did the SSME fail). In some cases, the magnitude of the OMS dump required to make up for the MPS underspeed may make it impossible for the orbiter to reach even 150 n.mi. In other cases, it may still be possible to reach 150 n.mi. but at the cost of giving up deorbit capability - and that means NASA would have to carefully weigh the risks of standalone repair/compromised entry vs JURe/CSCS/LON.
Post by: Jorge on 07/28/2007 05:39 pm
Quote
spacemuppet - 28/7/2007 12:29 PM
On the Eileen Collins flight where 2of the 3 computers crapped out, what exactly would have happened if the third one died too?
You are confused. No main computers crapped out on STS-93. What happened was that an AC bus short caused two out of six main engine controllers to fail. There are two MECs on each engine and they are powered such that loss of an AC bus only results in loss of one MEC on two different main engines. If the other MEC had failed on either of those two SSMEs, the engine would have been lost and an intact abort (RTLS, TAL, ATO, or nominal MECO after the "press to MECO" call) would have resulted, depending on when the MEC failed.
Post by: Chris Bergin on 07/28/2007 05:49 pm
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=442&start=1
Attached is a short clip from the L2 video of the whole ride to MECO (with the LOX low level cut off and resulting underspeed), showing the faults being relayed on the MCC loop video.
Post by: Danny Dot on 07/28/2007 05:50 pm
Quote
Jorge - 28/7/2007 12:35 PM
snip
Jim is partially right and partially wrong. JURe is a real capability and there are flight rules and procedures governing it. However, whether it will be used (and whether it can save the crew) depends on circumstances. There is an internationally agreed-to minimum survivable altitude for ISS (150 n.mi., or 278 km), and under no circumstances would ISS be deboosted below that altitude in order to complete a JURe. So the answer to the survivability question depends on just how bad the shuttle's underperformance was (in other words, how early during the ascent did the SSME fail). In some cases, the magnitude of the OMS dump required to make up for the MPS underspeed may make it impossible for the orbiter to reach even 150 n.mi. In other cases, it may still be possible to reach 150 n.mi. but at the cost of giving up deorbit capability - and that means NASA would have to carefully weigh the risks of standalone repair/compromised entry vs JURe/CSCS/LON.
Does station carry anywhere close to enough fuel to drop to 150 NM and not deorbit due to drag -- before more fuel can be brought up? It must deorbit in a few days from 150 NM.
Danny Deger
Post by: Jorge on 07/28/2007 05:54 pm
Quote
spacemuppet - 28/7/2007 12:03 PM
What would happen if say before the shuttle even cleared the tower the entire autopilot system went down and the CDR had to assume manual control all the way to orbit? Is this theoretically possible and would he have anything to reference, anything to "aim for"? What about the roll? Is there an actual throttle lever in the cockpit? I assume that even if this is all possible the chances of living through it are slim and the chances of reaching a mission orbit are probably close to zero...(?)
It depends on what you mean by "entire". If all four PASS computers go down, the CDR engages the BFS and the BFS flies to orbit. If both PASS and BFS go down (highly remote, but then again I thought the same of the Russian computers on ISS until recently), the vehicle is lost. The CDR's stick inputs always go through the flight control software and if there is no flight software running, either PASS or BFS, then there is nothing to connect the stick inputs with the gimbal outputs needed to control flight.
If only PASS navigation and/or guidance is lost, but PASS flight control is still GO, a manual ascent is possible, but only after T+90 seconds. Flight Rules forbid manual control prior to T+90 seconds since it is thought to be impossible to manually fly the "load relief" portion of ascent - the CDR cannot react quickly enough to high-altitude wind shears. After T+90, the CDR can fly manually using cue cards. They are best-available pre-flight estimates and are a bit crude. Like Danny says, they will probably get the crew to a safe orbit but ISS rendezvous may not be possible.
BFS supports only automatic flight control during ascent.
Post by: Jorge on 07/28/2007 05:58 pm
Quote
Danny Dot - 28/7/2007 12:50 PMQuoteJorge - 28/7/2007 12:35 PM
snip
Jim is partially right and partially wrong. JURe is a real capability and there are flight rules and procedures governing it. However, whether it will be used (and whether it can save the crew) depends on circumstances. There is an internationally agreed-to minimum survivable altitude for ISS (150 n.mi., or 278 km), and under no circumstances would ISS be deboosted below that altitude in order to complete a JURe. So the answer to the survivability question depends on just how bad the shuttle's underperformance was (in other words, how early during the ascent did the SSME fail). In some cases, the magnitude of the OMS dump required to make up for the MPS underspeed may make it impossible for the orbiter to reach even 150 n.mi. In other cases, it may still be possible to reach 150 n.mi. but at the cost of giving up deorbit capability - and that means NASA would have to carefully weigh the risks of standalone repair/compromised entry vs JURe/CSCS/LON.
Does station carry anywhere close to enough fuel to drop to 150 NM and not deorbit due to drag -- before more fuel can be brought up? It must deorbit in a few days from 150 NM.
Danny Deger
Station has a truly prodigious fuel reserve right now - the FGB tanks are topped off by each Progress. It can survive at 150 n.mi. for about 90 days, I believe. Getting it back to nominal operating altitude would require a salvo of Progress launches (or one ATV launch).
Post by: Danny Dot on 07/28/2007 06:08 pm
Quote
Jorge - 28/7/2007 12:58 PM
snip
Station has a truly prodigious fuel reserve right now - the FGB tanks are topped off by each Progress. It can survive at 150 n.mi. for about 90 days, I believe. Getting it back to nominal operating altitude would require a salvo of Progress launches (or one ATV launch).
Is that 90 days AFTER it lowers its orbit to 150 to meet up with shuttle? It costs just a much to lower an orbit by 1NM as it costs to raise an orbit by 1NM.
Danny Deger
Post by: Jorge on 07/28/2007 06:24 pm
Quote
Danny Dot - 28/7/2007 1:08 PMQuoteJorge - 28/7/2007 12:58 PM
snip
Station has a truly prodigious fuel reserve right now - the FGB tanks are topped off by each Progress. It can survive at 150 n.mi. for about 90 days, I believe. Getting it back to nominal operating altitude would require a salvo of Progress launches (or one ATV launch).
Is that 90 days AFTER it lowers its orbit to 150 to meet up with shuttle?
That is my understanding.
Post by: spacemuppet on 07/29/2007 01:15 am
Post by: mkirk on 07/29/2007 02:36 pm
Quote
spacemuppet - 28/7/2007 8:15 PM
How far can the shuttle translate in orbit with its OMS fuel? Meaning, how much of an altitude change can it do or how many orbit changes can it do before it reaches whatever NASA calls "bingo" "fuel?
Well as always it depends on the timing, weight (mass), and the situation. Typically by the time you get to flight day 2 with a space station flight (after all the ascent burns and an initial rendezvous burn such as the NC1) you generally have in the neighborhood of 450 to 500+ feet per second of delta V with the OMS engines. By the time you are in the space station orbit you have about 330 feet per second left in OMS delta V capability. These numbers do not take into account RCS capability.
A general rule of thumb is that 2 feet per second equates to a 1 nautical mile change in altitude for Hp (height/altitude of perigee). So you can do the math from there but remember you have to leave enough gas to come back down and de-orbit.
FYI: 1 nautical mile = 1.15 statute miles or 1.85 kilometers
Mark Kirkman
Post by: spacemuppet on 07/30/2007 02:31 am
I do know there were at one point before 1986 plans for an upper stage, I believe they called it "Centaur" or something of the like.
Post by: Danny Dot on 07/30/2007 02:42 am
Quote
spacemuppet - 29/7/2007 9:31 PM
How "deep" into space could the shuttle go if the entire payload bay was loaded with a huge OMS fuel tank? I know this would never happen, just a question for fum.
I do know there were at one point before 1986 plans for an upper stage, I believe they called it "Centaur" or something of the like.
If you put additional 50,000 lbs of OMS propellant, the shuttle might make it up to about a 650 NM orbit. Not that high.
Danny Deger
Post by: SpaceNutz SA on 07/30/2007 10:29 am
How relevant is a leak check done at sea level (1atm) to the conditions in space (pratically 0 atm)? If the compartment is simply pressurised to 2atm to give the same pressure difference it would have the same mathematical difference (1atm) but the differential would only be 2x (2atm/1atm) as opposed to space (1atm/0atm = inf).
I know from scuba diving that the pressure differential from surface to 10m is 1atm but 2x. From surface to 20m is 2atm but 3x ie for every 10m descent the ambient pressure rises by 1atm but the differential for each 10m descent becomes less noticeable the deep you go. This is why the most equalising of ears etc occurs in the forst 10m. Working this backwards - going into space is like the ascent in scuba diving - moving to a lower ambient pressure with the differential becoming more pronounced as you ascend - the last 10m being the highest pressure change.
Just wondering how all of this ties up with the pressure changes on the vehicle?
Post by: SpaceNutz SA on 07/30/2007 11:19 am
A container filled to 2atm at sea level has double the pressure inside than outside.
A container filled to 1atm at an outside pressure of 0.5 atm is double the outside pressure.
A container filled to 1atm at an outside pressure of 0.25 atm is 4x the outside pressure.
A container filled to 1atm at an outside pressure of 0.01 atm is 100x the outside pressure - this is approaching (but not nearly close to) the condition of the orbiter in orbit.
How much pressure must the orbiter be exposed to at sea level for the leak check test to be relevant to conditions on orbit? What pressure is actually used for theleak check?
Post by: Jim on 07/30/2007 11:28 am
Quote
spacemuppet - 29/7/2007 10:31 PM
How "deep" into space could the shuttle go if the entire payload bay was loaded with a huge OMS fuel tank? I know this would never happen, just a question for fum.
I do know there were at one point before 1986 plans for an upper stage, I believe they called it "Centaur" or something of the like.
Centaur was for spacecraft, not shuttle. There were other upperstages: IUS, TOS, PAM-D, PAM-D2,
Post by: Jim on 07/30/2007 11:30 am
Quote
SpaceNutz SA - 30/7/2007 6:29 AM
Just wondering how all of this ties up with the pressure changes on the vehicle?
The cabin leak check doesn't use more than a few psi above ambient. It is not pressurized to 2 atm.
Post by: SpaceNutz SA on 07/30/2007 11:55 am
Quote
Jim - 30/7/2007 1:30 PMQuoteSpaceNutz SA - 30/7/2007 6:29 AM Just wondering how all of this ties up with the pressure changes on the vehicle?The cabin leak check doesn't use more than a few psi above ambient. It is not pressurized to 2 atm.
That doesn't seem to be a very good test IMHO. A capsule containing humans going into a virtually 0atm environment where the inside pressure is 100's if not 1000's of times greater which hasn't been tested at even 2x? Am I missing something here?
Post by: Jim on 07/30/2007 12:03 pm
Quote
SpaceNutz SA - 30/7/2007 7:55 AMQuoteJim - 30/7/2007 1:30 PMQuoteSpaceNutz SA - 30/7/2007 6:29 AM Just wondering how all of this ties up with the pressure changes on the vehicle?The cabin leak check doesn't use more than a few psi above ambient. It is not pressurized to 2 atm.That doesn't seem to be a very good test IMHO. A capsule containing humans going into a virtually 0atm environment where the inside pressure is 100's if not 1000's of times greater which hasn't been tested at even 2x? Am I missing something here?
leak testing is not a ratio, only a difference. This is not pressure testing
Post by: pippin on 07/30/2007 12:06 pm
Post by: henrycheck on 07/30/2007 01:14 pm
Quote
SpaceNutz SA - 30/7/2007 7:19 AM
Let me put my question in a less confusing manner:
A container filled to 2atm at sea level has double the pressure inside than outside.
A container filled to 1atm at an outside pressure of 0.5 atm is double the outside pressure.
A container filled to 1atm at an outside pressure of 0.25 atm is 4x the outside pressure.
A container filled to 1atm at an outside pressure of 0.01 atm is 100x the outside pressure - this is approaching (but not nearly close to) the condition of the orbiter in orbit.
How much pressure must the orbiter be exposed to at sea level for the leak check test to be relevant to conditions on orbit? What pressure is actually used for theleak check?
Presumably the on-orbit pressure differential is factored into the determination of the allowable sea level leak rate. On orbit the allowable crew cabin leak rate is likely greater than 0.022 psi per 4 hours, which is really a tiny leak rate.
1 / (0.022/4) = 182 hours to drop one psi.
Post by: Danny Dot on 07/30/2007 03:37 pm
Quote
Jim - 30/7/2007 6:28 AMQuotespacemuppet - 29/7/2007 10:31 PM
How "deep" into space could the shuttle go if the entire payload bay was loaded with a huge OMS fuel tank? I know this would never happen, just a question for fum.
I do know there were at one point before 1986 plans for an upper stage, I believe they called it "Centaur" or something of the like.
Centaur was for spacecraft, not shuttle. There were other upperstages: IUS, TOS, PAM-D, PAM-D2,
And it was canceled post Challenger for safety reasons. NASA thought a LOX/LH2 payload was too dangerous. If the shuttle had gone RTLS or TAL with a Centaur in the payload, it would have dumped the Centaur's fuel overboard while flying the abort. I used to work with a guy that was working the Centaur abort modes. He was VERY happy when they canceled Centaur on shuttle.
Danny Deger
Post by: brihath on 07/30/2007 04:14 pm
Quote
Danny Dot - 30/7/2007 11:37 AMQuoteJim - 30/7/2007 6:28 AMQuotespacemuppet - 29/7/2007 10:31 PM
How "deep" into space could the shuttle go if the entire payload bay was loaded with a huge OMS fuel tank? I know this would never happen, just a question for fum.
I do know there were at one point before 1986 plans for an upper stage, I believe they called it "Centaur" or something of the like.
Centaur was for spacecraft, not shuttle. There were other upperstages: IUS, TOS, PAM-D, PAM-D2,
And it was canceled post Challenger for safety reasons. NASA thought a LOX/LH2 payload was too dangerous. If the shuttle had gone RTLS or TAL with a Centaur in the payload, it would have dumped the Centaur's fuel overboard while flying the abort. I used to work with a guy that was working the Centaur abort modes. He was VERY happy when they canceled Centaur on shuttle.
Danny Deger
Yes, I remember that. I think the Centaur servicing arm to the fixed service structure was actually built. It was sitting near some other old tower components in the Industrial Area at the Cape. There were several Centaur missions manifested on shuttle. I think Galileo, ISPM were originally manifested for Centaur, then switched to IUS post Challenger. I wonder how the astronauts at the time felt about THAT idea- putting a potential bomb in the payload bay.
Post by: GLS on 07/30/2007 04:46 pm
The base was installed in late 83 or so (39A)... the arm was installed in the summer of 85 (39A), so 7 or so missions had the complete system...
Post by: Antares on 07/31/2007 04:54 pm
Post by: brahmanknight on 07/31/2007 05:00 pm
Post by: Jim on 07/31/2007 05:00 pm
Quote
Antares - 31/7/2007 12:54 PM
Any idea why certain streets in the KSC industrial area are 4 lanes instead of 2? 5th west of C. All of C. E north of 2nd. I assume it was payloads, but that doesn't really explain 5th since it doesn't go to D. Was E widened for Station? Probably not because the O&C is there too.
E was for payloads
5th maybe just an artifact from the intitial contruction
Post by: Austin on 07/31/2007 05:05 pm
Quote
brahmanknight - 31/7/2007 1:00 PM
Does anyone have a clue as to the weight that the SRB's can tolerate before being bent severely? I mean, they hold the ET and the shuttle with a total of eight hold down bolts. I'm just wondering what the limit is, theoretically.
And to piggyback on brahmannight's question (sort of), I've always been amazed that the forward (V-shaped) ET to orbiter attach strut is tough enough to handled the weight and aerodynamic forces of launch, especially the first 2 minutes. How do these suckers hold together? What are they made of?
Post by: Jim on 07/31/2007 05:44 pm
Quote
Austin - 31/7/2007 1:05 PM
And to piggyback on brahmannight's question (sort of), I've always been amazed that the forward (V-shaped) ET to orbiter attach strut is tough enough to handled the weight and aerodynamic forces of launch, especially the first 2 minutes. How do these suckers hold together? What are they made of?
It doesn't carry weight. Only side to side loads and towards/away from the ET loads (no up and down)
The aft Orbiter/ET attachments carry the weight
Post by: Austin on 07/31/2007 06:44 pm
Quote
Jim - 31/7/2007 1:44 PMQuoteAustin - 31/7/2007 1:05 PM
And to piggyback on brahmannight's question (sort of), I've always been amazed that the forward (V-shaped) ET to orbiter attach strut is tough enough to handled the weight and aerodynamic forces of launch, especially the first 2 minutes. How do these suckers hold together? What are they made of?
It doesn't carry weight. Only side to side loads and towards/away from the ET loads (no up and down)
The aft Orbiter/ET attachments carry the weight
Makes sense. Thanks.
Post by: SpaceNutz SA on 07/31/2007 07:24 pm
Quote
henrycheck - 30/7/2007 3:14 PMQuoteSpaceNutz SA - 30/7/2007 7:19 AM Let me put my question in a less confusing manner: A container filled to 2atm at sea level has double the pressure inside than outside. A container filled to 1atm at an outside pressure of 0.5 atm is double the outside pressure. A container filled to 1atm at an outside pressure of 0.25 atm is 4x the outside pressure. A container filled to 1atm at an outside pressure of 0.01 atm is 100x the outside pressure - this is approaching (but not nearly close to) the condition of the orbiter in orbit. How much pressure must the orbiter be exposed to at sea level for the leak check test to be relevant to conditions on orbit? What pressure is actually used for theleak check?Presumably the on-orbit pressure differential is factored into the determination of the allowable sea level leak rate. On orbit the allowable crew cabin leak rate is likely greater than 0.022 psi per 4 hours, which is really a tiny leak rate. 1 / (0.022/4) = 182 hours to drop one psi.
OK - that makes sense - thanks. Also someone pointed out that the leak test is not a pressure test which also makes sense.
Is a pressure test of any kind undertaken at any stage? I mean what determines that the windows won't pop out when the orbiter reaches orbit or before?
Post by: Jim on 07/31/2007 08:13 pm
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SpaceNutz SA - 31/7/2007 3:24 PM
Is a pressure test of any kind undertaken at any stage? I mean what determines that the windows won't pop out when the orbiter reaches orbit or before?
that was done when the shuttle was built
Post by: SpaceNutz SA on 07/31/2007 08:18 pm
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Jim - 31/7/2007 10:13 PMQuoteSpaceNutz SA - 31/7/2007 3:24 PM Is a pressure test of any kind undertaken at any stage? I mean what determines that the windows won't pop out when the orbiter reaches orbit or before?that was done when the shuttle was built
Any detail on these tests available anywhere? Is it re-tested after crew compartment structural work - eg: window replacement?
Post by: Jim on 07/31/2007 08:26 pm
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SpaceNutz SA - 31/7/2007 4:18 PMQuoteJim - 31/7/2007 10:13 PMQuoteSpaceNutz SA - 31/7/2007 3:24 PM Is a pressure test of any kind undertaken at any stage? I mean what determines that the windows won't pop out when the orbiter reaches orbit or before?Is it re-tested after crew compartment structural work - eg: window replacement?
No, Only leak checks are needed. Are you going to retest after every time a hatch is opened? It is only a pressure diffential of 15 psi, that does need repeated pressure tests.
Post by: shuttlefan on 08/01/2007 05:47 pm
Post by: brihath on 08/01/2007 06:52 pm
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shuttlefan - 1/8/2007 1:47 PM
If the hatch has to be reopened after a scrub, is there actually an audible and feelable rush of air that escapes the crew module?
I thought the crew compartment was just pressurized to atmosphere once the crew was on board. You wouldn't want to have a pressure differential when you open the hatch anyway. Could be hazardous to people outside the hatch.
Post by: Jim on 08/01/2007 07:33 pm
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shuttlefan - 1/8/2007 1:47 PM
If the hatch has to be reopened after a scrub, is there actually an audible and feelable rush of air that escapes the crew module?
No, because it isn't pressurized
Post by: Andy_Small on 08/02/2007 04:49 pm
Thanks :)
Post by: Selmuir on 08/04/2007 01:41 pm
I was just wondering in any spaceship what positions do the people take like Engeneer , Pilot etc
Could you tell me all the positions the humans take up
Thanks
Post by: Danny Dot on 08/04/2007 02:26 pm
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Selmuir - 4/8/2007 8:41 AM
Hi ,
I was just wondering in any spaceship what positions do the people take like Engeneer , Pilot etc
Could you tell me all the positions the humans take up
Thanks
In the shuttle the commander is really the pilot (as well as the commander), the pilot is really the co-pilot (the commander does 99% of the piloting), Mission Specialist -2 (MS-2) is the flight engineer. The other MS's are full time shuttle people. Payload Specialists are anyone else flying that are not full time shuttle astronauts (e.g. senators, teachers, etc.).
Can't speak for other systems.
Danny Deger
Post by: Selmuir on 08/04/2007 06:03 pm
Sorry for all these questions but i serched for a topic like this and i couldent find any so anyway heres my question,
If i wanted to become a Astronaut where would i start because i live in Scotland ?
Thanks
Post by: SpaceNutz SA on 08/04/2007 06:07 pm
Post by: Danny Dot on 08/04/2007 06:21 pm
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SpaceNutz SA - 4/8/2007 1:07 PM
What determines the launch window on an ISS bound flight? Is it the position of the ISS relative to KSC? If so why then does it take about 2 days to play catch-up once in orbit?
Let me try to answer this using simple English instead of NASA jargon. The launch window is defined by the left and right -- crosstrack -- part of getting into the right orbit. When the ground track of station is over Florida, the shuttle launches. The station can be right over Florida, or it can be on the other side of the Earth. It doesn't matter. The shuttle launches anyway.
Catching up over time is the fore and aft part of getting to station. It is possible, if the fore and aft is just right, to rendezvous sooner -- Gemini used to rendezvous a couple of hours after launch. Some of the reasons for the delay in rendezvous is to give the crew time to transition the shuttle to orbit ops, day 2 is now dedicated to looking over the shuttle's thermal protection system, and sometimes crew members have motion sickness the first couple of days. Even if the orbital mechanics line up for a rendezvous on day 1 or day 2, the rendezvous is slowed down for other scheduling reasons. The rate of catch up is based on how much lower the shuttle is than the station. If at the same altitude, there is no catchup. If you need to catch up a lot, the shuttle is kept at a lower orbit.
Danny Deger
Post by: Selmuir on 08/04/2007 06:25 pm
Quote
Selmuir - 4/8/2007 1:03 PM
Hi ,
Sorry for all these questions but i serched for a topic like this and i couldent find any so anyway heres my question,
If i wanted to become a Astronaut where would i start because i live in Scotland ?
Thanks
Anyone ?
Post by: TFGQ on 08/04/2007 07:05 pm
Post by: MKremer on 08/04/2007 07:40 pm
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Selmuir - 4/8/2007 1:03 PM"Astronaut" isn't a career (and won't be for a long, long time). If you read through all the bio's for both NASA and ESA astronauts, all those people already had established, successful careers in lots of different fields (most with advanced college degrees) for many years until they applied and were finally accepted for astronaut training. Even the Shuttle pilots are mostly career military (with test pilot training) and have years and years of flying experience (and also have advanced degrees).
If i wanted to become a Astronaut where would i start because i live in Scotland ?
Thanks
The other option would be new.space - private spaceflight companies - but even then they'll likely only be hiring highly experienced test pilots for a while.
Post by: MKremer on 08/04/2007 07:41 pm
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TFGQ - 4/8/2007 2:05 PM
i have a question at T-3hrs i noticed water comming out of the side of the water tower what is the reason for that
Overflow from pumping water to top off the water tank.
Post by: brahmanknight on 08/04/2007 08:51 pm
Post by: Jim on 08/04/2007 10:02 pm
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brahmanknight - 4/8/2007 4:51 PM
How is power supplied to the orbiter on the ground?
Through the T-0 umbilicals
Post by: SpaceNutz SA on 08/05/2007 06:31 am
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Danny Dot - 4/8/2007 8:21 PMQuoteSpaceNutz SA - 4/8/2007 1:07 PM What determines the launch window on an ISS bound flight? Is it the position of the ISS relative to KSC? If so why then does it take about 2 days to play catch-up once in orbit?Let me try to answer this using simple English instead of NASA jargon. The launch window is defined by the left and right -- crosstrack -- part of getting into the right orbit. When the ground track of station is over Florida, the shuttle launches. The station can be right over Florida, or it can be on the other side of the Earth. It doesn't matter. The shuttle launches anyway. Catching up over time is the fore and aft part of getting to station. It is possible, if the fore and aft is just right, to rendezvous sooner -- Gemini used to rendezvous a couple of hours after launch. Some of the reasons for the delay in rendezvous is to give the crew time to transition the shuttle to orbit ops, day 2 is now dedicated to looking over the shuttle's thermal protection system, and sometimes crew members have motion sickness the first couple of days. Even if the orbital mechanics line up for a rendezvous on day 1 or day 2, the rendezvous is slowed down for other scheduling reasons. The rate of catch up is based on how much lower the shuttle is than the station. If at the same altitude, there is no catchup. If you need to catch up a lot, the shuttle is kept at a lower orbit. Danny Deger
Thanks Danny - nice explanation which is partly understood :)
So if I understand: the ground track over the launch site is important to put the shuttle in the same orbit as the station although with some displacement in distance. The launch trajectory of the shuttle is designed to put the shuttle in the same 51.6deg inclination as the ISS - it's just a case of waiting for the ISS to be on the correct ground track so that the 2 orbits co-incide. Am I understanding this correctly? One part I don't understand is why the launch window is so short. The ISS ground track will be 'over' the launch site for an entire orbit which is 92 minutes. Why then is the launch window only in the order of 10 min's long? The part about delayed rendezvoux for mission activities is understood.
Is there a good online tutorial on orbital mechanics?
Thanks
Post by: MKremer on 08/05/2007 07:00 am
If you think about it that way, you can see the Shuttle has a limited period of time to launch, so that by the time it reaches orbit it's own orbital line (which by then is now also moving West every second) closely matches the ISS orbit line. If it launches too early, or too late, it will require too much extra propellent for additional burns to align both orbits.
That limited time is the launch window. If they manage to get the launch off exactly right, the orbiter will only need tiny alignment corrections and preserve propellent for the rendezvous burns themselves.
Try this link for orbital mechanics: http://www.braeunig.us/space/orbmech.htm
Post by: SpaceNutz SA on 08/05/2007 08:52 am
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MKremer - 5/8/2007 9:00 AM It may be easier to think of the ISS orbit track as a solid line (a circle around the Earth, angled at 51.6 degrees) - as the Earth rotates, that solid line keeps moving further West every second (the orbit is fixed - the Earth rotates underneath it). If you think about it that way, you can see the Shuttle has a limited period of time to launch, so that by the time it reaches orbit it's own orbital line (which by then is now also moving West every second) closely matches the ISS orbit line. If it launches too early, or too late, it will require too much extra propellent for additional burns to align both orbits. That limited time is the launch window. If they manage to get the launch off exactly right, the orbiter will only need tiny alignment corrections and preserve propellent for the rendezvous burns themselves. Try this link for orbital mechanics: http://www.braeunig.us/space/orbmech.htm
Many thanks for that - much clearer now.
Post by: HarryM on 08/05/2007 02:10 pm
Post by: Danny Dot on 08/05/2007 02:33 pm
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SpaceNutz SA - 5/8/2007 3:52 AMQuoteMKremer - 5/8/2007 9:00 AM It may be easier to think of the ISS orbit track as a solid line (a circle around the Earth, angled at 51.6 degrees) - as the Earth rotates, that solid line keeps moving further West every second (the orbit is fixed - the Earth rotates underneath it). If you think about it that way, you can see the Shuttle has a limited period of time to launch, so that by the time it reaches orbit it's own orbital line (which by then is now also moving West every second) closely matches the ISS orbit line. If it launches too early, or too late, it will require too much extra propellent for additional burns to align both orbits. That limited time is the launch window. If they manage to get the launch off exactly right, the orbiter will only need tiny alignment corrections and preserve propellent for the rendezvous burns themselves. Try this link for orbital mechanics: http://www.braeunig.us/space/orbmech.htmMany thanks for that - much clearer now.
Even I understand it now :-)
Danny Deger
Post by: brahmanknight on 08/05/2007 07:06 pm
Post by: Lee Jay on 08/05/2007 07:10 pm
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brahmanknight - 5/8/2007 1:06 PM
What moves the RSS? A modified locamotive?
Small electric motors.
http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=29136
Post by: el_nino on 08/06/2007 12:02 am
Post by: Danny Dot on 08/06/2007 12:17 am
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el_nino - 5/8/2007 7:02 PM
With the talk of launch windows earlier on this page, I have a question about them. I understand how and why we have a window for the missions that rendevous with the ISS. However, my question is what about the earlier shuttle missions? What determined a launch window for one of the missions that were going to deploy a communications satellite? There was nothing in orbit they were already trying to catch up to. Now, I understand there are things such as the amount of daylight at the TAL sites, etc. but was there more to it than that? For instance, I witnessed the launch of STS-29 and if I recall they were launching one of the TDRS satellites on that mission. Lift off happened shortly before 10am that day after a long delay because of fog. They had a 2.5 hour launch window that day. What determined the length of that window? It certainly wasn't dark at the TAL sites by then yet.
The time the crew can stay in the cockpit is often the limit for these flights.
Danny Deger
Post by: Jim on 08/06/2007 12:27 am
Post by: mkirk on 08/06/2007 03:59 am
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Jim - 5/8/2007 7:27 PM
crew on back times was a 2.5 to 3 hour limit
More precisely the LCC (launch commit criteria) is 5 hours 15 minutes in the Launch Seat Posture, so subtract Ingress time and that gives you the availabel hold time based on being in the seat.
Of course as most of you all know the current launch windows never come up against this constraint.
Mark Kirkman
Post by: STS-500Cmdr on 08/06/2007 05:57 am
Post by: psloss on 08/06/2007 09:56 am
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STS-500Cmdr - 6/8/2007 1:57 AMPrior to the station rendezvous/docking missions that began in 1995, there were others besides the Spacelab missions...IIRC, the last long hold at T-9 minutes was probably for STS-64 (approx. 2 hours on a mid/late afternoon in Sept. 1994).
The 5 plus hours rule would apply to missions such as a Spacelab mission
After STS-63, it was pretty much station, Spacelab, and HST servicing missions (the latter usually having approx. 60 minute launch windows), with a few exceptions like STS-95 or STS-99.
Post by: henrycheck on 08/06/2007 10:22 am
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el_nino - 5/8/2007 8:02 PM
With the talk of launch windows earlier on this page, I have a question about them. I understand how and why we have a window for the missions that rendevous with the ISS. However, my question is what about the earlier shuttle missions? What determined a launch window for one of the missions that were going to deploy a communications satellite? There was nothing in orbit they were already trying to catch up to. Now, I understand there are things such as the amount of daylight at the TAL sites, etc. but was there more to it than that? For instance, I witnessed the launch of STS-29 and if I recall they were launching one of the TDRS satellites on that mission. Lift off happened shortly before 10am that day after a long delay because of fog. They had a 2.5 hour launch window that day. What determined the length of that window? It certainly wasn't dark at the TAL sites by then yet.
I think the question here might be more general like “Why is there a launch window at all?” On such missions as TDRS launches “Why not just always launch at 10:30 AM, say?”
Possible considerations would be the allowable time between launch and the two IUS firings (thermal and power issues), the need to have the IUS burns occur within the tracking view of the IUS control center at White Sands, and a maximum amount of drift from the initial geostationary longitude to the final orbital location.
Post by: psloss on 08/06/2007 11:35 am
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henrycheck - 6/8/2007 6:22 AMAnother example from the STS-7 press kit (http://www.jsc.nasa.gov/history/shuttle_pk/pk/Flight_007_STS-007_Press_Kit.pdf):
Possible considerations would be the allowable time between launch and the two IUS firings (thermal and power issues), the need to have the IUS burns occur within the tracking view of the IUS control center at White Sands, and a maximum amount of drift from the initial geostationary longitude to the final orbital location.
Quote
The opening of the first segment of the launch window is driven by the earth horizon sensor (EHS) sun "cutout" constraint on the Palapa B spacecraft for a revolution 19A injection. This opening time also roughly corresponds to the revolution 113 Edwards Air Force Base landing lighting constraint. This first segment is closed by an earth horizon sensor constraint on the Anik C spacecraft for a revolution 8A injection.
The opening of the second segment is driven by an earth horizon sensor Palapa B constraint for a revolution 19A injection. The second segment is closed by the aft thermal constraint on the Anik C for a revolution 8A injection.
Post by: Jim on 08/06/2007 12:10 pm
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henrycheck - 6/8/2007 6:22 AM
Possible considerations would be the allowable time between launch and the two IUS firings (thermal and power issues), the need to have the IUS burns occur within the tracking view of the IUS control center at White Sands, and a maximum amount of drift from the initial geostationary longitude to the final orbital location.
IUS control center was in the AFSCF and the burns could be in view of the many AFSCN stations
Post by: henrycheck on 08/06/2007 01:29 pm
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Jim - 6/8/2007 8:10 AMJim,Quotehenrycheck - 6/8/2007 6:22 AM
Possible considerations would be the allowable time between launch and the two IUS firings (thermal and power issues), the need to have the IUS burns occur within the tracking view of the IUS control center at White Sands, and a maximum amount of drift from the initial geostationary longitude to the final orbital location.
IUS control center was in the AFSCF and the burns could be in view of the many AFSCN stations
You're the undoubted expert here but I have some recollection of early IUS missions requiring direct White Sands tracking. I also recall a launch where there was an issue with the availability of the White Sands tracking site, although that might be the drugs from the sixties playing tricks with me.
Post by: psloss on 08/06/2007 01:43 pm
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henrycheck - 6/8/2007 9:29 AMThis is a wild "reach," but is it possible that you're thinking of delays to STS-8 and STS-9 in order to allow TDRS-1 verification testing (at White Sands) to progress?
I also recall a launch where there was an issue with the availability of the White Sands tracking site, although that might be the drugs from the sixties playing tricks with me.
Post by: henrycheck on 08/06/2007 02:57 pm
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psloss - 6/8/2007 9:43 AMQuotehenrycheck - 6/8/2007 9:29 AMThis is a wild "reach," but is it possible that you're thinking of delays to STS-8 and STS-9 in order to allow TDRS-1 verification testing (at White Sands) to progress?
I also recall a launch where there was an issue with the availability of the White Sands tracking site, although that might be the drugs from the sixties playing tricks with me.
The circumstance I'm remembering was after the down period following the first IUS partial failure on STS-6. Might only have been a launch hold or a one-or-two day postponement. Don’t waste too much time researching this as I sort of remember Elvis being at the launch.
Post by: psloss on 08/06/2007 03:19 pm
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henrycheck - 6/8/2007 10:57 AMNo worries -- just wondering...
The circumstance I'm remembering was after the down period following the first IUS partial failure on STS-6. Might only have been a launch hold or a one-or-two day postponement. Don’t waste too much time researching this as I sort of remember Elvis being at the launch.
Post by: Jim on 08/06/2007 04:57 pm
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henrycheck - 6/8/2007 9:29 AMQuoteJim - 6/8/2007 8:10 AMJim,Quotehenrycheck - 6/8/2007 6:22 AM
Possible considerations would be the allowable time between launch and the two IUS firings (thermal and power issues), the need to have the IUS burns occur within the tracking view of the IUS control center at White Sands, and a maximum amount of drift from the initial geostationary longitude to the final orbital location.
IUS control center was in the AFSCF and the burns could be in view of the many AFSCN stations
You're the undoubted expert here but I have some recollection of early IUS missions requiring direct White Sands tracking. I also recall a launch where there was an issue with the availability of the White Sands tracking site, although that might be the drugs from the sixties playing tricks with me.
TDRS control center is a White Sands
Post by: SpaceNutz SA on 08/06/2007 09:54 pm
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MKremer - 5/8/2007 9:00 AM It may be easier to think of the ISS orbit track as a solid line (a circle around the Earth, angled at 51.6 degrees) - as the Earth rotates, that solid line keeps moving further West every second (the orbit is fixed - the Earth rotates underneath it). If you think about it that way, you can see the Shuttle has a limited period of time to launch.....
Spent some time pondering this which prompts another question. When the earth rotates under this orbital circle, KSC can pass under this circle in 2 different positions each day - one where the ISS has a NE track and the other on a SE track. Obviously the launch trajectory would be different in each case. Is either of these situations prefered? Is the shuttle equipped (by way of different launch trajectories) for each case?
BTW thanks for the reference to the orbital mechanics tutorials sites. Been doing the online tutorials with varying degrees of success.
Post by: DaveS on 08/06/2007 10:02 pm
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SpaceNutz SA - 6/8/2007 11:54 PMYes, they always launch on Ascending Node pass, this when the track travells up towards the north pole as that's where the TAL sites are, in addition to that you pass over the Atlantic during early launch.
Is either of these situations prefered?
Launching on a Descending Node pass you wouldn't have access to any of the TAL sites plus you would come dangerously close to dumping the SRBs into Cuban or Bahamas waters.
Just imagine all the political trouble NASA would have to go through just to recover the spent SRBs.
Post by: Jorge on 08/06/2007 10:03 pm
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SpaceNutz SA - 6/8/2007 4:54 PMQuoteMKremer - 5/8/2007 9:00 AM It may be easier to think of the ISS orbit track as a solid line (a circle around the Earth, angled at 51.6 degrees) - as the Earth rotates, that solid line keeps moving further West every second (the orbit is fixed - the Earth rotates underneath it). If you think about it that way, you can see the Shuttle has a limited period of time to launch.....Spent some time pondering this which prompts another question. When the earth rotates under this orbital circle, KSC can pass under this circle in 2 different positions each day - one where the ISS has a NE track and the other on a SE track. Obviously the launch trajectory would be different in each case. Is either of these situations prefered?
The northerly trajectory is not only preferred, the southerly one is forbidden due to range safety considerations for SRB splashdown/ET debris footprint.
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Is the shuttle equipped (by way of different launch trajectories) for each case?
No.
Post by: SpaceNutz SA on 08/06/2007 10:19 pm
Post by: DaveS on 08/06/2007 10:46 pm
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SpaceNutz SA - 7/8/2007 12:19 AMYes, it's called the Launch Hazard Area(LHA). The Superintendent for Range Operations(SRO) can call a hold in countdown if a boat goes into the restricted waters. Same thing goes for unauthorized aircraft.
OK - understood. How is commercial shipping traffic restricted in the SRB splashdown zone? Does NASA (or the US) have jurisdiction over that area of ocean during launch? I'd guess some precautions would need to be considered aganst and SRB landing on the deck of a commercial vessel.
Here's the LHA notice for STS-118: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=8328&start=51#M167374
Post by: Jim on 08/06/2007 11:57 pm
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SpaceNutz SA - 6/8/2007 6:19 PM
OK - understood. How is commercial shipping traffic restricted in the SRB splashdown zone? Does NASA (or the US) have jurisdiction over that area of ocean during launch? I'd guess some precautions would need to be considered aganst and SRB landing on the deck of a commercial vessel.
A Notice to Mariners is issued
It is in international waters, no one has jurisdiction.
Post by: shuttlefan on 08/07/2007 01:39 pm
Post by: DaveS on 08/07/2007 01:45 pm
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shuttlefan - 7/8/2007 3:39 PMThere's some wiring between the crew module and the forward fuselage that cannot be inspected.
After an orbiter is built, can every inch of its wiring be inspected, or is there some that the technicians can't get at? ;)
Post by: el_nino on 08/07/2007 05:44 pm
Post by: shuttlefan on 08/07/2007 05:52 pm
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el_nino - 7/8/2007 12:44 PM
The problems with the SRB's before mission STS-51L have been well documented. I know that during the down time between STS-51L and STS-26 that the SRB's were redesigned with a 3rd o-ring, heaters, etc. Have there been any problems with the SRB's that could have caused another disaster during launch since STS-26?
Basically, no. There were some concerns in 1993 with the chamber pressures in the SRBs. On some launches one SRB had more chamber pressure than the other one. That was was taken care of.(Maybe Jim or somebody could elaborate more on this.) Also in 1995 there was some very minor o-ring erosion discovered after STS-71 and STS-70 but that was also corrected.
Also in 1996 on STS-79, some of the nozzle insulation was eroded but prior to the next flight, STS-80, they took care of it. In terms of nearly causing a disaster, though, I don't think there were any major problems after 51-L. ;)
Post by: shuttlefan on 08/07/2007 05:54 pm
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DaveS - 7/8/2007 8:45 AMQuoteshuttlefan - 7/8/2007 3:39 PMThere's some wiring between the crew module and the forward fuselage that cannot be inspected.
After an orbiter is built, can every inch of its wiring be inspected, or is there some that the technicians can't get at? ;)
That wiring would probably be less-susceptable to damage though, because it gets left alone, correct?
Post by: Endeavour118 on 08/07/2007 06:43 pm
Post by: psloss on 08/07/2007 06:47 pm
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Endeavour118 - 7/8/2007 2:43 PMSTS-33
what was the first NIGHT launch after the challenger disaster?
Post by: el_nino on 08/07/2007 07:06 pm
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shuttlefan - 7/8/2007 1:52 PM
Also in 1996 on STS-79, some of the nozzle insulation was eroded but prior to the next flight, STS-80, they took care of it.
Was this the same problem that nearly caused disaster on STS-8?
Post by: LSainsbury on 08/08/2007 12:21 pm
Just joined up on L2 so awaiting the launch later today!
I have a question: Have there been any missions that have nearly invoked an abort option like RTLS, or any of the other abort options?
Post by: Jim on 08/08/2007 12:26 pm
I corrected my error
Post by: psloss on 08/08/2007 12:27 pm
Post by: LSainsbury on 08/08/2007 12:30 pm
What are the chances of an RTLS during launch? I don't think any have occurred so far, what are the chances of one happening during the rest of the STS's life?
Post by: shuttlefan on 08/08/2007 12:41 pm
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LSainsbury - 8/8/2007 7:30 AM
What are the chances of an RTLS during launch? I don't think any have occurred so far, what are the chances of one happening during the rest of the STS's life?
No RTLS has ever ocurred. The chances of one ocurring during the rest of the program are very small.
Post by: Lee Jay on 08/08/2007 01:54 pm
Post by: Jim on 08/08/2007 02:01 pm
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Lee Jay - 8/8/2007 9:54 AM
Is tank fill/tank topping stopped before engine start at t-6.6 seconds, or do the tanks continue to receive propellant while the engines are running?
Replenishing ends earlier in the count. LO2 at 4:55 and LH2 at 1:57
Post by: Lee Jay on 08/08/2007 02:17 pm
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Jim - 8/8/2007 8:01 AMQuoteLee Jay - 8/8/2007 9:54 AM
Is tank fill/tank topping stopped before engine start at t-6.6 seconds, or do the tanks continue to receive propellant while the engines are running?
Replenishing ends earlier in the count. LO2 at 4:55 and LH2 at 1:57
Wow...that's kind of early. Is this done so early in order to stabilize tank pressure for launch, or is there some other reason?
Post by: Jim on 08/08/2007 02:30 pm
Post by: brahmanknight on 08/08/2007 05:54 pm
Post by: DaveS on 08/08/2007 06:19 pm
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brahmanknight - 8/8/2007 7:54 PM1: It has 76 wheels
What is the 36 wheeled transporter named that moves the shuttle from OMF to VAB?
2: It's OPF, not OMF
3: It's called the Orbiter Transporter System or OTS for short.
Post by: Lee Jay on 08/08/2007 06:52 pm
Post by: mkirk on 08/08/2007 06:59 pm
But it also says that max thrust (vacuum) at 60 degrees F is 3,160,498 lbs and at 90 degrees F it is 3,306,190 lbs.
Mark Kirkman
Post by: Lee Jay on 08/08/2007 07:12 pm
Post by: kneecaps on 08/08/2007 08:28 pm
I've created these with a tone generator based on what the Shuttle Crew Operations manual says they sound like (frequencies and times).
I've heard the SM and Class 2 alarms direct from nasa sources (background during missions)..so I think they are fine...but I can't vouch for the class 1's ....:)
EDIT: Siren has been updated... joshb noticed it was wrong vs spec
Post by: joshb on 08/08/2007 08:46 pm
Post by: Andy_Small on 08/08/2007 08:48 pm
Quote
joshb - 8/8/2007 3:46 PM
Thanks kneecaps
INDEED! Thank you
Post by: Jim on 08/08/2007 09:52 pm
Post by: mkirk on 08/08/2007 09:55 pm
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Jim - 8/8/2007 4:52 PM
Mark Kirkman would have to make the final call, but they don't sound like what I have heard
I have all my players streaming video/data right now so I will have to listen to them post launch...those sounds are burned into my brain as I am sure they are for a couple of other folks here so we should be able to judge them acurately.
Mark Kirkman
Post by: stockman on 08/08/2007 11:03 pm
What is that exactly??
Post by: kneecaps on 08/08/2007 11:10 pm
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stockman - 8/8/2007 12:03 AM
What are those tubes they have on their arms??? While the crew was getting prepped in the white room one at a time I noticed for the first time one of the USA workers put what looked like a 5 to 6 inch blue tube inside a pocket on the crew members arm ( I think there may have been one on each arm). It appeared to be a liquid but I am not sure.
What is that exactly??
They are simple Cyalume Light sticks. You snap them and they light up. Its a rescue aid for if the crew had to bail out and be rescued from sea.
Post by: DaveS on 08/08/2007 11:12 pm
Quote
stockman - 9/8/2007 1:03 AMGlow sticks. Used in low visibility situations to locate crew members.
What are those tubes they have on their arms??? While the crew was getting prepped in the white room one at a time I noticed for the first time one of the USA workers put what looked like a 5 to 6 inch blue tube inside a pocket on the crew members arm ( I think there may have been one on each arm). It appeared to be a liquid but I am not sure.
What is that exactly??
Post by: mastronaut on 08/08/2007 11:15 pm
Post by: MKremer on 08/08/2007 11:19 pm
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mastronaut - 8/8/2007 6:15 PM
During the first 10-15 seconds into Endeavour's launch I noticed what looked like a flare or hiccup from one of the SSMEs is this normal? It can be seen quite plainly on the launch replay...
I saw that, too. Not sure if it was from the engine itself, but it was right around the time when the throttle bucket starts occuring.
Post by: mastronaut on 08/08/2007 11:22 pm
Post by: j2_ on 08/08/2007 11:27 pm
Post by: MKremer on 08/08/2007 11:29 pm
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j2_ - 8/8/2007 6:27 PM
How long does the ET LO2 feed line camera continue transmitting after ET sep?
Until the batteries run out or it gets destroyed with the rest of the tank on reentry. Not sure how long NASA continues recieving and recording the signal, though.
Post by: Danny Dot on 08/08/2007 11:51 pm
Danny Deger
Post by: Danny Dot on 08/08/2007 11:57 pm
Danny Deger
Post by: SpaceNutz SA on 08/08/2007 11:57 pm
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Danny Dot - 9/8/2007 1:51 AM I just heard a second shuttle will be on the second pad ready to go during the shuttle's Hubble repair mission. Is there a plan to be able to move all crew members to the second shuttle if the first is crippled? Danny Deger
For the LON mission - the crew do not have the ISS to take refuge on so the normal 40-day call-up for the LON will not work. The LON mission needs to be on the pad before the HST mission launches.
Post by: Danny Dot on 08/09/2007 12:02 am
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SpaceNutz SA - 8/8/2007 6:57 PMQuoteDanny Dot - 9/8/2007 1:51 AM I just heard a second shuttle will be on the second pad ready to go during the shuttle's Hubble repair mission. Is there a plan to be able to move all crew members to the second shuttle if the first is crippled? Danny DegerFor the LON mission - the crew do not have the ISS to take refuge on so the normal 40-day call-up for the LON will not work. The LON mission needs to be on the pad before the HST mission launches.
But if the LON is needed, how does the crew transfer to the second shuttle? Are the shuttles going to fly close to each other and have the entire crew EVA over?
Danny Deger
Post by: SpaceNutz SA on 08/09/2007 12:07 am
There is quite a bit of info in the threads and on the internet.
Post by: erioladastra on 08/09/2007 12:39 am
Bad shuttle leaves ISS remotely and reenters. New shuttle docks to ISS.
Post by: MKremer on 08/09/2007 12:46 am
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Danny Dot - 8/8/2007 7:02 PMI believe there's an older L2 thread detailing some of the docking and crew transfer options for the STS-125 LON mission.
But if the LON is needed, how does the crew transfer to the second shuttle? Are the shuttles going to fly close to each other and have the entire crew EVA over?
Danny Deger
Post by: elmarko on 08/09/2007 08:19 am
Quote
erioladastra - 9/8/2007 1:39 AM
"But if the LON is needed, how does the crew transfer to the second shuttle? Are the shuttles going to fly close to each other and have the entire crew EVA over? "
Bad shuttle leaves ISS remotely and reenters. New shuttle docks to ISS.
Danny's question was specifically related to the HST mission.
Post by: Danny Dot on 08/09/2007 03:26 pm
Three options are currently being considered for docking the two Orbiters, and for transferring the crew from the crippled HSM vehicle to the rescue Orbiter. In the first, and apparently preferred, option, the Remote Manipulator System on the HSM Orbiter would grapple the Shuttle Crew Rescue (SCR) Orbiter. The SCR RMS would be used to transfer the crew, suited for EVA, from the HSM Orbiter to the SCR vehicle. This unique dual-RMS operation would eliminate the need for labor-intensive stationkeeping.
Two EVAs would occur on Flight Day 4. During the first EVA, the flight crew member responsible for RMS operation on the HSM flight would be transferred to the SCR. In addition, the SCR RMS would be used to transfer 4 Launch and Entry Suits (LES) from the HSM vehicle to the SCR, and two additional Extravehicular Mobility Units (EMUs) would be transferred from the SCR to the HSM.
Danny Deger
Post by: SpaceNutz SA on 08/09/2007 03:55 pm
One thing is for sure - if it ever came to this (on this mission or any other) it will be game over for any future shuttle flights.
Post by: HarryM on 08/09/2007 04:45 pm
Post by: HarryM on 08/09/2007 04:49 pm
http://upload.wikimedia.org/wikipedia/en/9/97/Sts-300.recumbent-seats.png
Post by: bernse on 08/09/2007 05:08 pm
I recall during the Columbia investigation, there was talking about using other assets to image the vehicle during orbit.
Now, I seem to vaguely recall very early in the program (STS-1 or 2) seeing images on TV of the shuttle in orbit, taken from a ground based telescope. The resolution likely wouldn't have been good enough to see Columbia sized damage, but nevertheless, it wasn't a terrible image. I remember the atmosphere distorting the image a bit too. I seem to also recall the image was taken from Hawaii.
Assuming I'm not dreaming of that (I was about 10 years old at the time!) does anyone else recall "official" ground based photos/imaging? These were nothing like some of the images we see often now from amateurs of it in orbit, it was a quite large, somewhat "clear" image I think with the idea of seeing if there was major sections of tile shedding.
Secondly, are there any publicly available images of the shuttle made from other assets in orbit (other than ISS)? I'm thinking something like keyhole satellite? Or heck, even Soviet if anyone knows of such a thing?
Post by: Jim on 08/09/2007 06:27 pm
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-107/html/jsc2003e13227.html
Not going to see phots from "other" assets
Post by: Jorge on 08/09/2007 06:31 pm
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HarryM - 9/8/2007 11:45 AM
How many crew on the LON flight?
Four. CDR, PLT, and two EVA-qualed MSes.
Post by: bernse on 08/09/2007 07:11 pm
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Jim - 9/8/2007 12:27 AMThanks very much! Ironic it's of 107. If only the resolution was a bit better. :(
see here
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-107/html/jsc2003e13227.html
Not going to see phots from "other" assets
Post by: SpaceNutz SA on 08/09/2007 07:16 pm
Post by: Danny Dot on 08/09/2007 07:20 pm
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SpaceNutz SA - 9/8/2007 2:16 PM
How would the shuttle perform if it did not do the normal throttle-down-throttle-up through Max Q (ie: went through it at full taps)?
I am not sure how much more payload could be carried, but the orbiter would arrive into space without any wings :)
Danny Deger
Post by: SpaceNutz SA on 08/09/2007 07:34 pm
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Danny Dot - 9/8/2007 9:20 PMQuoteSpaceNutz SA - 9/8/2007 2:16 PM How would the shuttle perform if it did not do the normal throttle-down-throttle-up through Max Q (ie: went through it at full taps)?I am not sure how much more payload could be carried, but the orbiter would arrive into space without any wings :) Danny Deger
Thanks Danny. I recall someone posted a graph of the velocity, dynamic pressure and altitude vs time some time back but I can't seem to find it. Anyone have the link to this graph? Thanks
Post by: Lee Jay on 08/09/2007 08:52 pm
That morning, I was watching preparations on TV before school. Just before I left, they announced that the flight had been canceled due to weather and they were about to begin detanking. I grabbed my bag and went to school. A few hours later I heard about the accident and couldn't understand how the thing could have "exploded" (the term that was used at the time) when it had no fuel. A few minutes later I found out it was in flight when it was destroyed and was even more perplexed.
Does anyone remember a mistaken announcement or a release by NASA that could have been mistaken by TV news as a cancellation? I remember very specifically the cancellation call and I wasn't that young (16 - 10th grade) so I don't think it was me.
Post by: bernse on 08/09/2007 10:35 pm
Grade 8 Science Class. I remember the news vividly. We were watching some taped broadcast about Voyager @ Uranus and at the tail end they had a news blurb about the Shuttle launch. The teacher kept that recorded news blurb about the shuttle on, and immediately afterward, he said "I left that part on as I just heard on the news that it reportedly exploded just after launch." :(
Post by: SpaceNutz SA on 08/10/2007 01:32 pm
Post by: Jim on 08/10/2007 04:13 pm
There doesn't need to be more detail.
Post by: Lee Jay on 08/10/2007 04:42 pm
Post by: USFJoseph on 08/11/2007 11:57 am
For those who have not read FD04 Execute Package:
Quote
MSG 026 (15-0902) - EXECUTE PACKAGE SNEAKERNET FROM ISS SSCS
Page 1 of 1
The following procedure should be followed on MCC “Go” to perform a sneakernet transfer
of execute package messages from the ISS SSCs to the Shuttle PGSCs. During the
docked timeframe, the Shuttle Ku coverage is very limited in the hours before crew wakeup
due to ISS blockage. The Shuttle OCA OFFICER will uplink the Shuttle execute package to
a Shuttle PCMCIA card (inserted into an ISS SSC) and you (shuttle crew) will move the
PCMCIA card to a Shuttle PGSC in the morning and run a batch file to copy the execute
package files to their standard location on the KFX PGSC.
Prior to Sleep,
1. Insert a Shuttle "Late Update" PCMCIA card into an ISS SSC (SSC 4 or 6 should
be fine, but coordinate with the ISS crew).
2. Verify that KFX is running on that SSC.
3. Inform the MCC which SSC was used.
During sleep,
The MCC will uplink the execute package files to the PCMCIA card in the SSC
At Wakeup,
1. Remove the "Late Update" PCMCIA card from the SSC in the ISS
2. Insert the "Late Update" PCMCIA card into the KFX PGSC in the Shuttle
3. On the KFX PGSC Desktop, double click the "DistributeShuttleUplink.bat" icon.
This will copy all of the files from the PCMCIA card to the correct folders on the
KFX PGSC.
4. On the KFX Desktop, double click the "Ex Pkg # 2" shortcut to initiate the printing
of the messages.
Post by: Jim on 08/11/2007 12:17 pm
Shared power was major mod.
Post by: C5C6 on 08/11/2007 02:38 pm
Post by: LSainsbury on 08/11/2007 03:10 pm
Post by: Launch Fan on 08/11/2007 03:28 pm
Post by: j2_ on 08/11/2007 03:32 pm
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C5C6 - 11/8/2007 7:38 AM
I'm watching EVA1 preparations and there are two astronauts wearing the spacesuits and other two helping them......the camp-out is done by those four or only by the 'spacewalkers'???
Only the spacewalkers participate in the camp-out.
Post by: Thorny on 08/11/2007 03:51 pm
Quote
Lee Jay - 9/8/2007 3:52 PM
Does anyone remember a mistaken announcement or a release by NASA that could have been mistaken by TV news as a cancellation? I remember very specifically the cancellation call and I wasn't that young (16 - 10th grade) so I don't think it was me.
It was delayed all morning by the cold temperature, but there was no scrub call. One of the talking heads on Morning TV must have misinterpreted a comment about extended holds due to weather for a scrub of the launch.
Post by: erioladastra on 08/12/2007 01:05 am
As someone already noted, the orbiter only has laptops and ancient GPCs. Only minimal caution and warning data is exchanged and some other commands and telemetry but no real network between the ISS and orbiter laptops. So if they want to exchange info it is sneakernet.
Post by: parham55 on 08/12/2007 01:20 am
Post by: MKremer on 08/12/2007 02:28 am
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parham55 - 11/8/2007 8:20 PM
Is the orbiter/ISS stack traveling -X in the velocity vector to protect the TPS, or is it maybe a radiator issue? Thanks.
The former. It's only in that attitude when an orbiter is docked.
Post by: dantdbv on 08/12/2007 06:46 am
These have annoyed me for a while, so now is the time to do something about it.
On the STS-1 & STS-2 ET's there were black numbers as seen on the pics mentioned below, but i haven't seen anything about them anywhere.
What i would like to know is, if any of you know what, why, how and when they are, and if you do know, then please share it with me.
These pics were from the now defunct STSliftof site, i've made an 11MB rar file and have uploaded it on rapidshare.com
http://rapidshare.com/files/48466406/sts12etn.rar.html Scroll down and click on the free button. If you see these lines, then XXX tells you how long you have to wait until you can download again.
You have reached the download-limit for free-users. Want to download more? (in red)
Get your own Premium-account now! Instant download-access! (Or wait XXX minutes)
Use winrar or similar to unpack the file
KSC-80pc-746 3.574KB
KSC-80pc-747 3.320KB
80pc-0608 1.865KB
80pc-0709 1.614KB
And these from KSC, if you don't like to go straight to the highress pics, then go here to get the options
http://images.ksc.nasa.gov/photos/1981
Or browse through KSC pics from 1950 to 2005 here
http://images.ksc.nasa.gov/photos
STS-1 http://images.ksc.nasa.gov/photos/1981/high/KSC-81PC-0164.jpg
STS-1 http://capcomespace.net/dossiers/espace_US/shuttle/ksc/LC39_chrono_part2.htm
Just below the 1980 headline.
STS-2 http://images.ksc.nasa.gov/photos/1981/high/KSC-381C-2366.03.jpg
STS-2 http://images.ksc.nasa.gov/photos/1981/high/KSC-81PC-0681.jpg
By the way, thank you for all of the truly good information, that you have all given me since i joined up
Happy day
Post by: Endeavour118 on 08/12/2007 07:06 am
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Thorny - 11/8/2007 11:51 AMyeah the LCC people and the MMT people say one thing the media assumes another. and assumption is the mother of all foul ups!QuoteLee Jay - 9/8/2007 3:52 PM
Does anyone remember a mistaken announcement or a release by NASA that could have been mistaken by TV news as a cancellation? I remember very specifically the cancellation call and I wasn't that young (16 - 10th grade) so I don't think it was me.
It was delayed all morning by the cold temperature, but there was no scrub call. One of the talking heads on Morning TV must have misinterpreted a comment about extended holds due to weather for a scrub of the launch.
Post by: gordo on 08/12/2007 02:30 pm
Quote
erioladastra - 12/8/2007 2:05 AM
"Is there not a shared network between the shuttle and ISS? "
As someone already noted, the orbiter only has laptops and ancient GPCs. Only minimal caution and warning data is exchanged and some other commands and telemetry but no real network between the ISS and orbiter laptops. So if they want to exchange info it is sneakernet.
got to be in bluetooth range lol
Post by: Lee Jay on 08/13/2007 02:55 am
Post by: rdale on 08/13/2007 03:01 am
Post by: Jorge on 08/13/2007 03:08 am
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Lee Jay - 12/8/2007 9:55 PM
Why don't the FD2 OBSS inspections include the leading edge of the vertical stabilizer?
OBSS inspections are very time-consuming and are generally reserved for areas where the critical damage tolerance is small enough that only the OBSS sensors are good enough.
The critical damage tolerance for the vertical stabilizer is loose enough that any critical damage can be spotted in the RPM photos.
Post by: Lee Jay on 08/13/2007 03:11 am
Post by: Lee Jay on 08/13/2007 03:13 am
Post by: Jorge on 08/13/2007 04:36 am
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Lee Jay - 12/8/2007 10:11 PM
Or, is that an error by me? Anyway, it seems the V-stab gets less attention than the wing leading edges, yet losing it means losing the vehicle and crew too. Just wondering about that.
All true... but the v-stab also has less fragile TPS than the WLE, sees lower temperatures during entry, and as others have pointed out, is generally outside the path of debris from the SRBs/ET. And as you've pointed out, it's easily photographed by the shuttle crew from the aft windows, just like the OMS pods.
Post by: Lee Jay on 08/13/2007 01:17 pm
Quote
Jorge - 12/8/2007 10:36 PMQuoteLee Jay - 12/8/2007 10:11 PM
Or, is that an error by me? Anyway, it seems the V-stab gets less attention than the wing leading edges, yet losing it means losing the vehicle and crew too. Just wondering about that.
All true... but the v-stab also has less fragile TPS than the WLE, sees lower temperatures during entry, and as others have pointed out, is generally outside the path of debris from the SRBs/ET. And as you've pointed out, it's easily photographed by the shuttle crew from the aft windows, just like the OMS pods.
Okay, as long as it gets a formal looking over. It just never gets mentioned that I can recall and so I was wondering if it gets photos or a looking at through binoculars or something. Of course, before the last flight, I never heard them inspecting the OMS pods either.
Post by: joncz on 08/13/2007 03:13 pm
If they've already got the launch cradle for the CMG, why are they not returning the failed one on STS-118? I heard commentary (and verified in the execute package) that they're stowing the CMG on the ESP to be returned at a later date.
Post by: DaveS on 08/13/2007 03:16 pm
Quote
joncz - 13/8/2007 5:13 PMThw new CMG-3 is on ESP-3 which is to be mounted on P3 and left at the station. So there goes your launch cradle!
Question related to today's EVA where they're R&R a CMG with one brought up in the payload bay.
If they've already got the launch cradle for the CMG, why are they not returning the failed one on STS-118? I heard commentary (and verified in the execute package) that they're stowing the CMG on the ESP to be returned at a later date.
Post by: joncz on 08/13/2007 03:29 pm
Post by: Danny Dot on 08/13/2007 06:36 pm
I have heard there is a kit on ISS that allows for an unmanned landing attempt. I have also heard the plan is for a deorbit burn with a planned burn up over an ocean. What is it?
What I know of shuttle design, it would be VERY difficult to automate everything for a landing attempt:
Close payload doors
Start APUs
Transition to OPS 3
Lower landing gear
Deploy airdata
My guess is the shuttle will be burned up over the ocean if it can't bring the crew home safely.
Danny Deger
Post by: JMS on 08/13/2007 06:51 pm
Quote
Danny Dot - 13/8/2007 1:36 PM
If a shuttle is found to be too dangerous to land, what happens to that shuttle?
I have heard there is a kit on ISS that allows for an unmanned landing attempt. I have also heard the plan is for a deorbit burn with a planned burn up over an ocean. What is it?
http://www.nasaspaceflight.com/content/?id=4582
Post by: MKremer on 08/13/2007 06:52 pm
Either way, that could probably be the end of the Shuttle program once a LON mission has to launch.
Post by: Jorge on 08/13/2007 07:16 pm
Quote
Danny Dot - 13/8/2007 1:36 PM
If a shuttle is found to be too dangerous to land, what happens to that shuttle?
I have heard there is a kit on ISS that allows for an unmanned landing attempt.
The "kit" consists of a cable from the GCIL to the affected control panels.
Quote
I have also heard the plan is for a deorbit burn with a planned burn up over an ocean. What is it?
Either. Depends on extent of damage and level of expectation the vehicle would survive.
Quote
What I know of shuttle design, it would be VERY difficult to automate everything for a landing attempt:
Close payload doors
Start APUs
Transition to OPS 3
Lower landing gear
Deploy airdata
The kit makes no attempt to automate anything. The cable from the GCIL to the switches allows MCC to "throw" the switches remotely using SPCs and RTCs. All the software stuff like item entries and OPS transitions are handled via DEU-equivalent uplinks.
Post by: Danny Dot on 08/13/2007 07:31 pm
Danny Deger
Post by: Jorge on 08/13/2007 07:39 pm
Quote
Danny Dot - 13/8/2007 2:31 PM
Does anyone have any pictures of this kit?
Not much to look at. It's just a cable.
Quote
Does it have little motors that physically throw the switches? I can see how this would work. The air data deploy would be tough because it has to be pulled out before it can be thrown.
No, the crew opens the panels and "hotwires" the cable to the wires running from the appropriate switches. The switches are not physically thrown.
Post by: gavsto2006 on 08/14/2007 09:16 am
Post by: joncz on 08/14/2007 09:40 am
Post by: elmarko on 08/14/2007 10:10 am
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830074554_1983074554.pdf
Flight Data File Materials Handbook, a very very early version from 1982, found knocking around on the NASA Technical Reports Server. Useful for all you FDF fans who want to know how the books are made, and what to use if you want to print your own replica copies out :-) Anyone know how relevant the information is now that it's 2007?
Also, it would go very well with this handbook:
http://shuttlepayloads.jsc.nasa.gov/training/pdf/09958B.PDF - Flight Data File Preparation Standards
That one in particular is superb, and gives more information on how the books are made and written.
Post by: Kyra's kosmos on 08/14/2007 04:45 pm
Obviously much has changed since the first document, with some suppliers not being around after 25 years. The expansion of COTS in the 1990's changed some things as well.
The second document under preparation standards holds fairly close to the current standard, but there are some noteworthy changes. For example the Helvetica font was considered a standard in the mid 90's FDF, but to ensure the font was available on Windows, Arial is considered the standard for most documents now. For those who wish to know what the nice looking font in the Flight Plan Detail pages, that is a very small Letter Gothic. Courier is still used in the attitude timelines for reasons of spacing (monospace). It lines up colums of numbers well.
BTW, on the matter of writing utensils outside of your Fisher Space Pen CH4, we see an interesting silver pencil with a flag bezel on top - that is made by Garland. (But difficult to find now) The black mechanical pencils are Skilcraft American Classic .9mm. As for markers, in addition to the Sharpie you also see Staedler Lumicolor. These have inks that are media marking safe. (Will not yellow or acidify plastic). And why .9mm instead of .5mm ? The leads break easily and could get in your eye (imagine that during an EVA if one was hiding in your helmet and "found" your eye) or be inhaled. Tiny solid objects produced by easy breakage are a big no for good reason. That's one of the big reasons they have an eyewash kit.
I have not seen who makes the book tethers, but I use parachute cord, because it is durable and does not tangle. The small pear shaped clips must also be a special order. (You will not find them at Wal-Mart or Ace :)
Kind of an interesting subtopic of spaceflight, I am reminded of the lyric "the simple things you see are all complicated" with regard to NASA spec.
Post by: elmarko on 08/14/2007 05:03 pm
It would be cool to keep it in one thread.
Post by: dantdbv on 08/14/2007 07:18 pm
Today i have bought Monogram's 1/72 scale Spaceshuttle for about 97,5$, if you take away 25% for vat, 2-6% importtax, i have chosen 4%, 25$ freight and 5$ give or take in exchange fee, then we get 40,2 $. I think that is a nice price. Guess what my new plans for STS-61 is going to be. Naah don't bother just look at my plans below.
A couple more pic links, i have just discovered the Marshall link today.
http://mix.msfc.nasa.gov Click on the yellow dots on top for relevant pics and moviefiles, Space Shuttle projects has 50 pages with 12 items on each. Click on the text to get resolution choice. Don't know whats here, have just startet using it.
http://dayton.hq.nasa.gov/IMAGES/ Unfortunately they jump in time and programs, no descriptions and it could be me, just being tired, when i looked trough the small pics, but i got the feeling that the smallpicnumbers didn't allways fit the bicpicnumbers. Well good luck.
Shuttleplans
1:
PlayShuttle, no paint, no filling just lightly sanding. Minicraft Orbiter, Revell stack and MLP
2:
Enterprise, ALT freeflight 5 on SCA 905 in flight. Revell Orbiter and 747, scratchbuild struts and stabilizers. On hold until Spacecraft Films finishes their Space Shuttle First Flights box.
3:
Columbia, STS-1 on pad, just after HBOI (sparklers) ignition, before SSME start, that should be between t-11 and t-6 seconds. Revell Orbiter/stack. First on modified Revell MLP, then scratchbuild correct MLP, then on just enough hardstand to fit in the FSS and RSS. On hold until Spacecraft Films finishes their Space Shuttle First Flights box.
4:
Challenger, STS-33/51L in flight at T+60 seconds, with visible flame From right SRB field joint. Revell Orbiter, Airfix/Minicraft stack? Stack decision will be made when i get the Airfix kit. Working on exhaust plumes from Orbiter and SRB's, they're gonna be lighted, i just don't know how yet, but i do have some ideas.
5:
Endeavour, STS-61 HSM-1 on orbit with baydoors open. Monogram 1/72 with Realspace payloadbay. Need to find good payloadbay pics and plans.
6:
Atlantis OMDP-2 1997 ferryflight with dummy OMS and FRCS pods and tailcone on cutout SCA 911 with landinggear down. Revell Orbiter and cutaway 747, scratchbuild interior, struts and stabilizers. If it where there at the time, then maybe in a scratchbuild mate-demate device at Palmdale. (yeah right, when i get a bigger place to live, maybe.) Need to find some more good pics and/or drawings of the interior, struts and stabilizers.
7:
Discovery STS-121 on runway. Need to find some good pics.
8:
Columbia STS-107 on orbit with closed baydoors.
Happy day.
Post by: Jim on 08/14/2007 07:27 pm
Post by: LSainsbury on 08/14/2007 08:00 pm
Obviously this site was around at the time of the loss of STS-107? Are there any FD-x threads still in here which go though how the whole day unfolded?
I've done a quick search but didn't find anything...
Post by: DaveS on 08/14/2007 08:06 pm
Quote
LSainsbury - 14/8/2007 10:00 PMNope. Not around for 107. But was around just in time as the real actvities for STS-114 was happing(rollover, rollout, tanking tests, rollback, de-mating and re-mating and re-rollout etc.)
STS-107..
Obviously this site was around at the time of the loss of STS-107? Are there any FD-x threads still in here which go though how the whole day unfolded?
I've done a quick search but didn't find anything...
Post by: Thorny on 08/14/2007 08:29 pm
Quote
LSainsbury - 14/8/2007 3:00 PM
STS-107..
Obviously this site was around at the time of the loss of STS-107? Are there any FD-x threads still in here which go though how the whole day unfolded?
I've done a quick search but didn't find anything...
Try a Google News (usenet) search of sci.space.shuttle for 1 Feb 03. It's sobering to go back a week or so before and see Jim Oberg's request for information whether or not Columbia had an RMS aboard because there was a really big debris strike. If only...
SpaceflightNow still has its 107 archive, last I checked. No public discussion, but lots of "as it happened" updates.
Post by: DaveS on 08/14/2007 08:36 pm
Quote
Thorny - 14/8/2007 10:29 PMYep: http://spaceflightnow.com/shuttle/sts107/
SpaceflightNow still has its 107 archive, last I checked. No public discussion, but lots of "as it happened" updates.
Post by: brahmanknight on 08/14/2007 09:40 pm
Post by: psloss on 08/14/2007 09:44 pm
Quote
brahmanknight - 14/8/2007 5:40 PMStealing a Jorge post:
Could someone explain "beta angle cutout" to me?
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6215&posts=6#M103920
Post by: Lee Jay on 08/14/2007 09:54 pm
Quote
Thorny - 14/8/2007 2:29 PM
Try a Google News (usenet) search of sci.space.shuttle for 1 Feb 03. It's sobering to go back a week or so before and see Jim Oberg's request for information whether or not Columbia had an RMS aboard because there was a really big debris strike. If only...
Actually, he asked if they had SAFER's on board. Was he thinking they'd use them like MMUs or something?
http://groups.google.com/group/sci.space.shuttle/browse_frm/thread/11d24a2ac85661fe/787d0d66fdd59e67?lnk=gst
Post by: dantdbv on 08/14/2007 10:17 pm
Post by: gavsto2006 on 08/14/2007 10:55 pm
Quote
joncz - 14/8/2007 10:40 AM
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=713&start=1
Thank you!!!
Post by: erioladastra on 08/15/2007 01:09 am
Beta angle is the angle between the orbital plane and the sun. There are cutouts because at high beta angles power production for ISS or temps (high or low) are reached. Therefore there is a cutout for a given activity for a given beta.
Post by: ChrisGebhardt on 08/15/2007 04:46 am
Post by: Jim on 08/15/2007 12:03 pm
Post by: Bret on 08/15/2007 04:03 pm
Post by: brahmanknight on 08/15/2007 06:19 pm
Post by: Jorge on 08/15/2007 06:42 pm
Quote
brahmanknight - 15/8/2007 1:19 PM
Did the pilots get RMS training before ISS flights?
Only if the flight had enough RMS work to require it. It happened but it wasn't common before the ISS era.
Post by: BigKiai on 08/15/2007 08:51 pm
Post by: gordo on 08/15/2007 08:54 pm
Quote
BigKiai - 15/8/2007 9:51 PM
Are the astronauts given "suicide pills" ?
no
Post by: AstroRJY on 08/16/2007 02:45 am
I have read that the 3 SSMEs have the energy equivalent generated by 18 or 23 Hoover Damns... Can anyone confirm the accuracy?
Also- what is the horsepower of the engines and SRBs. both separately and together. I am figuring it is in the 100-120 million range for the whole vehicle lifting off. I beleive someone said the Saturn V had 120 million horsepwoer and the shuttle has similar thurst.
In the STS-1 film from 1981, "Space Shuttle: A Remarkable Flying Machine" the narration said the 3 SSMEs on second stage generated "more than 42 million horsepower."
I read somewhere that the SRBs (this was also in a book from the early 1980s when the SRBs each had 2.9 or 2.95 million lbs. thrust, not 3.3 millions per today's vehicles) that the SRBs generated 44 million horsepower, but it didn't clarify if that was both or each SRB.
If anyone can provide accurate facts about the energy equivalency and thrust, I'd appreciate it.
Post by: AstroRJY on 08/16/2007 03:01 am
Quote
Trekkie07 - 15/8/2007 12:46 AM
Quick question... how long does it take to turn a shuttle launch pad around from launch to rollout of the next shuttle?
Well, the record for the same pad was 17 days between 2 shuttle launches on pad 39A from April 12th to April 29th, 1985 between STS-51D and STS-51B.
I do know they have stated they go through 8 full days of cleaning the launch pad and tower after a liftoff to scrub down and remove all the debris and dirt caused by the SRB smoke and heat from the engines.
After a rollout, Launch Director Mike Leinbach has said it takes anohter 8 days of validation/ verification checks to make sure the MLP is parked at precisely the correct points and that all the connections are secure and the vehicle is locked down properly. He stated this at a press conference in late August 2006 when they were deciding to rollback Atlantis / STS-115 stack because of a tropical storm threat close enough to the Cape Canaveral area. They did start the rollback but after only an hour or two the forecast completely changed, they changed their decision and returned the stack to the pad, and still had to go through the 8 days of checks and validations.
Post by: Lee Jay on 08/16/2007 03:03 am
Useful round numbers to me are that each SSME *consumes* around 6GW of chemical energy (18GW for all three) and each engine nozzle is providing around 300MW of heat to the fuel (which is used to cool the nozzle). To put that in context, all the thermal power plants running to supply my entire state (Colorado) with electrical power at the peak hour of the summer consume around that same amount (18GW), providing around 7GW of electricity. And that's the relatively-small (but supremely efficient) SSMEs. At launch the SRBs provide around 80% of the total combined thrust of the entire STS. They're big and powerful, but heavy and inefficient.
Post by: AstroRJY on 08/16/2007 03:05 am
I still need an answer on the totla thurst from someone else please.
Post by: Lee Jay on 08/16/2007 03:07 am
http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster
http://en.wikipedia.org/wiki/SSME
Post by: AstroRJY on 08/16/2007 05:08 am
Using this site to calculate power:
http://www.thesolarguide.com/energy-intro/amperes-volts-watts.aspx
Post by: LSainsbury on 08/16/2007 08:03 am
Quote
gordo - 14/8/2007 9:54 PMQuoteBigKiai - 15/8/2007 9:51 PM
Are the astronauts given "suicide pills" ?
no
Why would they? In what circumstances would they consider taking them?
Post by: SpaceNutz SA on 08/16/2007 10:15 am
Quote
LSainsbury - 16/8/2007 10:03 AMQuotegordo - 14/8/2007 9:54 PMWhy would they? In what circumstances would they consider taking them?QuoteBigKiai - 15/8/2007 9:51 PM Are the astronauts given "suicide pills" ?no
I think this question was asked during the Apollo era. Buzz Aldrin (I think?) answered that it wasn't neccessary - if you want to die in space simply open the hatch (or depress the cabin).
I can think of a number of situations where they COULD be considered where there was no hope of a successful re-entry (loss of main engines for TEI, failure to rendezvoux with the CSM or failure to lift off of the lunar surface) but the nature of the 'test pilot right stuff' people who flew the missions would be to keep trying till the bitter end.
Post by: padrat on 08/16/2007 10:39 am
Quote
Trekkie07 - 14/8/2007 11:46 PM
Quick question... how long does it take to turn a shuttle launch pad around from launch to rollout of the next shuttle?
Lately it's been a matter of 3 or four weeks. All really depends on how much launch damage there is. With minimal damage I'd say it could be done in two weeks with round-the-clock work. It actually would HAVE to be able to be done within a week or two for the LON option to even be viable.
Post by: brahmanknight on 08/17/2007 11:44 am
Post by: Jim on 08/17/2007 01:17 pm
Quote
brahmanknight - 17/8/2007 7:44 AM
Do the FRCS thrusters on the side ingest any plasma during re-entry?
Doesn't matter, since they expell "plasma"
Post by: brahmanknight on 08/18/2007 01:41 pm
Post by: brahmanknight on 08/18/2007 01:52 pm
Post by: GLS on 08/18/2007 01:57 pm
Post by: brahmanknight on 08/18/2007 02:13 pm
Post by: GLS on 08/18/2007 03:01 pm
There's a NASA pdf file with lot's of info on EVAs (this one too...)
spaceflight.nasa.gov/spacenews/factsheets/pdfs/EVACron.pdf
Post by: DaveS on 08/18/2007 07:59 pm
-ZLV +YVV: P000, Y090, R180, port wing into VV, hds dn
-ZLV -XVV: P180, Y000, R000, tail into VV, hds dn
+ZLV +XVV: P000, Y000, R000, nose into VV, hds up
Post by: Jorge on 08/18/2007 08:06 pm
Quote
DaveS - 18/8/2007 2:59 PM
I'm trying to decypher the attitude lines in the flight plans. I think that I have gotten things right, but could someone with more knowledge double-check my data?
-ZLV +YVV: P000, Y090, R180, port wing into VV, hds dn
-ZLV -XVV: P180, Y000, R000, tail into VV, hds dn
+ZLV +XVV: P000, Y000, R000, nose into VV, hds up
+YVV is starboard wing into VV.
When an attitude is at the yaw singularity (Y090 or Y270), there are an infinite number of combinations of pitch/roll that accurately describe that attitude. In those cases, NASA generally sets the roll to zero and puts the entire rotation into pitch. So NASA would describe the first attitude as P180 Y090 R000, although your numbers are still accurate.
Post by: DaveS on 08/18/2007 08:14 pm
Quote
Jorge - 18/8/2007 10:06 PMOK, thanks! To use a Apollo 13 movie quote: "but if this paperwork isn't right, who knows where we'll... we'll end up out here."
When an attitude is at the yaw singularity (Y090 or Y270), there are an infinite number of combinations of pitch/roll that accurately describe that attitude. In those cases, NASA generally sets the roll to zero and puts the entire rotation into pitch. So NASA would describe the first attitude as P180 Y090 R000, although your numbers are still accurate.
Post by: brahmanknight on 08/19/2007 10:44 am
Post by: mark147 on 08/19/2007 07:17 pm
Quote
PRE-ESP3 HANDOFFWhy is the available delta-v reduced after the shuttle hands off ESP3? I would have expected the reverse since the shuttle will then be lighter. What am I missing?
OMS 436 FPS
ARCS (TOTAL ABOVE QTY1) 38 FPS
TOTAL IN THE AFT 474 FPS
ARCS (TOTAL ABOVE QTY2) 68 FPS
FRCS (ABOVE QTY 1) 32 FPS
AFT QTY 1 83 %
AFT QTY 2 45 %
POST-ESP3 HANDOFF
OMS 378 FPS
ARCS (TOTAL ABOVE QTY1) 39 FPS
TOTAL IN THE AFT 417 FPS
ARCS (TOTAL ABOVE QTY2) 69 FPS
FRCS (ABOVE QTY 1) 32 FPS
AFT QTY 1 83 %
AFT QTY 2 45 %
Also, what do QTY1 and QTY2 refer to?
Post by: GLS on 08/19/2007 09:00 pm
Quote
brahmanknight - 19/8/2007 11:44 AM
GLS, is there a pdf that covers the spacewalks after Shuttle-Mir?
I haven't found anything.... :( :( :(
Post by: pkspx on 08/21/2007 08:21 pm
Post by: Jorge on 08/21/2007 08:34 pm
Quote
mark147 - 19/8/2007 2:17 PM
Why is the available delta-v reduced after the shuttle hands off ESP3? I would have expected the reverse since the shuttle will then be lighter. What am I missing?
ESP3 was in the aft end of the payload bay. Removing it shifts the orbiter c.g. forward, so I would guess they need to protect more aft prop as ballast to keep the c.g. within limits.
Post by: BenB5150 on 08/22/2007 02:45 pm
Post by: mkirk on 08/22/2007 03:12 pm
Quote
BenB5150 - 22/8/2007 9:45 AM
I was reading "Return-To-Flight Space Shuttle Discovery" and noticed that Discovery was using one of the OMS pods delivered with Challenger. I know that they swap around parts between the orbiters but does anyone know which OMS pods and FRCS are on which orbiter now?
Yeah you can find that in a lot of places. Many of the processing reports that get posted on here in the L2 section will have that info.
Also Bill Harwood always has a summary of the flight hardware for each mission. Click on the link below:
http://www.spaceflightnow.com/shuttle/sts118/fdf/118quicklook1.html
Mark Kirkman
Post by: SpaceFan on 08/22/2007 03:24 pm
Also, it seems like the number of flights to become a commander have dropped. I haven't gone through the numbers, but it seems like 10 years ago, you had to have 2 flights as a pilot before becoming a commander whereas recently, after one you were qualified.
Sorry if these are dumb questions, but was just wondering.
Thanks!
Post by: Danny Dot on 08/22/2007 03:34 pm
Danny Deger
Post by: DaveS on 08/22/2007 03:36 pm
Quote
Danny Dot - 22/8/2007 5:34 PMHere: http://www.nasa.gov/images/content/187279main_07pd2305.jpg
Where can I find post landing pictures of the tile damage area?
Danny Deger
Post by: Jim on 08/22/2007 04:24 pm
Quote
SpaceFan - 22/8/2007 11:24 AM
Long time lurker here with some questions I'll be posting over the next few weeks. I'll start with this one since I've been wondering about it since STS-118. What is the criteria for choosing a shuttle commander? For example, I noticed that Scott Kelly and Charlie Hobaugh each had one flight prior to STS-118, same military rank, etc. How do they choose one over the other?
Also, it seems like the number of flights to become a commander have dropped. I haven't gone through the numbers, but it seems like 10 years ago, you had to have 2 flights as a pilot before becoming a commander whereas recently, after one you were qualified.
Sorry if these are dumb questions, but was just wondering.
Thanks!
There are no set standards nor logic in assigning crews or commanders
Post by: AstroRJY on 08/22/2007 04:49 pm
Quote
SpaceFan - 22/8/2007 11:24 AM
Long time lurker here with some questions I'll be posting over the next few weeks. I'll start with this one since I've been wondering about it since STS-118. What is the criteria for choosing a shuttle commander? For example, I noticed that Scott Kelly and Charlie Hobaugh each had one flight prior to STS-118, same military rank, etc. How do they choose one over the other?
Also, it seems like the number of flights to become a commander have dropped. I haven't gone through the numbers, but it seems like 10 years ago, you had to have 2 flights as a pilot before becoming a commander whereas recently, after one you were qualified.
Sorry if these are dumb questions, but was just wondering.
Thanks!
Not really. Many if not most CDRs flew as a PLT only once- Crippen, Truly, Shaw, Scobee, Walker, Bobko, Brandenstein, Gibson, Coats... that's just a few from the 1980s era and it's the same today. It is actually more rare to have a PLT fly as a PLT twice, and usally the reason for that is becasue he (or she) 's already been assigned to a second flight before he's flown his first. You can't become a CDR though until you've actually flown a mission as a PLT. Also, I really don't think which branch of service or military rank has much to do with it, more your technical knowledge and flight skills. Hope that is more helpful.
Post by: brahmanknight on 08/22/2007 05:17 pm
Post by: SpaceNutz SA on 08/22/2007 08:14 pm
Slower = higher and faster = lower. How is it then that for a spacecraft to re-enter it must slow down (which means higher) and not speed up (which means lower)??
Post by: rdale on 08/22/2007 08:16 pm
Post by: BWP on 08/22/2007 08:26 pm
Post by: rdale on 08/22/2007 08:30 pm
The search feature will show you that there has been lengthy discussions about this topic.
Post by: Jim on 08/22/2007 09:27 pm
Quote
SpaceNutz SA - 22/8/2007 4:14 PM
Basic Orbital Mechanics Question:
Slower = higher and faster = lower. How is it then that for a spacecraft to re-enter it must slow down (which means higher) and not speed up (which means lower)??
Engine burns add or subtract energy not speed. Orbits are determined by kinetic (velocity) and potential (altitude) energy. Deorbit burn reduces the kinetic energy of the shuttle and it goes into a lower orbit. It may speed up but the overall combination of velocity and altitude are at a lower energy level
Post by: Jim on 08/22/2007 09:27 pm
Quote
BWP - 22/8/2007 4:26 PM
will any of the shuttle's be displayed at Edward's? once there retired. I mean it should because half of the shuttle flight's were at Edward's
Look up orbiter retirement
Post by: SCE2Aux on 08/23/2007 11:26 am
Post by: cabbage on 08/23/2007 12:52 pm
There's only a 15psi difference between sea-level atmospheric pressure and vacuum, which compared to the 300-odd psi they're inflated to anyway isn't much of a difference.
Post by: MKremer on 08/23/2007 12:55 pm
Post by: SpaceFan on 08/23/2007 01:49 pm
Thanks!
Post by: joncz on 08/23/2007 01:53 pm
Post by: mkirk on 08/23/2007 05:13 pm
Quote
SpaceFan - 23/8/2007 8:49 AM
Thanks to those who replied to my first question, but now it's time for dumb question #2. At the end of the STS-118 flight, they were discussing which runway to land on. Weren't they just discussing essentially which end of the runway to land on? I remember them being concerned with crosswinds and it seems like if that's what they were concerned about, why would changing the direction of landing by 180 degrees matter? The crosswinds would just be hitting the other side of the shuttle.
Thanks!
There are other factors used in picking which end to land on. Winds at both the surface and at altitude are evaluated along with sun angle, visibilty, cloud coverage along the approach paths, turbulence, proximity to rain/thunderstorms, runway lighting, HAC turn angle, approach and touchdown energy state, and so on.
These are all considered by the STA pilot in conjunction with the weather folks (SMG, Weather Flight, and Capcom) and the Mission Control Team (particularly FIDO).
Mark Kirkman
Post by: BigKiai on 08/23/2007 06:58 pm
How is the shuttle, ET and boosters firmly bolted to the launch pad so that it does not tip?
Is the shuttle only attahed to the ET on the launch pad?
Sorry for all the newbie questions, but this has been bugging me for a long time. Thanks in advance.
Post by: Jim on 08/23/2007 07:03 pm
Quote
BigKiai - 23/8/2007 2:58 PM
1. What is a TCS strap?
2. How is the shuttle, ET and boosters firmly bolted to the launch pad so that it does not tip?
3. Is the shuttle only attahed to the ET on the launch pad?
.
1. need more info, TCS could be thermal control system
2. Four bolts on each SRB
3 Correct
read this for more info
http://spaceflight1.nasa.gov/shuttle/reference/shutref/index.html
Post by: Jorge on 08/23/2007 07:04 pm
Quote
BigKiai - 23/8/2007 1:58 PM
How is the shuttle, ET and boosters firmly bolted to the launch pad so that it does not tip?
Eight hold-down bolts on the SRBs support the weight of the entire stack.
Quote
Is the shuttle only attahed to the ET on the launch pad?
Yes, and the ET is in turn supported by the SRBs. The orbiter is attached to the Tail Service Masts through the T-0 umbilicals but those are not load-bearing.
Post by: BigKiai on 08/23/2007 07:15 pm
On today's story on the main page of nasaspaceflight.com, it says the only items they found on the runway post-landing were the chute and related items, plus a TCS strap. I was wondering that the TCS strap is.
Thanks for helping out a newbie,
Mike
Quote
Jim - 23/8/2007 12:03 PMQuoteBigKiai - 23/8/2007 2:58 PM 1. What is a TCS strap? 2. How is the shuttle, ET and boosters firmly bolted to the launch pad so that it does not tip? 3. Is the shuttle only attahed to the ET on the launch pad? .1. need more info, TCS could be thermal control system 2. Four bolts on each SRB 3 Correct read this for more info http://spaceflight1.nasa.gov/shuttle/reference/shutref/index.html
Post by: swhitt on 08/23/2007 10:19 pm
What are the dots and circles?
Why are they there?
Do they mean anything?
Thanks.
Steve Whitt
Post by: Jim on 08/23/2007 10:27 pm
Post by: C5C6 on 08/24/2007 12:34 am
1. the other two 'doors', have got high-bays?
2. have those ever been used for apollo/shuttle?
3. in case there are 4 high-bays, dont you think there are too many?
4. which high-bay is going to be modified for project constellaton?
thanksssss
Post by: DaveS on 08/24/2007 12:49 am
Quote
C5C6 - 24/8/2007 2:34 AM1: Yes, they're designated High Bays 2 and 4.
in the VAB, you got high-bay 1 that has been used for the last flights, high-bay 3 which also faces the atlantic.....
1. the other two 'doors', have got high-bays?
2. have those ever been used for apollo/shuttle?
3. in case there are 4 high-bays, dont you think there are too many?
4. which high-bay is going to be modified for project constellaton?
thanksssss
2: Yes, on multiple occations. High Bay 2 has only been used once as a potential storm shelter for a rolled back shuttle stack, STS-106.
3: Nope. The current situation shows that they're really handicapped by the fact that only one integration cell is available(HB 1).
4: All of them once the shuttle program is over,
Post by: Thorny on 08/24/2007 01:01 am
Quote
C5C6 - 23/8/2007 7:34 PM
in the VAB, you got high-bay 1 that has been used for the last flights, high-bay 3 which also faces the atlantic.....
1. the other two 'doors', have got high-bays?
2. have those ever been used for apollo/shuttle?
thanksssss
Here's a photo of Apollo 10 coming around the VAB after rollout from High Bay 2.
http://www.hq.nasa.gov/office/pao/History/alsj/a410/ap10-69-HC-309.jpg
Post by: Ankle-bone12 on 08/24/2007 05:57 am
Post by: Jim on 08/24/2007 10:22 am
Post by: Complex39 on 08/24/2007 08:55 pm
You hear and read a lot about launch windows and how the timing of a shuttle launch depends on things like the mission objectives (whether it be rendezvous with ISS or satellite launch/retrieval etc.), but I never see anything explaining landing opportunities and what factors determine when the shuttle can be brought back to Earth. A friend recently asked me why NASA sometimes land the shuttle at night....and I didn't know the answer! Could they not just wait untill a later orbit when daylight is available at the preferred landing site?
Thanks in advance.
Post by: Jim on 08/24/2007 09:00 pm
Quote
Complex39 - 24/8/2007 4:55 PM
A Could they not just wait untill a later orbit when daylight is available at the preferred landing site?
Thanks in advance.
There might not be daylight opportunities, depending on the orbit, inclination and launch time
Post by: Jim on 08/24/2007 09:04 pm
You can see it in the last two pics of this thread
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9560&posts=8#M180055
Post by: ChrisGebhardt on 08/24/2007 09:26 pm
Quote
Complex39 - 24/8/2007 4:55 PM
Apologies if this has already been asked but a search of the forum didn't reveal an answer to my question.
You hear and read a lot about launch windows and how the timing of a shuttle launch depends on things like the mission objectives (whether it be rendezvous with ISS or satellite launch/retrieval etc.), but I never see anything explaining landing opportunities and what factors determine when the shuttle can be brought back to Earth. A friend recently asked me why NASA sometimes land the shuttle at night....and I didn't know the answer! Could they not just wait untill a later orbit when daylight is available at the preferred landing site?
Thanks in advance.
The Shuttle orbits the Earth roughly 14 times per day. Of those 14 orbits, there are only a certain number of orbits (about 8 per day) that allow the Space Shuttle to reach one of the 3 landing facilities in the U.S. If you look at a ground track of the Shuttle's orbit, you'll notice that the Shuttle doesn't always pass over, or near, the U.S. For that reason, those orbits are not available for landing opportunities. Therefore, sometimes the orbits available for landing mean the Shuttle lands at night. If you want more information, just PM me.
Post by: Complex39 on 08/24/2007 09:31 pm
Quote
Jim - 24/8/2007 10:00 PM
There might not be daylight opportunities, depending on the orbit, inclination and launch time
Would you mind elaborating a little? I realise that in order for the orbiter to landing at a specific location (e.g. KSC) the de-orbit burn has to occur at a certain time and with the shuttle at a certain 'point' in orbit but I don't really understand how the 3 things you mentioned (orbit, inclination and launch time) are used to determine this.
Is there anywhere on the web that documents the de-orbit-burn/landing process and the theory behind it?
Thanks.
Edit: Many thanks Trekkie. I had already posted my repsonse to Jim before I read your post!
Post by: psloss on 08/24/2007 09:52 pm
Quote
Trekkie07 - 24/8/2007 5:26 PMFWIW, the orbital period for the ISS (which orbiters are docked to a lot of the time they are in orbit nowadays) is ~90 minutes, which works out to ~16 orbits in a 24 hour period.
The Shuttle orbits the Earth roughly 14 times per day.
Post by: ChrisGebhardt on 08/24/2007 10:01 pm
Quote
Complex39 - 24/8/2007 5:31 PMQuoteJim - 24/8/2007 10:00 PM
There might not be daylight opportunities, depending on the orbit, inclination and launch time
Would you mind elaborating a little? I realise that in order for the orbiter to landing at a specific location (e.g. KSC) the de-orbit burn has to occur at a certain time and with the shuttle at a certain 'point' in orbit but I don't really understand how the 3 things you mentioned (orbit, inclination and launch time) are used to determine this.
Is there anywhere on the web that documents the de-orbit-burn/landing process and the theory behind it?
Thanks.
Edit: Many thanks Trekkie. I had already posted my repsonse to Jim before I read your post!
No prob. I'll take a crack at answering this one if I can. For my examples, I'll assume the Shuttle is landing at KSC. So, not only, does the Shuttle have to be at a specific point in its orbit, but it has to be on a certain orbit (i.e. Orbit 201, 202, 203 etc... [but understand that these are not the only orbit #s the shuttle has to be on]) to properly align with the desired runway's location. Orbital Inclination matters because this effects which orbit NASA targets for landing. For missions to the ISS, NASA usually targets "ascending trajectories" for landing opportunities. This means that the Shuttle is travelling in a Northeasterly direction as it passes over the Pacific Ocean and Central America before it makes its final series of turns to percisely align with the Shuttle Landing Facility (SLF). Finally, the time of day the Shuttle is launched at determines whether is lands in daylight or at night. For a 13day Shuttle mission to the ISS (which is what Endeavour just completed on STS-118), the first landing opportunity occurs roughly 12days and 18hours after launch. For Endeavour, that meant a landing at 12:32pm because is launched at 6:36pm. Atlantis' STS-115 flight back in September 2006 launched at 11:15am which in turn meant a landing around 6:30am... a nighttime landing. Hope this helps. Let me know if you want more information.
Post by: ChrisGebhardt on 08/24/2007 10:02 pm
Quote
psloss - 24/8/2007 5:52 PMQuoteTrekkie07 - 24/8/2007 5:26 PMFWIW, the orbital period for the ISS (which orbiters are docked to a lot of the time they are in orbit nowadays) is ~90 minutes, which works out to ~16 orbits in a 24 hour period.
The Shuttle orbits the Earth roughly 14 times per day.
Right you are. Sorry about that. Just bad math for a minute.
Post by: Thorny on 08/24/2007 10:02 pm
The space station is in an orbit inclined 51.6 degrees to the equator. That means the most northerly point of each orbit is 51.6 degrees north latitude and the most southerly is 51.6 degrees south latitude. The orbit is more or less fixed in space, relative to the background stars. The Earth rotates beneath the orbit... about 1,100 miles at the equator per orbit. (Earth is not a perfect sphere, so the orbit does 'precess' a little on each orbit, but that's a detail.) A point on the Earth's surface, say Cape Canaveral, will rotate beneath the Station's orbit twice per day, once on the "ascending node" (the Station is travelling on the northward leg of its orbit) and once on the descending node (southward.) That means a Shuttle coming home from the Space Station has two* opportunities to land at Cape Canaveral, think: about 12 hours apart. But one of those opportunities, the descending node, would bring the Shuttle in over the continental United States (coming down over Minnesota, Illinois, Tennessee, etc.) and since the Columbia accident, NASA prefers not to risk that approach anymore. That leave the ascending node, with a Shuttle coming in over Central America, the Caribbean, and Cuba.
That only happens once a day, and depending on the launch time, it might be at night.
*The Shuttle has enough cross-range capability, flying to the east or west of its orbit to reach Cape Canaveral, that it can make two attempts to land at Cape Canaveral, on succeeding orbits.
Post by: psloss on 08/24/2007 10:22 pm
Quote
Trekkie07 - 24/8/2007 6:02 PMNo worries -- actually, you can see how many orbits per day in one of the fields in two line elements, which are updated frequently. The revs/day for the ISS and HST elements I got here (http://www.celestrak.com/NORAD/elements/) are highlighted:
Right you are. Sorry about that. Just bad math for a minute.
Quote
ISS (ZARYA)
1 25544U 98067A 07236.22846339 .00011130 00000-0 73407-4 0 8467
2 25544 51.6358 112.6735 0008016 282.9306 175.5430 15.76194975501511
HST
1 20580U 90037B 07235.72978304 .00000290 00000-0 96584-5 0 9449
2 20580 28.4673 109.6773 0003754 99.1977 260.9037 15.00270904750110
(Fixed-width data formats don't display real well in proportional fonts like this...)
Post by: Complex39 on 08/24/2007 10:23 pm
Post by: MKremer on 08/25/2007 01:14 am
Quote
Jim - 24/8/2007 4:04 PM
When did the landing convoy ECS trailer get switched to a KAMAG transporter?
You can see it in the last two pics of this thread
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9560&posts=8#M180055
June, 2002
short press release - http://quest.nasa.gov/news/space/2002/06-26a.txt
USA newsletter announcement (p.6) - http://www.unitedspacealliance.com/news/newsletters/PDFs_NewsletterIssues/issue038.pdf
Post by: DaveS on 08/25/2007 01:40 am
Quote
MKremer - 25/8/2007 3:14 AMMKremer, that's the Convoy Command Vehicle. The vehicle Jim is talking about is the big blue vehicle with three big red air purge ECS hoses coming from it.QuoteJim - 24/8/2007 4:04 PM
When did the landing convoy ECS trailer get switched to a KAMAG transporter?
You can see it in the last two pics of this thread
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9560&posts=8#M180055
June, 2002
short press release - http://quest.nasa.gov/news/space/2002/06-26a.txt
USA newsletter announcement (p.6) - http://www.unitedspacealliance.com/news/newsletters/PDFs_NewsletterIssues/issue038.pdf
Post by: John2375 on 08/25/2007 01:49 am
Does that mean they landed on the descending orbit?? I remember seeing a video about STS-74 and they definitely did, since they had spectacular footage coming in over the Canadian Rockies and down through the midwest and into Florida..
Doesn't that also have to do more w/the sleep cycles too?? When they're on the descending orbit, they're usually asleep??
Post by: ChrisGebhardt on 08/25/2007 01:58 am
Quote
John2375 - 24/8/2007 9:49 PM
Doesn't that also have to do more w/the sleep cycles too??
It can. And on that mission it did. However, since RTF, all flights have (and it's my understanding that the remianing ones will) landed on ascending trajectories. My previous posts used an ISS mission scenario after RTF. But you are correct as well. I was trying to keep things as simple as possible and just explain why some missions landing at night.
Post by: ChrisGebhardt on 08/25/2007 02:06 am
Post by: Jorge on 08/25/2007 02:12 am
Quote
Thorny - 24/8/2007 5:02 PM
A point on the Earth's surface, say Cape Canaveral, will rotate beneath the Station's orbit twice per day, once on the "ascending node" (the Station is travelling on the northward leg of its orbit) and once on the descending node (southward.) That means a Shuttle coming home from the Space Station has two* opportunities to land at Cape Canaveral, think: about 12 hours apart.
Not quite right. It would be 12 hours if KSC was on the equator, but because it isn't, the descending opportunity is typically 4 orbits (6 hours) after the ascending opportunity.
Quote
But one of those opportunities, the descending node, would bring the Shuttle in over the continental United States (coming down over Minnesota, Illinois, Tennessee, etc.) and since the Columbia accident, NASA prefers not to risk that approach anymore. That leave the ascending node, with a Shuttle coming in over Central America, the Caribbean, and Cuba.
While true, that's not the main reason. NASA avoided the descending opportunities for ISS flights even before the Columbia accident because they typically required a lot of crew sleep-shifting, and because of concerns over noctilucent clouds during the summer months.
Post by: Thorny on 08/25/2007 02:23 am
STS-63: 12:22am 6:50am (8 Days)
STS-71: 3:32pm 10:55am (10 Days)
STS-74: 7:30am 12:02pm (8 Days)
STS-76: 3:13am 8:29am (9 Days)
STS-79: 4:54am 8:13am (10 Days)
STS-81: 4:27am 9:23am (10 Days)
STS-84: 4:07am 9:27am (9 Days)
STS-86: 10:34pm 5:55pm (11 Days)
STS-89: 9:48am 5:36pm (11 Days)
STS-91: 6:06pm 2:00pm (10 Days)
STS-88: 3:35am 10:53pm (12 Days)
STS-96: 6:49pm 2:02am (10 Days)
STS-101: 6:11am 2:20am (10 Days)
STS-106: 8:45am 3:56am (12 Days)
STS-92: 7:17pm 1:50pm (13 Days)
STS-97: 10:06pm 6:04pm (11 Days)
STS-98: 6:13pm 3:33pm (13 Days)
STS-102: 6:42am 2:31am (13 Days)
STS-100: 2:40pm 3:10pm (11 Days)
STS-104: 5:04am 11:39pm (13 Days)
STS-105: 5:10pm 2:23pm (12 Days)
STS-108: 5:19pm 12:56pm (12 Days)
STS-110: 4:44pm 12:27pm (11 Days)
STS-111: 5:22pm 1:58pm (14 Days)
STS-112: 3:46pm 11:45am (11 Days)
STS-113: 7:50pm 2:37pm (14 Days)
STS-114: 10:39am 5:11am (14 Days)
STS-121: 2:38pm 9:15am (13 Days)
STS-115: 11:15am 6:21am (12 Days)
STS-116: 8:47pm 5:32pm (13 Days)
STS-117: 7:38pm 3:49pm (14 Days)
STS-118: 6:36pm 12:32pm (13 Days)
Post by: Jim on 08/25/2007 04:59 am
Quote
Trekkie07 - 24/8/2007 10:06 PM
OK. Now it's time for me to ask a question. How long does it take to turn a High Bay around after a rollout to the start of SRB stacking for the next mission?
o minutes. Just like an OPF, there is nothing consumable that prevents another MLP form going ine
Post by: ChrisGebhardt on 08/25/2007 05:37 am
Quote
Jim - 25/8/2007 12:59 AMQuoteTrekkie07 - 24/8/2007 10:06 PM
OK. Now it's time for me to ask a question. How long does it take to turn a High Bay around after a rollout to the start of SRB stacking for the next mission?
o minutes. Just like an OPF, there is nothing consumable that prevents another MLP form going ine
Thanks. But how long would it take to reposition the work platforms from a rollout config to a SRB stacking config? Minutes... hours?
Post by: Jim on 08/25/2007 12:38 pm
Quote
Trekkie07 - 25/8/2007 1:37 AMQuoteJim - 25/8/2007 12:59 AMQuoteTrekkie07 - 24/8/2007 10:06 PM
OK. Now it's time for me to ask a question. How long does it take to turn a High Bay around after a rollout to the start of SRB stacking for the next mission?
o minutes. Just like an OPF, there is nothing consumable that prevents another MLP form going ine
Thanks. But how long would it take to reposition the work platforms from a rollout config to a SRB stacking config? Minutes... hours?
0 minutes. There are none needed right away. The SRB holddown posts on the MLP have to be aligned. When the SRB aft segment is stacked, none are needed
Post by: Thorny on 08/25/2007 06:33 pm
Quote
Jorge - 24/8/2007 9:12 PM
Not quite right. It would be 12 hours if KSC was on the equator, but because it isn't, the descending opportunity is typically 4 orbits (6 hours) after the ascending opportunity.QuoteBut one of those opportunities, the descending node, would bring the Shuttle in over the continental United States (coming down over Minnesota, Illinois, Tennessee, etc.) and since the Columbia accident, NASA prefers not to risk that approach anymore. That leave the ascending node, with a Shuttle coming in over Central America, the Caribbean, and Cuba.
While true, that's not the main reason. NASA avoided the descending opportunities for ISS flights even before the Columbia accident because they typically required a lot of crew sleep-shifting, and because of concerns over noctilucent clouds during the summer months.
Thanks, Jorge. Would it be correct to say that the second opportunity is 6 hours after the first, and then you don't get another one for another 18 hours?
And I know at least two landings came in over the U.S. on descending node (I witnessed STS-79 from northeast of Atlanta) what were the exceptions that NASA would do this for?
Post by: Jim on 08/25/2007 06:41 pm
Post by: Jorge on 08/25/2007 08:32 pm
Quote
Thorny - 25/8/2007 1:33 PMQuoteJorge - 24/8/2007 9:12 PM
Not quite right. It would be 12 hours if KSC was on the equator, but because it isn't, the descending opportunity is typically 4 orbits (6 hours) after the ascending opportunity.QuoteBut one of those opportunities, the descending node, would bring the Shuttle in over the continental United States (coming down over Minnesota, Illinois, Tennessee, etc.) and since the Columbia accident, NASA prefers not to risk that approach anymore. That leave the ascending node, with a Shuttle coming in over Central America, the Caribbean, and Cuba.
While true, that's not the main reason. NASA avoided the descending opportunities for ISS flights even before the Columbia accident because they typically required a lot of crew sleep-shifting, and because of concerns over noctilucent clouds during the summer months.
Thanks, Jorge. Would it be correct to say that the second opportunity is 6 hours after the first, and then you don't get another one for another 18 hours?
What Jim said. :)
Quote
And I know at least two landings came in over the U.S. on descending node (I witnessed STS-79 from northeast of Atlanta) what were the exceptions that NASA would do this for?
Non-summer flight (so no concern over noctilucents) combined with a mission timeline that puts the descending opportunity during the crew's awake period. The latter was more often the case for Shuttle-Mir flights since the shuttle crew was sleep-shifted to match the Mir crew. For Shuttle-ISS flights the two crews tend to meet in the middle so it's more typical for the descending opportunity to wind up during crew sleep.
Post by: Ankle-bone12 on 08/25/2007 11:15 pm
Quote
Jim - 24/8/2007 5:22 AM
Not in the MPLM. The crew has no access to it in the payload bay of the shuttle (there is no tunnel). On spacehab missions, there is a tunnel and the crew has slept in the module.
Ok. But I saw in the STS126 FDRD on L2 that the MPLM has 3 crew quarters and teadmil etc. I wonder if astronauts sleep there when birthed to station, Or is that not what that is.
Post by: brahmanknight on 08/26/2007 12:20 am
Post by: MKremer on 08/26/2007 01:04 am
Post by: John2375 on 08/27/2007 12:54 am
That's only a northern hemisphere thing for some reason?? Because coming in the other way they still are at extreme southern latitudes..
Post by: Jim on 08/27/2007 01:13 am
Quote
John2375 - 26/8/2007 8:54 PM
noctilucents.. i'm just finding out and learning about this now.. -
That's only a northern hemisphere thing for some reason?? Because coming in the other way they still are at extreme southern latitudes..
Coming the other way, the shuttle would be at higher altitudes during the higher latitudes
Post by: ChrisGebhardt on 08/27/2007 04:52 am
Post by: Jim on 08/27/2007 11:05 am
Post by: mjp25 on 08/28/2007 02:10 am
Post by: Jim on 08/28/2007 02:20 am
Post by: GLS on 08/28/2007 10:55 am
Post by: MKremer on 08/28/2007 11:52 pm
Post by: spaceshuttle on 08/29/2007 06:35 am
Post by: GLS on 08/29/2007 10:27 pm
Post by: spaceshuttle on 08/29/2007 10:33 pm
Quote
GLS - 29/8/2007 5:27 PM
I think that's recently applied foam (light color, although some foam types are lighter than others...), either to repair a damaged foam area or because they needed to re-check weld thickness... or it could be that the foam was too thick and they trimmed it down. Each tank has it's own history.
Awesome! Thanks! :laugh:
Post by: tnphysics on 08/30/2007 01:05 am
Post by: Lee Jay on 08/30/2007 01:12 am
Quote
tnphysics - 29/8/2007 7:05 PM
Why isn't the RCS a TPS breach?
I don't know, but it seems to me that any rocket nozzle capable of handling the continuous burning of hypergolic propellants inside without damage is also likely to have what it takes to withstand reentry plasma.
Post by: tnphysics on 08/30/2007 01:25 am
Post by: Jim on 08/30/2007 11:41 am
Quote
tnphysics - 29/8/2007 9:25 PM
Not if it's regeneratively cooled.
They are radiation cooled and made of carbon-carbon
Post by: ChrisGebhardt on 08/30/2007 09:27 pm
Post by: Jim on 08/30/2007 09:44 pm
Quote
Trekkie07 - 30/8/2007 5:27 PM
Can someone provide me with/direct me to a list of all the LCC calls to the PLT and CDR during the final 9min of the countdown. Thanks.
Look at the countdown on NASA.gov
Post by: ChrisGebhardt on 08/31/2007 12:39 am
Quote
Jim - 30/8/2007 5:44 PMQuoteTrekkie07 - 30/8/2007 5:27 PM
Can someone provide me with/direct me to a list of all the LCC calls to the PLT and CDR during the final 9min of the countdown. Thanks.
Look at the countdown on NASA.gov
Could you be a little more specific... simply looking at countdown doesn't give me what I'm looking for. I'm looking for the calls like, "OTC to PLT, preform APU start." Thanks
Post by: swhitt on 08/31/2007 12:47 am
Quote
Trekkie07 - 30/8/2007 5:39 PMQuoteJim - 30/8/2007 5:44 PMQuoteTrekkie07 - 30/8/2007 5:27 PM
Can someone provide me with/direct me to a list of all the LCC calls to the PLT and CDR during the final 9min of the countdown. Thanks.
Look at the countdown on NASA.gov
Could you be a little more specific... simply looking at countdown doesn't give me what I'm looking for. I'm looking for the calls like, "OTC to PLT, preform APU start." Thanks
google "countdown nasa.gov"
select the 6th item on the list
Jim's answers are short, but usually right. :-)
Post by: Jim on 08/31/2007 01:21 am
Quote
Trekkie07 - 30/8/2007 8:39 PMQuoteJim - 30/8/2007 5:44 PMQuoteTrekkie07 - 30/8/2007 5:27 PM
Can someone provide me with/direct me to a list of all the LCC calls to the PLT and CDR during the final 9min of the countdown. Thanks.
Look at the countdown on NASA.gov
Could you be a little more specific... simply looking at countdown doesn't give me what I'm looking for. I'm looking for the calls like, "OTC to PLT, preform APU start." Thanks[/QUOTE
Why can't people search for themselve? I would have had to done the search myself using google
Post by: AstroRJY on 08/31/2007 01:49 am
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Post by: ChrisGebhardt on 08/31/2007 02:00 am
Quote
AstroRJY - 30/8/2007 9:49 PM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Thank you. I tried searching nasa.gov and found that other document but it did not contain all the calls I was interested in. So thank you!!!!!!!!!!!!
Post by: mkirk on 08/31/2007 09:04 pm
Quote
AstroRJY - 30/8/2007 8:49 PM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Just FYI
"AC Bus Sensors to Monitor" is done at T-3 hours now by the ASP (Astronaut Support Person or "Cape Crusader") before Crew Ingress. With these sensors in monitor any overload, over or under voltage conditon on the busses would be anunciated but the busess will not be automatically taken off line.
"Connect Essential Busses to the Fuel Cells" is done at T-8 minutes. They wait until around T-8 minutes to do this so that the ground (i.e. Launch Control Center) can retain the ability to remotely power down the vehicle in an emergency, after this procedure the crew would have to power it down.
The only other formal call I can think of in the T-9 time frame would be to "Clear the hardware Caution and Warning Memory". This is done about 5 minutes prior to coming out of the hold at T-9.
Mark Kirkman
Post by: AstroRJY on 09/01/2007 01:33 am
Post by: GLS on 09/01/2007 12:10 pm
Quote
AstroRJY - 31/8/2007 2:49 AM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Isn't APU pre-start at T-6:15????
Post by: TJL on 09/01/2007 01:22 pm
Thank you.
Post by: Jim on 09/01/2007 01:39 pm
Quote
TJL - 1/9/2007 9:22 AM
How is it determined which payloads are installed in the payload bay while the shuttle is in the OPF and which are installed at the pad?
Thank you.
It depends on how the payload is built up, what testing it needed and whether it is hazardous. Spacelabs were the primary horizontal installations. Spacehab went vertical after it demonstrated itself with the shuttle and the reduced time at the pad was better for them.
Post by: LSainsbury on 09/01/2007 01:45 pm
Do they actually open the cargo bay doors at the pad to install payloads then?
Post by: AstroRJY on 09/01/2007 01:46 pm
Quote
GLS - 1/9/2007 8:10 AMQuoteAstroRJY - 31/8/2007 2:49 AM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Isn't APU pre-start at T-6:15????
No. THe OTC asks for the hydraulic pressure recorders to start about T- 6:15 then once they are started he calls for the APU pre-start at T - 6 minutes. Sometimes the might do it a few seconds early but the timeline is T-6 minutes.
Post by: psloss on 09/01/2007 02:01 pm
Quote
LSainsbury - 1/9/2007 9:45 AMMost of the payloads have been installed at the pad -- for years and years.
Installed at the pad?
Do they actually open the cargo bay doors at the pad to install payloads then?
Post by: LSainsbury on 09/01/2007 02:03 pm
Post by: GLS on 09/01/2007 02:21 pm
Quote
AstroRJY - 1/9/2007 2:46 PMQuoteGLS - 1/9/2007 8:10 AMQuoteAstroRJY - 31/8/2007 2:49 AM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Isn't APU pre-start at T-6:15????
No. THe OTC asks for the hydraulic pressure recorders to start about T- 6:15 then once they are started he calls for the APU pre-start at T - 6 minutes. Sometimes the might do it a few seconds early but the timeline is T-6 minutes.
I've seen a couple of timelines and they had T-6:15... anyone has the S0007????
Post by: mkirk on 09/01/2007 02:42 pm
Quote
GLS - 1/9/2007 9:21 AMQuoteAstroRJY - 1/9/2007 2:46 PMQuoteGLS - 1/9/2007 8:10 AMQuoteAstroRJY - 31/8/2007 2:49 AM
Trekkie I can tell you the calls right off the top of my head from watching dozens of launches, here ya go:
T-8 minutes: PLT take AC bus sensors to MONITOR. (1980s and 1990s)
T-7:45 (approxiamtely) PLT configure FUEL CELL/ ESSENTIAL BUS SOURCE switches
T-6 minutes PLT perform APU pre-start
T-5 minutes PLT perform APU start
T-5 minutes CDR reconfigure heaters (turn the orbiter's FLASH EVAPORATOR FEEDLINE heaters A and B to OFF)
T-2:30 PLT clear Caution/ Warning memory, verify no unexpected messages.
T- 2 minutes. Flight crew close and lock visors, open suit O2 valves.
All of these are from the OTC. And the network communicaiton format is "PLT, OTC perform.. " or "CDR, OTC perform..." , etc.
Isn't APU pre-start at T-6:15????
No. THe OTC asks for the hydraulic pressure recorders to start about T- 6:15 then once they are started he calls for the APU pre-start at T - 6 minutes. Sometimes the might do it a few seconds early but the timeline is T-6 minutes.
I've seen a couple of timelines and they had T-6:15... anyone has the S0007????
Per the Ascent Checklist and S0007 the APU Pre-Start is at T-6:15 by the clock. You may hear the actual call from OTC a little later but that is when it is planned for. The APU Pre-Start is not as time critical as the actual APU Start-Up procedure at T-5 minutes since it is mostly a check of switches and breakers that sholud already be in the proper configuration (only nine actual switch throws).
If the pilot is slow to get all 3 APUs up and running during the Start procedure the countdown clock could enter an unplanned hold at T-4:00. This is because the GLS performs a status check of various APU parameters (such as turbine speed and supply pressures) at T-4:05, if the status check is not passed then the clock will automatically enter a hold at the next GLS milestone which is T-4 minutes.
I believe this actually happened to Andy Allen on STS-46. Ooops! ;)
Mark Kirkman
Post by: brahmanknight on 09/01/2007 09:15 pm
Post by: Jim on 09/01/2007 09:29 pm
Quote
brahmanknight - 1/9/2007 5:15 PM
Can anyone explain why some flights need a payload commander, and others don't?
It depends on how crew intensive the mission is. And if the MS needs to be assigned earlier. this was applicable to science (module) missions
Post by: brahmanknight on 09/01/2007 09:57 pm
Post by: Jim on 09/01/2007 10:14 pm
Post by: APG85 on 09/02/2007 09:19 pm
Post by: Jorge on 09/02/2007 09:59 pm
Quote
APG85 - 2/9/2007 4:19 PM
I had read at one time that Columbia was to heavy to ever be used for ISS missions. Was this really the case
Columbia was too heavy to be used for most ISS assembly missions. She was scheduled to be the orbiter for STS-118, and that was only possible because the S5 truss segment was relatively light and the primary mission was resupply via Spacehab (which could not be loaded as fully as it would have been on any other orbiter).
Quote
and were there plans to reduce it's weight (if this was true)?
No. Most of the easy stuff (removing development flight instrumentation, etc) had already been done. Most of the rest of the difference was structural weight and there were no plans to try to shave that. Ironically, one of the few things that could have been removed but wasn't - the OEX recorder - later proved useful to the Columbia Accident Investigation Board.
Quote
Had it survived, would Challenger have had the same issue?
No. Challenger was lighter than Columbia, more similar to the other orbiters.
Post by: APG85 on 09/02/2007 10:22 pm
Post by: usn_skwerl on 09/03/2007 02:24 pm
Post by: APG85 on 09/03/2007 02:51 pm
Post by: Danny Dot on 09/03/2007 03:09 pm
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usn_skwerl - 3/9/2007 9:24 AM
one thing ive wondered about...when the shuttle reenters after deorbit burn, it comes in with a ~40 degree angle relative to the atmosphere. wouldnt its shape force it to pitch down with 0 degree AoA? a "pointy end forward" profile? i understand the air is relatively thin, and they do use the RCS for att. control, but it just seems like its almost against physics, considering one end is pointy and one end has the "aerodynaminticity" of a dinner table.
The elevons and body flap go up and the shuttle is in trim at the 40 degrees angle of attack. RCS is not used except in the very early entry for pitch. It is used down to Mach 1 for lateral direction control, but not for pitch.
Danny Deger
Post by: Jim on 09/03/2007 03:09 pm
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usn_skwerl - 3/9/2007 10:24 AM
one thing ive wondered about...when the shuttle reenters after deorbit burn, it comes in with a ~40 degree angle relative to the atmosphere. wouldnt its shape force it to pitch down with 0 degree AoA? a "pointy end forward" profile? i understand the air is relatively thin, and they do use the RCS for att. control, but it just seems like its almost against physics, considering one end is pointy and one end has the "aerodynaminticity" of a dinner table.
Not with the aerosurfaces keeping the pitch up, just like aircraft flaring before touchdown.
Post by: GLS on 09/03/2007 03:20 pm
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APG85 - 3/9/2007 3:51 PM
What was the fastest orbiter turn-around time (from landing to it's next launch)? I was thinking Atlantis 51J - 61B. Is this correct? Thanks.
Yep, that's correct!
Post by: APG85 on 09/03/2007 03:22 pm
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GLS - 3/9/2007 11:20 AMQuoteAPG85 - 3/9/2007 3:51 PM
What was the fastest orbiter turn-around time (from landing to it's next launch)? I was thinking Atlantis 51J - 61B. Is this correct? Thanks.
Yep, that's correct!
I'd love to know the inside story on how they turned Atlantis so quickly!
Post by: GLS on 09/03/2007 04:15 pm
Post by: TJL on 09/03/2007 07:11 pm
Anyone know if Bowen's been re-assigned to a downstream shuttle flight?
Thank you.
Post by: DaveS on 09/03/2007 07:14 pm
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TJL - 3/9/2007 9:11 PMCheck this thread: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=740&posts=516&start=1
Looks like Stephen Bowen has been replaced on STS-124 by Greg Chamitoff.
Anyone know if Bowen's been re-assigned to a downstream shuttle flight?
Thank you.
Post by: shuttlefan on 09/07/2007 01:32 am
Post by: Jim on 09/07/2007 01:35 am
Post by: pippin on 09/07/2007 08:05 am
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shuttlefan - 7/9/2007 3:32 AM
I know that the shuttle PROBABLY achieved its highest altitude on the Hubble missions but is it possible that since we don't have that information from the DOD missions, that it could have actually climbed to a higher altitude on at least one of those flights?
Maybe our Russian friends here on the site can find out about that ;-)
Post by: Lee Jay on 09/07/2007 10:17 pm
I *know* I saw a map of the VAB here at some point. But searching and searching hasn't found it for me. Does someone have a link to such a floor plan?
Post by: SiameseCat on 09/08/2007 01:31 pm
Edit: After doing a bit more math, if the shuttle has a payload of about 22300kg, the SSMEs can maintain 3g acceleration at 67% thrust. For missions with lighter payloads, is ballast added to maintain this weight?
Post by: pippin on 09/08/2007 10:52 pm
How is it to be done for LON missions?
Post by: Jim on 09/09/2007 04:32 am
Post by: SiameseCat on 09/09/2007 05:19 am
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Jim - 9/9/2007 12:32 AM
Falacy is that all the ET propellants are burned. They aren't, there is more left in the ET when there is a lighter payload
So what happens in a STS-93 situation, where a minor fuel leak causes a low-level cutoff?
Post by: MKremer on 09/09/2007 06:49 am
Post by: SiameseCat on 09/09/2007 12:43 pm
Post by: mkirk on 09/09/2007 04:15 pm
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SiameseCat - 9/9/2007 12:19 AMQuoteJim - 9/9/2007 12:32 AM
Falacy is that all the ET propellants are burned. They aren't, there is more left in the ET when there is a lighter payload
So what happens in a STS-93 situation, where a minor fuel leak causes a low-level cutoff?
I am not sure what you are asking with regard to the “Low Level Cut”, can you expand your question a little?
A Low Level Cut is a bad thing and at no time do you ever want to run a tank dry. In the case of 93 it was obviously not planned or expected. Although fuel (LH2) was leaking, the resultant shift in mixture caused the LO2 to run out – fortunately it happened right at the planned MECO when the engines had already throttled back and were in the process of shutting down. An underspeed of around 15-16 feet per second occurred, this was not big enough to necessitate an OMS-1 burn and the OMS-2 and subsequent burns allowed mission to continue.
Jim is right about the ET fuel loading/consumption. The ET is always filled to 100% for both LO2 and LH2. During the flight design process it is the LO2 that determines if the intended mission is achievable. So for every shuttle ascent there should always be LH2 remaining in the ET and some LO2 (with the remaining LO2 being referred to as the performance margin).
Many variables constrain the ascent; G-loading, MECO targets (velocity, range, altitude, theta), weight, cg (center of gravity) location, OMS/RCS delta V available, ascent performance margin, trajectory shape, abort capability/targets, and ET impact point are just some that readily come to mind.
The actual structural limit on ascent is about 3.5 Gs with 3 G throttling being imposed to protect that limit with a little bit of safety margin. Certified minimum power for the SSMEs is 67% (used to be 65%) so if a flight designer sees that 3 G throttling at 67% does not ensure the vehicle remains at or below 3 Gs then one of the other variables needs to be changed or the mission is not going to be flown. I don’t think the program has ever flow with ballast that was only intended for this purpose. If a violation of the G limit was the only constraint to the intended flight profile then it makes more sense to re-manifest payload items until you are within the desired weight.
Ballast (usually in the form of extra OMS/RCS propellant) is flown in order to manage CG limits.
Mark Kirkman
Post by: kneecaps on 09/09/2007 05:26 pm
Post by: mkirk on 09/09/2007 05:50 pm
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kneecaps - 9/9/2007 12:26 PM
What is the Major New Flight Support Software Item in the STS-120 PCRB documents? It referred to as MCR 23448 (ECO Sensor System Instrumentation Installation)?
You are going to have to be more specific about which document you are referring to.
However, this is the first flight of the OI-32 software upgrade and I think the item you listed is just referencing the same ECO mod that was flown on 118. I would have to know the context in order to be sure.
Mark Kirkman
Post by: SiameseCat on 09/09/2007 07:27 pm
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mkirk - 9/9/2007 12:15 PMQuoteSiameseCat - 9/9/2007 12:19 AMQuoteJim - 9/9/2007 12:32 AM
Falacy is that all the ET propellants are burned. They aren't, there is more left in the ET when there is a lighter payload
So what happens in a STS-93 situation, where a minor fuel leak causes a low-level cutoff?
I am not sure what you are asking with regard to the “Low Level Cut”, can you expand your question a little?
My question was referring to the ability of a lightweight shuttle to keep acceleration below 3g before MECO. I referred to a low level cutoff to create a situation where the ET was as close to empty as possible.
Post by: Jim on 09/09/2007 08:31 pm
Post by: kneecaps on 09/09/2007 10:30 pm
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mkirk - 9/9/2007 6:50 PMQuotekneecaps - 9/9/2007 12:26 PM
What is the Major New Flight Support Software Item in the STS-120 PCRB documents? It referred to as MCR 23448 (ECO Sensor System Instrumentation Installation)?
You are going to have to be more specific about which document you are referring to.
However, this is the first flight of the OI-32 software upgrade and I think the item you listed is just referencing the same ECO mod that was flown on 118. I would have to know the context in order to be sure.
Mark Kirkman
Thanks Mark! The document is the STS-120 PRCB Program Freeze Point dated 07/24/7.
Page 66 of 119.
ECO sensor mod? I may must have missed this? I'm not sure if the document is referring to a software or hardware change.
Pete
Post by: psloss on 09/09/2007 11:28 pm
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kneecaps - 9/9/2007 6:30 PMNote that it says "First OV-103 implementation of..." If you go back and look at the STS-118 documentation, you'll see MCR 23448 there, as Mark already noted.
The document is the STS-120 PRCB Program Freeze Point dated 07/24/7.
Page 66 of 119.
ECO sensor mod? I may must have missed this? I'm not sure if the document is referring to a software or hardware change.
(And I believe this change was also made to OV-104 and backed out prior to STS-117.)
Post by: thomasafb on 09/11/2007 10:40 am
i am looking for a detailed floorplan of the flight deck. So far, i only found a drawing without scale and even in the SCOM there are only floorplans of the mid deck and the panel overview for the flight deck. I know that there is not much floor up there since it is rather crammed, especially with the MS seats, but i'd like to have the dimensions nevertheless.
Any help would be very much appreciated.
Thomas
Post by: SpaceNutz SA on 09/12/2007 06:41 am
Post by: GLS on 09/12/2007 12:46 pm
Post by: hmh33 on 09/12/2007 04:17 pm
I'm not sure about any of this though, would be good to hear from someone who is? :)
Post by: mkirk on 09/12/2007 04:39 pm
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hmh33 - 12/9/2007 11:17 AM
I thought it changed not just from flight to flight but actually during the entry process itself, adjusting depending on how much energy the orbiter is predicted to have when it reaches the HAC. The way I understand it, the HAC is basically a controlled way to dump the remaining energy in order to land at a safe speed. So if the orbiter is low on energy the HAC will become smaller, and vice versa.
I'm not sure about any of this though, would be good to hear from someone who is? :)
I don’t know how detailed you want to get but since it is lunch time I will start with the quick and simple and will follow up if that isn’t enough.
For starters, and there are other variables involved, the HAC size is actually altitude dependent. Think of it as an upside down cone rather than a cylinder, as you decrease altitude the diameter will decrease.
Mark Kirkman
Post by: brahmanknight on 09/12/2007 04:48 pm
Post by: SpaceNutz SA on 09/12/2007 06:09 pm
Post by: Danny Dot on 09/13/2007 04:22 pm
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mkirk - 12/9/2007 11:39 AMQuotehmh33 - 12/9/2007 11:17 AM
I thought it changed not just from flight to flight but actually during the entry process itself, adjusting depending on how much energy the orbiter is predicted to have when it reaches the HAC. The way I understand it, the HAC is basically a controlled way to dump the remaining energy in order to land at a safe speed. So if the orbiter is low on energy the HAC will become smaller, and vice versa.
I'm not sure about any of this though, would be good to hear from someone who is? :)
I don’t know how detailed you want to get but since it is lunch time I will start with the quick and simple and will follow up if that isn’t enough.
For starters, and there are other variables involved, the HAC size is actually altitude dependent. Think of it as an upside down cone rather than a cylinder, as you decrease altitude the diameter will decrease.
Mark Kirkman
Very true. Normally the diameter of the HAC is just a function of altitude. This is done because at higher altitude the shuttle is flying a higher true airspeed and needs more room to turn. The HAC is a cone.
There is also a provision that if the shuttle gets very low energy, the HAC will also shrink. As far as I know this has happened twice in the history of the shuttle.
Danny Deger
Post by: GLS on 09/13/2007 07:02 pm
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Danny Dot - 13/9/2007 5:22 PM
There is also a provision that if the shuttle gets very low energy, the HAC will also shrink. As far as I know this has happened twice in the history of the shuttle.
That's the MEP (Minimum Entry Point), and I think the A/L interface goes down to 5Kft in those cases...
Do you know which 2 missions had the MEP??? STS 37???
Post by: mkirk on 09/13/2007 10:30 pm
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GLS - 13/9/2007 2:02 PMQuoteDanny Dot - 13/9/2007 5:22 PM
There is also a provision that if the shuttle gets very low energy, the HAC will also shrink. As far as I know this has happened twice in the history of the shuttle.
That's the MEP (Minimum Entry Point), and I think the A/L interface goes down to 5Kft in those cases...
Do you know which 2 missions had the MEP??? STS 37???
NO! I am afraid you are confusing a couple of different concepts. So let me attempt to make this as clear as mud.
Space Shuttle Landing 201
Prerequisites: Space Shuttle Landing 101*
(*Please note Shuttle Landing 101 is not offered during the Fall, Spring, or Summer Semesters, so plan accordingly when attempting to satisfy this requirement.) ;)
Nominally the HAC is an imaginary, upside down cone, located about 7 nautical miles away from the runway and tangent to the runway centerline (i.e. the approach path). This establishes a Nominal Entry Point (NEP) at 12,000 feet and 7 miles out.
As Danny indicated, the HAC is an energy management tool that is intended to allow the orbiter to “roll out” on final at the appropriate altitude, distance, and airspeed.
Getting to the original question, about HAC size and diameter, the size is a direct function of altitude which means as the altitude decrease the diameter decreases. If you were to look at the actual ground track of the orbiter as it flies around the HAC it would appear as a spiral if it were drawn on the ground.
The angle formed between the points where the orbiter enters the HAC and the point where it is lined up with the runway (NEP or MEP) is known as the HAC Turn Angle (HTA). A large HTA, let’s say over 300 degrees, will result in a larger diameter HAC to allow the orbiter to bleed off the extra altitude and airspeed.
In a situation where the orbiter is low on energy when it arrives at and flies around the HAC the crew has the option of selecting a Minimum Entry Point (MEP) HAC which basically moves the HAC closer to the runway (about 4 nautical miles instead of the nominal 7).
Do not confuse NEP and MEP with the Nominal and Close-In aim points. Aim points are located on the ground in front of the runway and help establish the intended glide slope. The Nominal aim point is located about 7500 feet in front of the runway while the Close-In aim point is located 6000 feet in front of the runway. Normally the orbiter is targeted to touchdown on the runway at 2500 feet past the runway threshold at either 195 or 205 knots (depending on weight), if the orbiter is predicted to touchdown at less than 1000 feet from the threshold then the crew will select the Close-In aimpoint.
All of these changes (MEP vs NEP, Nominal vs Close-In, etc) are made by typing in specific item entries to the SPEC 50 Horizontal Situation Display of the General Purpose Computers. (see the attached photo below Item Entry 7 and 8 respectively)
As for the HAC shrink that Danny Dot referred too, that is not the same thing as MEP. HAC shrink would occur if the orbiter was very low in altitude during the HAC phase. The orbiter’s guidance system would shrink the diameter of the HAC in an effort to decrease the total range the orbiter still has to fly to get to the runway. The magnitude of this shrink adjustment is dependent on the HTA remaining and the amount of altitude error (i.e. how low the orbiter is compared to the planned trajectory). If the orbiter has an HTA of less than 90 degrees then the shrink function is inhibited.
Here are some "ROUGH" numbers for the approximate altitude of the orbiter at a given point on the HAC (HTA) - Nominally.
360 - 50,000 feet
270 - 38,000
180 - 28,000
90 - 20,000
0 - 12,000
Mark Kirkman
Post by: GLS on 09/14/2007 12:20 am
I wasn't even thinking about the aim points (I was still in the HAC).... I didn't knew of the *automatic* HAC shrinkage... is that what happened on the 2 missions instead of MEP???
Also, one small question (small answer will do ;)), on MEP the HAC is closer to the runway but also lower, right?! Those altitudes you give above would be lower and A/L I/F would also be lower, to keep the OGS at 18-20 degrees, right?!
Post by: mkirk on 09/14/2007 02:06 am
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GLS - 13/9/2007 7:20 PM
Hi mkirk, thanks for that piece of bible!!!!
I wasn't even thinking about the aim points (I was still in the HAC).... I didn't knew of the *automatic* HAC shrinkage... is that what happened on the 2 missions instead of MEP???
Also, one small question (small answer will do ;)), on MEP the HAC is closer to the runway but also lower, right?! Those altitudes you give above would be lower and A/L I/F would also be lower, to keep the OGS at 18-20 degrees, right?!
I new that you were not confusing NEP/MEP with the aimpoints, I was just making a general statement for people not to confuse them because they often do.
I don't know what happened on the missions Danny is talking about, I will have to research that.
I have attached a diagram that should show you how the entry points line up. In this case with both the NEP and MEP using the same aimpoint (nominal 7500 feet) the glide slope geometry is the same and a 12,000 foot nominal entry point (at t nautical miles) lines up with a 6000 foot minimum entry point (at 4 nautical miles).
Mark Kirkman
Post by: GLS on 09/14/2007 01:26 pm
Post by: APG85 on 09/16/2007 12:15 pm
Post by: psloss on 09/16/2007 12:50 pm
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APG85 - 16/9/2007 8:15 AMColumbia still had the ejection seats for the CDR and PLT at that point.
On STS-5, why did Joe Allen sit on the mid-deck for launch? With only four crew members on board there should have been room for him upstairs. Just curious. Thanks.
FYI, this was already asked:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6156&start=166#M115293
Post by: APG85 on 09/16/2007 01:37 pm
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psloss - 16/9/2007 8:50 AMQuoteAPG85 - 16/9/2007 8:15 AMColumbia still had the ejection seats for the CDR and PLT at that point.
On STS-5, why did Joe Allen sit on the mid-deck for launch? With only four crew members on board there should have been room for him upstairs. Just curious. Thanks.
FYI, this was already asked:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6156&start=166#M115293
Are ejection seats that much bigger? I read that prvious post but it doesn't go into detail. If you can get three upstairs with ejection seats, why not four? I'm assuming there was only room for a seat between the CDR and PLT (aft)... Thanks.
Post by: Jim on 09/16/2007 02:09 pm
Post by: APG85 on 09/16/2007 02:12 pm
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Jim - 16/9/2007 10:09 AM
The ejection seats were a lot bigger
What became of those two seats - museum, storage, junk?
Post by: brahmanknight on 09/17/2007 12:09 pm
Post by: MKremer on 09/17/2007 02:27 pm
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APG85 - 16/9/2007 9:12 AM
What became of those two seats - museum, storage, junk?
Or maybe just refurb'd and put back into the vendor's spares inventory.
Post by: Danny Dot on 09/17/2007 03:12 pm
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mkirk - 13/9/2007 9:06 PM
snip
I don't know what happened on the missions Danny is talking about, I will have to research that.
Mark Kirkman
One was a flight that the shuttle was poorly flown while the crew was transitioning from PLT flying to CDR flying while on the HAC (the shuttle went to almost wings level for a few seconds). After this flight, it became an unwritten rule to not let the PLT fly part of the HAC. The crew made up the energy and had a normal landing. I am pretty sure STS-37 had HAC shrink also.
Danny
Post by: kimmern123 on 09/17/2007 03:30 pm
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Danny Dot - 17/9/2007 5:12 PMQuotemkirk - 13/9/2007 9:06 PM
snip
I don't know what happened on the missions Danny is talking about, I will have to research that.
Mark Kirkman
One was a flight that the shuttle was poorly flown while the crew was transitioning from PLT flying to CDR flying while on the HAC (the shuttle went to almost wings level for a few seconds). After this flight, it became an unwritten rule to not let the PLT fly part of the HAC. The crew made up the energy and had a normal landing. I am pretty sure STS-37 had HAC shrink also.
Danny
But don't they let the PLTs fly part of the HAC now? I'm Mark Kelly on STS-121 and Chris Ferguson on STS-115 flew part of the HAC. I'm not sure about the flights after those though.
Post by: nathan.moeller on 09/17/2007 04:11 pm
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kimmern123 - 17/9/2007 10:30 AMQuoteDanny Dot - 17/9/2007 5:12 PMQuotemkirk - 13/9/2007 9:06 PM
snip
I don't know what happened on the missions Danny is talking about, I will have to research that.
Mark Kirkman
One was a flight that the shuttle was poorly flown while the crew was transitioning from PLT flying to CDR flying while on the HAC (the shuttle went to almost wings level for a few seconds). After this flight, it became an unwritten rule to not let the PLT fly part of the HAC. The crew made up the energy and had a normal landing. I am pretty sure STS-37 had HAC shrink also.
Danny
But don't they let the PLTs fly part of the HAC now? I'm Mark Kelly on STS-121 and Chris Ferguson on STS-115 flew part of the HAC. I'm not sure about the flights after those though.
There are plenty of times that CDRs will let the PLTs fly part of the HAC nowadays. All depends on the CDRs choice. Pam Melroy got a shot on STS-112, Lockhart on STS-113, Jim Kelly on STS-114, Mark Kelly, Chris Ferguson, etc. Not sure about any flights after that. It's not uncommon anymore.
As for the orbiter that went wide around that HAC, I'm not sure which mission it was, but it was an Edwards landing. If it had been a KSC landing, the orbiter would have been in the swamp.
Post by: Danny Dot on 09/17/2007 06:25 pm
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nathan.moeller - 17/9/2007 11:11 AMQuotekimmern123 - 17/9/2007 10:30 AMQuoteDanny Dot - 17/9/2007 5:12 PMQuotemkirk - 13/9/2007 9:06 PM
snip
I don't know what happened on the missions Danny is talking about, I will have to research that.
Mark Kirkman
One was a flight that the shuttle was poorly flown while the crew was transitioning from PLT flying to CDR flying while on the HAC (the shuttle went to almost wings level for a few seconds). After this flight, it became an unwritten rule to not let the PLT fly part of the HAC. The crew made up the energy and had a normal landing. I am pretty sure STS-37 had HAC shrink also.
Danny
But don't they let the PLTs fly part of the HAC now? I'm Mark Kelly on STS-121 and Chris Ferguson on STS-115 flew part of the HAC. I'm not sure about the flights after those though.
There are plenty of times that CDRs will let the PLTs fly part of the HAC nowadays. All depends on the CDRs choice. Pam Melroy got a shot on STS-112, Lockhart on STS-113, Jim Kelly on STS-114, Mark Kelly, Chris Ferguson, etc. Not sure about any flights after that. It's not uncommon anymore.
As for the orbiter that went wide around that HAC, I'm not sure which mission it was, but it was an Edwards landing. If it had been a KSC landing, the orbiter would have been in the swamp.
I got out of training entry in 1995. Things might have changed. Keep in mind the PLT can fly part of the profile from Mach .95 to HAC intercept without flying any of the HAC itself. I know this is so common as to be standard proceedure.
I think transitioning while on the HAC would be OK as long at they have been trained to make sure the orbiter does not roll out of its needed bank angle during the transition.
Post by: mkirk on 09/18/2007 01:02 am
The General preference is to allow the PLT to fly during the period from .95 MACH to HAC intercept. If you listen to the air to ground comm when MCC reads up the DEL PAD you will hear something called "Delta T MACH < 1 to HAC". Some times this number is just a few seconds other times it will be a minute or more (For 118 I believe it was just over a minute).
Anyway as long as this interval is long enogh for the handover then that is when it will occur. Once the orbiter is stabilized and subsonic the CDR will hand over to the PLT for a portion of the interval and will retake control prior to rolling onto the HAC (i.e. CDR will execute the roll)
If there is not enough real time prior to HAC intercept then the handover will be on the HAC (assuming nominal conditions and a big enough HAC turn angle). Once the CDR has the orbiter stabilized he/she will hand over to the PLT for few seconds. Typically the CDR should have control back befor reaching the 90 degree point.
Mark Kirkman
Post by: C5C6 on 09/18/2007 01:59 pm
Post by: Lee Jay on 09/18/2007 02:06 pm
Quote
C5C6 - 18/9/2007 7:59 AM
just wanted to ask......in cases like STS-120, you can see that the payload bay is not completely occupied........why don't they occupy it with a smaller payload for the iss, or an independent sattelite/experiment......looks like they were wasting payload capability......
Empty space does not mean available lift performance. ISS is in a tough orbit to get to and most of the remaining flights are very performance limited.
Post by: Jorge on 09/18/2007 02:07 pm
Quote
C5C6 - 18/9/2007 8:59 AM
just wanted to ask......in cases like STS-120, you can see that the payload bay is not completely occupied........why don't they occupy it with a smaller payload for the iss, or an independent sattelite/experiment......looks like they were wasting payload capability......
It is completely occupied, regardless of what it looks like. Payload is typically constrained by mass and c.g. location, not volume.
Post by: TJL on 09/19/2007 01:43 am
Is this the first time a single director isn't used for both events?
Thank you.
Post by: psloss on 09/19/2007 10:42 am
Quote
TJL - 18/9/2007 9:43 PMNo, they just did that on STS-116 with Norm Knight. Given that this will be Bryan Lunney's first shift as Entry FD, I'm assuming it's the same thing, too -- Steve Stich was promoted and Lunney has moved into the Ascent/Entry FD role.
STS-120 has a two different flight directors for launch and entry.
Is this the first time a single director isn't used for both events?
Post by: shuttlefan on 09/19/2007 01:26 pm
Post by: brahmanknight on 09/20/2007 03:37 pm
Post by: Jim on 09/20/2007 04:32 pm
Quote
brahmanknight - 20/9/2007 11:37 AM
Why are there built in holds in the shuttle, and other rocket's, countdown?
Shuttle does things just a little different from ELV's. The "countdown" is always 43 hours. The holds are lengthened and shortened to accomodate differences in the missions (payload). The holds are always in the same place in the countdown. What controls what happens in the holds is the S0007 schedule.
ELV always use the same countdown and the holds don't change (. Their countdowns are also shorter (tens of hours shorter). The procedures before the countdown (coutntdown preps) take care of differences
Post by: Thorny on 09/20/2007 05:46 pm
Quote
pad rat - 20/9/2007 11:13 AM
It allows time to catch up on tasks that may have fallen behind a bit on the schedule, as well as time to deal with issues that may have arisen during the count.
But technically, why does the countdown clock have to stop? Instead of a 43 hour countdown that takes 70-odd hours with built-in holds, why don't they just use a 70-hour countdown with no holds?
Post by: Jim on 09/20/2007 06:17 pm
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Thorny - 20/9/2007 1:46 PMQuotepad rat - 20/9/2007 11:13 AM
It allows time to catch up on tasks that may have fallen behind a bit on the schedule, as well as time to deal with issues that may have arisen during the count.
But technically, why does the countdown clock have to stop? Instead of a 43 hour countdown that takes 70-odd hours with built-in holds, why don't they just use a 70-hour countdown with no holds?
Like I said the holds times increase and decrease and like pad rat said the holds are to make up work. The actual countdown procedure is tied to specific T- times. This would entail a rewrite of the procedure for each mission. Launch is not at the same amount of time from the beginning of the count
Post by: GLS on 09/20/2007 06:17 pm
Quote
Thorny - 20/9/2007 6:46 PMQuotepad rat - 20/9/2007 11:13 AM
It allows time to catch up on tasks that may have fallen behind a bit on the schedule, as well as time to deal with issues that may have arisen during the count.
But technically, why does the countdown clock have to stop? Instead of a 43 hour countdown that takes 70-odd hours with built-in holds, why don't they just use a 70-hour countdown with no holds?
During BIHs there's not much to do, and so the BIHs act like a overrun when major activities are delayed. It's like a buffer zone.
The clock stops because it's easier, you start the countdown at the top of the hour, the BIHs start/end at *round* times and you just have to think minutes and seconds in the end of the countdown.
It's just better.
Post by: Ender0319 on 09/20/2007 10:02 pm
Besides... Shuttle has always done it this way with holds...
Quote
Jim - 20/9/2007 1:17 PM
Like I said the holds times increase and decrease and like pad rat said the holds are to make up work. The actual countdown procedure is tied to specific T- times. This would entail a rewrite of the procedure for each mission. Launch is not at the same amount of time from the beginning of the count
Post by: mkirk on 09/20/2007 11:34 pm
Quote
Ender0319 - 20/9/2007 5:02 PM
Oh but they do rewrite the S0007 (and S0017) procedure for every mission. People submit redlines, they reprinte the volumes of the books, kill trees, destroy ink supplies, etc. It's crazy but they do it. So I think it would be feasible to have a much longer countdown without holds but I think you've made the correct arguments as to why there are holds in the countdown.
Besides... Shuttle has always done it this way with holds...QuoteJim - 20/9/2007 1:17 PM
Like I said the holds times increase and decrease and like pad rat said the holds are to make up work. The actual countdown procedure is tied to specific T- times. This would entail a rewrite of the procedure for each mission. Launch is not at the same amount of time from the beginning of the count
Built in holds (BIH) have been around since long before the Shuttle. With regard to the manned vehicles BIHs were of particular importance during Gemini because they were running parallel countdowns (one for the Atlas Agena rendezvous target vehicle and another for the Gemini Titan) and they were dealing with small launch windows.
Shuttle Countdowns are far more integrated than previous vehicles like Apollo – meaning that a single controlling document runs all of the test operations. During Apollo you had parallel countdowns for the Booster, Spacecraft, and LM with everyone synching up during the last few minutes of the count.
I should also point out that it took a long time to “standardize” and streamline the current shuttle countdown. For example the countdown for STS-1 started at T-73 hours and had 30 hours and 20 minutes of built in hold time. That made the total countdown over 103 hours long. Tasks, such as GN2 and Helium pressurization of the OMS/RCS, that are currently done “pre-count” now, were done within the S0007 structure for the first few shuttle flights.
STS-6 had a 96 hour countdown with 26.5 hours of built in hold time added to that. I believe STS-8 was the first countdown to get into the 40 hour range. It took another few years and several more flights (well past the first return to flight era) before the current 43 hour countdown was formulated.
As time went on the launch teams were able to reduce the times needed for many tasks, reduce the number of test requirements, and improve task, hardware, and process efficiency.
ENDER0319 is right about the dead trees. I was always amazed at how many trees have given their lives for the good of the program. Every single flow the S0007 gets revised. There were times when we were less than a week away from call to stations – I already had one dead tree in my countdown notebook (i.e. about a thousand pages per volume with S0007 consisting of 5 volumes back then – it is now 6) and sure enough a brand new revision would come out which made my previous dead tree completely useless. At least the world of adobe PDF has saved one or two trees compared to how things used to be.
Currently the basic space shuttle countdown structure is always the same, meaning the holds are always in the same places, but the sequencing gets adjusted and the hold durations are changed based on mission and payload requirements.
The idea and philosophy is to standardize as much of the process as possible in an environment where things are always changing. ;)
Mark Kirkman
Post by: brahmanknight on 09/21/2007 06:22 pm
Post by: MKremer on 09/21/2007 06:53 pm
Post by: Jim on 09/21/2007 07:07 pm
Post by: jeff122670 on 09/23/2007 12:41 am
I haven't noticed it on any other launches and at that time the only pad being used was 39-A, so I dont think it is pad specific, but it certainly is "interesting" looking especially since I havent seen it on any other launches.
Does anyone know if it is simply a function of the water flowing through the pipes at differernt speeds (ie, this always happens, but we never see it because it is masked by the falling water) or was this a change to the water system.
Thanks!!
Jeff
Post by: GLS on 09/23/2007 10:58 am
Quote
jeff122670 - 23/9/2007 1:41 AM
I noticed that on the 41-D FRF as well as the launch right at about T-15 seconds, the water system seems a bit different. As the water activates, it appears as though there is a "fan" of water that sprays UP from underneath the MLP. This fan of water starts first and then all of the other water starts dumping down.
I haven't noticed it on any other launches and at that time the only pad being used was 39-A, so I dont think it is pad specific, but it certainly is "interesting" looking especially since I havent seen it on any other launches.
Does anyone know if it is simply a function of the water flowing through the pipes at differernt speeds (ie, this always happens, but we never see it because it is masked by the falling water) or was this a change to the water system.
Thanks!!
Jeff
On the North side of the flame trench there's 2 pipes that inject water into the flame trench and part of that water is routed up to the MLP, by pipes on the 2 SRB flame deflectors (I think that's the correct name...), to the pipes around the SRB flame hole, and the water is then injected just below the SRB nozzle to supress the shock wave generated at ignition. Those SRB flame deflectors move on tracks from the "parking" position, just to the North of the MLP, to the launch position, below the MLP, with their pipes connecting the pipes on the trech to the pipes on the MLP.
On the FRF these flame deflectors aren't needed (no SRB firing), so the connections on the flame trench pipes are not used, so probably they are covered. The "fan like spray" is probably water leaking from that cover.
Post by: jeff122670 on 09/24/2007 12:10 am
ALSO, within the last several years, i have noticed that the actual beenie cap now has what APPEAR to be "whiskers" sticking out from the perimeter of the cap. looks like a lightning protection system, but not sure. they appear to run circumferentially (spell?) around the cap.
thanks for the help!
Jeff
Post by: Jim on 09/24/2007 12:19 am
Post by: parham55 on 09/24/2007 01:14 am
Post by: Lee Jay on 09/24/2007 01:24 am
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parham55 - 23/9/2007 7:14 PM
Any close up pictures of the sling attatchment points on the orbiters? Thanks.
Do a search here:
http://mediaarchive.ksc.nasa.gov/
for "sts-117 mate demate".
When it was up on the mate/demate device at KSC, they got some tight pictures.
Post by: mkirk on 09/24/2007 01:59 pm
Quote
jeff122670 - 23/9/2007 7:10 PM
does anyone know the story with the STS-1 GOX vent arm. i noticed it wasnt used during the final count of STS-1 and then with STS-2, the vent piping system was changed to what we see now. i have some video somewhere that showed STS-1 at night on the pad with the vent arm being retracted and LOX venting from the tip of the external tank. was there a problem with the arm or beenie cap?
Jeff
During STS-1 the arm was retracted just prior to comming out of the built in hold at T-9 minutes and the ET vent valve was allowed to continue to vent on its own until ET LO2 Pressurization. It was assumed that during that short period no significant ice accumulation would occur on the vent valve louvers.
After STS-1 flew they realized that ice was a big problem and was attributed to the tile damage that occured on the orbiter.
Begining with STS-2 the GOX ARM ws modified to more efficently pump in warmed GN2 to the valve area, and vent off the gaseous oxygen. It was also decided that the arm would be retracted later in the countdown (just prior to LO2 vent valve closure and tank pressurization) in an effort to keep the valve warm for as long as possible and to minimize the opportunity for ice formation.
Post by: parham55 on 09/24/2007 04:25 pm
Post by: Jones36 on 09/29/2007 07:47 pm
Post by: BigKiai on 10/02/2007 05:09 pm
What is that grid of connections for at the left rear side of the orbiter in the picture above?
Why does pad processing take so long - why does the shuttle sit at the pad for weeks before launch?
Thanks,
Mike
Post by: DaveS on 10/02/2007 05:19 pm
Quote
BigKiai - 2/10/2007 7:09 PMIt's the so called T-0(pronounced T zero) umbilical connections. There's a set on the right side of the orbiter.
What is that grid of connections for at the left rear side of the orbiter in the picture above?
Quote
BigKiai - 2/10/2007 7:09 PMThere's much work that needs to be done out at the pad, many operations that take a long time. Below is a link to a list of the various operations that are done once the stack arrives at the pad and is harddown: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=2629&start=1#M37882
Why does pad processing take so long - why does the shuttle sit at the pad for weeks before launch?
Post by: BigKiai on 10/02/2007 09:20 pm
Post by: Jim on 10/02/2007 10:50 pm
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BigKiai - 2/10/2007 5:20 PM
Has there ever been a case where one of the T-0 umbilical connections did not separate mechanically, and then got ripped out on launch? Does the launch power down / cancel if the they don't separate?
Not on the shuttle. They separate at liftoff, there is no going back
Post by: BigKiai on 10/02/2007 11:13 pm
Post by: tnphysics on 10/02/2007 11:19 pm
Post by: ChrisGebhardt on 10/02/2007 11:41 pm
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BigKiai - 2/10/2007 7:13 PM
Hypothetically, what happens if one does not separate as planned on liftoff?
Once the countdown reaches T-0 and the SRBs ignite, the shuttle is launching... whether the T-0 umbilicals have separated or not.
Post by: stockman on 10/03/2007 12:17 am
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Trekkie07 - 2/10/2007 7:41 PMQuoteBigKiai - 2/10/2007 7:13 PM
Hypothetically, what happens if one does not separate as planned on liftoff?
Once the countdown reaches T-0 and the SRBs ignite, the shuttle is launching... whether the T-0 umbilicals have separated or not.
Yep... one of the astronauts (forget which one) said a while back that once the solids ignite you're definitely going somewhere!! :)
Post by: Jim on 10/03/2007 02:46 am
Quote
BigKiai - 2/10/2007 7:13 PM
Hypothetically, what happens if one does not separate as planned on liftoff?
They will come off, it is just a weight on a pulley to pull it off
Post by: BigKiai on 10/03/2007 03:00 am
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Jim - 2/10/2007 7:46 PMQuoteBigKiai - 2/10/2007 7:13 PM Hypothetically, what happens if one does not separate as planned on liftoff?They will come off, it is just a weight on a pulley to pull it off
What if the pulley system fails and one or more of the cables remain attached. Could they hit one of the main engines and damage them?
Do they have a contingency plan in place for this?
Mike
Post by: nathan.moeller on 10/03/2007 03:50 am
Quote
stockman - 2/10/2007 7:17 PMQuoteTrekkie07 - 2/10/2007 7:41 PMQuoteBigKiai - 2/10/2007 7:13 PM
Hypothetically, what happens if one does not separate as planned on liftoff?
Once the countdown reaches T-0 and the SRBs ignite, the shuttle is launching... whether the T-0 umbilicals have separated or not.
Yep... one of the astronauts (forget which one) said a while back that once the solids ignite you're definitely going somewhere!! :)
I think it was Endeavour's former flow director who said 'When those kick on, you're gonna go somewhere. The shuttle will not stay at the pad.' I forget his name but I remember it clearly.
Post by: Jorge on 10/03/2007 06:00 am
Quote
BigKiai - 2/10/2007 10:00 PMQuoteJim - 2/10/2007 7:46 PMQuoteBigKiai - 2/10/2007 7:13 PM Hypothetically, what happens if one does not separate as planned on liftoff?They will come off, it is just a weight on a pulley to pull it off
What if the pulley system fails and one or more of the cables remain attached. Could they hit one of the main engines and damage them?
Do they have a contingency plan in place for this?
Mike
Not specifically. If an engine fails due to contact with a T-0 umbilical, the contingency plan is "abort RTLS at T+2:30" - same as for any other engine failure during first stage.
Post by: STS-500Cmdr on 10/03/2007 06:17 am
Post by: Lee Jay on 10/04/2007 02:47 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2424&Itemid=2
Post by: psloss on 10/04/2007 03:57 pm
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Lee Jay - 4/10/2007 10:47 AMThe other one is normally shown on camera 049/149...
About 1/4 of the way in on this video is camera 050. It shows the T-0 umbilical disconnecting at launch.
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2424&Itemid=2
Post by: Jorge on 10/04/2007 07:06 pm
Quote
pad rat - 4/10/2007 9:22 AM
The T-0 umbilicals are mounted on a sturdy steel carrier plate that engages latches on the orbiter's fuselage. It's likely that failure of a carrier plate to separate would result in significant structural damage to the area around the T-0 panel. Since there are wiring and plumbing runs on the inside wall of that area, there would likely be electrical faults, possibly a bus drop, pneumatic leaks, and hydraulic leaks. There would be so many strikes against the vehicle/crew that I'd venture to say a successful RTLS would be out of the question.
I would think the exterior umbilicals would be the weak point, and would rip loose long before the carrier plate. So you would wind up with the shuttle lifting off with the carrier plate still firmly latched to the orbiter, trailing a bunch of torn umbilicals.
Post by: stockman on 10/04/2007 07:18 pm
Quote
Jorge - 4/10/2007 3:06 PMQuotepad rat - 4/10/2007 9:22 AM
The T-0 umbilicals are mounted on a sturdy steel carrier plate that engages latches on the orbiter's fuselage. It's likely that failure of a carrier plate to separate would result in significant structural damage to the area around the T-0 panel. Since there are wiring and plumbing runs on the inside wall of that area, there would likely be electrical faults, possibly a bus drop, pneumatic leaks, and hydraulic leaks. There would be so many strikes against the vehicle/crew that I'd venture to say a successful RTLS would be out of the question.
I would think the exterior umbilicals would be the weak point, and would rip loose long before the carrier plate. So you would wind up with the shuttle lifting off with the carrier plate still firmly latched to the orbiter, trailing a bunch of torn umbilicals.
why do I suddenly get the mental picture of the old lady driving away from the gas station with the gas nozzel and hoze still attached... :)
Post by: Lee Jay on 10/04/2007 07:34 pm
Quote
Jorge - 4/10/2007 1:06 PMQuotepad rat - 4/10/2007 9:22 AM
The T-0 umbilicals are mounted on a sturdy steel carrier plate that engages latches on the orbiter's fuselage. It's likely that failure of a carrier plate to separate would result in significant structural damage to the area around the T-0 panel. Since there are wiring and plumbing runs on the inside wall of that area, there would likely be electrical faults, possibly a bus drop, pneumatic leaks, and hydraulic leaks. There would be so many strikes against the vehicle/crew that I'd venture to say a successful RTLS would be out of the question.
I would think the exterior umbilicals would be the weak point, and would rip loose long before the carrier plate. So you would wind up with the shuttle lifting off with the carrier plate still firmly latched to the orbiter, trailing a bunch of torn umbilicals.
I'm surprised. I would think the latches on the orbiter would be the weak point and if the vehicle tried to leave the pad still attached that they would fracture and the plate would pull away without causing damage to anything but the latches themselves. But of course, I don't know how this thing is designed.
Post by: bholt on 10/04/2007 11:22 pm
Brent
Post by: Jim on 10/05/2007 12:03 am
Post by: jeff122670 on 10/05/2007 01:07 am
anyone have any idea what that is???
thanks!
Jeff
Post by: psloss on 10/05/2007 01:27 am
Quote
jeff122670 - 4/10/2007 9:07 PMSomeone asked about it in a thread here (maybe L2) during one of the last two launches, but I don't remember what the answer was...
regarding the T-0 umbilicals.....has anyone ever noticed a light that appears to come on around T-13 seconds or so. it seems to come from inside the tail service mast and shines right on the umbilical. it is almost as though they are using the light for a better camera image. i have looked at it several times and it is NOT a reflection of the hydrogen burn ignitors....furthermore it comes on around t-13 or t-14 seconds....
anyone have any idea what that is???
Post by: BigKiai on 10/05/2007 04:58 pm
Post by: shuttlefan on 10/06/2007 04:23 pm
Post by: Jim on 10/06/2007 04:24 pm
Post by: hyper_snyper on 10/07/2007 12:37 am
Anyway, what kind of maintenance is need for the engines after flying?
Post by: Lee Jay on 10/07/2007 01:02 am
Quote
hyper_snyper - 6/10/2007 6:37 PM
Is it true that the SSME destroys its turbines after every flight?
No. I don't know the answer to the rest of your question but at least some turbine parts (including blades) get used again.
Post by: GLS on 10/07/2007 11:37 am
Quote
jeff122670 - 5/10/2007 2:07 AM
regarding the T-0 umbilicals.....has anyone ever noticed a light that appears to come on around T-13 seconds or so. it seems to come from inside the tail service mast and shines right on the umbilical. it is almost as though they are using the light for a better camera image. i have looked at it several times and it is NOT a reflection of the hydrogen burn ignitors....furthermore it comes on around t-13 or t-14 seconds....
anyone have any idea what that is???
thanks!
Jeff
There's a camera inside the TSMs looking at the plates (I've seen a diagram somewhere...) The light has to be for a better image as the plate comes off the OV and the TSM door closes...
Post by: brahmanknight on 10/07/2007 02:47 pm
Post by: Jim on 10/07/2007 02:58 pm
Post by: ShuttleDiscovery on 10/07/2007 03:02 pm
Quote
Jim - 7/10/2007 3:58 PM
define "shorter"
I think he means why the shuttle's nose is lower than the back (not level) during landing..
Post by: brahmanknight on 10/07/2007 03:20 pm
Post by: Jim on 10/07/2007 04:39 pm
Post by: jeff122670 on 10/07/2007 09:04 pm
my guess at least...
jeff
Post by: MKremer on 10/07/2007 09:34 pm
Post by: brahmanknight on 10/08/2007 03:38 pm
Post by: jok on 10/08/2007 03:49 pm
Hypergolic Umbilical System
http://www-pao.ksc.nasa.gov/nasafact/count4rss.htm
jok
Post by: ChrisGebhardt on 10/09/2007 02:26 am
Post by: usn_skwerl on 10/09/2007 05:55 pm
are there still servicing points within the cargo bay that still allow hookup of LOX and LH2? i think i remember there being something like that back in the 80's?
thanks.
Post by: DaveS on 10/09/2007 05:58 pm
Quote
usn_skwerl - 9/10/2007 7:55 PMYou're thinking about the umbilical system for the Centaur upperstage. That has been since long removed. And only Atlantis, Discovery and Challenger was modified to support it. The Extended Duration Orbiter(EDO) cryokit was loaded the same way that the fuel cell reactant storage spheres are loaded: through the Orbiter Mid-Body Umbilical Unit(OMBUU).
are there still servicing points within the cargo bay that still allow hookup of LOX and LH2? i think i remember there being something like that back in the 80's?
Post by: Chris Bergin on 10/09/2007 06:09 pm
Quote
Real Madrid - 9/10/2007 6:56 PM
and what happens as a crewmember are sick ?
From STS-4 onwards, NASA halted the appointment and training of complete backup flight crews. Instead, individual flight crew members may have designated backups who could take their place within the prime crew. The decision on whether to appoint a reserve crew member is made on a per-flight basis by flight management teams at Johnson Space Center. Consequently, the last NASA flight crew to have a full-time backup crew was STS-3.
Post by: Jorge on 10/09/2007 06:11 pm
Quote
MKremer - 7/10/2007 4:34 PM
Jim's reply is probably correct - no real reason since it wasn't designed to gain lift and take off from a horizontal runway. The only reason I can think of to have the nose gear a bit longer is to make for a bit gentler touchdown at the front end before the control surfaces lose most of their effect and drop the nose onto the runway.
There is one other reason to have a longer nose gear strut: the negative angle of attack resulting from the shorter nose gear increases loads on the main gear as the nose gear derotates and slaps down. Buran had a longer nose gear strut for this reason. The Soviets had to design the crew compartment differently to accommodate this, so retrofitting the Buran design onto the shuttle is not practical. But a telescoping nose gear strut has been proposed from time to time as an orbiter upgrade.
Post by: Jorge on 10/09/2007 06:15 pm
Quote
usn_skwerl - 9/10/2007 12:55 PM
we all know the shuttle cant get out of LEO. with little more than 7 crew, a satellite cradle, and the RMS, what is the maximum possible altitude the shuttle can get to if absolutely necessary, if required to do some necessary maintenance to a satellite, something like the hubble servicing missions?
Not much higher than the highest Hubble missions (~340 n.mi.). On Hubble missions, the orbiter spends practically half its OMS propellant on the OMS-2 burn, and the other half on deorbit. There isn't a whole lot of margin to increase the orbit further. The payload bay for Hubble missions doesn't have much more than the necessary RMS, airlock, Hubble FSS (cradle), and Hubble servicing hardware.
Post by: Jim on 10/09/2007 07:35 pm
Quote
usn_skwerl - 9/10/2007 1:55 PM
we all know the shuttle cant get out of LEO. with little more than 7 crew, a satellite cradle, and the RMS, what is the maximum possible altitude the shuttle can get to if absolutely necessary, if required to do some necessary maintenance to a satellite, something like the hubble servicing missions?
thanks.
It is in an earlier post on this thread
Post by: usn_skwerl on 10/09/2007 10:32 pm
besides, i was also accounting for the (now deleted) cargo bay access points being factored in for a little extra deltaV and altitude.
Post by: Jim on 10/09/2007 10:42 pm
Quote
usn_skwerl - 9/10/2007 6:32 PM
yes, i found it now, but you DO realize that there are well over 170 pages of shuttle Q & A to wade through, even using search.
besides, i was also accounting for the (now deleted) cargo bay access points being factored in for a little extra deltaV and altitude.
The LH2 and LO2 acess point were not for the shuttle but for the centaur upperstage. This propellants were not available to the shuttle. You might be thinking of the OMS kits that would have been carried in the payload bay. They were never developed and Direct insertion provided the higher altitudes required
Post by: usn_skwerl on 10/10/2007 02:52 am
ok, another one, maybe a little more difficult to answer.....
is there an animation or video of a SIMULATED RTLS sequence? i know the consequences and possible dangers of that evolution, but ive never seen a good visual of it, just a crappy sequential line drawing years ago in a library book
Post by: Jim on 10/10/2007 11:10 am
Quote
usn_skwerl - 9/10/2007 10:52 PM
thanks jim, i thought it could feed the shuttle, not just pull from it. i
The connection weren't to "pulled" propellant from the shuttle. They were feedthru's to ground connections to load the Centaur. There was no interconnection between the shuttle propulsion system and the LO2 and LH2 ducts in the payload bay. There was even a separate T-0 umbilical on the outside of the orbiter which fueled the centaur through the payload bay
Post by: brahmanknight on 10/10/2007 03:44 pm
Do operations cease in case the Atlas veers off course, or is it something else?
Post by: Jim on 10/10/2007 04:07 pm
Post by: RafaelCE on 10/12/2007 04:17 pm
Post by: DaveS on 10/12/2007 04:30 pm
Quote
RafaelCE - 12/10/2007 6:17 PMRCS hotfire involves firing each and every one of the 44 RCS jets(38 primary, 6 verniers) to verify that they work OK for entry.
I have searched for the Hotfire term along the site. Only found refferences to the term but not an explanation of what that is. I've heard of RCS hotfire, APU hotfire, hotfire tests. etc. Can someone elaborate on what that is and how is performed?
APU hotfire involves running all APUs at high speed setting for about a minute or so to verify their operation.
It all depends on what system is involved.
Post by: Joffan on 10/12/2007 04:37 pm
Post by: DaveS on 10/12/2007 04:41 pm
Quote
Joffan - 12/10/2007 6:37 PMRCS hotfire tests are only done on-orbit on the day prior to planned de-orbit and landing.
Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
Post by: Jim on 10/12/2007 04:46 pm
Quote
Joffan - 12/10/2007 12:37 PM
Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
Usually that is called a cold flow test.
(aerospace engineering) A test of a liquid rocket without firing it to check or verify the integrity of a propulsion subsystem, and to provide for the conditioning and flow of propellants (including tank pressurization, propellant loading, and propellant feeding).
Post by: usn_skwerl on 10/13/2007 03:18 am
and at T-0, is the stack's CG usually between the orbiter and ET, and under the first joint of the payload bay door (simple diagram below)
Fwd (nose) |_____|_____|_____|____|Aft (tail)
CG at T-0?..........X........<~at point marked "X"?
Post by: Jorge on 10/13/2007 04:31 am
Quote
usn_skwerl - 12/10/2007 10:18 PM
where is the CG for the shuttle roughly when configured for reentry? for an external reference on the fuselage, is it typically somewhere between the Ensign and the "U" in "United States?" (when looking at port fuselage)
This document has c.g. locations for the first 91 shuttle missions:
http://spaceflight.nasa.gov/shuttle/reference/green/massprop.pdf
This schematic relates the c.g. locations above to position on the vehicle:
http://spaceflight.nasa.gov/shuttle/reference/sodb/2-2a.pdf
Post by: usn_skwerl on 10/13/2007 06:29 am
(heres my before and after)
before and after (http://s5.photobucket.com/albums/y193/usn_skwerl/?action=view¤t=shuttleBA.gif)
the link you provided me will help me make sure my angles, datum, etc. are accurate. again, thanks so much!
Post by: TJL on 10/13/2007 07:12 pm
Is it the individuals choice wether or not to take a new photo?
Post by: kimmern123 on 10/13/2007 07:53 pm
Post by: mkirk on 10/13/2007 11:22 pm
Quote
DaveS - 12/10/2007 11:41 AMQuoteJoffan - 12/10/2007 6:37 PMRCS hotfire tests are only done on-orbit on the day prior to planned de-orbit and landing.
Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
Interestingly, or perhaps not, depending on your point of view, previous manned spacecraft such as Gemini would perform an RCS Hot Fire Test late in the pre launch countdown after the crew was strapped in and the erecter had been retracted.
Mark Kirkman
Post by: HIPAR on 10/14/2007 12:53 am
Obviously, an additional boost is required to leave earth orbit. Might a rocket be attached while the shuttle is in LOE? Can the retro engines place the shuttle into lunar orbit and be fired again to leave lunar orbit? Finally, might some sort of aerobraking be employed to slow the shuttle upon return to the earth atmosphere?
--- CHAS
Post by: Lee Jay on 10/14/2007 01:56 am
Quote
HIPAR - 13/10/2007 6:53 PMProbably hallucinogenic substances.
What would be required to send a space shuttle to the moon?
Quote
With that huge payload bay, a substantial lander or cargo could be carried there.Not really.
Quote
Obviously, an additional boost is required to leave earth orbit. Might a rocket be attached while the shuttle is in LOE?
And where would that come from, and how would it be attached?
Quote
Can the retro engines place the shuttle into lunar orbit and be fired again to leave lunar orbit?Not even close.
Quote
Finally, might some sort of aerobraking be employed to slow the shuttle upon return to the earth atmosphere?
Not and have the craft survive.
Post by: Namechange User on 10/14/2007 02:25 am
Quote
HIPAR - 13/10/2007 7:53 PM
What would be required to send a space shuttle to the moon? With that huge payload bay, a substantial lander or cargo could be carried there.
Obviously, an additional boost is required to leave earth orbit. Might a rocket be attached while the shuttle is in LOE? Can the retro engines place the shuttle into lunar orbit and be fired again to leave lunar orbit? Finally, might some sort of aerobraking be employed to slow the shuttle upon return to the earth atmosphere?
--- CHAS
This question has been asked many times and there are some folks out there that actually believe the shuttle goes to the moon. Unfortunately that is not the case and never will be.
First, beyond all the other technical issues, upon rentry to Earths atmosphere the orbiter would break up. The TPS nor the structure is designed to carry those loads. The OME's (orbital maneuvering engines) produce 6K thrust each. While this could do the job if fired long enough the problem of course is the amount of prop available. There is simply not enough room in the tanks for anywhere near this kind of job with the mass of the orbiter.
The orbiter just was never designed for this kind of mission and to try to make it into that would be problematic, expensive and disaterous.
Post by: Endeavour118 on 10/14/2007 03:22 am
1. what does take air data mean
2. when they show the ascent flight control video at about t-11 seconds what do they mean all vents open
Post by: Lee Jay on 10/14/2007 03:53 am
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Endeavour118 - 13/10/2007 9:22 PMhttp://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/avionics/gnc/ads.html
2 questions:
1. what does take air data mean
Quote
2. when they show the ascent flight control video at about t-11 seconds what do they mean all vents openI'm not positive about this one. The shuttle is pretty much sealed and, of course, full of air when it's on the ground. During ascent, it's going to very quickly get to a pretty effective vacuum (like in less than 2 minutes). It needs to vent the air inside so it doesn't damage the structure trying to get out (overpressure). The same is true on decent, but in reverse (vacuum, air pressure, crush...). It has vents for this purpose, but I'm not certain that this call is referring to those.
Post by: Danny Dot on 10/14/2007 06:33 am
Quote
Endeavour118 - 13/10/2007 10:22 PM
2 questions:
1. what does take air data mean
After the airdata probes are deployed during an entry, the crew and the flight controllers look over the data before the data is used by flight software. "Take air data" lets the crew know the ground approves of the data and the crew then tell the computers to start using the air data. This action is done by typing on the computer's key board.
Danny Deger
Post by: usn_skwerl on 10/14/2007 08:29 am
TPS and airframe cant handle reentry. is aerobraking impossible with the orbiter? im assuming it is, considering how deep it would have to get into the atmosphere enough to drop below escape velocity, otherwise it'd skip off and go right back up. is this a correct assumption?
Post by: DaveS on 10/14/2007 08:53 am
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usn_skwerl - 14/10/2007 10:29 AMTotally impossible. The orbiter wasn't designed to handle entry speeds more than 9 km/s. Lunar entry speeds are in excess of 10 km/s.
i know the moon trip with an orbiter is a dead horse, but im just gonna kick it in the hoof once....
TPS and airframe cant handle reentry. is aerobraking impossible with the orbiter? im assuming it is, considering how deep it would have to get into the atmosphere enough to drop below escape velocity, otherwise it'd skip off and go right back up. is this a correct assumption?
Post by: ShuttleDiscovery on 10/14/2007 11:20 am
Quote
kimmern123 - 13/10/2007 8:53 PM
With the STS-122 crew I've noticed that the astronauts that've updated their portraits are the ones that haven't taken a portrait in the launch and entry-suit before. Steve Frick updated his portrait from the old blue flighsuit one, while Rex Walheim, for instance, who already took his OSS-portrait before STS-110 did not get a new portrait.
Well Stefanie Wilson for STS-120 has not a portrait in a launch and entry suit at all that I know of, just the blue flighht suit one from when she was selected...
Post by: TJL on 10/14/2007 02:48 pm
Quote
ShuttleDiscovery - 14/10/2007 7:20 AMQuotekimmern123 - 13/10/2007 8:53 PM
With the STS-122 crew I've noticed that the astronauts that've updated their portraits are the ones that haven't taken a portrait in the launch and entry-suit before. Steve Frick updated his portrait from the old blue flighsuit one, while Rex Walheim, for instance, who already took his OSS-portrait before STS-110 did not get a new portrait.
Well Stefanie Wilson for STS-120 has not a portrait in a launch and entry suit at all that I know of, just the blue flighht suit one from when she was selected...
...as does STS-117 CDR Rick Sturckow.
Post by: mkirk on 10/14/2007 03:41 pm
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Lee Jay - 13/10/2007 10:53 PMQuoteEndeavour118 - 13/10/2007 9:22 PMhttp://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/avionics/gnc/ads.html
2 questions:
1. what does take air data meanQuote2. when they show the ascent flight control video at about t-11 seconds what do they mean all vents openI'm not positive about this one. The shuttle is pretty much sealed and, of course, full of air when it's on the ground. During ascent, it's going to very quickly get to a pretty effective vacuum (like in less than 2 minutes). It needs to vent the air inside so it doesn't damage the structure trying to get out (overpressure). The same is true on decent, but in reverse (vacuum, air pressure, crush...). It has vents for this purpose, but I'm not certain that this call is referring to those.
“All Vents Open” is a MMACS (mechanical, maintenance, arem and crew systems) console call out at about T-11 seconds. MMACS is acknowledging that the Vent Door Open Sequence is complete. If I recall correctly the Open Sequence begins at T-28 seconds. Prior to this point the doors are in the purge position. When the sequence starts the doors are staggered open in 2.5 second intervals, MMACS checks to see that the sequence is complete and that all the vents are open at T-11 seconds.
Mark Kirkman
Post by: kimmern123 on 10/14/2007 04:38 pm
Quote
TJL - 14/10/2007 4:48 PMQuoteShuttleDiscovery - 14/10/2007 7:20 AMQuotekimmern123 - 13/10/2007 8:53 PM
With the STS-122 crew I've noticed that the astronauts that've updated their portraits are the ones that haven't taken a portrait in the launch and entry-suit before. Steve Frick updated his portrait from the old blue flighsuit one, while Rex Walheim, for instance, who already took his OSS-portrait before STS-110 did not get a new portrait.
Well Stefanie Wilson for STS-120 has not a portrait in a launch and entry suit at all that I know of, just the blue flighht suit one from when she was selected...
...as does STS-117 CDR Rick Sturckow.
I'm also guessing it's based on the astronauts' preferences as well. Some may just not see the need for a new portrait after the blue flight suit one.
Post by: The-Hammer on 10/15/2007 10:32 am
Why was STS-117 able to carry 7 when STS-115 could only carry 6? Did 115 have more cargo beyond the Truss Segment than did 117? Was NASA being conservative in regards to launch mass with 115? Something else entirely?
Post by: Jorge on 10/15/2007 10:55 am
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The-Hammer - 15/10/2007 5:32 AM
I have a question regarding STS-115 and 117. The wikipedia article on STS-115 states that the crew was limited to 6 because of the mass of the P3/P4 Truss Segment. (One of the links is to a NASA podcast that backs up this claim.) However, STS-117, which carried the S3/S4 Truss Segment, was able to carry 7 astronauts. Both missions used Atlantis.
Why was STS-117 able to carry 7 when STS-115 could only carry 6? Did 115 have more cargo beyond the Truss Segment than did 117? Was NASA being conservative in regards to launch mass with 115? Something else entirely?
NASA had to offload about 400 lbs of middeck cargo from 117 to accommodate the seventh crewmember.
Post by: DaveS on 10/15/2007 10:58 am
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Jorge - 15/10/2007 12:55 PMAlso, STS-117 was a 6-member crew flight. The addition of Clay Anderson was a late addition made when Atlantis was in the VAB for ET hail repairs. If STS-117 had launched in March as originally planned, Clay Anderson would have flown up on STS-118 as originally planned.QuoteThe-Hammer - 15/10/2007 5:32 AM
I have a question regarding STS-115 and 117. The wikipedia article on STS-115 states that the crew was limited to 6 because of the mass of the P3/P4 Truss Segment. (One of the links is to a NASA podcast that backs up this claim.) However, STS-117, which carried the S3/S4 Truss Segment, was able to carry 7 astronauts. Both missions used Atlantis.
Why was STS-117 able to carry 7 when STS-115 could only carry 6? Did 115 have more cargo beyond the Truss Segment than did 117? Was NASA being conservative in regards to launch mass with 115? Something else entirely?
NASA had to offload about 400 lbs of middeck cargo from 117 to accommodate the seventh crewmember.
Post by: Endeavour118 on 10/16/2007 01:22 am
Quote
TJL - 14/10/2007 10:48 AMsame with sts-110 CDR mike bloomfieldQuoteShuttleDiscovery - 14/10/2007 7:20 AMQuotekimmern123 - 13/10/2007 8:53 PM
With the STS-122 crew I've noticed that the astronauts that've updated their portraits are the ones that haven't taken a portrait in the launch and entry-suit before. Steve Frick updated his portrait from the old blue flighsuit one, while Rex Walheim, for instance, who already took his OSS-portrait before STS-110 did not get a new portrait.
Well Stefanie Wilson for STS-120 has not a portrait in a launch and entry suit at all that I know of, just the blue flighht suit one from when she was selected...
...as does STS-117 CDR Rick Sturckow.
Post by: ChrisGebhardt on 10/16/2007 02:53 am
Quote
DaveS - 15/10/2007 6:58 AMQuoteJorge - 15/10/2007 12:55 PMAlso, STS-117 was a 6-member crew flight. The addition of Clay Anderson was a late addition made when Atlantis was in the VAB for ET hail repairs. If STS-117 had launched in March as originally planned, Clay Anderson would have flown up on STS-118 as originally planned.QuoteThe-Hammer - 15/10/2007 5:32 AM
I have a question regarding STS-115 and 117. The wikipedia article on STS-115 states that the crew was limited to 6 because of the mass of the P3/P4 Truss Segment. (One of the links is to a NASA podcast that backs up this claim.) However, STS-117, which carried the S3/S4 Truss Segment, was able to carry 7 astronauts. Both missions used Atlantis.
Why was STS-117 able to carry 7 when STS-115 could only carry 6? Did 115 have more cargo beyond the Truss Segment than did 117? Was NASA being conservative in regards to launch mass with 115? Something else entirely?
NASA had to offload about 400 lbs of middeck cargo from 117 to accommodate the seventh crewmember.
I think Wayne Hale said that it also had to do with the time of year the missions were launched... something abaout gaining extra performance with a June launch than a March launch. I'm not 100% on this. Please correct me if I'm wrong or thinking of something else.
Post by: Lee Jay on 10/16/2007 03:12 am
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Trekkie07 - 15/10/2007 8:53 PM
I think Wayne Hale said that it also had to do with the time of year the missions were launched... something abaout gaining extra performance with a June launch than a March launch. I'm not 100% on this. Please correct me if I'm wrong or thinking of something else.
Please look at my post and the answer that followed on page 52 of this thread.
Post by: ChrisGebhardt on 10/16/2007 03:31 am
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Lee Jay - 15/10/2007 11:12 PMQuoteTrekkie07 - 15/10/2007 8:53 PM
I think Wayne Hale said that it also had to do with the time of year the missions were launched... something abaout gaining extra performance with a June launch than a March launch. I'm not 100% on this. Please correct me if I'm wrong or thinking of something else.
Please look at my post and the answer that followed on page 52 of this thread.
OK. Thanks. The search functon doesn't work on my computer. Chris is aware of the problem.
Post by: zerm on 10/16/2007 10:24 pm
Post by: mkirk on 10/16/2007 11:05 pm
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zerm - 16/10/2007 5:24 PM
I've been watching the STS112 onboard launch video and in the process of cleaning up the voicetrack I heard the PLT make the call "mini-bucket" a few seconds after liftoff. I've searched the Q&As here and not found a referance. Although I know what the term "bucket" refers to- I was wondering the exact meaning of the "Mini-bucket" call.
As you probably already know the throttle bucket is a reference to the main engine throttle down sequence that occurs early during the first stage ascent to minimize aerodynamic loading. The engines are throttled back for a brief time before returning to the normal power setting of 104.5%. The term bucket comes from the way a graph that plots the throttle setting over time would look, in other words the reduced power area of the graph would look like a bucket.
Typically shuttle ascents are planned with a single throttle down event known as a single stage bucket. However dispersions in the performace of the SRBs (solid rocket boosters), either hot or cold, as assesed by the shuttle's guidance system at about the twenty second mark in the ascent, may dictate either a shallower bucket than orginally planned or a two stage bucket. The two stage bucket for example might result in a reduction of power to 80% then a few seconds later the engines would throttle back further to 72%.
This change from the planned power setting (determined pre-launch) as seen on the Main Propulsion System Chamber Pressure Gauges is what Pam was referring to.
Mark Kirkman
Post by: dking023 on 10/17/2007 03:33 am
Post by: Ankle-bone12 on 10/17/2007 04:03 am
Quote
dking023 - 16/10/2007 10:33 PM
I am a space flight fan, I always have been...however my knowledge of science (particularly astrophysics) is very limited. A question that I have always wanted answered is whether the space shuttle could manuever and survive in open space rather than in the earth's orbit. I understand the it is called an "orbiter", however I was just curious if the shuttle could even though it was not designed for such an event.
If a propellant tank, RCS, OMS, and extra life support could be stored in the payload bay, Possibly. Maybe the OMS pods could be fired long enough for the orbiter to escape earths gravity, and head for lunar orbit. This is not an answer to your question but more of an expansion on it.
Post by: Stowbridge on 10/17/2007 04:04 am
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dking023 - 16/10/2007 10:33 PM
I am a space flight fan, I always have been...however my knowledge of science (particularly astrophysics) is very limited. A question that I have always wanted answered is whether the space shuttle could manuever and survive in open space rather than in the earth's orbit. I understand the it is called an "orbiter", however I was just curious if the shuttle could even though it was not designed for such an event.
Welcome to the site.
No, orbiters can do all manner of movement in space, but only along her actual LEO (Low Earth Orbit). Someone asked the other day if orbiters could go to the moon. Problem is, even if they could, on the way back into Earth's atmosphere they'd be travelling so fast, they'd break up, unlike a capsule.
Shuttles are space planes and LEO is their domain.
Post by: rdale on 10/17/2007 04:13 am
http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html
...and voila, answer to the question.
Post by: Jorge on 10/17/2007 04:56 am
Quote
Ankle-bone12 - 16/10/2007 11:03 PMQuotedking023 - 16/10/2007 10:33 PM
I am a space flight fan, I always have been...however my knowledge of science (particularly astrophysics) is very limited. A question that I have always wanted answered is whether the space shuttle could manuever and survive in open space rather than in the earth's orbit. I understand the it is called an "orbiter", however I was just curious if the shuttle could even though it was not designed for such an event.
If a propellant tank, RCS, OMS, and extra life support could be stored in the payload bay, Possibly. Maybe the OMS pods could be fired long enough for the orbiter to escape earths gravity, and head for lunar orbit.
No, not even close. An orbiter weighs ~ 200 klb and can carry a ~ 55 klb payload. Even if the entire payload were OMS prop (Isp 316 sec), you'd still have a much worse mass fraction than an Apollo stack (CSM+LM+IU+dry S-IVB weighs about 145 klb, S-IVB prop ~ 160 klb, and J-2 Isp 421 sec). At best you could reach a somewhat higher Earth orbit - probably lower than 1000 n.mi.
Post by: HIPAR on 10/17/2007 05:57 am
...'and voila, answer to the question'
At the risk of aggravating the experts, I'll have to say I don't like that answer. That answer is rather shallow because it assumes an unaugmented STS for the lunar mission. Certainly the shuttle will need some extra help in the form of extra propulsion for leaving and retuning to earth. No one here proposes to to land a shuttle on the moon.
So the question should be, 'What would be required to configure a shuttle-centric lunar mission'? How do we impart additional energy for the escape trajectory? How do we slow the spaceship on its return before we ask it to plunge and take the heat?
The consensus here is a shuttle lunar mission is impossible because it was designed to be an orbiter. Certainly, during the 25 years the shuttle has been flying, someone must have performed an analysis (maybe a thesis) on configuring it for a different mission. It's an obvious question and there is always someone out there with unconventional insight.
I'm perfectly aware that feasibility doesn't imply practicality.
--- CHAS
Post by: brahmanknight on 10/17/2007 12:30 pm
Post by: DaveS on 10/17/2007 12:34 pm
Quote
brahmanknight - 17/10/2007 2:30 PMPretty much no. They happen over water and is directed downwards towards the water so, no you can't hear them.
Are sonic booms audible when the shuttle breaks the the speed of sound during liftoff?
Post by: Lee Jay on 10/17/2007 12:54 pm
Quote
HIPAR - 16/10/2007 11:57 PM
At the risk of aggravating the experts, I'll have to say I don't like that answer....
Certainly, during the 25 years the shuttle has been flying, someone must have performed an analysis (maybe a thesis) on configuring it for a different mission....
I'm perfectly aware that feasibility doesn't imply practicality.
And that's why I'd be surprised if anyone ever looked at it in-depth. Since it's totally impractical, why would anyone look at it? It would be far less expensive to construct a new vehicle that's actually designed for lunar operations. The Shuttle would be about the worst lunar vehicle anyone could dream up.
Post by: Jorge on 10/17/2007 02:13 pm
Quote
HIPAR - 17/10/2007 12:57 AM
...'and voila, answer to the question'
At the risk of aggravating the experts, I'll have to say I don't like that answer.
Fair enough. I'll hazard a guess that you won't like my answer either.
Quote
That answer is rather shallow because it assumes an unaugmented STS for the lunar mission. Certainly the shuttle will need some extra help in the form of extra propulsion for leaving and retuning to earth. No one here proposes to to land a shuttle on the moon.
So the question should be, 'What would be required to configure a shuttle-centric lunar mission'? How do we impart additional energy for the escape trajectory? How do we slow the spaceship on its return before we ask it to plunge and take the heat?
The consensus here is a shuttle lunar mission is impossible because it was designed to be an orbiter.
No. The consensus here is that it may be possible but it's not worth wasting brain cells analyzing because it would be far more expensive than a purpose-built lunar craft and would not perform as well. It's just a silly idea all around.
I'm sure I could convert my car into a boat if I really wanted to. All I'd need is to waterproof the bottom and add gearboxes converting the steering wheel into a rudder and the driveshaft into a propeller shaft. And I'm equally sure it's not worth wasting brain cells on because I'd wind up spending more money doing that than it would cost to just go out and buy a freaking boat, and that boat would perform better as a boat than my converted car would. It's a silly idea.
Quote
Certainly, during the 25 years the shuttle has been flying, someone must have performed an analysis (maybe a thesis) on configuring it for a different mission.
I'm sure someone has written a thesis about it as well. I have long ceased to be amazed at the silly things academics write theses about, especially if they can get a government or industry grant to do it. Mating habits of Norwegian blue parrots, why smoking really isn't bad for your health, how to send a shuttle to the moon... the list is endless.
The only way that makes sense for my car to make a boating trip is to tow the boat to the slip and put the boat in the water. Likewise, the only way that makes sense to use a shuttle on a lunar mission is to launch components of a purpose-built lunar craft into LEO and assemble them there.
Post by: joncz on 10/17/2007 02:36 pm
Quote
Jorge - 17/10/2007 10:13 AM
I'm sure someone has written a thesis about it as well. I have long ceased to be amazed at the silly things academics write theses about, especially if they can get a government or industry grant to do it. Mating habits of Norwegian blue parrots, why smoking really isn't bad for your health, how to send a shuttle to the moon... the list is endless.
Beautiful plumage, the Norwegian Blue!
;)
Post by: zerm on 10/17/2007 03:56 pm
Quote
mkirk - 16/10/2007 6:05 PMQuotezerm - 16/10/2007 5:24 PM
I've been watching the STS112 onboard launch video and in the process of cleaning up the voicetrack I heard the PLT make the call "mini-bucket" a few seconds after liftoff. I've searched the Q&As here and not found a referance. Although I know what the term "bucket" refers to- I was wondering the exact meaning of the "Mini-bucket" call.
Typically shuttle ascents are planned with a single throttle down event known as a single stage bucket. However dispersions in the performace of the SRBs (solid rocket boosters), either hot or cold, as assesed by the shuttle's guidance system at about the twenty second mark in the ascent, may dictate either a shallower bucket than orginally planned or a two stage bucket. The two stage bucket for example might result in a reduction of power to 80% then a few seconds later the engines would throttle back further to 72%.
This change from the planned power setting (determined pre-launch) as seen on the Main Propulsion System Chamber Pressure Gauges is what Pam was referring to.
Mark Kirkman
Looks as if you hit this answer directly on target- in looking at the time on the sound-track, she calls "Mini-bucket" at 23 seconds after SRB ignition- so the 20 second update would have been displayed, read and called in that 3 second period.
Thanks! That answers my question 104% ;-)
BTW- I'd advise everyone to go to L2 and watch this STS112 onboard video. There are a ton of little moments that will really tickle you. The crew CDR waving to the camera as the whiteroom retracts and then being given "major style points" by the PLT for doing so for example. Also, the 4 way handshake as they pass through 50 NM and the rookies become "rookies no more" really touched me. These folks were a real happy crew and it's is fun to watch them on the adventure. I only wish we had a lot more such videos. If your are not an L2 member- JOIN! This is just a sample of the really cool stuff kept there.
Post by: swhitt on 10/17/2007 05:56 pm
If you can point me to the docs on the following that would be great.
Is the OMS 2 burn the same as the NC1?
How long is the typical OMS 2 burn?
Are all NCx burns RCS burns?
Are all NCx burns determined after launch, based on the performance of previous burns, or are any of them of predetermined length?
And finally, what would be the typical numbers for NC1, NC2, NC3, and NC4 burns?
Thanks.
Post by: Jorge on 10/17/2007 06:38 pm
Quote
swhitt - 17/10/2007 12:56 PM
I have looked around and not really found an answer to the following questions.
If you can point me to the docs on the following that would be great.
Is the OMS 2 burn the same as the NC1?
No. OMS-2 is the final orbital insertion burn. It is performed at or near apogee of the post-MECO suborbital trajectory to raise perigee at least above "Safe HP" (80 nmi). Beyond that, on non-rendezvous flights it is typically used to circularize the orbit, and on ground-up rendezvous flights (which all shuttle flights are these days) it can be used as a rendezvous phasing (NC) burn, but it is never labeled as NC.
NC1 is a separate burn, though it is sometimes designed as a post-OMS-2 correction burn and can be deleted if not required.
Quote
How long is the typical OMS 2 burn?
Varies widely. For ISS flights, typical post-MECO orbit is 122x30 nmi, so OMS-2 will always be at least long enough to raise perigee above 80 nmi. Beyond that depends on the mission and (for rendezvous flights) the phase angle. For historical data, see:
http://spaceflight.nasa.gov/shuttle/reference/green/ascorb.pdf
Quote
Are all NCx burns RCS burns?
No, it is not uncommon for NC burns to be OMS burns. The last NC burn (NC4 for flight day 3 rendezvous, NC6 for FD4 RNDZ) is almost always an OMS burn unless the phase angle is very small.
Quote
Are all NCx burns determined after launch, based on the performance of previous burns, or are any of them of predetermined length?
The former. An NC burn is a rendezvous phasing burn designed to put the orbiter at some downrange distance (or phase angle) with respect to the target at some future time. So it depends on tracking of both the orbiter and the target. Flight Design makes pre-flight predictions for each NC burn based on a predicted target state vector and a reference liftoff date/time, but the actuals usually differ.
Quote
And finally, what would be the typical numbers for NC1, NC2, NC3, and NC4 burns?
Nothing "typical". The only thing you can say with certainty is that they are all "horizontal" burns (delta-V parallel to the velocity vector) and further, for a ground-up rendezvous profile, they will all be posigrade (delta-V in same direction as velocity).
Post by: Danny Dot on 10/17/2007 07:40 pm
Quote
swhitt - 17/10/2007 12:56 PM
snip
Are all NCx burns RCS burns?
snip
If I recall correctly the break over to use the OMS is about 4 feet/second on the burn amount.
Post by: Jorge on 10/17/2007 09:12 pm
Quote
Danny Dot - 17/10/2007 2:40 PMQuoteswhitt - 17/10/2007 12:56 PM
snip
Are all NCx burns RCS burns?
snip
If I recall correctly the break over to use the OMS is about 4 feet/second on the burn amount.
Close. Multiaxis RCS is used for less than 4 fps, +X RCS between 4 and 6 fps, and OMS for greater than 6 fps.
Post by: Jorge on 10/18/2007 01:07 am
Quote
tnphysics - 17/10/2007 8:00 PM
Why?
Why what?
There are thousands of questions answered in this thread. You should quote the post you're replying to.
Post by: tnphysics on 10/18/2007 01:09 am
Quote
Jorge - 17/10/2007 5:12 PMQuoteDanny Dot - 17/10/2007 2:40 PMQuoteswhitt - 17/10/2007 12:56 PM
snip
Are all NCx burns RCS burns?
snip
If I recall correctly the break over to use the OMS is about 4 feet/second on the burn amount.
Close. Multiaxis RCS is used for less than 4 fps, +X RCS between 4 and 6 fps, and OMS for greater than 6 fps.
Why?
Post by: tnphysics on 10/18/2007 01:11 am
Post by: Jorge on 10/18/2007 01:33 am
Quote
tnphysics - 17/10/2007 8:09 PMQuoteJorge - 17/10/2007 5:12 PMQuoteDanny Dot - 17/10/2007 2:40 PMQuoteswhitt - 17/10/2007 12:56 PM
snip
Are all NCx burns RCS burns?
snip
If I recall correctly the break over to use the OMS is about 4 feet/second on the burn amount.
Close. Multiaxis RCS is used for less than 4 fps, +X RCS between 4 and 6 fps, and OMS for greater than 6 fps.
Why?
OMS is generally more propellant-efficient than RCS (Isp is higher), but OMS guidance runs open-loop for the last six seconds of a burn to avoid large guidance transients. For very short burns, this can result in large residuals that must be trimmed out with the RCS. Below 6 fps it is more efficient to just do the whole burn with the RCS. OMS engine lifetime is rated in number of starts so this also reduces unnecessary starts.
FRCS propellant is typically more limited than ARCS, so it is desirable to limit the amount of FRCS propellant used during an RCS burn. Above a certain point, it is more efficient to maneuver to +X RCS attitude, even though the maneuver itself uses some FRCS peopellant. MCC uses the criteria of 2 fps FRCS propellant to decide between multiaxis and +X, but the crew has no easy way to determine the FRCS contribution to a burn, so it is simpler to just draw the line at a total delta-V of 4 fps.
These are all guidelines and can be overridden by MCC depending on propellant margins and/or system malfunctions.
Post by: Jorge on 10/18/2007 01:42 am
Quote
tnphysics - 17/10/2007 8:11 PM
What happens if the throttle down fails?
The shuttle will accelerate too quickly, resulting in max-Q above load limits, possibly resulting in structural damage or loss of vehicle. If all three SSMEs fail to throttle down, Flight Rules require the crew to take manual throttle control. If one SSME fails to throttle down, no action is required. If two SSMEs fail to throttle down during second stage 3-g throttling, the crew is required to manually shut down one of the stuck engines, but is not required to take action during first stage.
Post by: tnphysics on 10/18/2007 02:08 am
This is the FOS.
Post by: Jorge on 10/18/2007 02:16 am
Quote
tnphysics - 17/10/2007 9:08 PM
Would it be more than 1.4 times max nominal load?
This is the FOS.
Depends on how many engines don't throttle down. The flight rules I cited should give you a clue.
Post by: swhitt on 10/18/2007 03:19 am
Quote
Jorge - 17/10/2007 2:12 PM
Close. Multiaxis RCS is used for less than 4 fps, +X RCS between 4 and 6 fps, and OMS for greater than 6 fps.
All of this is excellent information. Thank you very much.
Post by: usn_skwerl on 10/18/2007 08:15 am
Post by: kimmern123 on 10/18/2007 10:09 am
Post by: mkirk on 10/18/2007 02:19 pm
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usn_skwerl - 18/10/2007 3:15 AM
what is the orbiter's nominal angle relative to horizon at SRB SEP? (i know it's inverted)
Kimmern123 is correct, the pitch or theta is about 18-20 degrees. It varies from flight to flight by a degree or so. I should point out that pitch angle relative to the horizon is not as important as angle of attack (or alpha) - which is the angle between the wing chord line and the ralative wind. Proper anlge or attack is critical to ensuring a clean seperation.
A good place to find the approximate pitch angle for a given flight would be in the Ascent Checklist for the specific mission. It would be listed on the ADI Cue Card (page 2-28 ish) , under the second column (theta) after the line labled staging (this would be an approximation of the theta). These checklists are available here on Chris' site and usually available on the public NASA site.
Mark Kirkman
Post by: SiameseCat on 10/19/2007 02:00 am
Post by: mkirk on 10/19/2007 02:40 pm
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SiameseCat - 18/10/2007 9:00 PM
One of the methods for targeting OMS burns is called PEG4, where C1, C2, HT and thetaT are entered, and these values specify the target orbit (I think). Does anyone know what these inputs actually mean ?
In the PEG 4 (powered explicit guidance) targeting scheme C1 and C2 are the slope and intercept that define the relationship between the horizontal and vertical components of the burn velocity.
V(vertical ) = C2 V(horizontal) + C1
HT is the height above the earth in nautical miles.
Theta T is the angular location of the target in degrees. For OPS 1 burns (such as OMS 1 an OMS2) this is the downrange angle from the launch site to the radius target vector. For OPS3 burns such as the deorbit burn it is the angle from the point of ignition (or TIG) to Entry interface.
I might have some notes or documents that explain this better, if I do I will post them here.
Mark Kirkman
Post by: dawei on 10/19/2007 03:20 pm
How many OMS engines are in the current inventory?
Are the OMS engines integral to the OMS pods or can an engine be changed out without removing/changing the pod?
Thanks in advance.
Post by: C5C6 on 10/19/2007 03:45 pm
Post by: DaveS on 10/19/2007 03:48 pm
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C5C6 - 19/10/2007 5:45 PMBarge.
while ETs are delivered to KSC by barge, how would it have been delivered to VAFB???
Post by: C5C6 on 10/19/2007 03:57 pm
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DaveS - 19/10/2007 12:48 PMthen it should have gone through the panama canal??? that would have taken weeks!!!QuoteC5C6 - 19/10/2007 5:45 PMBarge.
while ETs are delivered to KSC by barge, how would it have been delivered to VAFB???
Post by: DaveS on 10/19/2007 05:02 pm
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C5C6 - 19/10/2007 5:57 PMBingo. That is the route that it would have taken.QuoteDaveS - 19/10/2007 12:48 PMthen it should have gone through the panama canal??? that would have taken weeks!!!QuoteC5C6 - 19/10/2007 5:45 PMBarge.
while ETs are delivered to KSC by barge, how would it have been delivered to VAFB???
Post by: Namechange User on 10/19/2007 05:17 pm
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dawei - 19/10/2007 10:20 AM
What is the "lifetime" of an OMS engine, measured in engine starts?
How many OMS engines are in the current inventory?
Are the OMS engines integral to the OMS pods or can an engine be changed out without removing/changing the pod?
Thanks in advance.
The OMS engines are quite robust and we do a maintenance cycle on the during the orbiter OMDP. The are removed from the pod and sent to White Sands for this. There is no limit on starts.
We have enough engines for the entire fleet with approximately 4 spares. The engines are obviously integrated onto the pod but they are there own seperate LRU (Line Replaceable Unit). Yes we can remove and change an engine if necessary without removing the pod. We have done this several times in the past in the OPF.
Post by: C5C6 on 10/20/2007 01:22 am
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DaveS - 19/10/2007 2:02 PMare you aware how much time it would have taken to do the whole trip?? wasn't there any other way ever considered??QuoteC5C6 - 19/10/2007 5:57 PMBingo. That is the route that it would have taken.QuoteDaveS - 19/10/2007 12:48 PMthen it should have gone through the panama canal??? that would have taken weeks!!!QuoteC5C6 - 19/10/2007 5:45 PMBarge.
while ETs are delivered to KSC by barge, how would it have been delivered to VAFB???
Post by: Jim on 10/20/2007 01:18 pm
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C5C6 - 19/10/2007 9:22 PMQuoteDaveS - 19/10/2007 2:02 PMare you aware how much time it would have taken to do the whole trip?? wasn't there any other way ever considered??QuoteC5C6 - 19/10/2007 5:57 PMBingo. That is the route that it would have taken.QuoteDaveS - 19/10/2007 12:48 PMthen it should have gone through the panama canal??? that would have taken weeks!!!QuoteC5C6 - 19/10/2007 5:45 PMBarge.
while ETs are delivered to KSC by barge, how would it have been delivered to VAFB???
just a few weeks. The second stage of the Saturn V had to almost make the same trip the other way.
There really was no alternative
Post by: DaveS on 10/20/2007 01:28 pm
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Jim - 20/10/2007 3:18 PMJust to throw it out there: Early in the program they investigated the possibility of carrying the ET atop the SCA. But this idea died quickly after a set windtunnel tests showed that the buffeting off the ET was too severe for the SCA to handle.
There really was no alternative
Post by: ChrisGebhardt on 10/21/2007 05:49 am
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DaveS - 20/10/2007 9:28 AMQuoteJim - 20/10/2007 3:18 PMJust to throw it out there: Early in the program they investigated the possibility of carrying the ET atop the SCA. But this idea died quickly after a set windtunnel tests showed that the buffeting off the ET was too severe for the SCA to handle.
There really was no alternative
But what a site that would have been! :cool:
Also, in relation to a post about the second stage of the Saturn V almost making the trip from California, was the second stage originally to have been manufactured out in the CA?
Post by: Jim on 10/21/2007 02:53 pm
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Trekkie07 - 21/10/2007 1:49 AMQuoteDaveS - 20/10/2007 9:28 AMQuoteJim - 20/10/2007 3:18 PMJust to throw it out there: Early in the program they investigated the possibility of carrying the ET atop the SCA. But this idea died quickly after a set windtunnel tests showed that the buffeting off the ET was too severe for the SCA to handle.
There really was no alternative
But what a site that would have been! :cool:
Also, in relation to a post about the second stage of the Saturn V almost making the trip from California, was the second stage originally to have been manufactured out in the CA?
It wasn't almost. The S-II was built in Seal Beach, CA
Post by: nsf-rt on 10/22/2007 11:44 pm
* Activate the orbiter's fuel cells (8:23 p.m.)
This got me wondering why they're starting them so far before launch, if they need power why not use power from the ground?
Just before launch we're going to get:
"Fuel cells to internal reactants (T-2:35) "
So presumably now they're on "external reactants" - how are they supplied and why not just supply power?
I've found lots of information at:
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/eps/pwrplants.html
This let me know that warming the fuel cells up to operating temperature takes 25 minutes, so that can't be the reason for starting them so early.
I'm also aware that we get the famous step that we hear on the launch commentary:
Orbiter transfers from ground to internal power (T-0:50 seconds)
Perhaps the fuel cells are "active" but there is no - or little power drawn from them between now and T-50 seconds?
Perhaps that "little" power is just the fuel cell's internal systems?
Post by: mkirk on 10/23/2007 12:08 am
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nsf-rt - 22/10/2007 6:44 PM
On the STS-120 Live thread I've just seen:
* Activate the orbiter's fuel cells (8:23 p.m.)
This got me wondering why they're starting them so far before launch, if they need power why not use power from the ground?
Just before launch we're going to get:
"Fuel cells to internal reactants (T-2:35) "
So presumably now they're on "external reactants" - how are they supplied and why not just supply power?
I've found lots of information at:
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/eps/pwrplants.html
This let me know that warming the fuel cells up to operating temperature takes 25 minutes, so that can't be the reason for starting them so early.
I'm also aware that we get the famous step that we hear on the launch commentary:
Orbiter transfers from ground to internal power (T-0:50 seconds)
Perhaps the fuel cells are "active" but there is no - or little power drawn from them between now and T-50 seconds?
Perhaps that "little" power is just the fuel cell's internal systems?
There is actually a lot to those questions but I will start with a simple answer and if you need more detail after that then I, or someone else, will provide it.
The simple answer for the apparently early activation is that the launch team needs to ensure the fuel cells are on line and working properly. The launch team evaluates the performance of the individual cells (96 per fuel cell) as well as the overall ability of the fuel cells to provide the correct electrical loads to the vehicle. Performance calibrations are conducted and a purge of the fuel cells is performed to ensure the fuel cells are free of contaminants that could degrade performance. Activating the fuel cells at this point also provides some time to trouble shoot any issues that may arise.
Total power to the vehicle is shared between the ground support equipment and the fuel cells until the switch to internal power at T-50 seconds. The lswitch over is a gradual process (i.e. the load on the fuel cells is slowly increased) that is completed at T-50 seconds.
During the count, as systems are activated and brought online, the folks in the launch control center monitor the performance of the fuel cells and the entire shuttle electrical power and distribution system. I should also point out that the Ascent Flight Control Team in the Mission Control Center, while not actually responsible for the vehicle until liftoff/tower clear, are also watching the fuel cells and electrical system closely during the count.
Ground support equipment continues to provide reactants for the fuel cells until late in the countdown because this ensures the maximum amount of reactants available to support the requirements of the mission.
Mark Kirkman
Post by: nsf-rt on 10/23/2007 12:27 am
Post by: mkirk on 10/23/2007 12:40 am
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nsf-rt - 22/10/2007 7:27 PM
Thanks for that - does the fact that the fuel cells need to be online and working for so long to check they're OK indicate they're a in some way temperamental / unreliable / inconsistent?
No, not in my opinion. I wouldn’t characterize them that way at all.
It is just that the Fuel Cells and electrical power system are mission critical systems that operate 24/7 during the mission; the time to ensure they are up to the task is while you are still on the ground.
Mark Kirkman
Post by: Davejfb on 10/23/2007 10:10 am
When, at the end of the count, they say: 3, 2, 1, booster ignition and ........ Then they say a line. Who comes up with those lines? Does the PAO selected them or someone else? I collect all the calls on tape. So i was wondering who makes them?
Thanks.
Post by: Jim on 10/23/2007 10:59 am
Post by: hutchel on 10/23/2007 11:25 pm
Lee
Post by: MKremer on 10/23/2007 11:55 pm
(The camera has its own batteries, electronics box, and transmitter/antennas; it's a separate self-contained system by itself. see: http://www.eclipticenterprises.com/products_overview.php )
Post by: Jim on 10/24/2007 12:03 am
Post by: psloss on 10/24/2007 12:24 am
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9814&start=1#M186120
Post by: STS-500Cmdr on 10/24/2007 01:07 am
Post by: Namechange User on 10/24/2007 02:42 am
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nsf-rt - 22/10/2007 7:27 PM
Thanks for that - does the fact that the fuel cells need to be online and working for so long to check they're OK indicate they're a in some way temperamental / unreliable / inconsistent?
Not at all but with all things in the count there is a time to do things so that things can continue to progress in an orderly fashion. The fuel cells are powered on the ground via external reactants being fed through the T-0 connections, so they are not using any of the LH2/LO2 loaded into the PRSD system. Since they are not using any onboard consumables this is not a limiting factor. Also the fuel cells share the electrical load with the ground power system. Once the fuel cells are put through their paces, via high/low load calibrations everything is then at nominal levels and the ET is loaded. Finally, you can't go anywhere without electrical power so it would be a real shame and a waste if the ET was loaded and you were much further into the count and then found an issue with the fuel cells.
Post by: Avron on 10/24/2007 02:55 am
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psloss - 23/10/2007 8:24 PM
Jorge covered a lot of this, so hopefully his answer will "stick" for a few pages:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9814&start=1#M186120
Any idea as to the range from orbiter to tank at breakup? and the angle, i.e would it be aft of the orbiters orbit?
Post by: MKremer on 10/24/2007 03:23 am
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Avron - 23/10/2007 9:55 PMIt'd be interesting to see what the average range would be.Quotepsloss - 23/10/2007 8:24 PM
Jorge covered a lot of this, so hopefully his answer will "stick" for a few pages:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9814&start=1#M186120
Any idea as to the range from orbiter to tank at breakup? and the angle, i.e would it be aft of the orbiters orbit?
As far as which is ahead, the tank is peaking at apogee and descending in a ballistic freefall while the orbiter is doing its OMS 2 burn. The tank should be trailing by a number of degrees by the time it starts to heat and break up.
Post by: Jorge on 10/24/2007 03:51 am
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MKremer - 23/10/2007 10:23 PMQuoteAvron - 23/10/2007 9:55 PMIt'd be interesting to see what the average range would be.Quotepsloss - 23/10/2007 8:24 PM
Jorge covered a lot of this, so hopefully his answer will "stick" for a few pages:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9814&start=1#M186120
Any idea as to the range from orbiter to tank at breakup? and the angle, i.e would it be aft of the orbiters orbit?
As far as which is ahead, the tank is peaking at apogee and descending in a ballistic freefall while the orbiter is doing its OMS 2 burn. The tank should be trailing by a number of degrees by the time it starts to heat and break up.
Actually, the tank will be leading by a fair amount. The OMS-2 burn raises the orbiter's orbit, resulting in a longer orbital period and causing it to fall behind the tank. But the amount will vary depending on the size of the OMS-2 burn, which is different on every rendezvous mission.
Post by: MKremer on 10/24/2007 05:58 am
the orbiter is making an OMS burn - accelerating for a couple minutes before coasting and decelerating into its larger orbit...
the tank is starting to accelerate via gravity on its ballistic reentry path down, but will start to encounter higher atmospheric density which will start to slow it while also affecting it via rapid heating
Post by: LSainsbury on 10/24/2007 08:21 am
Can anybody point me to a hi-res photo of the flight deck - like the one on this article?
http://www.nasaspaceflight.com/content/?cid=5254
Cheers!
Post by: rfoshaug on 10/24/2007 12:23 pm
Does anyone know how much propellants that normally remain in the tank after MECO? How much reserve propellants do they carry, and does this amount vary much from mission to mission?
Post by: cozmicray on 10/24/2007 05:15 pm
http://www.nasa.gov/centers/langley/news/releases/2000/GCTHUMBNAILS_prt.htm
or QTVR at
http://www.panoscan.com/CubicDemos/Shuttle.html
Post by: nathan.moeller on 10/24/2007 05:40 pm
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rfoshaug - 24/10/2007 7:23 AM
According to Wikipedia (i know, i know...), the External Tank holds 106,261 kg of LH2 and 629,340 kg of LOX at liftoff for a total of 735,601 kg of propellants.
Does anyone know how much propellants that normally remain in the tank after MECO? How much reserve propellants do they carry, and does this amount vary much from mission to mission?
I don't have time to do the math, but I once heard that the SSMEs normally shut down when the tank's fuel level reaches about 2%.
Post by: Jorge on 10/24/2007 05:54 pm
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nathan.moeller - 24/10/2007 12:40 PMQuoterfoshaug - 24/10/2007 7:23 AM
According to Wikipedia (i know, i know...), the External Tank holds 106,261 kg of LH2 and 629,340 kg of LOX at liftoff for a total of 735,601 kg of propellants.
Does anyone know how much propellants that normally remain in the tank after MECO? How much reserve propellants do they carry, and does this amount vary much from mission to mission?
I don't have time to do the math, but I once heard that the SSMEs normally shut down when the tank's fuel level reaches about 2%.
The SSMEs normally shut down at a MECO target velocity, not prop level. They also shut down if the ECO sensors go dry but that's lower than 2%.
ET residual prop statistics for the first 100 flights are in Jenkins, 3rd ed, p. 332. I don't know of an online source of this data.
Post by: Avron on 10/25/2007 04:04 am
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MKremer - 24/10/2007 1:58 AM
I think it would be really interesting to find out what the actual positions would be:
the orbiter is making an OMS burn - accelerating for a couple minutes before coasting and decelerating into its larger orbit...
the tank is starting to accelerate via gravity on its ballistic reentry path down, but will start to encounter higher atmospheric density which will start to slow it while also affecting it via rapid heating
A min - max range/angle plot would be really interesting..
Post by: spaceshuttle on 10/25/2007 06:07 am
Post by: DaveS on 10/25/2007 08:27 am
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spaceshuttle - 25/10/2007 8:07 AMThey're GSE acccess doors for the S&A devices. For flight, they're removed and replaced with white flight doors.
On the SRBs during rollout, what are the yellow boxes near the nose for?
Post by: LSainsbury on 10/25/2007 10:51 am
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cozmicray - 23/10/2007 6:15 PM
Glass Cockpit at
http://www.nasa.gov/centers/langley/news/releases/2000/GCTHUMBNAILS_prt.htm
or QTVR at
http://www.panoscan.com/CubicDemos/Shuttle.html
Cool - thanks for those!
In the QTVR of the flight deck, in the middle just above the CRT power switches, there's a hatched yellow / black section with what appears to be a key with a large red tag....whats that???
Post by: Real Madrid on 10/25/2007 12:07 pm
Post by: DaveS on 10/25/2007 12:29 pm
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Real Madrid - 25/10/2007 2:07 PMThe orbiters will be museum items. Try doing a search for "orbiter retirement".
what happens there with the space shuttle in 2010, after the last mission?
Post by: Real Madrid on 10/25/2007 12:37 pm
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DaveS - 25/10/2007 2:29 PMQuoteReal Madrid - 25/10/2007 2:07 PMThe orbiters will be museum items. Try doing a search for "orbiter retirement".
what happens there with the space shuttle in 2010, after the last mission?
why museum items?
Post by: DaveS on 10/25/2007 12:39 pm
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Real Madrid - 25/10/2007 2:37 PMWhat else? NASA has always donated stuff they no longer use to the NASM. See Enterprise.QuoteDaveS - 25/10/2007 2:29 PMQuoteReal Madrid - 25/10/2007 2:07 PMThe orbiters will be museum items. Try doing a search for "orbiter retirement".
what happens there with the space shuttle in 2010, after the last mission?
why museum items?
Post by: Real Madrid on 10/25/2007 12:42 pm
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DaveS - 25/10/2007 2:39 PMQuoteReal Madrid - 25/10/2007 2:37 PMWhat else? NASA has always donated stuff they no longer use to the NASM. See Enterprise.QuoteDaveS - 25/10/2007 2:29 PMQuoteReal Madrid - 25/10/2007 2:07 PMThe orbiters will be museum items. Try doing a search for "orbiter retirement".
what happens there with the space shuttle in 2010, after the last mission?
why museum items?
okay,
Post by: LSainsbury on 10/25/2007 02:35 pm
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pad rat - 24/10/2007 2:59 PM
That's the pull handle for jettisoning the overhead window for ground escape.
Ahh I see...hence the warning / danger type layout!
Post by: Danny Dot on 10/25/2007 03:49 pm
Danny Deger
Post by: rdale on 10/25/2007 03:57 pm
Post by: Danny Dot on 10/25/2007 05:06 pm
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rdale - 25/10/2007 10:57 AM
I think that was rehashed over and over when the issue came up if you search the old threads. That's all opinion based. If you want them to shut down the shuttle until it's 100% safe, it'll be a long shutdown.
Can you point me to those threads? I looked but couldn't find them. Even if it has been discussed in the past, the quotes from Gerstemaier in Av Week is new information.
Danny Deger
Post by: rdale on 10/25/2007 05:08 pm
Post by: MKremer on 10/25/2007 11:52 pm
How much blank printer paper do they have available? (And how many spare print cartridges?)
I'm guessing they leave most of their extra paper and printer supplies on the station when they leave.
Is it an off-the-shelf inkjet, or does it need special mods for zero-G operation and vibration isolation?
Post by: James Lowe1 on 10/27/2007 05:08 am
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rdale - 25/10/2007 12:08 PM
Maybe they were in L2. The quotes from Gerst came from the press conference last week, so that's not really new either...
If they were quotes from a press conference then it wouldn't be in L2, or did you mean something else? If so, I can search and give an answer to this.
Post by: rdale on 10/27/2007 02:32 pm
If you want to start a discussion about the shuttle program going down the wrong path, I'd think the Q&A section is not the right topic.
Post by: Chris Bergin on 10/27/2007 05:26 pm
Post by: John2375 on 10/27/2007 10:15 pm
Thanks,
John
Post by: DaveS on 10/27/2007 10:18 pm
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John2375 - 27/10/2007 12:15 AMThey don a pure O2 mask prior to Quest repress and egress.
Question about "camping out" _ when the EVA people for the next day "camp out" over night in Quest, I know they do that to purge their system of nitrogen. However, what about going to the bathroom? Do they use something there or can they come out and use the station/shuttle toilet or would that not be possible because of what they're trying to accomplish??
Thanks,
John
Post by: tmckinley on 10/28/2007 03:36 am
Post by: MKremer on 10/28/2007 04:12 am
If one vehicle launches, and the other launches within 24 hrs all the way across the CONUS into an entirely different orbital plane, and they're calculated to guarantee there's no hazards for the 2nd vehicle to launch, I can't see any reason they can't both launch on the same day.
Post by: Jim on 10/28/2007 12:23 pm
2. NASA has one group that manages it's ELV launches and they have a 7-10 gap required.
3. Since ULA handles Delta and Atlas, they will avoid scheduling launches close together because of common support. Previously, there also existed a minimum gap between Delta II and Delta IV.
4. 48 hr turnaround on the same range
5. Launches from different ranges still may share assets.
But after all this, VAFB and CCAFS launches still could happen on the same day
Also NASA could support a VAFB ELV and a shuttle launch
risk adverseness would probably prevent this
Post by: blazotron on 10/29/2007 04:12 am
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blazotron - 28/10/2007 10:20 PM
This might well have been answered somewhere, but I can't find it through a search (although that may be a function of not knowing what to search for). I'm trying to figure out what all the regions and labels on the world map with ISS and shuttle orbits they sometimes have up in MCC and on the NASA TV feeds when there isn't more interesting stuff to show, as we have seen several times today. For instance here:
http://forum.nasaspaceflight.com/forums/get-attachment-big.asp?acti...
I know some of the labels are SAA: South Atlantic Anomoly and ZOE: Zone of Exclusion, although I am not sure exactly what the ZOE is. There are some small roundish regions over Asia with labels lie SHKR, ULDM, USKR, PPKR, which be the ranges where the Russian ground stations can the station, but I am not sure. There are also three large regions roughly centered around the Sahara, southern Mexico, and Austrailia. I'm thinking these might be the ranges of the TDRSS satellites, but they do seem to roughly correlate to the locations of the large DSN dishes in CA, Spain, and Austrailia. Thanks for the help.
And the reply from that thread
Quote
Life_Support_32 - 28/10/2007 9:17 PM
ZOE- The area where neither of the 2 primary TDRS satellites can reach. There is a satellite over the ZOE, but is not used during stage ops (when the shuttle is not there).
The roundish regions over Asia are the RS ground sites, which shows that communication using Russian assets is very limited.
The three large regions are the areas where the TDRS satellite associated with it cannot reach. So, you associate the color of the satellite with the oval color and you can see which satellite is in range over the ground track. (In the picture, the ISS is over the ZOE and has no signal from T174W or T045W).
Hope this helped!
Post by: usn_skwerl on 10/29/2007 10:10 am
Post by: Jim on 10/29/2007 10:22 am
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usn_skwerl - 29/10/2007 7:10 AM
Does anyone know where I could find a hi-res image of this, please?
That is a fake picture so I doubt there is a hi-res of it
Post by: usn_skwerl on 10/29/2007 10:34 am
Ah well, it's not too hard to englarge and include particular detail in photoshop I guess :)
thanks anyway.
Post by: TJL on 10/29/2007 08:03 pm
Will this be the lightest orbiter on entry / landing?
Post by: jmjawors on 10/29/2007 08:20 pm
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TJL - 29/10/2007 4:03 PMLooking at Discovery in orbit, I can't recall seeing such a "vacant" payload bay. Will this be the lightest orbiter on entry / landing?
I don't have the same impression. Surely Atlantis was as empty after delivering P3/4 and S3/4. And I believe Atlantis weighs less than Discovery.
Post by: psloss on 10/29/2007 08:26 pm
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TJL - 29/10/2007 5:03 PMNot sure about landing weight, but any of the ISS assembly missions bringing up the large truss segments (spacers aside) would have looked very similar to that -- 8A/110, 9A/112, 11A/113, 12A/115, 13A/117.
Looking at Discovery in orbit, I can't recall seeing such a "vacant" payload bay.
Will this be the lightest orbiter on entry / landing?
Edit -- added a picture from the station of STS-110 after undock...
Post by: C5C6 on 10/29/2007 08:32 pm
Post by: TJL on 10/29/2007 09:06 pm
Post by: DaveS on 10/29/2007 09:23 pm
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C5C6 - 29/10/2007 10:32 PMWhen the orbiter is docked, PMA-2 is in the way. The SSRMS is used to unberth/berth the OBSS by grappling its mid grapple fixture letting the SRMS grapple the forward grapple fixture.
what's the whole purpose of the OBSS handoff from SSRMS to SRMS??? i dont understand.....isn't the OBSS returned to its position in the payload bay after flight day 2 inspections??? there's somwething i'm not aware of........
For this flight they they the hand-off as the OBSS was in the way for Node 2 unberth.
Post by: Ford Mustang on 10/29/2007 09:25 pm
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C5C6 - 29/10/2007 5:32 PM
what's the whole purpose of the OBSS handoff from SSRMS to SRMS??? i dont understand.....isn't the OBSS returned to its position in the payload bay after flight day 2 inspections??? there's somwething i'm not aware of........
On 120, they had to unberth Node 2, which would have hit the OBSS had it not have been handed off to the SSRMS.. After that, it is then returned to the payload bay. This is also the case if they need to do focused inspections (like on 118), seeing as how Destiny and the PMA are in the way of the SRMS (which would hit into Destiny had it try to grapple the OBSS).
Post by: joncz on 10/31/2007 02:46 pm
Post by: rdale on 10/31/2007 02:53 pm
Post by: nathan.moeller on 10/31/2007 04:26 pm
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Jim - 29/10/2007 6:22 AMQuoteusn_skwerl - 29/10/2007 7:10 AM
Does anyone know where I could find a hi-res image of this, please?
That is a fake picture so I doubt there is a hi-res of it
It's a mosaic that was made to be a poster. It's available at www.thespacestore.com. Feel free to scan it for us when you get it ;)
EDIT: Here - http://www.thespacestore.com/amspshfl.html
Post by: The-Hammer on 11/02/2007 02:03 pm
Seems like it would be a useful ability to have, especially if they have problems with the S6 SAW deploy (however unlikely that may be).
Also, if the grapple could additionally be modified to allow data connections that would help alleviate the concerns about the late inspection on the mission where they have to leave the OBSS at the station (123?).
Also, there has been discussion on the forum about the possibility of leaving "a" boom (not necessarily the OBSS) at the station following STS-133. If the OBSS could be modified to receive power and data from the SSRMS, STS-133 could just leave the OBSS at the station and use the SSRMS with OBSS for the late inspection.
Post by: DaveS on 11/02/2007 02:13 pm
Quote
The-Hammer - 2/11/2007 4:03 PMLots. The electrical connectors on the SSRMS LEEs are arranged differently than on the SRMS EEn.
How much effort (for future flights) would it take to modify the OBSS middle grapple position (where the SSRMS grapples the OBSS) to allow the SSRMS to provide power to the OBSS heaters?
.
The SSRMS LEE is configured with the electrical and data connectors in a X type configuration where the end effector grapple snare is located in a cylinder in the middle of the X.
The SRMS electrical connector is located in the six o'clock position at the bottom of the the end effector.
So it would have to be modified with a dedicated Power and Data Grapple Fixture(PDGF) which is much larger than a standard grapple fixture.
Attached is two images, the first one is of a ordinary grapple fixture. The second one is of a PDGF.
Post by: Andy_Small on 11/02/2007 11:03 pm
Post by: Lee Jay on 11/02/2007 11:24 pm
Quote
Andy_Small - 2/11/2007 6:03 PM
what is the velocity of the vehicle at SRB separation?
Usually a little better than Mach 4, or about 3000mph.
Post by: psloss on 11/02/2007 11:50 pm
http://www.cbsnews.com/network/news/space/120/120ascentdata.html
Post by: Skinny on 11/03/2007 12:59 am
Shuttle Q&A Part 4 (http://forum.nasaspaceflight.com/index.php?topic=10600.0)