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#80
by
mkirk
on 04 Feb, 2007 15:58
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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
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#81
by
mkirk
on 04 Feb, 2007 16:00
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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
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#82
by
TJL
on 04 Feb, 2007 16:14
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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?
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#83
by
rdale
on 04 Feb, 2007 16:59
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Per the press conference instead of additional help being in the ISS it would be given direct from the ground...
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#84
by
Jorge
on 04 Feb, 2007 17:03
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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
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#85
by
Jorge
on 04 Feb, 2007 17:05
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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
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#86
by
spacemuppet
on 05 Feb, 2007 02:28
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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?
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#87
by
nathan.moeller
on 05 Feb, 2007 02:30
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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.
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#88
by
Antares
on 05 Feb, 2007 02:44
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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.
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#89
by
spacemuppet
on 05 Feb, 2007 02:53
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Yea so what did happen during that landing?
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#90
by
Paul Howard
on 05 Feb, 2007 02:55
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Another subject already covered on here. Please do a search before starting new threads.
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#91
by
nathan.moeller
on 05 Feb, 2007 02:57
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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.
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#92
by
Chris Bergin
on 05 Feb, 2007 03:15
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#93
by
mkirk
on 05 Feb, 2007 19:59
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Most of the STS-3 stuff has been discussed in the STS-3 video thread. Lets cut Jack a little slack here though because de-rotation in the shuttle is a little tricky. In fact the standard procedure is to not even use CSS (control stick steering – i.e. “the control stick”) like you would in an aircraft such as the T-38, rather the commander will push and hold the “Beep Trim” switch full forward to initiate the pitch down. This ensures a 1-2 degree per second pitch rate that is within the limits of the nose gear (slap down loads) – and helps prevent the potential for overcontrolling.
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
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#94
by
TJL
on 05 Feb, 2007 20:24
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Does anyone know where I can find the payload weights for each of the 20 Space Shuttle missions sent to ISS?
Thanks!
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#95
by
DMeader
on 05 Feb, 2007 23:02
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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.
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#96
by
Jim
on 05 Feb, 2007 23:13
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DMeader - 5/2/2007 7:02 PM
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.
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
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#97
by
C5C6
on 06 Feb, 2007 00:20
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by the way, wouldn't it be awesome if we gather every question and its complete answer and make a special section in the web called "SHUTTLE FAQ", we make a special search tool for that and voilà!!!! that would be great for newest users, also for people looking for interesting facts (I enter everyday only to look at the Q&A, since i cant answer anything and dont have questions)
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.....
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#98
by
elmarko
on 06 Feb, 2007 08:38
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A shuttle wiki, based on the wikipedia software, would have the potential to be the single most coolest thing on NSF, in my opinion. (Excluding L2, naturally)
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.
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#99
by
STS-500Cmdr
on 06 Feb, 2007 16:20
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Alot of good STS-3 discussion came out during the end of STS-116 when we thought Discovery was going to White Sands--was discussed i think in a couple threads. Amazing what you can learn here
