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#2580
by
Jim
on 02 Apr, 2012 01:27
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flight suit. Just like Air Force pilots
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#2581
by
Namechange User
on 02 Apr, 2012 01:27
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flight suit
Damn. Beat me to it.
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#2582
by
Namechange User
on 02 Apr, 2012 01:30
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Since the OMS were hypergolic, the difference between a dump and a burn is symantics.
No, not really. One is just dumping propellant to shed mass, the other is is shedding mass in the form of increased performance via the burn.
When it became clear that increased performance was required, there was a trade to make. Just not load extra prop, or load it and burn it once the stack got to sufficient altitude for the engines.
The net result was increased performance because mass was still being "shed" but in the form of thrust.
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#2583
by
wolfpack
on 02 Apr, 2012 13:59
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Question re: STS-88. According to the post-mission report, Endeavour conducted a Dual Engine OMS Assist maneuver (102 seconds in duration) at 00:02:14 MET, just after SRB speration. Why was that maneuver performed? Unity's mass? Rendezvous considerations? Something else? Thanks!
Reminds me of Mike Mullane's book. He was the astronaut working with flight dynamics during the Challenger stand-down when the idea of pre-MECO OMS burns was hatched. Apparently John Young hated the idea.
Hence the comment in this video of 135's launch.
On another note, did we ever figure out why they put the gas cap on the left side? I'm guessing because it was made in America. Our cars are all like that. It's those European imports that always have me pulling up to the pump twice at the service station!
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#2584
by
NavySpaceFan
on 03 Apr, 2012 21:16
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Does anyone have any information re: the 20-g floor modification that the orbiters went through? Based on what I have seen so far, it sounds like a re-enforcement of the flight deck around the seating areas. Is that the case, or is it something else?
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#2585
by
Mark Dave
on 05 Apr, 2012 13:43
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How are the AFRSI and Nomex FRSI blankets replaced? I saw video of how the tiles are replaced, just chisel out the old tiles by hand and clean up the metal surface for the new tile. How are the blankets replaced?
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#2586
by
sivodave
on 09 Apr, 2012 12:12
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Hi all.
two questions again about rendezvous profile.
1. Why MC2 burn was targeted for being carried out based at a specific elevation angle? Was because in this way the star trakkers/COAS/radar had the best field of view of the target, or some other reason?
2. Which is the difference between an NH maneuver in which the height of the orbit is changed and NC maneuver in which the phase of the orbit is changed? are not the same thing? If you do a NC maneuver for changing the closure rate with the target, are you not changing also the shape (and therefore the height) of the orbit?
Thanks very much
Davide
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#2587
by
Jim
on 09 Apr, 2012 13:48
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How are the AFRSI and Nomex FRSI blankets replaced? I saw video of how the tiles are replaced, just chisel out the old tiles by hand and clean up the metal surface for the new tile. How are the blankets replaced?
Same way, they are also attached with RTV.
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#2588
by
sivodave
on 16 Apr, 2012 16:25
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Hi all.
One question about DOLILU. I’ve learned from [link=http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110003654_2011001858.pdf] this [/link] document, that as part of the DOLILU analyses, there was the determination of the Structural Load Indicator (SLI) Constraints for 40 critical points on the structure.
Always as part of DOLILU, there was also the determination for each Mach number of different Q-plane constraints. One of these plane, was the Orbiter Q-plane, which the file, said was used to determine the orbital structural load redlines.
My question is: which is the difference between the SLI constraints and the Orbiter Q-plane?
Thanks very much
Davide
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#2589
by
Jorge
on 16 Apr, 2012 17:49
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Hi all.
two questions again about rendezvous profile.
1. Why MC2 burn was targeted for being carried out based at a specific elevation angle? Was because in this way the star trakkers/COAS/radar had the best field of view of the target, or some other reason?
Targeting MC2 on an elevation angle constraint results in zero inertial line-of-sight rates during manual takeover, making it easier for the crew to discern motion of the target against a fixed star background. Buzz Aldrin explained this effect in his doctoral dissertation.
http://dspace.mit.edu/handle/1721.1/126522. Which is the difference between an NH maneuver in which the height of the orbit is changed and NC maneuver in which the phase of the orbit is changed? are not the same thing? If you do a NC maneuver for changing the closure rate with the target, are you not changing also the shape (and therefore the height) of the orbit?
The difference is the constraint being targeted. NH targets delta-H at a future time and NC targets a given downrange distance at a future time. There is no difference, obviously, in how each type of burn is actually performed, and targeting one constraint obviously affects the other.
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#2590
by
spacecane
on 18 Apr, 2012 13:00
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I have a question regarding rain on the orbiter. I have read recently that the tiles and thermal blankets absorbed water in the rain and that in the cases where this happened after landing there was sometimes a need to dry them out during processing. I have also read that the absorbed water added a lot of weight and was a constraint for SCA transport.
Here is my question. I attended the launch of STS-128 including the original scrub. At one point during the night of the first attempt there was such hard rain over the pad that the entire stack seemed to disappear like a David Copperfield trick. At this point there was no RSS protecting the Orbiter. Why didn't this rain cause any issue? I would have thought that at the very least it would have added launch weight which would have affected ascent performance. I would also think that there would be issues with the water freezing once it got into space.
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#2591
by
Jim
on 18 Apr, 2012 13:13
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I have a question regarding rain on the orbiter. I have read recently that the tiles and thermal blankets absorbed water in the rain and that in the cases where this happened after landing there was sometimes a need to dry them out during processing. I have also read that the absorbed water added a lot of weight and was a constraint for SCA transport.
Here is my question. I attended the launch of STS-128 including the original scrub. At one point during the night of the first attempt there was such hard rain over the pad that the entire stack seemed to disappear like a David Copperfield trick. At this point there was no RSS protecting the Orbiter. Why didn't this rain cause any issue? I would have thought that at the very least it would have added launch weight which would have affected ascent performance. I would also think that there would be issues with the water freezing once it got into space.
The tiles and blankets are waterproofed (with Scotchgard, I believe). The problem is that it is burned off after entry and has to be reapplied during processing. So that is why it is a post landing issue and not a prelaunch issue.
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#2592
by
ChrisC
on 23 Apr, 2012 03:21
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Question for you all ...
The Shuttle Carrier Aircraft 747 has two vertical stabilizer surfaces added to the ends of the horizontal stabilizer to improve "directional stability".
Do those two additional surfaces articulate, i.e. move along with the main rudder? Or are they static, and the central rudder is the sole provider of yaw control authority?
Here's the best pic I've found of the tail:
http://www.collectspace.com/news/news-041212c.html(scroll to bottom)
EDIT: thanks Jim
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#2593
by
Jim
on 23 Apr, 2012 10:53
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Question for you all ...
The Shuttle Carrier Aircraft 747 has two vertical stabilizer surfaces added to the ends of the horizontal stabilizer to improve "directional stability".
Do those two additional surfaces articulate, i.e. move along with the main rudder? Or are they static, and the central rudder is the sole provider of yaw control authority?
Static
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#2594
by
MP99
on 23 Apr, 2012 20:45
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What temperature are the gasses fed into the ET as pressurant?
Thanks, Martin
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#2595
by
Art LeBrun
on 23 Apr, 2012 20:58
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Question for you all ...
The Shuttle Carrier Aircraft 747 has two vertical stabilizer surfaces added to the ends of the horizontal stabilizer to improve "directional stability".
Do those two additional surfaces articulate, i.e. move along with the main rudder? Or are they static, and the central rudder is the sole provider of yaw control authority?
Static
Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
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#2596
by
Jim
on 24 Apr, 2012 01:47
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Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
I believe there is still enough control authority in the rudder.
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#2597
by
Jim
on 24 Apr, 2012 01:49
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What temperature are the gasses fed into the ET as pressurant?
Thanks, Martin
Prelaunch
Helium for the LH2 tank and I think nitrogen for the LOX tank
During flight, the SSME provide heated gases.
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#2598
by
JayP
on 24 Apr, 2012 13:12
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Since the shuttle blanks much of the effect of the vertical stabilizer could we assume the rudder is also somewhat blanked and hence engine power is used to aid in turns (yaw)?
Not really. Remember, in a normal, coordinated turn, the rudder is not used very much if at all. It is used in skid / slip conditions like when making an approach to landing in a crosswind, but the SCA / Orbiter configuration has pretty stringent limits on crosswind velocity. It would also be used in an engine out situation. I don't believe they ever did any testing of that, but that would be one reson why those flights are practically flown as test flights.
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#2599
by
Prober
on 24 Apr, 2012 15:01
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Would the Space shuttle have benefited from the use of a fairing during assent?
