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#1980
by
mmeijeri
on 25 May, 2009 02:54
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Atlantis did not carry the RCO cable necessary for deploying the landing gear.
What was the reason for that?
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#1981
by
ChrisGebhardt
on 25 May, 2009 03:00
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Atlantis did not carry the RCO cable necessary for deploying the landing gear.
What was the reason for that?
A function of land overflight rules and the fact that our repair options for a damaged orbiter are fairly decent. If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
Also, if you brought it down, Endeavour would have had to haul it back to the ISS. In a program where APM is everything, you want to try to reduce lift-off weight by as much as possible.
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#1982
by
ginahoy
on 25 May, 2009 03:21
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...Also, if you brought it down, Endeavour would have had to haul it back to the ISS.
Oh, so there's only one RCO cable and it's currently on ISS? Now I understand.
If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
I had in mind the case where the damage or repair was 'on the margin' in terms of confidence level. Chances are very good it would be fine, but not high enough to risk the crew.
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#1983
by
ChrisGebhardt
on 25 May, 2009 03:33
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...Also, if you brought it down, Endeavour would have had to haul it back to the ISS.
1. Oh, so there's only one RCO cable and it's currently on ISS? Now I understand.
If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
2. I had in mind the case where the damage or repair was 'on the margin' in terms of confidence level. Chances are very good it would be fine, but not high enough to risk the crew.
1. Correct.
2. Always a possibility. That was one of the factors in the analysis that determined they didn't need to bring the RCO cable back from ISS for this mission.
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#1984
by
Ronsmytheiii
on 25 May, 2009 03:36
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also a general RCO note, I believe the landing site is Vandenberg for any RCO landing attempt. Just wondering, will the cable probably be returned on STS-134?
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#1985
by
Jorge
on 25 May, 2009 03:51
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also a general RCO note, I believe the landing site is Vandenberg for any RCO landing attempt.
White Sands is still prime, last I heard. VAFB is not in the mix until they upgrade their MSBLS Jr. to full MLS. Without it an automated orbiter cannot land accurately enough to stay on the runway.
Just wondering, will the cable probably be returned on STS-134?
While there's an ongoing need to declutter ISS, the RCO cable probably isn't the biggest priority. I could see it being trashed with a Progress.
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#1986
by
AnalogMan
on 25 May, 2009 10:03
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...Also, if you brought it down, Endeavour would have had to haul it back to the ISS.
1. Oh, so there's only one RCO cable and it's currently on ISS? Now I understand.
If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
2. I had in mind the case where the damage or repair was 'on the margin' in terms of confidence level. Chances are very good it would be fine, but not high enough to risk the crew.
1. Correct.
2. Always a possibility. That was one of the factors in the analysis that determined they didn't need to bring the RCO cable back from ISS for this mission.
An RCO cable was planned to be manifested on STS-125, according to documentation on L2.
MOD delta FRR April 14, 2009
EVA, Robotics & Crew Systems Division
"New Operations - IFM
- Remote Controlled Orbiter Cable (RCO) manifested to facilitate an unmanned landing in the event of a LON rescue scenario" For those with L2 access see page 5 of the presentation here:
http://forum.nasaspaceflight.com/index.php?topic=16661.0
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#1987
by
mmeijeri
on 25 May, 2009 14:12
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You guys are kidding there is only one RCO cable, right?
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#1988
by
psloss
on 25 May, 2009 15:08
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You guys are kidding there is only one RCO cable, right?
Wouldn't be surprised if there was only one flight cable; if it was used, it would very likely only be used once.
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#1989
by
ChrisGebhardt
on 25 May, 2009 17:43
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...Also, if you brought it down, Endeavour would have had to haul it back to the ISS.
1. Oh, so there's only one RCO cable and it's currently on ISS? Now I understand.
If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
2. I had in mind the case where the damage or repair was 'on the margin' in terms of confidence level. Chances are very good it would be fine, but not high enough to risk the crew.
1. Correct.
2. Always a possibility. That was one of the factors in the analysis that determined they didn't need to bring the RCO cable back from ISS for this mission.
An RCO cable was planned to be manifested on STS-125, according to documentation on L2.
MOD delta FRR April 14, 2009
EVA, Robotics & Crew Systems Division
"New Operations - IFM
- Remote Controlled Orbiter Cable (RCO) manifested to facilitate an unmanned landing in the event of a LON rescue scenario"
For those with L2 access see page 5 of the presentation here:
http://forum.nasaspaceflight.com/index.php?topic=16661.0
I think this is a case of differing information. MOD said there was an RCO cable on Atlantis for STS-125. However, there was no mention (that I saw) of manifesting the RCO cable as downmass on STS-119 and the SSP FRR documents for STS-125 all talked about ditching the order in the Pacific Ocean in the event of LON. There was no mention of performing a controlled unmanned reentry in the SSP documents.
I've seen contradictions before between the MOD and SSP FRR documents (heck, sometimes there are even contradictions within the SSP FRR documents themselves).
If someone out there at Dryden working on Atlantis knows for certain, it would be greatly appreciated.
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#1990
by
Jorge
on 25 May, 2009 17:56
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You guys are kidding there is only one RCO cable, right?
Correct. There is only one flight cable. There was an engineering cable used for the SAIL tests that could have been certified as a second flight cable for 125.
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#1991
by
mmeijeri
on 25 May, 2009 18:01
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Correct. There is only one flight cable. There was an engineering cable used for the SAIL tests that could have been certified as a second flight cable for 125.
It sounded a bit weird at first to have only one copy of such an important piece of equipment, but the explanation psloss gave makes sense. Having to use it once probably means the end of the shuttle program. Still, I find it funny imagining an engineer asking "OK people, where's that darn RCO cable? Who had it last?".
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#1992
by
Jorge
on 25 May, 2009 18:04
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...Also, if you brought it down, Endeavour would have had to haul it back to the ISS.
1. Oh, so there's only one RCO cable and it's currently on ISS? Now I understand.
If the damage was significant enough that the available means of on-orbit repair were not acceptable, then Atlantis wouldn't survive reentry or at least would not be in a controllable configuration after reentry to safely make it to a runway.
2. I had in mind the case where the damage or repair was 'on the margin' in terms of confidence level. Chances are very good it would be fine, but not high enough to risk the crew.
1. Correct.
2. Always a possibility. That was one of the factors in the analysis that determined they didn't need to bring the RCO cable back from ISS for this mission.
An RCO cable was planned to be manifested on STS-125, according to documentation on L2.
MOD delta FRR April 14, 2009
EVA, Robotics & Crew Systems Division
"New Operations - IFM
- Remote Controlled Orbiter Cable (RCO) manifested to facilitate an unmanned landing in the event of a LON rescue scenario"
For those with L2 access see page 5 of the presentation here:
http://forum.nasaspaceflight.com/index.php?topic=16661.0
I think this is a case of differing information. MOD said there was an RCO cable on Atlantis for STS-125. However, there was no mention (that I saw) of manifesting the RCO cable as downmass on STS-119 and the SSP FRR documents for STS-125 all talked about ditching the order in the Pacific Ocean in the event of LON. There was no mention of performing a controlled unmanned reentry in the SSP documents.
If the intent was to certify the SAIL cable, there would have been no need to bring the original back from ISS.
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#1993
by
Jorge
on 25 May, 2009 18:10
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Correct. There is only one flight cable. There was an engineering cable used for the SAIL tests that could have been certified as a second flight cable for 125.
It sounded a bit weird at first to have only one copy of such an important piece of equipment, but the explanation psloss gave makes sense. Having to use it once probably means the end of the shuttle program. Still, I find it funny imagining an engineer asking "OK people, where's that darn RCO cable? Who had it last?".
You also need to understand that neither MOD nor SSP consider RCO "an important piece of equipment" in the sense that other orbiter systems are.
Wayne Hale has been quoted as saying he considers RCO to be a "cheap insurance policy" to provide *some* possibility of intact return of a damaged orbiter.
It is by definition not critical to crew safety - it will only be installed if the crew is abandoning the orbiter to unmanned entry.
It is not critical to safety of people on the ground - the damaged orbiter can always be targeted for destructive entry over the Pacific, without the RCO cable, to avoid populated areas.
It is not critical to mission success, since the event that already decided the success or failure of the mission has already happened by the time it's installed.
It is not critical to the future of the shuttle program, since as psloss wrote, the unspoken assumption within NASA is that if there's ever a TPS damage event bad enough to need it, the program is over.
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#1994
by
mmeijeri
on 25 May, 2009 18:13
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It is not critical to the future of the shuttle program, since as psloss wrote, the unspoken assumption within NASA is that if there's ever a TPS damage event bad enough to need it, the program is over.
Yeah, that makes sense. Still, if they managed to land the stricken orbiter safely, that would likely improve chances a bit. Not enough probably.
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#1995
by
mmeijeri
on 25 May, 2009 18:18
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Another scenario: what if there is a medical emergency and both the commander and the pilot are unable to fly the shuttle?
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#1996
by
Jorge
on 25 May, 2009 18:25
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Another scenario: what if there is a medical emergency and both the commander and the pilot are unable to fly the shuttle?
If the CDR and PLT are still alert and physically able to flip switches, I think they'd stay in the front seats and just leave the DAP in AUTO.
If they're not able to do even that, I think they'd put MS1 and another MS in the front seats (with MS2 remaining in the accustomed center seat) to do the switch flipping, and again leave the DAP in AUTO.
I don't believe they'd even consider installing RCO for the case where the crew is still on board.
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#1997
by
mmeijeri
on 25 May, 2009 18:34
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If they're not able to do even that, I think they'd put MS1 and another MS in the front seats (with MS2 remaining in the accustomed center seat) to do the switch flipping, and again leave the DAP in AUTO.
Would they know what to do, or would they have to be talked through by mission control?
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#1998
by
Jorge
on 25 May, 2009 18:58
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If they're not able to do even that, I think they'd put MS1 and another MS in the front seats (with MS2 remaining in the accustomed center seat) to do the switch flipping, and again leave the DAP in AUTO.
Would they know what to do, or would they have to be talked through by mission control?
MS2 would know, because that's the only crewmember sitting in the accustomed seat. MS2 is the "flight engineer" during ascent and entry, and choreographs all procedures that require both CDR and PLT actions. (The CDR and PLT procedures contain only their steps; the MS2 procedures are complete). Plus, there are some switches only MS2 can reach. So MS2 is the ideal "big-picture person" for this highly unlikely scenario. That is why I deemed it important to keep MS2 in the accustomed seat rather than moving to a front seat.
MS1 would be passingly familiar with the flight deck switches by virtue of having trained in the MS1 seat. MS1 doesn't get involved in the nominal procedures; MS1's main role is to identify criticalities and commonalities when things start breaking. But MS1 would know enough to be able to flip switches at the direction of MS2 (or MCC).
Whichever MS gets the other front seat might have a rougher time of it. They'd need a lot of hand-holding by both MS1 and 2. During a nominal entry, the PLT actually has more switch throws than the CDR. So I'd consider putting MS1 in the right seat and the other MS in the left.
All this assumes, of course, that automatic GNC remains "go" throughout entry so that the DAP can be kept in AUTO and no hand-flying is necessary. I'd even consider having the front seaters turn the FLT CNTLR PWR switches OFF so that they don't downmode the DAP if they accidently bump the stick. (It's simple to turn them back on if they find they do need to fly.) If there's any indication prior to entry that hand-flying might be necessary, all these assignments go out the window and I'd put the best remaining stick jockeys in the front seats. There is almost always at least one MS with a PPL.
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#1999
by
mmeijeri
on 25 May, 2009 19:02
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Thanks again Jorge. As always you are a fount of knowledge.
