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STS-125: NASA updates debris risks for Atlantis' mission to Hubble
by
Chris Bergin
on 15 Apr, 2009 11:21
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#1
by
shuttlefan
on 15 Apr, 2009 13:36
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So would a waiver then be required to accept this debris threat, being it falls out of the guidlines?
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#2
by
rfoshaug
on 15 Apr, 2009 14:26
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Great article!
However, I have one question:
"On the other hand, the MMOD LOCV ratio for the STS-400 rescue flight is 1 in 294 - with late-inspection of the Wing Leading Edge (WLE) panels and Nose Cap on FD-5 and a short mission duration of seven days driving the calculations.
If the STS-400 crew does not perform any TPS inspection, the LOCV ratio rises to 1 in 217."
Is this due to STS-400's ability to repair damages using and astronaut at the end of the RMS arm?
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#3
by
KEdward5
on 15 Apr, 2009 16:30
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Great work explaining that complicated presentation Chris G!
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#4
by
JSC Phil
on 15 Apr, 2009 23:00
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Very good work with the article Chris G.
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#5
by
ChrisGebhardt
on 15 Apr, 2009 23:11
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Great article!
However, I have one question:
"On the other hand, the MMOD LOCV ratio for the STS-400 rescue flight is 1 in 294 - with late-inspection of the Wing Leading Edge (WLE) panels and Nose Cap on FD-5 and a short mission duration of seven days driving the calculations.
If the STS-400 crew does not perform any TPS inspection, the LOCV ratio rises to 1 in 217."
Is this due to STS-400's ability to repair damages using and astronaut at the end of the RMS arm?
Not really. It's mainly because of the short mission duration and the ability to detect damage. Note that the article also mentions that if a day or two of the STS-125 mission were cut from the flight, the risk ratio would decrease simply because of the shorter mission.
The STS-400 crew will have the same repair options available to them as the STS-125 crew will have.
And the thanks for all the kind words everyone.
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#6
by
Stowbridge
on 17 Apr, 2009 04:17
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It's comical how the media works sometimes.
Presentation from which the above article is based on is published on L2 last Thursday.
Chris writes it up into an article nearly a week later on Wednesday.
The next day another site runs with a short story on the subject, saying "NASA officials said Thursday".
That means they saw the article, thought they better do something too, ask a NASA guy, run a story as if NASA just revealed it.
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#7
by
MKremer
on 17 Apr, 2009 05:52
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The next day another site runs with a short story on the subject, saying "NASA officials said Thursday".
That means they saw the article, thought they better do something too, ask a NASA guy, run a story as if NASA just revealed it.
Eh, it's mainly because we're spoiled here with the amount of immediate internal info available. Can't help it if just about everyone else plays catch-up (and some might do some spin in their favor depending on their sources).
The only contact most sites have for the latest NASA and Shuttle info (including most traditional media publications) is via each Center's Public Affairs Officers. Even Bill Hardwood almost always writes his articles based on the 'official word' (however he knows the correct questions to ask) and only fills in with other sources if absolutely needed.
Not that this site would, but it would be like Chris was collecting info to write a front page article about the latest updates available for the Mars Rovers, but there were no 'insider' documents or contacts available. I've no doubt the JPL PAO he talks to would try to be as helpful as possible, but the info given would still be dated and filtered through them and then out to the public reading the article.
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#8
by
Analyst
on 17 Apr, 2009 07:22
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Back to topic. I know criticizing an analysis done by NASA - in particular SSP risk related stuff - is not well recieved here.
Anyway. With this high MMOD LOCV risk for a 10 day mission, wouldn't the probability of HST itself suffering a MMOD LOV event be in the same ballpark? Let us say it is 1:500. HST is smaller, but it can not adjust its orbit. Not all Shuttle surfaces are critical, just like not every HST surface. HST has no late inspections. No crew which can repair a hole or a critical components. There are many other differences, working into both directions. But this is only a back of the envelope calculation.
HST is in this orbit ~7,000 days, 700 times as long as STS-125 will. This gives a very high probability of getting a fatal hit in 19 years: More than 100%. (You can adjust the parameters: Go from 1:500 to 1:1,000 or say there is more debris in recent years or ... You will still end up with two digit percent numbers.) Only it has not happened: HST has not suffered a fatal hit. Can be luck, sure. Can be the analysis or its assumtions.
Analyst
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#9
by
David Bang
on 19 Apr, 2009 10:59
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What do the Space Shuttle (STS) contingency plans call for in respects as the ability to continue the completion of scheduled and not currently scheduled shuttle missions in the event of a possible failure to a shuttle such as a detrimental MMOD strike? This of course implies the safe and smooth return of all crew members. Hopefully not another two to three year hiatus of activity in the program.
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#10
by
psloss
on 19 Apr, 2009 11:14
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What do the Space Shuttle (STS) contingency plans call for in respects as the ability to continue the completion of scheduled and not currently scheduled shuttle missions in the event of a possible failure to a shuttle such as a detrimental MMOD strike? This of course implies the safe and smooth return of all crew members. Hopefully not another two to three year hiatus of activity in the program.
Politically, any loss-of-vehicle at this stage in the program history would likely end shuttle flights.
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#11
by
cb6785
on 19 Apr, 2009 11:37
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Another interesting question/scenario: What would happen in a LON situation where the damaged orbiter would be able to land successfully via remote controle? Repair and continue to fly? Standing down and replanning the remaining manifest? End of program?
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#12
by
charlieb
on 19 Apr, 2009 11:48
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Another interesting question/scenario: What would happen in a LON situation where the damaged orbiter would be able to land successfully via remote controle? Repair and continue to fly? Standing down and replanning the remaining manifest? End of program?
If an orbiter were able to land - successfully - via remote control in an LON situation, it wasn't too damaged to begin with. Good subject for a fiction novel.
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#13
by
cb6785
on 19 Apr, 2009 12:18
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Another interesting question/scenario: What would happen in a LON situation where the damaged orbiter would be able to land successfully via remote controle? Repair and continue to fly? Standing down and replanning the remaining manifest? End of program?
If an orbiter were able to land - successfully - via remote control in an LON situation, it wasn't too damaged to begin with. Good subject for a fiction novel.
Actually it would be the most likely outcome of a LON situation IMO. Before they got the OBSS and RPM quiet some orbiters landed sucessfully with bigger heatshield damage. Just nobody knew about it before they landed. Today nobody would risk the crew in such a situation but I'm pretty sure in most cases the orbiter would come down in one piece.
