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#60
by
daniela
on 04 Jan, 2010 16:02
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There is truth to the fact that Atlantis is the "least fit" of the orbiters, although many issues have been worked out and things don't look nearly as bad as they did some time ago. It is of course garbage to imply that Atlantis is not fit enough to fly the 135 mission. If you are into Wikipedia, you should edit that.
The STS-135 mission (and also possibly 136 and 137) are in limbo, they are not funded and it is not known to anyone if they will become real. The decision makers will certainly wait and see what will be of the STS program in the 2010 fiscal year. If the program goes smoothly and with no large slips (this is why it's important to assess docked operations etc.) then 135 has some good chance of flying. That it will be Atlantis to fly it, at present, is not as sure as it may seem, and it is total speculation to figure out if the extension - if any - will be one flight, two flight, three flights. Officially the "LON" for all missions will be funded, but even now, people dont really rely on that. What is clear is that the STS program will not be able to function for long on two orbiters, but, that is not going to happen anyway no matter what.
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#61
by
Alpha Control
on 04 Jan, 2010 16:24
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A wikipedia article on STS 135
http://en.wikipedia.org/wiki/STS-135
It mentions as a limitation that "Atlantis may also be considered the "least fit" of the orbiters, as it was discovered to have unrepairable tank issues and a host of other problems which caused extreme repair following its STS-125 flight"
Can some one comment on the correctness of this statement ? (No references are given in the article)
As the article says if Atlantis has some serious problems, then why would NASA use it to fly STS 135?
Well, if it were in that bad of shape it wouldn't have flown STS-129. I think that shows how reliable a source Wikipedia is......
Indeed. As several of the industry professionals here on NSF have said many times, Wikipedia is not reliable when it comes to space-related facts.
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#62
by
daniela
on 04 Jan, 2010 16:36
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Nor do the issues with Atlantis have anything to do with STS-125 or with the workflow that was done after that mission.
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#63
by
steveS
on 20 Jan, 2010 02:34
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When will a firm decision on STS-135 come out ? Assuming that NASA hopes to launch it in late 2010 or early 2011, will it have enough time?
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#64
by
daniela
on 20 Jan, 2010 11:30
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Yes, there will be enough time if they decide to; and this is most certainly the case for sts-135 as Atlantis is supposed to undergo nominal processing flow after sts-132 and be configured for logistic carrier. This is officially because of STS-335 LON. All this is already paid for. (But, there is no authorization at the moment to launch without a LON, and in addition there is no authorization at the moment to fly any sts mission without another shuttle standing by for LON).
It is true that the time for the two possible other extra flights (with completion of the ETs) is starting to run short, but even for them, there would be time. Except that the political will, which was low to begin with, is even less than it was, so, at this point their likelyhood is low, but not for technical reasons.
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#65
by
Lambda-4
on 20 Jan, 2010 12:04
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Yes, there will be enough time if they decide to; and this is most certainly the case for sts-135 as Atlantis is supposed to undergo nominal processing flow after sts-132 and be configured for logistic carrier. This is officially because of STS-335 LON. All this is already paid for. (But, there is no authorization at the moment to launch without a LON, and in addition there is no authorization at the moment to fly any sts mission without another shuttle standing by for LON).
There is even a risk to STS-135. The LON requirement can only go away if there is a viable alternative plan with a good paper trail for a Soyuz rescue in place. And while the Russians nod all the time and say they can do that, they aren't exactly keen on spending money on doing the required paperwork. Yes, Soyuz has been launched unmanned before and docked, but the last time I know of was Soyuz-20 (which docked to Salyut 4) back in 1976. Even at a low crew size of 5 (I doubt they go to 4) on STS-135, it would be critical to get the next Soyuz up quickly and unmanned, dock it and get the STS-135 crewmembers back (first 2 crew members from STS-135 get back on one of the already docked Soyuz).
So at the end it all boils down to how cooperative the Russians are, not so much on what NASA does.
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#66
by
daniela
on 20 Jan, 2010 12:25
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I would not say there is a "risk" to sts-135 as it was never really a done deal at any point, I agree with you its likelyhood is low. The Russians nod but are unlikely to certify (and they have a point: is the Shuttle certified for a LON, after all? Did it ever successfully demonstrate such capability? And should this certification be done for increasing confidence in a single emergency rescue which would address very few of the possible failure modes, namely a MMOD or spacejunk that strikes the TPS so badly that it can not be reliably repaired.... The capability won't be useful again in the rest of life of ISS, and to say it all, in the rest of life of the Soyuz program.)
It is also not very likely that they send up an unmanned Soyuz if there is no immediate urgency.... more likely they send one crewmember on the next Soyuz which was supposed to do crew rotation and another one on the following.
I am confident it is possible to fly the orbiter with 4 crew, adding time for undocked operations, but I am not sure what would be more advisable. Already 5 people is a "skeleton" crew for the ISS missions + undocked ops.
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#67
by
Colds7ream
on 20 Jan, 2010 12:43
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Indeed. As several of the industry professionals here on NSF have said many times, Wikipedia is not reliable when it comes to space-related facts.
Look, we're doing our best, OK? For instance, I just completed a THREE YEAR stint of work to get the International Space Station article up to featured article status. We don't get paid for this, you know. In reality, the STS-135 article shouldn't really exist as it has hardly any citations, but we kept it due to the likelihood at the time of the mission going ahead. Of course, given that Wikipedia is the encyclopedia that anyone can edit, feel free to correct it; as we're reminded many times in
The Wikipedia Revolution: How We Are Editing Reality, if you see something on an article that's wrong and you leave it, its officially your fault that its there.
Please stop bashing us; we're working on this on a voluntary basis.
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#68
by
psloss
on 20 Jan, 2010 13:32
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Look, we're doing our best, OK? For instance, I just completed a THREE YEAR stint of work to get the International Space Station article up to featured article status. We don't get paid for this, you know. In reality, the STS-135 article shouldn't really exist as it has hardly any citations, but we kept it due to the likelihood at the time of the mission going ahead.
Fair enough.
In my opinion, the issue is not with the source (Wikipedia), but the consumers of the source. It's just the same old problem of "I read it on [source], so it must be true." Same could be said for other media like the New York Times, Washington Times, ABC News, CNN, Fox News, etc.
Of course, given that Wikipedia is the encyclopedia that anyone can edit, feel free to correct it; as we're reminded many times in The Wikipedia Revolution: How We Are Editing Reality, if you see something on an article that's wrong and you leave it, its officially your fault that its there.
Ouch. If the implication is that I'm
obligated to fix any errors on a site, that's just incentive for me to stop visiting there. But I don't agree that I am.
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#69
by
Analyst
on 20 Jan, 2010 13:54
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Drop the LON "requirement" for the last Shuttle mission and you are done. Should the orbiter be unable to return - the probability being pretty much zero anyway - this can (and will) be handled. No partner - not the Russians or others - will refuse to help in this highly unlikely szenario. Asking them to plan for this in advance (and invest real own money) is a lot to ask for.
Or more simply: Stop being extremely risk averse and you can achieve much more. (This being true for CxP as well).
Analyst
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#70
by
Lambda-4
on 21 Jan, 2010 15:23
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I would not say there is a "risk" to sts-135 as it was never really a done deal at any point, I agree with you its likelyhood is low. The Russians nod but are unlikely to certify (and they have a point: is the Shuttle certified for a LON, after all? Did it ever successfully demonstrate such capability? And should this certification be done for increasing confidence in a single emergency rescue which would address very few of the possible failure modes, namely a MMOD or spacejunk that strikes the TPS so badly that it can not be reliably repaired.... The capability won't be useful again in the rest of life of ISS, and to say it all, in the rest of life of the Soyuz program.)
It is also not very likely that they send up an unmanned Soyuz if there is no immediate urgency.... more likely they send one crewmember on the next Soyuz which was supposed to do crew rotation and another one on the following.
I am confident it is possible to fly the orbiter with 4 crew, adding time for undocked operations, but I am not sure what would be more advisable. Already 5 people is a "skeleton" crew for the ISS missions + undocked ops.
The problem is, you need the paper trail for a viable emergency scenario to fly STS-135 without a LON, as said above. The reason I was talking about an uncrewed Soyuz flight is as follows: once a no-return for the Shuttle is issued for STS-135, you lose your lifeboat on the ISS too, because there will be more people on the ISS than Soyuz seats. And you can't launch a new Soyuz earlier than currently planned. That means a Soyuz launch every 3 months. The Shuttle cannot stay at the ISS for that long. It would be undocked. In case of an emergency on the ISS, you are now several Soyuz seats short, also putting the Russian crew members at risk, as more people will be trying to get to the 2 Soyuz spacecrafts than can actually get in there.
A possible emergency rescue scenario with Soyuz that eliminates the lifeboat risk is as follows:
a. Crew of 4 on STS-135
b. Crew on ISS before STS-135, only 5 (one US slot not taken but paid for)
c. One Soyuz ready to be launched unmanned within 2 weeks from STS-135 launch
This would result in no lifeboat seat short-comings, however has the disadvantage of a temporarily cut-down of the permanent crew size to 5 (although we just did that without a real reason), requires the Russians to come up with a sufficient paper trail to emulate Soyuz-20, requires the minimum crew size for docking on the last Shuttle flight and schedule coordination of STS-135 with Soyuz.
The efforts required may just be higher than the benefits if you look at it from a STS program management perspective.
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#71
by
Analyst
on 21 Jan, 2010 16:18
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Why do we plan for multiple worst case failures at the same time? E.g. when your launch vehicle fails, your have a LAS. But if the LAS fails, you don't have a second one.
Here we go to extremes to achieve this: When Shuttle is damaged, you have ISS save heaven for a very long time. You don't plan for ISS evacuation given the Shuttle is damaged. These two together won't happen with any meaningful probability.
Analyst
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#72
by
daniela
on 21 Jan, 2010 16:25
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The efforts required may just be higher than the benefits if you look at it from a STS program management perspective.
Right, and this is why the possibility is losing favor even if the funding for the flight would mostly be there.
If there is a contingency of the Shuttle, full evacuation capability is lost. This in all scenarios, including the Shuttle rescue. Either a or b would be implemented certainly on sts-135 but that would not eliminate the loss of emergency seats; there would be ten astronauts on the ISS and two Soyuzes for a total of six seats. The two Soyuzes currently planned at April and June would fly (basically on the same date, as it's not possible to speed them up very much) with only one cosmonaut and so the full lifeboat capability would be restored. Probably one of the Soyuz that are supposed to stay docked would fly back, cutting short the expedition of three crewmembers, in order to reduce wear on the ISS that with 10 people and no orbiter would be put to the test (and with no emergency capability). The Orbiter would be jettisoned just a little bit later than at end of nominal mission (especially if it were Atlantis that has no power transfer system)
Unmanned Soyuz would be sent up only in very exceptional cases, as it does not make much of a difference. There is no way to fit 4 people on a Soyuz for landing.
I agree with Analyst on his previous post and the one he wrote while I was typing this, but, someone among the decisionmakers at NASA must say so (do i remember right that even the Congress was involved in the requirement of a LON for every shuttle flight and must waive?)
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#73
by
psloss
on 21 Jan, 2010 16:57
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The efforts required may just be higher than the benefits if you look at it from a STS program management perspective.
Right, and this is why the possibility is losing favor even if the funding for the flight would mostly be there.
What is your source for this (losing favor)?
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#74
by
Lambda-4
on 21 Jan, 2010 19:12
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Why do we plan for multiple worst case failures at the same time? E.g. when your launch vehicle fails, your have a LAS. But if the LAS fails, you don't have a second one.
Here we go to extremes to achieve this: When Shuttle is damaged, you have ISS save heaven for a very long time. You don't plan for ISS evacuation given the Shuttle is damaged. These two together won't happen with any meaningful probability.
Analyst
We plan for ISS evacuation in an emergency situation right now, for every single day. Changing that is a fundamental shift in policy, no matter how slim the chances are that the ISS has to be evacuated at any given point. The lesson from Mir is that you don't want to give up your lifeboat safety option - ever.
Your argument basically goes to the question of why we have LON at all. If we were less risk averse, we could just fly without the LON requirement and put a generic "Soyuz-rescue" back up in place which abandons the principle of Soyuz-lifeboat at all time. NASA doesn't want that and from a program management view I sympathize with them.
We can start to be less risk averse when we don't have any other choice. But with the ISS and the Shuttle LON requirement we don't need to, LON provides for a good rescue scenario. Soyuz not so much.
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#75
by
Analyst
on 21 Jan, 2010 19:26
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I disagree. We "need to" if we want to use all the assets (ET-122) we have. You are planning for multiple failures occuring at once. Which is costly, and therefore seldom done.
It being done here is the reason why many worthy things are not done, including one single flight without LON after more than 100 of these were flown in over two decades. The last percentage digit of safety always is the most expensive. This is were risk aversion turns into waste. Same for CxP Orion/Ares I.
Analyst
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#76
by
Lambda-4
on 21 Jan, 2010 19:44
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I disagree. We "need to" if we want to use all the assets (ET-122) we have. You are planning for multiple failures occuring at once. Which is costly, and therefore seldom done.
It being done here is the reason why many worthy things are not done, including one single flight without LON after more than 100 of these were flown in over two decades. The last percentage digit of safety always is the most expensive. This is were risk aversion turns into waste. Same for CxP Orion/Ares I.
Analyst
I disagree with the notion we can just fly one single last flight without LON. NASA has decided to implement the LON requirement for good reason and shouldn't abandon it without good reason. Bringing some upmass to the ISS with STS-135 isn't a good reason enough.
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#77
by
jacqmans
on 21 Jan, 2010 19:50
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Soyuz has been launched unmanned before and docked, but the last time I know of was Soyuz-20 (which docked to Salyut 4) back in 1976.
The last Unmanned Soyuz mission was Soyuz TM-1 (May 23-29, 1986)....Mission to MIR.
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#78
by
psloss
on 21 Jan, 2010 20:06
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I disagree with the notion we can just fly one single last flight without LON. NASA has decided to implement the LON requirement for good reason and shouldn't abandon it without good reason. Bringing some upmass to the ISS with STS-135 isn't a good reason enough.
Guess we'll have to agree to disagree, then. The requirement isn't launch-on-need, it's safe return of the crew. The purpose of Shuttle LON is safe return of a crew stranded on the station in the event the previous Shuttle orbiter is judged unsafe for entry. Flying a smaller Shuttle crew and altering Soyuz crew rotation sizes can provide the same safe return capability, so that part of the "trade space" is a wash.
The trade isn't safe crew return vs. station logistics, it's other things, which may or may not be purely fiscal or logical.
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#79
by
steveS
on 28 Jan, 2010 11:52
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When will we know for sure whether STS-135 will fly or STS-133 will be the last shuttle flight? When will NASA officially announce ?