In addition, the shuttle only carries two spacesuits, not enough for the entire crew. I seem to remember at the beginning of the program a “rescue bubble” the astronauts could zip themselves into with a small life support unit inside. The bubble then could be used for a crew transfer to a rescue craft. I don’t know if this was ever built of if it was just a proposal.
Maybe CNN was wrong, but it said ALL the astronaughts wore “pressure suits” and were required to wear them during launch and reentry in case of depressurization. Which indicates to me they could take a vaccuum.
Actually it doesn’t matter, since this is predicated on a rescue ship. Suits or survival bags could be hauled up later.
Look at it this way: The risk of death would proabably be much higher in a never-been-tried, hastily planned rescue mission that involved spacewalks by untrained personnel than it would be to let a shuttle land with minor damage to its protective tiles.
Assuming for a moment that NASA is telling the truth, any damage to the tiles must have seemed fairly minor. In fact, it may turn out that the tiles had nothing to do with the shuttle’s disintegration. Minor damage to tiles, I believe, is fairly common on shuttle flights. So why should NASA have thought it wise to launch a rescue mission?
Now, in a hypothetical situation where it was clear the shuttle could never land safely, then yes, I can imagine speeding up the next shuttle launch and trying a rescue. But I have no idea whether NASA has the capability of tracking and guiding two shuttles at once. That may be a very real technical limitation.
I do not believe that they knew that a problem existed. The supposition that the foam piece took out some tiles is, at this point, just supposition. The NASA people are saying that (a) you can’t see individual tiles from the ground, and, that (b) you can’t fix them even if you knew they were gone. They knew from the outset that too many damaged tiles would have the same effect as an Apollo/Gemini/Mercury capsule without a heat shield. You can’t have a backup heat shield.
If you don’t know what a problem is, then the rescue shuttle might have that problem too, hence no shuttle-based rescue.
I’m not trying to argue, or simply parrot the NASA line. The space program is based on risk. Where the risk line is drawn is a huge, political, financial, and engineering decision. You could have a safer orbiter, but have fewer of them for the cost. You can have an orbiter service station in the space station, if someone will pay for it.
Without knowing all the details, this is the one thing that I might fault NASA for.
I disagree with this. I believe that NASA has learned from Challenger. If they had moved up the next shuttle mission and turned it into a resue mission that the crew was not trained for that would put the rescue mission at risk. At this point it does not appear that the political implications will be a major issue. I have not heard a great political outcry about this. Yes, it is a tragedy, but most people (even politicians!) seem to see this as the regrettable accident that it was.
I think the main issue is money. NASA could have a special rescue team trained for these continencies, but they have budget constraints like any other business. They didn’t even have enough money to accelerate their safety upgrade program. I hope that the one positive that comes from the loss of Columbia and her crew is that NASA gets the budget that they need to make this type of accident that much more unlikely in the future.
Columbia was not equipped with the robot arm for this mission.
My point is that the second shuttled was/is. A second shuttle could carry needed spacesuits, as all astronauts are given more than one set. A second shuttle could have inspected Columbia.
**Clark K/b], why do you assume the damage to the tiles was “minor”? What data have you to conclude that? Isn’t it prudent not to make assumptions based on incomplete data? (Think telescope.) The “supposition” you allude to, re: the delaminating foam insulation, certainly was ( in NASA’s mind, as their top technical people have already admitted they worked through the numbers (and incomplete data) and concluded the orbiter could safely deorbit.
Miatachris, NASA’s top flight team has already admitted they knew a problem existed. They knew the foam insulation had struck the orbiter’s wing and, by their own account, apparently suspected that some tiles had been knocked off.
Why not at least try to telescopically inspect the orbiter, so as to assess the extent of the presumed damage? Can one reasonably conclude NASA had a sufficiently large sample size of similar accidents (re: foam/tiles) to make an intelligent decision re: damage in this particular case? Why not obtain data from other sources?
From television interviews, it seems NASA made its determination based on television images of the foam striking the wing section. If you’re going to rely on one set of long-distance photos to base your decision, why rule out another set?
As for using a ground-based telescope, have any of you ever seen telescope pictures of an orbiter? I have. Had NASA decided to go that route, they would have been able to determine whether a wing was missing, and that’s about it. Much easier to just phone up the astronauts and ask “Say, by the way, do you guys still have both wings attached? Yes? OK, good.”. This is not a case of them neglecting to get potentially useful information. This is a case of them not getting information which would be completely useless.
And by the way, for a few days last year, we did have two Shuttles up simultaneously. It did invite some comment, but it wasn’t considered out of the question.
From everything I hear, though, there were absolutely NO indications whatsoever that anything was/would go wrong. NASA said that the shuttle was “perfect” throughout the 16 days it was up there, and that there was no cause for concern up until the last couple of minutes before Columbia was lost. Even then, apparently, the loss of sensors and data up until communication was cut off, was NOT enough to concern them - the shuttle could have landed properly without that data being received, it was irrelevant, additional information that really could only be used in preparation for another shuttle flight. Also, apparently, the tile loss and foam falling wasn’t that uncommon an event, and it wasn’t a reason to be any more concerned than for any other “problem” that they had during all the other successful missions. As I said, Columbia was behaving perfectly up until the moment it exploded. Obviously something went wrong, and it may or may not have had anything to do with those tiles, but up until that moment, no one could have predicted the disaster.
At least thats what I understand of the situation, but I could be missing some details.
These links touch on the relevant issues and–to be completely impartial–discuss the technical difficulties.
Chronos, are you saying that you have seen telescopic photos of the orbiter–taken from the best telescopes available? I heard NASA’s top operations director yesterday say they have used a telescope on an earlier flight to visually inspect a blown-off PANEL on an orbiter. Please explain. (No chance a KH-11 could redirect its cameras? [Just a thought experiment, really.])
FROM 1997…
http://www-pao.ksc.nasa.gov/kscpao/status/stsstat/1997/dec/12-15-97.htm
NOTE: Shuttle Endeavour is mated to the external tank and solid rocket boosters (SRB) in Vehicle Assembly Building (VAB) high bay 1. The Shuttle interface test is in work through tomorrow afternoon. Tonight, technicians will begin sanding operations to remove a thin layer of the foam insulation on the STS-89 external tank, in a small area located near the SRB attach points.
While investigations into the cause of Columbia’s unusual tile damage continue, managers hope the additional work will reduce the possibility of external tank foam debris contributing to Shuttle tile damage. Sanding the foam will not compromise the tank’s thermal protection and does not violate any engineering or design parameters. Endeavour will roll out to the launch pad no earlier than Dec. 17.
http://ltp.arc.nasa.gov/space/chats/archive/katnik_chat2.html
This shows that refitting tiles while in space is near impossible. Someone suggested this in another thread…
How many hours does it take to put the tiles?
Sofia, sometimes it takes almost two weeks to install a tile because it must be manufactured, cut to the proper shape, test fitted, glued in place, an then tested.
How many people does it take to put the tiles on the space shuttle?
Sofia, quite a few. There are different people to make a tile, cut and check it, install it on the Orbiter, test it, and then still more different people who check the work again.
http://faculty.erau.edu/ericksol/projects/futurspcrft/Ismail/STS.html
The thermal protection materials must be maintained at optimum effectiveness because the integrity of the insulation is critical to the safety of the Orbiter. Because the Orbiter is exposed to extremely hazardous flight conditions, especially from debris during ascent and from micrometeoroids while in orbit, the tiles and insulation layers can be easily damaged. This means that each Orbiter requires critical evaluation of the condition of the entire surface insulation after each flight, primarily during the Orbiter’s stay in the OPF.(WWW-8)
Repair & replacement
HRSI (High Temperature Reusable Insulation) tile replacement operations entail exacting measurements and fitting (generally less than .005" on the edges with a 0.045" ± .020 gap between tiles) which takes approximately two weeks from removal to completed replacement.
I’m missing something here. How can a U.S. spy satellite image down to the size of a license plate, yet our best ground-based telescopes can only resolve to what you claim is the size of an orbiter wing?
Seems to me back in the early years (maybe even the very first flight) there was a released telescopic picture of the orbiter while in orbit. It really wasn’t that bad. IIRC, it was to see if, indeed, any tiles came off during launch, and no large patches were missing so all was declared good. The pic was televised, and while you could see some of what appeared to be atmospheric disturbance, it really wasn’t that “bad”.
I’ve spent the past while trying to find a copy of that pic online, but no luck so far.
http://antwrp.gsfc.nasa.gov/apod/ap011012.html
This was a pic taken with an 8" reflector. I have no doubts that bigger scopes could have done a lot better. Althogh, this looks great for an amateur (I’d be tickled pink if my 10" looks that good!). Surely, you could see a lot better detail then if a “wing” had fallen off.
I believe that’s wrong. Within an hour or two of the breakup, they were showing video of whatever it was that came loose during launch. And whatever it was, it was BIG.
This indicates a few things to me. Some people inside NASA knew there was a real potential problem there. There was a decision not to investigate further, not because they didn’t think it was a potential problem, but because they were helpless to fix it if it were. I hate to say this, but they were thinking of the hardware, not the people.
I could be wrong. Is there any defintive info available on how long the crew could have survived had they stayed in orbit and gone onto a mimimum consumtion mode.
BTW, a Soyuz launched TODAY to deliver supplies to the ISS. That Soyuz could have been launched to rendevous and provide supplies to the Shuttle.
The tiles are fitted to great tollerance, but It would seem safe to assume that:
1 - tiles fall off and that’s OK as the shuttle landed safely w/o them
2 - a patch job of fitting a too small tile into an empty space (missing tile space) up in space should be better then not having that tile.
The NASA people said that they did not think the foam separation was a problem, so they stopped because they can’t see well enough to do any good, and can’t go outside to do any good either. The first set of photos, don’t forget, was taken on ascent, not on orbit. I would like to see an image taken of a shuttle on orbit from the ground in which individual tiles could be discrimininated. I would think that their assertion that they couldn’t see tiles on orbit was experience rather than supposition talking. I think capability rather than will ruled out further photographic inspection.
http://satobs.org/telescope.html
For those curious, some telescopic views of the Shuttle and MIR. Quality varies greatly.
The links to the images thoughtfully provided by other dopers do not approach anything near individual tile discrimination. The clearest pictures taken from the ground show blurry outlines of what is clearly a shuttle orbiter.
I think it’s important to remember that the tile-killling foam is still a theory at this point.
tsunamisurfer, you and I both sound like space cadets and I’m glad that we can have a pleasant, meaningful discussion.
That foam breaks off all the time. On almost every flight. And it has struck the orbiter before. After the launch, the tape is always closely analyzed. They analyzed it, saw the foam break off, did an engineering analysis, and concluded that any damage done was minor.
And shuttles routinely lose tiles as well. One or two is typically not a big deal. You’d have to lose a bunch in the same area before you have a problem. But clearly, since tiles ARE lost, it’s always a remote possibility that you could lose enough of them to cause a problem.
But what are you going to to about it? The Columbia was flying spacehab, and therefore wasn’t carrying the Canadarm. There were no EVA suits, no repair kits, and the astronauts weren’t trained for repairs anyway.
A rescue flight? That’s a pipedream. There is no training for rescue, no space on a shuttle for the extra people, and the next shuttle wasn’t ready to fly for a month. You say it would be ‘easy’ to speed up that launch by two weeks. Do you have evidence for that, or are you guessing? My understanding is that prep for a shuttle launch is highly choreographed, and you can’t just eliminate half the steps left or speed them up by a factor of two. Maybe they could have shaved a few days offf the launch, but cut the prep time in half?
There are ALWAYS safety tradeoffs in engineering. ALWAYS. We could engineer cars to have half the safety rate they have today. We could build shuttles that are twice as big, with mini escape pods in each one. We could always prepare shuttle flights two at a time by building twice as many orbiters and two VFAB buildings, and twice the number of people. We could always keep one on the pad in case an in-space rescue is required. But that would double the cost of the program, for very marginal safety benefit (most accidents are going to happen on launch, and most of the ones that would happen on descent wouldn’t be knowable anyway).
It’s easy in hindsight to say, “Why didn’t they prepare for this problem?” Because in hindsight you are only dealing with the one problem. But there are MANY problems that can happen. Thousands. If you build in added safety around all of them, suddenly the whole program becomes impractical. Sure, we could build ejection seats or a a jettisonable crew compartment. Sure, there could be a second shuttle on the ready, or a crew escape vehicle as part of the shuttle. Sure, every shuttle could be sent up with six months’ worth of consumables so that they could stay in orbit for a rescue flight.
But we don’t, because you have to draw the line somewhere, and the decision was made that those things were impractical and cost too much for the minor added safety margins they provide.
True, but none of them were done with the the best available ground scope and little (if any) image processing. Most were done by scopes that amateurs own… 8" and thereabouts (yes, there were a couple exceptions).
This is all hindsight, of course. I am sure NASA did what it thought necessary at the time.
What I am getting at, is that if NASA (or other gvt agency) really wanted to, I strongly suspect they could image the Shuttle quite well. Maybe not down to inch resolution, but I’d suspect well enough to see if a “patch” of tiles were missing.
If there were any real doubt in the minds of resposible NASA people as to the safety of returning the shuttle, and] any real possibility of rescue, a rescue would have been undertaken.
Why not?
The rescue effort would have been carried out very much in the public eye, and with all possible caution. Whether a success or a failure, trying would have produced, at the least, a few more heros. And at best, live astronauts and one hell of a publicity coup for NASA.
Peace,
mangeorge
The flip side of that is they knew that a rescue was NOT possible, and chose not to look closer at the wing because it would have made no difference at all, it would either survive deorbit or not. And that (hypothetical) fact that they knew about it and could do nothing to help the crew would erode public confidence. Cynical, yes.
Going for an outside view would publicize the issue. Plausible deniability?
Geez, I sound like a conspiracy theorist.