In real life, we’re talking about a handful of loose or missing tiles that are so small each one wouldn’t even resolve as a pixel under the best of circumstances.
Regarding the possibility of photographing the damage, as has been mentioned elsewhere, we have other assets that could possibly have been employed, from the ISS to spy satellites.
I don’t know enough about their capabilities to state this definitively, though.
More convincing to me, however, is that NASA thought enough of the idea of ground-based photography to have tried it in the past. So it couldn’t have been that bad of an idea, and may not have deserved to be dismissed out of hand. It’s my understanding that photographic quality in the past varied greatly, and was utimately deemed not useful. Who knows what would have happened in this instance if they had tried?
Keep in mind, too, that the telescopes employed on spy satellites observing the ground are far smaller than telescopes on the ground looking up.
That’s the rub, isn’t it? Some people invariably pop up in these threads to claim that spy satellites and telescopes and the like should be able to resolve, for instance, the American flag on the moon. And no matter how many times the people with real facts and data show up to demonstrate that no, you can’t get anywhere near that kind of resolution, people still chime in thinking such feats are possible.
If you wish to persist in this line of reasoning, perhaps you should first come up with the proof that it was technologically possible to inspect the shuttle for a handful of missing tiles, whether from the ground or from space? 'Cause every credible bit of evidence that has been produced tends to demonstrate exactly the opposite.
There’s a big difference between resolving an image in low Earth orbit (several hundred miles up), and resolving an image on the Moon (~250,000 miles away).
I don’t know that it was technically possible, and I’m not trying to prove anything. All I’ve asked was: for what reason was an attempt not made to photograph the orbiter from the ground or another space-based asset? Again, NASA thought it was a good enough idea to try in the past–why not in this case? Was it because it was indeed “not feasible,” or was it because they decided there was nothing they could do about it (should they find anything) anyway?
And minty, I’m well aware of the limitations of spy satellites and/or the ISS photographing the ground. Do these limitations extend to photographing an object in a lower orbit?
Secondly, can the limitations of a small space-based telescope photographing the ground be extended to assuming that a much larger ground-based telescope cannot get a useful image of an object in LEO? And please don’t start talking about photographing an object on the Moon. :rolleyes:
I’m more interested in why NASA, having seen the need to visually inspect the shuttle in past missions, failed to ever address the inspection issue, as I stated in this thread (which kind of got off topic from my rant of NASA Administrator O’Keefe spinning his interview on Sunday):
I said: “Actually, my larger question was why every mission was not provided with a safe means of inspecting the craft. I understand that, once up, this mission had few options.”
Two days before the Columbia disaster, a NASA engineering team sent an internal memo calculating a high probability that launch debris had caused a gash 7½ by 30 inches on the shuttle’s left wing, NBC’s Jay Barbree reported Monday. NASA engineers have talked of a heat spike and drag on the left wing, suggesting a potential problem with the thermal tiles there.
FROM NBC…
"Keyhole-class satellites are reputed to be able to see objects as small as 4 inches at a distance of 180 miles, Molczan said, and at a range of 70 miles, resolution would improve to about 1.5 inches.
But Molczan warned that the satellite’s angular velocity — the rate at which it turns to maintain a path along its orbit — might have blurred the image. He also questioned whether the contrast between the shuttle tiles and the surface to which they are bonded would have hindered image quality.
“If ... image quality was likely to have been poor, then I suppose it made sense not to request them,” Molczan noted. “On the other hand, it might be argued that if a sufficiently large defect existed on the shuttle, even a low-res image might have been worthwhile, if only to aid in diagnosis.”
Moreover, space historian William E. Burrows, in his book “Deep Black” reported that two ground imagery stations — “Teal Amber” in Malabar, Fla., and “Teal Blue” atop Mt. Haleakala in Hawaii — did take snapshots of the Columbia on that first mission. The cameras have long imaged satellites and orbital debris using sophisticated laser and electro-optical devices.
“Teal Amber and Teal Blue are so good they were used to scan the Columbia on her maiden flight in April 1981 in an effort to determine the extent of tile damage,” Burrows said.
I’ve had the opportunity to work with the people developing such systems, but as with anything, it’s just a matter of time and money. I’m not sure if I’m at liberty to talk about exactly how they work, but rest assured they are in development.
Ah, the joys of second guessing technical decisions after the fact with no technical training, no insight to what was done, no information about the process that was used, and no understanding of the concepts involved.
tsunamisurfer asked:
Based upon my insight into the shuttle preparation process for flight, I’ll take a stab at an answer.
First, you kick off the crew except commander and pilot, to make room to return the other crew. You can squeeze another 7 in. You probably don’t want to unload much of the payload. Here’s why. Shuttle flight planning requires a complex calculation of the weight and balance of the orbiter and payload. Sometimes ballast is placed to keep the center of gravity (cg) in the optimal position. Orbital flight path calculations, launch windows, etc all require a solid understanding of the weight and cg calculations. I’m not certain how much effort it would take to recalculate all this. Also, it would take more time to unload large payload elements. You’re probably wanting to push as quickly as possible to the PAD for launch. There would have to be some serious number crunching. If the orbiter is essentially ready for rollout to the PAD, better not to change anything, except of course the minimal amount to fit the new parameters.
What about fuel for the correct orbital path? Probably okay, but check. Since the next mission was ISS visit, it’s at a higher inclination, which takes more fuel to reach, so that’s in your favor.
With everyone working full steam, and given that the status was pretty close to launch ready, it is in the realm of possibility they could have crunched all the numbers, gotten to the PAD, and moved up the launch for a rescue. Could they have done it in a week? Hard for me to say. Two weeks would be a more reasonable guess for pushing the limits and rushing. Again, this is heavy speculation on my part.
This is difficult for laypeople to understand, but NASA operates under a principle of mitigated risk. You look closely at the risks and the ways of eliminating or reducing the risks. Some can be designed out. Others would either be too expensive or just plain impossible. (Example: you’re riding a rocket. You can’t remove the risk of riding a rocket and still get to space.) So there are evaluations of the likelihood of different problems occurring, then compare the likelihood and the resolution methods and come up with a balance between totally safe (i.e. safer than staying in bed all day) and breaking the bank (i.e. tripling the federal budget purely for NASA).
Once on orbit, there’s only one way home - back through the atmosphere. What could have been done differently? Emergency return capsules? A rescue vehicle on standby all the time? These types of solutions would require substantially more funding, and what is the amount of safety that you’re adding? Just how likely is the need to use them? NASA chose to make the system as robust as possible, to build in the best protection they could, and then accept some amount of risk that if damage occurred, there aren’t a lot of options. They did try to build a tile repair kit, but it didn’t really work, and the risk of creating more damage during the fix made that a simple decision.
What about docking with another shuttle? Well, that assumes you can get another shuttle up there. Logistics make that impractical. One could complain about how the Shuttle never lived up to the original promise of speed of turnaround, about the shortsitedness of the politicians pulling the purse strings, but what would be the point? Given the hardware system we have, processing logistics just doesn’t make it smart to keep a shuttle perpetually on standby whenever there’s a shuttle up.
In fact, though, that was part of ISS consideration. Since the shuttle can’t be ready for quick response, they incorporated plans for an emergency crew return vehicle into the ISS plan. Currently that role is fulfilled by the Soyuz craft. At one time there were plans for a stand alone, full time on station, 7 person capable return craft, but that got hammered by budget problems.
Assuming you had a second shuttle available, it wouldn’t be a problem to rendezvous. That now happens regularly with ISS. Flying two shuttles at once? I think at one time that was an issue, but when ISS came along they upgraded the systems so it is a possibility. How about the actual method of transfer? Columbia didn’t have the robotic arm, but the rescue vehicle could. If there’s a grapple fixture somewhere in the payload bay, you can grab ahold. The transfer itself would be more problematic. Can they get out the hatch with Spacehab installed? I don’t remember. I think so - there are contingency EVAs to close the payload bay doors, fasten latches, reel in the S-band antenna if it jams, etc. They want to keep those as possibilities, so I think there’s a way.
I would imagine the scenario would be to have someone drag a couple of space suits over from the rescue vehicle, and then ferry the people across, reusing the suits. You do have sizing problems, but for emergency use I would think if you can squeeze into the suit, you could be dragged by the other person. They would want to develop some procedure, involving use of safety tethers and maybe the RMS rope reel to create a temporary handrail between the two. The RMS is pretty difficult to hold onto and crawl along, so you wouldn’t really be able to use it to crawl back and forth, but with the two bays facing each other and a relatively small gap between them, it shouldn’t be too difficult to run the rope from one to the other, tied off to handrails on the forward bulkheads of each, and pull along the rope to cross across.
There’s the rub – NASA has thought in the past that ground-based photography might be useful. So they tried it in the past, and discovered that it delivers no useful data on the scale required. The very fact that they’ve used it before is why they didn’t use it this time – they had a firsthand understanding of the capabilities of ground-based telescopic photography, and it’s simply not good enough.
Suppose NASA figured out that there was a fatal problem while the shuttle was in orbit? Suppose that NASA also knew there was nothing they could do to rescue the astronauts? What good would it do to tell them? The possiblity of losing a crew on re-entry has come up before on John Glenn’s Mercury flight and on Apollo 13. In both cases NASA elected not to tell the astronauts about it.
I would hope there are ways to reduce risk and improve capability on the next generation of space vehicle. But I don’t think we can make the major types of changes being suggested for shuttle and still have a vehicle with any capability, and the costs would skyrocket.
And actually, the shuttles are pretty safe. Sounds odd in the face of a disaster, but it’s true.
k2dave, I don’t think the Soyuz has enough fuel to go from the ISS orbit to the orbit Columbia was in. And if it did, there’s no way to dock. And there were only two space suits. And the Soyuz can only carry 3 people. If you managed to get there once, ferrying back and forth would definitely be out from fuel standpoint.
tsunamisurfer said:
Past flight experience has shown that the data wouldn’t have been useful. The picture resolution just wouldn’t have been able to pick up the individual tiles. And even if a swath were damaged, it wouldn’t show how badly - how deep. Plus, debris has fallen off and hit the shuttle tiles before. Experience and calculations and evaluation by the best technical experts said the damage should be minimal. Were they concerned? Certainly. Safety is a big deal at NASA. You may not believe it, but I’ve been there, I can tell you from inside the amount of scrutiny that goes into safety. If they felt there was something to be concerned about and that the pictures would have been helpful, they would have used them. In fact, they have used them before - and that is why they didn’t think they would be useful this time. Experience and knowing the resolution wasn’t fine enough to give any more information.
And just what are your qualifications to state that? It’s very easy to second guess their decisions now, when you don’t know who was involved, and what they actually did do, and why and how they reached the decision they did. You assert that they might have obtained useful information from telescopes. Justify that. Show some telescopes that have high enough resolution to be useful.
An EVA would be dangerous as you state, and would likely (not possibly, but likely) cause more damage to the tiles. So what if you have a marginal case and you go to look and thereby cause enough damage that now you know you can’t come home. That’s smart.
The point is the experts looked at what they could see on launch, evaluated the numbers, considered the past experience with similar situations, considered what options they had to deal with it, and decided it was okay.
And I’m sure the investigation team will be heavily scrutizing that process, to determine if that played a role, if there was anything that should/could have been done differently, and if there was anyway they should have known differently. Let’s let them evaluate the actual evidence instead of speculating wildly.
Why is your immediate assumption that they didn’t have that information? Why is it your immediate assumption that they didn’t consult other sources? So they didn’t use telescopes to view the damage directly. Is that the only way you can think to evaluate what happened?
There’s a vast difference between long range ground viewing during take off, and trying to view on orbit.
Icerigger, that bubble thing was probably just a concept, because I’ve never heard of it. And I’ve looked through the EVA Tool Catalog, the list of all EVA tools ever flown by NASA.
yojimboguy said:
And whatever it was… Do you know what it was? The insulation from the bipod (liquid fuel lines from ET to orbiter) separated, bounced off the bottom, and then was burned up by the exhaust. The big flash you see by the wing is the insulation being vaporized. That’s why it looks so big.
Your conspiracy-mongering conclusion-jumping skills are finely honed, now how about your patience, reasonableness, and sense? You have no insight into what they were thinking, and to make that statement is pathetic.
Water’s no problem. They could have stretched their food a few days, and starvation is long anyway. But oxygen and carbon dioxide scrubbing would be the limiting factors. I don’t know what their starting resources were, but there’s typically a couple days contingency supplies beyond the nominal timeline, so I’m guessing maybe they could stretch an extra week.
Perhaps it could have been reoutfitted and launched to reach Columbia. But there’s no way to have docked with Columbia, and no RMS to capture the Progress Module (it was a Progress resupply module, not a Soyuz). I’m pretty sure they could get two crew members EVA, and then attempt capture by hand. I don’t know if they could get it opened.
k2dave said:
1 is yes, but 2 is more troublesome. Yes, filling a hole with gaps around it is better than not filling the hole at all. But the bigger problem is attaching the tiles, getting them to stick. The tile repair kit that was tested was, IIRC, some epoxy type resin that would be spread over nicks in the tile. There was a lot of question that the epoxy would be abraded during reentry and come off.
Dragonblink said:
The launch/reentry suits are the orange suits. They are not space suits. They are like aircraft pressure suits. The radiation risk is minimal, and in an extreme contingency not an issue. Thermally, they would be exposed for too short a time (crawling between two vehicles) to worry about. Micrometeoroid risk is small for such a short exposure. But they aren’t built for space vacuum. I don’t think they’d work.
About telescopes: aperature (diameter) is not magnification/resolution. Aperature is light gathering ability. Magnification occurs in the optics - the grind of the mirror, the lenses attached. Also, atmosphere is inherently blurring of the image, caused by pockets of various temperatures, air currents, etc. Astronomers term this seeing. Only recently have some large telescopes been built with adaptive optics that can adjust to work around bad seeing.
tsunamisurfer, you still haven’t proven that any of the ground based telescopes could have seen anything. That “Teal Amber” and “Teal Blue” were used to view the orbiter before does not prove that the images were useful.
[QUOTE]
*Originally posted by Irishman *
Ah, the joys of second guessing technical decisions after the fact with no technical training, no insight to what was done, no information about the process that was used, and no understanding of the concepts involved.
Based upon my insight into the shuttle preparation process for flight, I’ll take a stab at an answer.
[snip]
Again, this is heavy speculation on my part.
[snip]
Once on orbit, there’s only one way home - back through the atmosphere. What could have been done differently? Emergency return capsules? What about docking with another shuttle? Well, that assumes you can get another shuttle up there. Logistics make that impractical.
Irishman, you are writing when you should be reading. Check the previous 50 posts. Check the scheduled March 1 liftoff of the next shuttle.
Have you read that there was considerable dissent within NASA about the extent of the damage?
Can anyone here prove the telescopes cited above could NOT resolve the damage? What is the downside of doing so?
I would imagine the scenario would be to have someone drag a couple of space suits over from the rescue vehicle, and then ferry the people across, reusing the suits. You do have sizing problems.
It does’t say if Columbia could have been made to be able to dock one way or another though (even with a light load), but it gives me the impression that it couldn’t.
WHERE TSUNAMISURFER PLAYS THE HEALER…
In the final analysis, we all are grieving over the tragic deaths of the Columbia 7 and perhaps I am grasping at straws. What I do know, if I were mission director and one of you adversarial SOBs (just kidding) were on the orbiter, I would exhaust every damn option conceivable to save lives–including asking DoD to train their latest optics, even if a desperation stab, to detect tile damage–and then consider sending up the next shuttle ASAP.
The problem, of course, with the “abandon Columbia for a rescue shuttle because of the significant tile damage” is later convincing the American public that it was necessary to jettison Columbia into the Pacific–all $2.1 billion of her–over the possibility she couldn’t make it home safely. The uproar would be deafening.
That said, I think we’re going to learn some mighty interesting details in months to come–details NASA officials have as yet not been forthcoming in disclosing.
I don’t know much about telescoping imaging, so I’m not even going to touch that. But with regards to launching a rescue mission: IANAA, but I don’t think that you can just push a launch forward like that. Parly due to the logistics that Irishman outlined, but another huge factor is weather. Wind and/or rain and/or low visibility = no launch; as I understand it, that’s one of those things that’s simply not negotiable. Additionally, launch windows. There must be certain conditions at at least some of the abort sites, and rendezvous missions always have very small windows, because you’re trying to get two very fast-moving objects very close to each other.
With regards to docking with the ISS, I don’t know if that would have been possible, nor if the life-support systems (temp systems, air filtration, etc) of the ISS could suddenly support 7 extra bodies, regardless of whether or not the Columbia could have even gotten there.
Remember, there are certain parts of the launch process that simply cannot be sped up, no matter how much money or effort you throw at them. It will take almost a day just to get the shuttle situated on the crawler and ready for transport. The crawler will take half a day just to get the shuttle from the VAB to the launch pad. It will take a solid day just to fill the external tank with the necessary LOX and LH. And this is all assuming that the fuel is already on-hand and all the equipment is basically RTF. Just focusing on a very narrow part of the entire shuttle rollout process, it becomes obvious how hard it would be to push up a launch that much, even working around the clock.
Anyway, I think Irishman already covered this topic the best. The answer, IMO, is a definitive NO. They might be able to bump it up a few days, a week at most with favorable conditions, but to cut it from four weeks to one? Impossible. Period.
The answer to both questions is about a week according to this article from the Globe and Mail matt_mcl posted earlier:
But then, with the data they had they thought they were ok, they weren’t gonna send up another shuttle just in case. So the send up another shuttle argument only works if NASA knew the shuttle had lost too many tiles to survive re-entry.
Unfortunately they didn’t know how much damage had been done to the tiles so they didn’t know whether it was worth sending up another shuttle. Exactly how much tile damage does there have to be to justify an unprecedented, dangerous, ad hoc 2nd shuttle rescue mission?
Presumably the boffins at NASA have a pretty good idea how much tile damage will cause irretrievable break-up. But how could they know that the tile damage had passed critical point?
However, I still think it was worth photographing. Not from Earth but from spy satellites and the ISS. According to the thread Minty Green linked to earlier, spy satellites are pretty good these days (maybe 10 cm square to a pixel) and thats photographing the Earth through the atmosphere, a space-on-space photo will be much clearer. This link was posted earlier, if you scroll half-way down, you can see a satellite photo of the shuttle.
And they don’t just take one photo, they can take hundreds from different angles using conventional and inra-red. All this info can be processed by computers and then enhanced.
According to the article linked to above, the ISS passed within a couple of hundred kilometres of it several times.
They should have at least tried to photograph the damage. It wouldn’t have helped the crew of Columbia but it may be useful for future expeditions. But I think minature, manouverable cameras strategically placed around the ship are the way to go.
And they might as well give them a few spare tiles while they’re up there. If I was an astronaut, I’d prefer a risky do-or-die spacewalk with a few tiles and a pot of glue than certain death. There’s always rope after all to tie me to the ship.
One of the principal investigators of the Challenger disaster, an individual technical command of space flight surpasses every poster in this thread combined, expressed his shock today that NASA did not bother trying to telescopically image the orbiter.
He added that a second shuttle might have been able to rescue the crew, in a hail Mary operation.