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Prince
2003-Feb-02, 11:00 PM
If it is shown that the damaged wing tiles was the cause of the disaster, and if the damaged tiles had been spotted by eg an astronaut on EVA, and it determined that a standard reentry would be too unsafe, were there any options: could they have been rescued by another shuttle or Russian supply rocket (as in the 1971 film "Marooned")? How much supplies did they have left: days or weeks? How long could they remain in orbit? Could they have made it to the ISS and docked with it? Could they have effected repairs to the tiles with a patch? Could they have come in at a safer angle? Or might they have been doomed beyond rescue already at launch? If in the first minute after launch, if the observing of the dislodging of the tiles was blatant enough to make some quick thinking NASA observers realise that the reentry was compromised, how would they have aborted the mission? Fly on to land in Spain? Parachute out?

<font size=-1>[ This Message was edited by: Prince on 2003-02-02 18:38 ]</font>

Eric McLoughlin
2003-Feb-02, 11:17 PM
No

joema
2003-Feb-02, 11:58 PM
Columbia didn't have the delta-V to reach the ISS. EVAs never go below the orbiter belly. The remote manipulator arm won't reach there (which Columbia didn't carry, anyway).

There was a tile repair kit developed early in the shuttle program. I vaguely recall they flew it on STS-2, but never again. An EVA to repair (or even inspect) tiles is risky. There's also some doubt whether the repair kit would have provided sufficient thermal margin, or if the high-mach flow would scour away the relatively rough repaired surface.

There are no hand holds below the orbiter. They'd have to use a manned maneuvering unit of some kind (which Columbia didn't carry), and even that is questionable. The tiles are physically fragile. It's easily likely a foot strike, etc. could damage good tiles, resulting in a worse situation than before the repair.

There was no safer, more gentle approach angle. Every time, they generally use the safest, lowest heat angle and attitude.

The ET insulation strike wasn't seen until the following day on a frame-by-frame replay of ascent camera footage. So no launch abort was possible, no matter how much damaged they might conjecture.

The only conceivable rescue scenario would be if a KH-12 reconnisance satellite took high resolution pictures of the orbiter underside. A KH-11 allegedly did this on STS-1, http://www.msnbc.com/news/867770.asp?0cv=CB10 If this unambiguously showed major tile damage, it's (slightly) conceivable Columbia could have powered down (ala Apollo 13), stretched consumables, and Atlantis (which was almost ready for a March launch) could have attempted a rescue mission. It would depend how long Columbia could last, and how much Atlantis processing could be expedited.

However there are several problems with this: Even a KH-12 under optimal orbital and lighting conditions only has resolution of about 1 in. of another satellite. Each tile would only be a few pixels, probably not enough data to differentiate between nominal chipping (which happens on many flights) vs. deeper, serious damage. Without overwhelmingly clear evidence of major tile damage, it wouldn't be worth the substantial risk of an emergency expedite on an Atlantis rescue.

-- Joe Marler

2003-Feb-02, 11:59 PM
In the first press conference the Shuttle Program Manager was asked a question about identifying and potentially repairing damaged tiles while in orbit. The answers were:

1) It is not possible to perform an EVA that would access the underside of the Shuttle.

2) Even if it was possible to access the underside of the Shuttle it is not possible repair or replace the tiles while in orbit.

The only way to manage the risk is to ensure that the tiles are well designed and constructed prior to launch.

In short if Shuttle reaches orbit with a substantially damaged heat shield the crew members need to pray and hope that their chosen deity is smiling upon them.


<font size=-1>[ This Message was edited by: steve_remington on 2003-02-02 19:05 ]</font>

Prince
2003-Feb-03, 12:46 AM
What kind of an abort scenario is evisaged that would require a landing in Spain and how would it work? When would a parachute abort be used?

Irishman
2003-Feb-03, 01:01 AM
I don't recall seeing a tile repair kit in the EVA tool catalog. Unfortunately I am unable to check now. (Do not presently work for the space industry.) It may have been experimental. Ron Dittimore said today that that capability does not exist.

Regarding reentry angle, Norm Thagaard (former Shuttle and Mir astronaut) commented that one potential would be to reenter at a shallower angle. This is not a standard plan because it would allow heat to accumulate and bleed through the tiles and damage the aluminum frame. However, they might decide to accept damage to the airframe and sacrifice the vehicle from reuse if it would allow the crew safe return. I don't know how reasonable that assessment is. The way I say it, it doesn't sound very smart.

Kizarvexis
2003-Feb-03, 01:29 AM
On 2003-02-02 19:46, Prince wrote:
What kind of an abort scenario is evisaged that would require a landing in Spain and how would it work? When would a parachute abort be used?


As I remember from discussions when the Chandra telescope went up (On Columbia IIRC) and there were engine problems, they discussed a scenario where if the engines had problems and could not get the orbiter to space, then they would abort to other landing sites, like Spain. Basically, as I remember it, they ride out the SRB's until they shut off. They then eject the external tank and turn the shuttle around to try and land at an alternate site, which is determined by high far downrange they are. This has never been tested of course because it is dangerous, but it is at least a chance if the engines fail to provide enough thrust to get to orbit.

Kizarvexis

Forgot to add about parachutes. They are used when the shuttle is flying a airplane speeds. The crew bails out of a door in the side of the shuttle. I believe it works very similarily to what was shown in the movie "Space Cowboys".

<font size=-1>[ This Message was edited by: Kizarvexis on 2003-02-02 20:33 ]</font>

Prince
2003-Feb-03, 03:18 AM
If the crew had survived reentry, but with the shuttle breaking up, what is the maximum "airplane speed" and height that they could jump out with a chance of survival? Where is the escape hatch situated? Is there a risk of being blown into the wing or fin?

Kizarvexis
2003-Feb-03, 03:25 AM
On 2003-02-02 22:18, Prince wrote:
If the crew had survived reentry, but with the shuttle breaking up, what is the maximum "airplane speed" and height that they could jump out with a chance of survival? Where is the escape hatch situated? Is there a risk of being blown into the wing or fin?


I do not know. You might try NASA.gov and check the FAQs there. They might have those answers. I've only read that they can bail out when it is travelling slowly, e.g. airplane speeds. (200-500 mph for a SWAG?)

BTW, here is a good article of various rescue scenarios.

Could NASA have pulled an `Armageddon'-style space rescue? (http://www.sfgate.com/cgi-bin/article.cgi?f=/news/archive/2003/02/02/national1602EST0561.DTL)

Kizarvexis

joema
2003-Feb-03, 04:52 AM
On 2003-02-02 22:18, Prince wrote:
If the crew had survived reentry, but with the shuttle breaking up, what is the maximum "airplane speed" and height that they could jump out with a chance of survival? Where is the escape hatch situated? Is there a risk of being blown into the wing or fin?

The Inflight Crew Escape System allows crews to bail out via an escape pole if the shuttle is in stable gliding flight. The hatch on the left side is pyrotechnically jettisoned. The shuttle's autopilot holds it steady at 200 knots.

It's unlikely if the orbiter broke up and the detatched crew cabin was tumbling, that the crew could bail out due to g forces. Columbia wasn't even that fortunate -- it evidently burned up at very high hypersonic speed.

Here's info on the escape system: http://spaceflight.nasa.gov/shuttle/reference/shutref/escape/inflight.html

Here's detailed info on shuttle aborts: http://www.theandyzone.com/launchzone/default.htm

-- Joe