Columbia Was Beyond Any Help, Officials Say

New York Times ^ | 2/03/03 | KENNETH CHANG

[jayef]

[John Jamieson]

"In theory, NASA could have had the shuttle descend through the atmosphere at a much shallower angle of entry in hopes of relieving the heat on the ship."

Not really so. The minimal angle is determined by the Shuttle's hypersonic lift to drag ratio, which is very low. The reentry used now is the minimum heating path, without a larger surface area to weight ratio (except maybe for the "energy management" wiggles). Extra drag made it worse.

Landing speed would not change, but the location would: somewhere in the Atlantic.

IF, we had known that the tiles were in very bad shape, the correct moves would to have been to jettison the very heavy payload (and any other extra weight), skiped the "energy management" wiggles, and hoped that we could put them near a large dry lake bed for landing. It would have been Apollo 13 type pucker time, but they would have had a better chance than they did.

[Richard Kimball]

Bump

[John Jamieson]

I wonder about the numbers we're using.

STS97 was a ISS mission that brought up big parts, no metion of heavy returning payload, yet we know that Columbia was heavier than Anlantis and was bring back a 20,000 pound Double SpaceHab that itself can be loaded with up to 9,000 pounds of experiments. The numbers don't jive.

Could Columbia have really been pushing 250,000 pounds?

[is_is]

would it be feasible to boost a fuel source to the approximate orbit of the shuttle

Sure.....send up a "self Serve" Chevron station....who's going to get out and filler up!!?? They have said there were no space walk suits onboard....which brings up another thing.....WHY!!??...what if there was an easly fixed problem that would keep them from reentering???? Can you imagine looking out the shuttle window at the problem but can't get there???? It would be like having a flat in the middle of death vally with no car jack!!!! I see the easily fixable problem but i'm gonna die from the heat anyway....

[Bryan24]

I'm sitting here at MSFC wondering about this.

Could there have been a "break" in the insulation, allowing moisture to get in behind the insulation allowing ice to build up?

And then it was actually a chunck of ice, not insulation that hit the the underside of the wing?

[r9etb]

STS97 was a ISS mission ...

Typo on my part. What I meant was STS-95.

Typical landing weight for a Shuttle "deployable mission" runs right around 200,000 lb., plus or minus about 5,000. So the number sounds about right.

BTW: STS-58 landing weight was close to this mission: 229,753 lb.

[John Jamieson]

I'm find past spacehab missions listed as 244,400 pound landing weight: STS55 Columbia, STS57 Endeavor. Something's not making sense. I've got to stop soon, but I think I'll make a spreadsheet tomorrow.

[John Jamieson]

We don't know Bryan, it's just speculation. But January at KSC is a great time to form ice on the outside of the insulation. Any cracks would make it even worse.

[YaYa123]

"Yeah, let's just stop all attempts at advancement of knowledge because something bad might happen..."

Excellent example of dead on sarcasm that does seem to reflect the thinking of some, It would apply equally to the War With Iraq naysayers. They say, we can't start a war, we don't know how it will turn out, we don't know how long it will take, how costly, how many lives will be lost, how can we win the peace even if we do win the war?

and by the way, this article very accurately reflects what Dittimore said in his press conference yesterday, I'm astounded. ....and I'm worried. Because not only do I think I understood much of what he was saying, I believed him.

[supercat]

No, you're wrong, the problem was that even with training the walk would have been impossible without the mechanical arm to anchor the astronaut to the underside of the space craft. The arm was not on board because the tests that they were performing did not involve going outside the spacecraft.

If they could get into the cargo pay (even if it necessitated venting the cabin), couldn't they have used a hundred or so feet of rope or cable (electrical or otherwise) to make a really crude tether (tie one end to one side of the cargo bay, walk the rest of the spool/bundle to the other end, and throw the cable out; if done right, the cable should loop back to over the cargo bay. Tie it off, then use that as an anchor point for a sliding cable which can then be used as a launching point for another cable.

Nowhere near as good as proper EVA gear, but I would think something could be made to work.

Of course, there would be substantial risks with such an operation; unless they're smaller than the risks of doing nothing, it's not worth throwing the mission out the window to do such things.

[DaGman]

"But even a cursory examination of how society spends its money, makes decisions, reveals there's a price on human life...I've seen various studies that actually attempt to calculate it....but problems come in when people try to pretend there ISN'T a price."

Calculating the price of a human life is an everyday occurence in business. Businesses are capable of making products that are 100% safe. However, making a 100% safe product is not always profitable. Therefore, businesses will calculate the probability that a product will fail at various levels of quality. Then, businesses will forecast their likely average payout for a lawsuit and then maximize their profit based on calculations that include the above. So, putting a price on a life is a way of life in business.

An example of this is a friend I have that had a section of his colon removed because of cancer. The staples used to sew him back up failed. Of course, everyone went out of their way to make it right for him, including the doctor and the hospital. He also found out that the manufacturer of the staples had calculated a failure rate of 1 out of every 100,000 staples. The company decided that this level of quality was an acceptable risk so and they knew how much profit they could expect after figuring in legal costs related to the staples.

As a side note, if an assumption is wrong about product failure rates, or if they get hit with an unexpectedly high jury award, they then scream tort reform.

[Swordmaker]

Then built this:

Link

I agree. Data from your link:

Class: Manned. Type: Rescue. Nation: USA. Agency: NASA. Manufacturer: NASA Johnson.

Also known as ACRV (Assured Crew Return Vehicle), CERV (Crew Emergency Return Vehicle) and PLS (Personnel Launch System). NASA Langley design for a manned spaceplane as a backup to the space shuttle (in case it was abandoned or grounded) and as a CERV from the Freedom space station. Lifting body re-entry vehicle based on the Russian BOR-4 design. Designed for two flight crew, eight passengers, piloted landing at airfield on landing gear. During launch a fairing from the Titan IV booster to the spacecraft would have had solid rocket motors (154,000 kgf) for launch abort, with parachutes for a tail-down water landing. Although studied by contractors and a full size mock-up was built, the design was not selected for further development. Soyuz was designated as the International Space Station CERV. When doubts about the availability of Soyuz developed in 1995, NASA proceeded with development of the X-38, a NASA Johnson concept - a smaller version of the X-24 lifting body with a parafoil.

[nvskibum]

I have read a post from one Freeper, a former NASA executive, suggesting that one problem may have been the heavy weight of the Columbia vehicle. Columbia, being the oldest shuttle, was considerably heavier than newer shuttles. The post stated that heavy re-entry weight would tend to create more stress and heat upon re-entry. If this is true, and if NASA knew that the vehicle sustained damage which would make re-entry more dangerous, might the situation have been improved if the crew were instructed to toss out all unessential items, such as experiments, unneeded equipment, everything in the cargo bay, etc., before initiating re-entry, in order to reduce vehicle weight and stress?

[Swordmaker]

The answer to your question is a qualified yes. Lightening the load would remove some of the stress of re-entry... however, the problem is HOW do you lighten that load?

The HabLab is MOUNTED in the shuttle payload bay. It is not just "layed" in there like a bottle in a box. It is bolted in and in addition the crew compartment of the shuttle and the HabLab are connected by a passageway that is also firmly attached to both. There are also many attachments to the shuttle providing telemetry, etc. It would be a major task to eject it from the payload bay.

Removing excess weight from the lab and tossing them out the door of the shuttle is also problematic. First the door to the shuttle payload bay is the door they would normally use to do an EVA... but there is no airlock module attached because the HabLab is attached there. The door on the side is not meant to provide access to space and does not have an airlock on it either. The entire cabin would most likely have to be depressurized to throw anything away out that door.

Finally, since you can't eject the entire lab, the amount of weight that could be removed by taking things OUT of the lab would be constrained by the physical size of the doors and passageway between the HabLab and the cabin of the shuttle. Many of the more massive pieces were built in place inside the lab and would not fit through the door.

I doubt that would have made much difference.

[FReepaholic]

>>...Would it be practical to build a protective shield for the tiles which would be mechanically durable enough to provide useful protection during launch, but would burn away harmlessly during re-entry?...<<

Just this morning I thought of this very same thing. How 'bout a spray-on ablative coating.

(great minds think alike)