Space Shuttle to Receive Emegency Repairs

Tycow writes "The BBC are reporting that Discovery needs emergency repairs - dangling material has been spotted on the belly of the shuttle, and NASA are worried they could cause overheating on re-entry. 'Nasa is concerned the dangling material - called gap fillers - could cause part of the shuttle to overheat as it re-enters the atmosphere.The type of repairs being planned have never been conducted by astronauts on a spacewalk before.'"

Comments

Far More Informative (Detailed) Links

[Buran]

Spaceflight Now | STS-114 Shuttle Report | Shuttle mission extended to give bonus day at station

Spaceflight Now | STS-114 Shuttle Report | NASA gives go-ahead to spacewalk repair work

(and the headline says "Emegency" -- someone fix that, please)

Paranoia.

[Inominate]

It's a minor problem, which ordinarily would have gone unnoticed. It's probably happened many times before. NASA is just being paranoid because they can't afford another accident. Alternative theory, NASA wanted to find something wrong that isn't really a danger and prove they can fix it, and that there is no danger anymore in space travel.

Re:Paranoia.

[rhadamanthus]

NO. Boundary layer transition is not a very well understood phenomenon to begin with, and in this case you pushing the limits of both flight experience and analytical capability. Going from laminar to turbulent flow above mach 18 results in some very serious heating, ultimately effecting not just the thermal system, but also the structural margins.

Most importantly, this trip would spill over the side of vehicle and run down streamlines into the wing leading edge. Analysts put the increased heat loads even in a "best case" situation at 80% increase. At those temperatures (almost 3300F), the SiC coating will start to degrade. Dispersion in the entry tajectory could lead to an additional 150F. At that temperature the SiC will ablate, exposing the carbon-carbon substrate. It will oxidize and the temperature will skyrocket to 4000F. At that temp kiss the wing goodbye.

That all being said, I think it could make it down - the uncertainty in this situation is increasing conservatism - but I sure as hell won't take that risk when the EVA is quick and relatively simple.

Re:Tough cloth

[ranson]

(Sorry I pressed the wrong reply button the first time i posted this response) No it won't burn away, the cloth is ceramic-coated with the same material as the thermal tiles on the orberter belly; they can withstand thousands of degrees farenheit. The protrusions will break away some, but in past landings, they have measured protrusions of at least one half inch AFTER the craft has landed and the protusion was manipulated by the landing approach. There was no way to know how big the protrusions were prior to landing because they couldn't examine the craft to the level of detail they can post-Columbia.

I hope the shuttle comes home safe...

[ChiralSoftware]

I hope the shuttle comes home safe and then gets parked in a museum. The problem here is that the heat shields are exposed to stress during both launch and entry. All other spacecraft have a heat shield that is only used one way or the other way, and then is disposed of. It's a bit much for me to want to reuse something that has to be exposed to the rigors of launch and then reentry and then be reused. I'm glad that it has worked as many times as it has in the past but this does not seem like a safe design and does not seem like the right thing to use to protect astronauts. The heat shielding is the one part of the shuttle that has no redundancy; if tiles are lost in critical places, the shuttle disintegrates.

It also seems like they have spent a large fraction of their space-time on this mission simply making sure the shuttle is fit to return to Earth, rather than doing useful space work. The shuttle was sold on the promise of routine, cheap, quick flights to space, and we have something that flies so irregularly that it's hard to even say how often it flies (once a year or less?). It's such a bucket of bolts that astronauts then have to spend half their time just inspecting it for damage while they're in orbit. NASA should not be putting astronauts at risk in a ship like this. NASA should be spending its budget on programs that have a future, rather than programs which have been a dead end for a long time.

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nasa should talk to riaa

[yagu]

I don't know why anyone hasn't thought of this before, maybe it's just seredipity on my part. NASA should talk with the packaging industry, e.g., RIAA and how they package CD's (don't remember the last time I've opened a CD without it damaging the knife, jewel case, my hand, etc.), or the computer industry. I just purchased a logitech mouse and after what I went through to get the friggin' mouse out of its packaging, I'm pretty sure some of these materials and techniques could be useful in creating a more sound Shuttle. Certainly they're at least up to re-entry heat and forces.

Re:EPA destoyed Columbia and grounds Shuttle Fleet

[DerekLyons]

Very simply under Clinton the EPA refused to let NASA use Freon to apply the foam to the H2 tank.

[sigh] 'The Lie that Will Not Die' raises it's hoary head again... Once more into the breach.

The 'new' foam is only used on acreage foam. The hand sprayed/sculpted foam (which killed Columbia and produced the big scary chunk after SRB sep on the current flight) is still the old freon blown foam. This is very plainly spelled out in the CAIB report and recent NASA press releases.

http://www.newsmax.com/archives/ic/2005/7/28/93055 .shtml

This story is completely contradicted by the CAIB report - furthermore this graph/image plainly shows that NASA *has* been making progress in reducing foam shedding/tile damage caused by the 1998 switch to 'enviromentally friendly foam'.

The real reason isn't because it's an emergency!

[BritImp]

I spoke with a guy from the Mission Management Team (MMT) tonight here in Cape Canaveral. He confirmed that such small pieces of gap filler are not expected to affect the creation of the barrier layer during re-entry, and so do not pose a threat to the orbiter.

The real reason for this 'repair' is because this whole mission is to "test orbiter repair techniques" - and these virtually irrelevant pieces of gap filler provide an unexpected, but very fortunate opportunity to try a real repair technique out in a relatively safe and controlled fashion.

NASA doesn't yet know if it's even possible to have an astronaut perform repair-type work on the underbelly of the orbiter - they think it would be possible, but they have no hard data to say it can be done.

But these small bits sticking out give them the perfect excuse to go test it and get some real-world experience on the issue.

If it looks like the astronaut might damage some of the Thermal Protection System tiles down there, they'll just terminate the repair attempt and fly home as-is. If not, they'll demonstrate that astronauts can go under an orbiter and perform repair tasks down there safely and without harming the TPS.

But I'll bet you'll hear the popular press making too much out of this as usual...