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Minor Damage Found On Space Shuttle
The BBC is reporting on minor damage to the space shuttle Atlantis revealed by a 10-hour inspection in orbit. On the shuttle's right side, near where the wing joins the body, inspection revealed a 21" (53cm) line of chips in the tiles that make up the vehicle's heat shield. "...more analysis by engineers would determine whether a 'focused inspection' was needed in that specific area. If so, astronauts would use sensors to determine the exact depth of the damage to the heat shield tiles. NASA has placed the space shuttle Endeavour on stand-by to rescue the crew of Atlantis if they are endangered." The crew couldn't shelter on the ISS in case of trouble, because their orbit is higher and on a different inclination.
The astronauts pile into the less damaged orbiter and come home in it.
Then, they get home and buy Powerball tickets, because those kinds of odds are nearly as good as winning. The Shuttle has more or less always sustained some tile damage during launch; its heat shield is replaced after every launch as it wasn't designed to be perfect (well, it originally closer to perfect when it was to be built of solid titanium, but plans change...) The damage turned out to be a significant player in Columbia's loss, as it happened that the part of the shield that was damaged was extremely critical to the proper functioning of that area.
OTOH, here we see an almost pristine heat shield. The damage is long, but it's very narrow, likely caused by a single piece of falling debris striking in multiple locations. This isn't going to prevent them from coming home in Atlantis.
Haven't seen any stories on the U.S. news websites.
Then why all the bitching that /. is too US-centric? Or is "News for nerds" not a news website?
By the way, opening yahoo news it was right on top:
http://news.yahoo.com/s/afp/20090513/ts_alt_afp/usspaceastronomyhubble;_ylt=Aj3NU3nOc4iB6txwGUCXG3wPLBIF
It is dangerous to be right when the government is wrong.
I think the best solution would be if Atlantis could be brought back by autopilot. If the damage is marginal (that is they THINK it might destroy the shuttle but are not sure) then bringing it back unmanned would give you the possibility (if the damage is survivable) of recouping your billion dollar plus investment.
The problem is that I am not sure that the shuttles have autolanding capability. The astronauts may have lobbied to keep NASA from giving the shuttles the ability to land themselves (or via ground control) in an attempt to keep pilots from being made irrelevant. (Throwback to test-pilot days I guess). Does anyone know if the shuttle can be landed without a human crew?
The shuttle is an inherently flawed design, this isn't news. The crew-carrying module of any rocket should always be on the TOP, where it isn't going to be hit by debris. Also this configuration allows for a launch escape system, which every manned rocket ever made except the shuttle has. (All they have are parachutes which can only be used in level gliding flight, i.e. they're virtually useless.)
http://spaceflightnow.com/shuttle/sts125/090508sts400/
"When we made the decision, the odds were 1-in-473 that we would have a problem on the shuttle for which a rescue shuttle was the solution," Griffin said. "Now, there are a lot of problems you can have on the shuttle, right? There are a lot of ways you can die on the shuttle, which is what gives you the overall shuttle PRA (probabilistic risk assessment) of about 1-in-75 or so. So you're roughly five-and-a-half, six times likelier to die on the shuttle for some reason that the backup shuttle can't save you from than you are to die from one the backup shuttle can save you from. ... From a statistical point of view, it makes no real sense to have a backup shuttle.
"However, here's the flip side. ... Those numbers cannot be explained to politicians or the general public. And should we have a failure with those 1-in-473 or whatever odds it was, should we have a failure that the rescue shuttle could have saved you from and we had not done it, the consequence to NASA would have been incalculable. We would appear to have been cavalier with human life, we would appear to have not taken every possible precaution, we would appear to have been coldly calculating the odds and rolling the dice with people's lives. And the appearance of behaving that way, in my judgment, was unacceptable. I could not risk that for NASA."
While the overall risk of impact damage is about three times higher for a Hubble mission than a flight to the International Space Station, it is not as bad as flight planners initially feared.
"We know we're accepting a little higher risk for this flight," Steve Stich, manager of the orbiter project office at the Johnson Space Center, said in an interview. "That's why we've tracked it very carefully."
Even factoring in debris from a satellite collision in February between a defunct Russian Cosmos satellite and an Iridium telephone relay station, the mean odds of a catastrophic impact during the Hubble mission are on the order of 1-in-229, which is well below the 1-in-200 threshold that requires an executive-level decision by NASA's leadership.
A preliminary analysis put the odds at 1-in-185, but the numbers improved after recent radar observations and consideration of the shuttle's orientation in space during the Hubble mission. The planned orientation, or attitude timeline, reduces the crew's exposure to impacts that could damage critical areas of the ship's heat shield, the coolant loops in the shuttle's cargo bay door radiators and cockpit windows.
wot no sig
Essentially, the development of adaptive optics and better control algorithms has allowed ground-based telescopes to catch up on Hubble. Plus, they have larger mirrors for more light-gathering ability, all at substantially less cost.
What ground-based scopes can't do is analyze spectra that don't penetrate the atmosphere very well. Infrared and UV light, for example, are hard or impossible to read from the ground. Space-based telescopes are more useful there.
Hubble development was started when we were still fooling ourselves into believing that shuttle operations would be cheap. That turned out not to be the case, and the costs of servicing launches will almost pay for a new telescope anyways. Don't expect to see any new servicable ones built until we have a truly economical manned launch vehicle.
The meek may inherit the earth, but the strong shall take the stars.
I know it was a joke, but it would work.
They'd have to bring the orbital velocity down from the 17,000+mph to 0.
The reason for the high heat is the extreme orbital velocity required to keep them up. If they reduced it to 0, when they dropped back into the atmosphere, the atmosphere itself would act like a cushion, and as they fell into the atmosphere, their own terminal velocity would slow them down gracefully.
Search around for Joseph Kittinger (jump from 102,800 feet in 1960) and Roger Eugene Andreyev (jump from 80,325 in 1962)
There are a few problems with it though.
I don't know that there's enough fuel on the shuttle to bring it down to a geosynchronous orbit. They have oms thrusters, good for changing altitude on a mission and maintaining their orbit, but not dropping so much speed.
If they brought the whole shuttle in that way, assuming in a flat orientation (bottom down, top up, 0 ground speed), it would slow down very gracefully, but once in the atmosphere they would be in a stall, and I doubt the oms engines would be able to maintain it's attitude. It may be unrecoverable once it's in the air.
If they rode the shuttle down to a low geosynchronous orbit and then jumped, they would be in very close proximity to the shuttle for a long time. There would be a huge risk of encountering the shuttle or debris as they re-entered in such close proximity to each other. Getting smacked in the head by a 2,000 ton airplane in a free fall can hurt. People would likely have a higher terminal velocity than the orbiter (the orbiter has a lot more surface area than an EVA suit), so the people would likely drop faster, but once their parachutes deployed, they'd slow dramatically, where the still falling orbiter wouldn't.
It would take a lot of planning to avoid existing debris in orbit.
It would take a lot of planning and luck to drop them anywhere close to where they'd want to land. Landing in Nevada or landing in the Atlantic or Pacific ocean would almost be a crap shoot. If they came down in just EVA suits, landing in the water wouldn't be practical.
Dropping the orbiter out of the air, even aiming for Nevada, may land in an unpredictable area. Hitting a metro area within say 1000 miles would be a bad thing(tm).
The crew don't have EVA suits with enough air to make the jump from orbit to breathable atmosphere (10k feet).
I don't believe the EVA suits carry beacons that are trackable from the ground.
Most importantly, they don't have parachutes.
This would have been something excellent to test out years ago, and they've had plenty of chances to try it out with "crash dummies" and timed/altitude parachute deployments.
Serious? Seriousness is well above my pay grade.
"I don't know that there's enough fuel on the shuttle to bring it down to a geosynchronous orbit. They have oms thrusters, good for changing altitude on a mission and maintaining their orbit, but not dropping so much speed."
WTF?????
Geosynchronous orbit is about 36000 kilometers, while Shuttle's orbit is about 300 kilomterers, AFAIR.
In any case, going UP won't help you a bit (you'll still be in an inertial orbit). You need to _reduce_ your speed essentially to zero.
That means you have to expend _the_ _same_ _amount_ of fuel that was required to lift the Shuttle in the first place.
And that's completely impossible with chemical fuels.