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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.
fingers crossed. :/
.. if they launch Endeavour to rescue Atlantis, and Endeavour suffers damage at launch?
Can someone speculate the feasibility of "dropping" to meet ISS?
I mean, does NASA have equipments/knowledge/training to do such maneuver?
Virtual Betting on Facebook for non-geeks.
More info here: http://spaceflightnow.com/shuttle/sts125/090512fd2/index5.html
"And Scooter, also I've got some good news about the tile damage that we saw on the starboard chine area earlier today," astronaut Alan Poindexter radioed from mission control shortly after 8 p.m.
"Oh, I'm looking forward to that. Go ahead," replied shuttle commander Scott "Scooter" Altman.
"It turns out that a focussed inspection of that area on the starboard chine is not going to be required," Poindexter reported.
"All right, you've got some happy EVA campers on that," Altman said.
wot no sig
It's being covered by many US based media. You're denser than a neutron star!
So in case of any real damage, Endeavor blasts off (piloted by a 2 Astronaut crew?), all the Astronauts on board Atlantis pack their bags and take a seat in the other shutlle and live happily ever after, which is most important of all. But what would happen to Atlantis in that case? You obviously can't tow it or land it by remote, but leaving such a large object in a (decaying) orbit could cause a lot of trouble. So what would they do? Send it to the moon à la "Space Cowboys" or give it a gentle but controlled kick, letting it crash and burn up in the atmosphere?
It's been on the front page of CNN.com since the afternoon. Here's the story.
Searching "shuttle" on msnbc.com and foxnews.com shows that both of them are carrying the story too, though neither site has it "above the fold" right now.
Is this really a new development that the Shuttle gets increasingly fragile or is it just the fact that since Columbia it gets checked extra carefully and therefore revealing what before just went unnoticed?
Maybe NASA could build a capsule small enough to put into the shuttle through the side hatch. One crew member initiates re-entry then rides out aero braking inside the capsule. If the spacecraft burns up the capsule falls into the air. Parachutes open automatically.
As far as I know the pilot is only needed to manually deploy landing gear. Everything else can be automatic or remotely operated.
http://michaelsmith.id.au
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?
"Have Rockets Run Their Course?"
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
This is going to hurt its blue book value though.
--
Feeling slow today?
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
its heat shield is replaced after every launch as it wasn't designed to be perfect
The replacing the tiles after every launch was actually not part of the original program. Originally the Shuttle was supposed to have a 10 day turnaround time. Like, it lands, they clean it up a bit, and send it off to orbit, almost like an aircraft. You know, it is a -spaceplane-. I still have the Rockwell literature from when I was a kid on it.
Anyway, I think the first cracked or damaged tiles showed up on the first flight. Then the Challenger accident introduced even more procedures. Had we stuck to the original plans for the shuttle, and had a fleet of 10 or so, we would have had a much better STS.
I was actually pretty anti-shuttle for a while but I've come to really appreciate it. I'm actually secretly hoping that Congress will do the politically nutty thing and keep the shuttle, with incremental improvements, to sustain LEO development and recovery of in space objects, and also have the Constellation for long range missions.
This is my sig.
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.
No, I really meant down into a geosynchronous orbit. :)
At a low orbit with 0 ground speed, the orbit will decay fast, which is what you'd want. If it went up to where it could maintain that orbit, well, it wouldn't come down very easily.
Basically, do a burn similar to their deorbit burn. Spin it around backwards, fire the main engines for about 4 minutes, flip back around, and fly home. :)
When they do the deorbit burn, they slow down by about 150mph, and the orbit decays rapidly.
They don't carry enough fuel to bring that down to 0 though.
I went looking around, and found that there was a proposal a long time ago for basically a bean bag that an astronaut could climb into. More like a big foam filled sleeping bag. It had minimal heat shielding, but if they were dropped geosynchronous, they could make it back. It'd take about 4 hours or so, trapped inside a little bag, with no light, no communications, nothing. They'd just lay in it and wonder if they were going to survive. It was dropped because of the potential psychological effects, and they never tested it from a real altitude. The only "test" was throwing a crash dummy in the bag from a bridge.
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.
Low Earth Orbit velocity is approximately 7.8 km/s. The Hubble's orbit is slightly higher, with a slower velocity of 7.5 km/s.
The delta-v capability of a space shuttle after successfully completing a launch is approximately 600 mph (0.27 km/s), depending on the weight of the payload it's carrying. Dumping all their non-essential items out the airlock before the burn might gain them something, but not nearly enough. Remember that it takes two extra rockets and a full bolt-on fuel tank to achieve that 7.8 km/s in the first place (actually 9.3 km/s with atmospheric effects).
Even if a second rocket with a payload of nothing but fuel was launched to rendezvous with the shuttle, it would still not be enough to slow down the shuttle to zero tangential velocity. Nothing as big as the Stage 1 tank has ever been boosted into orbit in a single launch. It would take many launches and lots of complicated orbital rendezvous maneuvers to refuel the shuttle enough on-orbit to achieve a 7.5 km/s burn.
And even then, Main Engine Cutoff (MECO) during launch is at T+8 minutes; the shuttle engines can't burn a full tank of fuel much faster than that (they throttle down right at the end to keep the acceleration to 3g or less, but before that it's balls-to-the-wall). I'm not sure how long it would take the orbiter to reach the atmosphere during the deorbit maneuver--the shuttle would start to fall to the Earth immediately, in an arc that would end up perfectly vertical with respect to the ground--but 8 minutes seems like a long time. If the shuttle hit the atmosphere before the full 7.5 km/s delta-v was achieved, it would still have some tangential velocity, making for a bumpy ride, and the possibility of heating effects on unprotected surfaces.
In any case, there isn't nearly enough fuel up there to do this, and any secondary launch to bring them fuel may as well just bring a rescue capsule for the astronauts.
Thanks for the fun thought experiment, though.
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More as in geosynchronous - traveling synchronous with the geo (ground/earth). It would just fail to maintain it's orbit, but that's the idea. :)
0 forward velocity means less friction against the air. Zinging anything across the atmosphere really quickly will ... well ... make a lot of friction, and as it flies through the thinner parts of the atmosphere, it will get hot and not slow very well.
Serious? Seriousness is well above my pay grade.