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NASA Prepares for Space Rescues
wallstreetprodigy23 copies and pastes "Space shuttle commander Steve Lindsey is preparing for a mission he hopes will never launch: the rescue of other astronauts in orbit. If a crisis arises during shuttle Discovery's planned return to flight in May, Lindsey and a crew of three could be called upon to lift off aboard sister ship Atlantis on an emergency mission that would be the first in the history of human space exploration. Rescue flights were hotly debated at NASA after shuttle Columbia broke up in the skies above Texas two years ago this Tuesday. Questions arose about whether Columbia's seven astronauts could have been saved. Because of the accident, NASA will have a backup shuttle and rescue crew ready for at least the next two flights in case another ship suffers damage similar to what brought down Columbia."
People at NASA were aware that the foam hit the shuttle wing though, and simply dismissed it.
You can bet your ass if something similar happens on the next few flights, they're going to inspect the damage, rather than ignore it.
"If we let things terrify us, life will not be worth living."
- Seneca
Uh, if you lauch with no payload, there's no way in hell the crew weighs more than 65,300 pounds (Maximum Payload)
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If they implement everything as recommended there is no need for a rescue plan and I doubt such a plan would actually work, it seems more like a publicity stunt to reassure the masses.
Your post is a bit contradictory. First, you seem to indicate that the rescue is useless because the second shuttle could fail too. Second, you say that the chance of losing a shuttle is very small. These two concepts don't fit together.
Two shuttle in fifteen years is not small, because the shuttle launches so rarely. There have only been a little over a hundred shuttle launches, so the rate of failure is something like 1 in 70. While this is fairly comparable to, say, the Soyuz system, Soyuz is much older and more mature, and its recent accident rate is significantly lower. The shuttle's safety record is not that great compared to other launch systems. Soyuz has survived the rocket exploding on the pad. Apollo survived a lightning strike during launch. The shuttle was killed once by cold weather and once by a chunk of ice. The accidents weren't freak, they were symptoms of a systematic failure in design and management at NASA. These are efforts at patching those failures, which does make a certain amount of sense, even if they aren't likely to fix the root cause of the problem (namely, the shuttle is badly designed and NASA management believes that it's invulnerable).
That said, I have to agree that the rescue mission is useless. If NASA were still serious about manned spaceflight, they'd have dropped the shuttle when Columbia broke up (if not way sooner) and developed a system that actually makes sense.
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While a typical shuttle crew is seven, it can be flown with only a pilot and copilot. The rest are there for the non-flight bits, like seeing whether ants can learn to sort tiny screws in space. Can they come back to Earth with nine? I don't know, but it's not quite as bad as having to hold two full crews.
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Hm, lemme check, yep, the Space Station crew has a rescue plan: Jump into Soyuz and land back home.
The Columbia Accident Investigation Report listed one permutation of a rescue mission that could have been launched to save Columbia, if anyone had realized the true severity of the damage to her wing. According to the report, a second shuttle (I believe it was Endeavour, but it's been a while since I read the report) could have been rolled out and launched in a matter of days, skipping the normal three-month pre-launch safety checklist.
The second shuttle could have rendezvoused with Columbia and brought to station-keeping directly below her, such that the two shuttles' cargo bays were facing each other (Columbia would have been orbiting upside-down and backward relative to the ground, as is standard). Columbia's crew could then have transferred to the rescue shuttle via tether.
All of this could have been done inside the week-long window before Columbia's consumables were exhausted; after the rescue, Columbia would have been de-orbited into the ocean.
One of the things that will be mandatory on all remaining shuttle launches will be for all shuttles to be able to rendezvous and dock with the ISS, in the event something like this happens again. This was not an option for Columbia, for a couple of reasons--she was unable to boost to the ISS's altitude, and she lacked the correct docking mechanism to couple with the ISS.
They never "break the hold of gravity."
When they are orbiting the earth they are still subject to the earth's gravity - what is happening is that they are constantly falling towards the center of the earth.
This is why it is referred to as "free fall." In the astronauts local frame of reference it would seem that there is no gravity. It would be the same in an elevator whose cable broke and was falling down the shaft.
Earth's gravity still has them, they are still falling, they just never hit the earth because their forward velocity carries then past it as they fall.
It is the same for geosynchronous satellites even though they are circling at a slower speed.
Physics 101 - it is interesting!
I am very small, utmostly microscopic.
Thing is, the problem that destroyed Columbia was known about for 15 years. And had a nasty enough occurence only two flights before to ding one of the boosters. In fact, the second flight after Challenger came back with an underside that looked like it had been blasted with a shotgun due to foam coming off the tank.
Spotting the problem isn't the hard part, it's getting NASA to do anything about it before it's a PR problem.
Mix the failings of Usenet with the shortcomings of the World Wide Web and the result is slashdot.
Let me tell you the two most important things you need to know to get some idea of how staggeringly hard your proposal is to implement.
The first thing is the speeds involved. These guys are going 17,000 miles per hour. That's 7 times faster than a rifle bullet, and it weighs as much as 30 big SUVs. How do you propose to take this monster and make it "slow down a bit"? If they can't brake in the atmosphere, then need to use rocket power to slow back down to, say, 1,000 miles per hour (the speed of Earth's rotation at Florida plus a couple hundred mph) so they can land.
The second thing is even worse: the Tsiolkovsky rocket equation. It tells us how much propellant is needed to achieve a given speed change (impulse). This is not based on any particular rocket technology; it's a fundamental law derived directly from Newton's third law of motion (the equal-and-opposite-reaction one).
Tsiolkovsky's equation is calibrated to the exit velocity of the propellant. If you want your rocket's velocity to change by N times the propellant's exit velocity, its mass must reduce by a factor of e^N. In the case of the Shuttle going to orbit, N=2.7, and the "mass ratio" e^N=15.5, meaning that only about 1/15 of the vehicle makes it to orbit. The other 14/15 was rocket fuel.
If you want to deorbit the Shuttle using rockets, then you'll need to double your delta-V, because you must first go from zero to 17000, and then from 17000 back to zero. This gives N=2x2.7=5.4. However, this is too high, because you're not fighting air resistance and Earth's gravity when you're re-entering like you are when you're taking off. So let's be conservative and say it's only N=4.5. Then your mass ratio becomes 90, so the fuel tank needs to be 6.4 times larger than they already are! If you have seen the Shuttle's fuel tank, you know this is absurd.
The best thing about deorbiting in the presence of an atmosphere is that it costs no rocket fuel. However, it does have its dangers.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Since the space shuttle was designed to bring back satellites from orbit, I don't think a few extra people would make a difference. Satellites tend to be a lot heavier than people.
Not to mention that the shuttle is so heavy that a few extra people would hardly make a difference in the overall weight.