CNN
Posted on 02/01/2003 10:18:41 AM PST by Timesink
Seven astronauts, including the first Israeli in space, were lost Saturday when the space shuttle Columbia broke apart in the skies of Texas. The incident occurred at an altitude of some 200,000 feet, shortly after reentry and 15 minutes before Columbia had been scheduled to land at Cape Canaveral. TIME science correspondent Jeffrey Kluger explains some of the possible causes and consequences of the accident:
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TIME.com: What are the possible scenarios that could have caused this disastrous accident on the shuttle's reentry into the Earth's atmosphere?
Jeffrey Kluger: There are three possible scenarios that explain this event. The first, which I believe is the likeliest explanation, would be an aerodynamic structural breakup of the shuttle caused by it rolling at the wrong angle. Remember, after reentry, the shuttle is descending without power, which means astronauts at the controls can't compensate for a loss of attitude by using the engines, they can only do so using the flaps. And that's extremely hard. Astronauts describe piloting the shuttle on reentry as like trying to fly a brick with wings. It's very difficult to operate, and even more so to correct any problems.
A second explanation might be a loss of tiles leading to a burn-through. (The shuttle is covered with heat-resistant tiles to protect the craft and those inside it from burning up in the scorching temperatures caused by the friction of reentry.) But I think that explanation is unlikely, because the tile-loss would have had to have been quite substantial for that to become possible. You'll hear a lot in the next few days about things falling off the shuttle during liftoff. But it often happens that they lose a few tiles, and I'd be surprised if it happened on a scale that could make an accident of this type possible.
The last option is some kind of engine failure leading to fuel ignition. Although the main tanks are mostly empty, there should still be fuel left in the maneuvering tanks. But probably not enough for an explosion that could have caused this breakup.
And just in case anybody was wondering, you can almost certainly rule out terrorism as a cause. This incident occurred well above the range of shoulder-fired missiles. And it would probably be easier to sneak a bomb onto Air Force One than to get one onto the shuttle.
TIME.com: So is reentry the Achilles heel of the shuttle program?
JK: No, the Achilles heel has always been liftoff, and the dangers posed by massive fuel load involved. Reentry has, of course, always been a difficult part of the space program. But this is, in fact, our first fatal accident on reentry. Apollo 13 is remembered as our most difficult ever reentry, but the ship and crew survived. The Soviets lost a crew on reentry in 1970 after an oxygen leak that caused the cosmonauts to suffocate on the way down. Reentry is a very difficult process, but the Russians mastered it in 1961 and we did the same a few years later.
TIME.com: Are shuttle crews trained to respond to the scenarios you've described?
JK: Yes, they're trained to deal with loss of attitude on reentry, and a range of other emergencies. But astronauts are not trained to deal with situations that result in certain death, because that would be a bit like training for what you might do if your car went over a cliff — in some situations there simply isn't anything you can do. One irony, though, is that NASA hadn't trained astronauts to deal with the sort of quadruple failure that occurred in Apollo 13, because they assumed that such a scenario would result in certain death. But the astronauts survived.
TIME.com: What are the immediate implications for the space program of Saturday's disaster?
JK: Following the precedent of the Challenger disaster in 1996, it's unlikely that NASA will undertake any further shuttle missions or any other manned space flights for the next two years. One immediate problem, though, is the International Space Station, which currently has a crew of three on board. They might consider one further flight to bring that crew home — the other option would be for them to return aboard a Russian Soyuz craft, which isn't the most comfortable or the safest ride. Beyond that, however, the space station is likely to be left unoccupied for a long time. NASA won't want to use the shuttle again until it can establish the cause of today's accident, and fix it. Now that we've lost two shuttles out of a fleet of five, it's even conceivable that the shuttle won't fly again. The shuttle was built as a space truck, and then the International Space Station was built to give it something to do. Both programs are likely to suffer as a result of this disaster.
I truly don't know.
I remember when the Space Exploration Program lost out to ISS by one vote, in 1992 I think. I was employed by the Space Exploration Office and decried the circular reasoning that allowed the justification of ISS and shuttle.
You were closer to this than I was. I was working interplanetary missions at that time. I did not move to the space station program until much later.
I have a beautiful award framed on my wall from a Columbia launch. I will treasure it even more now.
No I do not think that at all. These folks, and I have met and talked with many of their colleagues, are ultimate professionals. As the castrophe unfolded, their attention would have been focused on surviving the anomolous circumstances. There would undoubtedly be important clues in those exchanges, given that there was time to have any discussion at all.
My gosh, what a moment in history. Like the Kennedy assasination, the Challenger is a moment when everyone remembers where they were.
To be part of that history....
Seems like a lifetime ago now. But today brought it all back like it was yesterday.
If I might change the subject to something trivial for a moment, did anyone else see Dan Rather make an idiot out of himself today, talking about how the wings on the SS don't actually support it like a "real" airplane?
Memo to Dan: "Shut your d*mned mouth when you have no idea what you are talking about."
What's he think holds the Shuttle up when it is in the atmosphere during re-entry, MAGNETS?
It's bad enough that diasaters like this happen from time to time; ignorant network boobs who are technically clueless only add insult to our injury.
Was the challenger replaced? The original plan was for a fleet of five, and I'm not aware of more than five ever having been built.
"Speaking on condition of anonymity, a U.S. official told NBC’s Miklaszewski that a heat spike appeared on military satellite data around the time shuttle was re-entering. The readings would be examined to see if they correlate to the shuttle’s breakup. The highly sensitive infrared satellite, known as the DSP, originally was developed to detect the heat spike of Soviet intercontinental missile launches. It also has been used to detect the heat signature of oil fires, volcanic eruptions and the explosion of TWA Flight 800 in 1996. "
Yes, it was replaced by order of President Reagan. I said the new shuttle was named Enterprise, but it was actually named the Endeavor, as pointed out by Radio Astronomer and Desdemona. I guess Enterprise was probably the first flight test vehicle as I now reconsider it.
Sheesh. I missed that.
Indeed it was. It was never designed to fly into space. It was too heavy to even try to retrofit it.
Lucky for your TV... I nearly threw a brick at mine when I heard him say it.
A good light moment at a tough time.
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