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.
It can be left unattended indefinitely as long as astronauts can at least get up there occasionally to perform maintenance. Without that minimal level of maintenance, though, the ISS runs a serious risk of becoming uninhabitable. And, of course, all the experiments and stuff currently on-board would be lost.
I sure hope so. BTW, it was replaced with the Endeavor. I hope the tooling was not destroyed after that shuttle was complete.
I have worked in the space program for the past 22 years and I have seen my share of mission failures. :-(
I thought we had three operational prior to todays tragedy. Does anyone know for sure?
It can be left unattended indefinitely as long as astronauts can at least get up there occasionally to perform maintenance. Without that minimal level of maintenance, though, the ISS runs a serious risk of becoming uninhabitable. And, of course, all the experiments and stuff currently on-board would be lost.
Remember, the Russians still can fly crews to the space station.
Everyone today's been saying four, and we're down to three now.
There was an accident, fueling related IIRC, in the 1970's that killed some people. The ship was on the launch pad at the time. This is the second Shuttle disaster.
"I have worked in the space program for the past 22 years and I have seen my share of mission failures. :-("
I have too worked in this business for a long time, and your comments do not take into account the many missions unborn because of failures on the ground (testing), failures of our politicians to fund good ideas, failures of the executive branch to recognise good ideas, failures due to incompetent program managers, etc etc.
It is a wonder that we have made the progress that we have. I grieve for the loss of human life today, and its effect on the friends and families of these brave sojourners, but we must also acknowledge the many more deaths that have occurred over the years right here on planet earth developing and testing the technology employed in our space program
I think this reply was for me, and yes, I completely agree.
Indeed. :-( Brings back the Challenger for me also. I was in a mission control room monitoring that launch at the time.
This time, I woke up to hear about the disaster.
True, but how long will ISS be viable without substantial US participation. If we have to pay Russians to do that which we intended to do then the program will crumble. There has been an incredible anount of friction between the USA and Russia during the execution of this project. I just can't see a way out of this box which would be palatable to NASA and Congress. Of course, I might be biased. 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.
As I recall, the transcript had comments that the family wanted with held due to their content.
Also, don't you think it's unlikely any meaningful conversations took place giving the rapid break up?
Same here - I was sleeping late today. I rolled downstairs around 10 AM to find my wife already watching the news of it.
Funny that we just had those remembrance threads about Challenger just a few days ago...
Just heard the Mission Control replay:
CAPCOM "we read your tire pressure messages and copy your last"
CDR: "Uh, roger ..." [loss of comm occurs]
IMO, this wasn't an instantaneous event but rather happening over a short period of time. Seems to me that if it was a spacecraft attitude problem, the words would have been different. I'd say a tile problem jumps to the head of the speculation line. Occam's razor and all that.
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