This is going to result in a certain cessation of manned space flight missions by NASA for an extended period of time. Years probably. It will indirectly put a huge pressure on Space and Missiles Center's launch office (http://www.losangeles.af.mil/SMC/CL/) to come up with a way to get military loads up into space on a more frequent basis. Up to now they were piggy backing on NASA for short term experimental projects.

i don't believe that this tradgedy was an act of terrorism, but it suprised me to find out that the isreali on board was one of the pilots that bombed the iraqi nuclear plant in the early '80s. wasn't this asking for a least an attempt on this mission?

Judging by the events of the last few years, any mission is a target because it contains Americans.

Any Israeli astronaut does represent a slightly increased security risk, but most of that risk centers around the launch window and is therefore controllable.

On re-entry, the shuttle is moving too fast to be a missile target until the very last stages, at which point it's a glider and so not really a heat source.

If this is a terrorist incident, it would have to be a damn brilliant one.

Apparently a piece of insulation detached during liftoff and hit one of the wings. According to comments from various engineers that I have read, it is possible that even mild damage to the wing would result in a high-g spin during re-entry. It appears that this tragedy is likely to be the result of simple mechanical failure. (Due to the shuttle design, once the booster rockets are lit the takeoff cannot be aborted.)

I think it's interesting to note something that I was just reminded of during the NASA news conference. Basically, any damage to the shuttle during take-off, especially any tile damage, is not repairable at any point during the flight. Thus, as much as we have grown used to seeing mission after successful mission (the Challenger notwithstanding), these missions always have a considerable risk factor. It is entirely possible that some tile damage occurred during lift-off, but the method of determining that is imprecise at best, and even if an accurate damage assessment could be made, there is virtually nothing that could be done about it. Basically, there is no way of knowing whether tile damage is catastophic until the shuttle re-enters the atmosphere. Very sobering thought and a reminder of the inherent risks and tremendous bravery of the crews.

You can be sure it's not a terrorist event. The shuttle was over 200,000 feet and moving at Mach 18. Maybe SDI could have hit it on a good day, but nothing else could have. Note: the top altitude on the SR-71 is about 100,000 feet and the U2 tops out around 75,000 feet.

All the NASA "experts" are saying that the foam insulation that came off the liquid fuel tank during the ascent and hit the orbiter left wing was unlikely to do damage - except, "why did it come off in the first place?" Maybe because it was coated with a thick layer of heavy ICE?

The orbiter was close to peak thermal load when it started to come apart . . . . . Instapundit's "zipper" theory doesn't ring as true to me as there being lots of tile damage (maybe just many loosened tiles) on the left wing from insulation & ice contact @ launch. It doesn't sound as if anyone could see the left wing to inspect it in orbit - and the NASA experts decided it was OK based on informed guesswork(or WAGS) and because there was no way to make repairs anyway.

So, enough tiles were off heat sensitive areas on the left wing (leading edge & underside) to allow burn through to start a disaster cascade - more tiles coming off, structural failure, hydraulics, whatever. Maybe the wing panel even came off (in the best video of the initial break-up, a white and rectangular piece comes loose - either a wing panel, vertical stabilizer or SOMETHING). It doesn't matter whether tiles were knocked off on the ascent, or whether just loosened enough to fall off early-on in the descent, the result would have been the same.

Question of the day: if you were the pilot, would you have wanted to know the wing was severely damaged in advance? I sure would have, and if NASA suspected something but didn't act on it because there was no solution anyway, I think they have an incredibly big problem on their hands.

One other thing. NASA used to estimate that about 1 in a hundred missions would fail due to the complexity of the orbiter and rocket motors. I heard they recently changed the statistical estimate to about 1 in 500.

Now, when he was alive, Richard Feynman said the missions were getting riskier rather than safer over time (leading up to the Challenger disaster). I think he based his estimate on the number of serious anomalies reported on each mission.

My question is: has the serious anomaly rate per mission been increasing, decreasing or constant over the past year or two? For the record, this was Columbia's 28th mission, and approximately the 130th shuttle mission since inception.

I find it hard to accept that an orbital EVA inspection wasn't done when it was known that the shuttle was impacted during lift-off.

It certainly wasn't my intent to imply that anyone at NASA knew there was a problem. In fact, I have to take them at their word at this point, when they say they looked at the tile/foam/ice that came off during launch and determined that it was not a problem. I was just trying to point out that, even though everything may have been done that is possible, there is a certain risk matrix fundamentally built into the design parameters of the shuttle that dates back to the late 60's/early 70's, that many people probably aren't aware of. Space travel is still a very dangerous business, and over the years, the perception has grown in the media/public at large that it's the equivalent of a ride in an airliner. NASA may be partially to blame for this, since they keep recruiting ordinary citizens, like teachers, to fly, when the risks are still enormous. I say, as long as passengers realize the risks, there's no ethical issue there at all, but it may confuse the public. If I were given a chance today, knowing what I know, I would still jump at a chance to fly in the shuttle, right now. And if something happened, I would accept that I took a huge risk for a once in a lifetime experience. Well, this turned into a rambling statement, but I'm just struck at how I had forgotten over the years how much risk there has always been with shuttle flight and had taken it all for granted. Let's hope that the problem is found, corrected, and manned space flight stays a priority in this country.

Given the tenacity with which failed federal bureaucracies hang onto their missions, no matter how many Americans they kill, we should consider swapping them instead.

I suggest we have NASA and the FBI swap managment. I've wanted to send FBI Director Mueller to Mars for 16 months now. Each agency's management could hardly do worse in their new roles than the existing management.

Trent, absolutely great work today. My sincere thanks.

We learned in the Challenger investigation that the root of the deaths of that crew was not ignorance but bad management in NASA making fatal decisions. I look forward to this investigation and am very pessimistic that we will learn that little changed at NASA after Challenger. We must not, whatever the root cause, allow the small minds use this to keep us from space. To Mars.

Regarding an EVA: we're not talking about walking around your car to see if a tire is flat. An unplanned EVA has many risks involved with it, would basically burn the mission timeline to the ground, and may not have been possible in any case.

The majority of NASA spacewalks are confined to the cargo bay of the Orbiter, or are assisted by the Manipulator Arm. Columbia wasn't carrying the Arm this time around. Safety tethers long enough to leave the bay, go underneath the shuttle, and cover the entire left wing may not (I'll venture to say "were not") carried on this flight. At worst, we could have lost an astronaut trying it. At best, we could have confirmed that there was a problem, and MAYBE been able to get the Orbiter to the ISS until another shuttle could get there. Certainly, in hindsight, an EVA may have been the right thing to do, but at the cost of the rest of the mission when prior experience has shown us that it would have been a waste of time.

Objects smack into the Orbiter all the time on takeoff. Ice, insulation, birds, and lightning have all been catalogued at one time or another. In the past, these haven't been enough to damage the heat tiles, and right now we don't have enough information to assume that that's what happened this time. We have circumstantial evidence only.

We don't even know exactly where the falling insulation struck the Orbiter, except that it was somewhere on the left wing. Logic would indicate that it was probably forward on the wing, but the sensors that stopped working were on the trailing edge (elevons) then the middle (wheel well), not the front.

Yes, initial guesses are that the insulation damaged some tiles, and that may have been enough to cause a burnthrough on the wing. It's also possible that something else entirely caused this disaster. We just don't know enough right now to guess.

There are just so many ways that a landing can go wrong that pointing at one thing at this point and saying "AHA! THAT'S WHAT CAUSED IT" is the last thing you want to do.

Oh, re: possible terrorist causes...

If something was shot at the shuttle when it was moving at Mach 16+, at 200,000 feet, without anybody noticing, I want the name of the company that created the weapon. Sounds like a helluva investment opportunity.
Yes, I'm joking. I think we can pretty much rule terrorism out in this case. Is it possible? Sure. ANYthing is possible. Aliens may have been doodling on the bottom of the Orbiter and accidentally loosened some tiles, too, but I think that's just as likely as a terrorist act.

Eric: Points well taken on the uncertainty of the exact cause, which won't be known for weeks or months . . . . . . informed speculation IS part of the learning process for us non-professionals, however.

My understanding is that even if there was a problem with the tiles or the structure, any kind of EVA could NOT have effected repairs, and the shuttle didn't have enough fuel to make the orbital changes necessary to get to the ISS AND without docking capability there wouldn't be a method to get people out of the Columbia and into the ISS. In short, even if the left wing was known to be severely compromised, there wouldn't have been ANYTHING to try other than a standard reentry . . . . . . makes me wonder if those circumstances colored any experts' judgement about the likelihood of the wing being damaged?

From early on, the shuttle has been an economic and scientific dodo. IF it had the orbital capability to get up to geosynchronous altitude where all the communications satellites are, maybe, just maybe the economics might justify the extremely high risk of failure, but as it is, the shuttle should have been shut down long, long ago.

And yes, I thought that before Columbia and before Challenger, even. So did most other halfway knowledgeable people who didn't have a hand in the NASA cookie jar . . . . .

The U.S. Space Program will emerge from this tragedy stronger and more determined to push forward the frontiers of human exploration.
There is no turning back on the path our Nation has pursued with courage and vision since Freedom 7. The future for humanity lies always on the distant horizons...the crew of STS-107
knew this and because of their sacrifice, we
on this beautiful Earth, are the benefactors.

God Bless the crew STS-107/Columbia...God Bless the USA...we will NEVER forget.

Feynman's report of the Challenger disaster included the engineering estimate of probability of failure at 1 in 100, while NASA management estimated 1 in 100,000. Feynman's last comment was especially to the point: "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled."

G. Haubold...
I don't disagree with you, about the "informed speculation." I'm just not sure we know enough to HAVE informed speculation, but that's not anything we can answer, really.

By the way, I'm no expert on the Orbiter, either. The only thing I'm an expert on is rubber duck collecting, and I'm just a guy who grew up a Shuttle Geek. All I've said on various weblogs today is stuff that's available online, from the news conferences, and run thru my personal knowledge base.

I surely don't want to get into a discussion about whether the whole Space Shuttle program is valuable or not in equality to its actual cost... I just don't think it's appropriate today.

When it comes to an incident like this, remember that my opinion is, at best, as good as yours, and quite possibly not as good.

Anything with the energy and intelligence that can create crop circles (pictograms) on the ground can probably degrade the integrity of a few shuttle tiles. I wouldn't care to speculate on the motive though.

So you're suggesting that a couple of drunk Britons downed the shuttle??

A.L.