THREE! (not one) pieces of insulation hit the left wing of Columbia. :(

“If we did not say three pieces at first,** it was completely inadvertent** on our part and it was a mistake. We certainly should have made that clear,” said NASA spokesman James Hartsfield.


I hate when they pull stuff like this. Another hit on the old credibility meter…

Since the foam and shuttle initially have the same momentum, does anyone know how fast they were moving in relation to each other?

The foam was said to impact on the orbiter at a speed of about 500 MPH.

When the foam left the tank, it was traveling at the same speed as the shuttle. How did that change to a difference of 500 mph?

Getting back to the actual OP, guys, this “revelation” on the part of NASA is astonishing.

They obviously lied. They concealed the truth and then inelegantly tried to spin their way out of it. Makes one wonder what other undisclosed truths exist…

I’d say that was a bit harsh. According to this, it’s happened before where foam’s fallen off and it didn’t cause any problems then.

So it’s possible that the folks at NASA made the natural assumption that since it didn’t do any harm before, it wouldn’t do any harm this time.

The shuttle was travelling at about mach 2 when the foam broke off. The foam pieces are very lightweight, so atmospheric drag would slow them down pretty quickly.

Why do you think they “obviously” lied? They left out a minor detail when talking to the press. Big deal. “They” didn’t “conceal the truth” since the people investigating the accident knew about it. NASA doesn’t have the obligation to disclose 100% of their findings to the press immediately.

When the insulation broke off, it no longer was experiencing the same acceleration force that the shuttle was. The shuttle continued to accelerate upwards, were as the acceleration of the insulation was downwards (due to gravity and frictional forces). So while the insulation was going the same speed as the shuttle at the instant it broke off, it would have a very large speed differential in a very short time period.

Also from the article:

To put it simply: BFD. So what? What does it matter if it was one piece of foam with X weight, or three pieces of foam totaling X weight? It doesn’t seem to change anything.

Also, on the issue of the force involved, it’s not the simple momentum but the angle of incidence of striking. The assumption was that the angle would have been too obtuse to allow much transferrence of force.

Yep. Here’s a thought experiment from the perspective of someone sitting in a shuttle, with the window rolled down.

I’m imagining driving down a highway at 100 mph (at night, lights off, radar detector on, watching for cops). Then I stick a big piece of foam outside my window and let go. What does it do? While I speed on, the foam flys out of my hand and drops to the ground and stays there. In other words, it goes from 100 to 0 pretty fast. Relative to my car, it goes from 0 to 100 pretty fast.

Imagine going Mach 2. That’s 10 times faster than a bad hurricane, or a few times faster than the meanest tornado every recorded. A wind like that could rip a house right out of Kansas and drop it down in Indiana. Stick a big piece of foam outside. Wham! Zero to very fast in the blink of an eye.

You forgot that the foam happens to be made from ceramics. They don’t wrap the shuttles in polystyrene, you know. :wink: Lightweight for ceramics, yes, but still a potential issue on a craft with critical vulnerabilities.

According to the external fuel tank’s foam is polyurethane.

Just like they did with the O-rings, huh? :rolleyes:

That assumption should be nicknamed the “Russian roulette” assumption. Regardless of its ‘naturalness’, it’s the sort of thing anyone with a modest scientific background should be able to see through. If NASA can’t, then the whole agency ought to be scrapped, and the US space program rebuilt from scratch under new management.

In all fairness, we have no idea what anyone assumed about anything.

A wonderful idea, but has already been discussed in other threads, an incredibly expensive proposition unlikely to happen at any time in the near future, if ever.

As for the O-Rings, NASA did a mea culpa on the whole thing and has tried to move on. Why can’t you?

High school physics nitpick:

The foam and shuttle initially had the same velocity. They did not have the same momentum.

(Momentum is equal to mass times velocity.)

And the Tacoma Narrows bridge, and the Hindenberg, and the De Havilland Comet, and all the rest of the engineering disasters. We’re only human - it’s inevitable that sooner or later we fail to anticipate one possibility of failure and it results in a disaster. When that happens we learn from it, improve the design and try again.

In the case of Columbia, some engineers may have expressed concern about the foam insulation. But I’m sure concerns are raised for just about every component on the spacecraft. NASA as a group failed to see that it is a seriuos problem. In hindsight it was a mistake, but that doesn’t mean the people are guilty of neglicence.

Ah…New Scientist reported it as ceramic. Interesting.