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I understand that the shuttle Columbia was moving very fast - perhaps several thousand miles per hour? - when the foam broke off the fuel tank. But the tank was traveling at the same speed. So, in my mind, at the instant the foam broke off it would have been travelling at the same speed as the fuel tank; and, therefor, at the same speed as the shuttle.
So how did the foam decelerate so rapidly in the fraction of a second between the time it broke loose and the time it hit the shuttle that the shuttle was moving over 500 MPH faster than the debris? It would seem (although it was sadly not the case) that the foam would have just drifted past the shuttle as it slowly lost momentum due to the pull of gravity and whatever atmospheric resistance might have existed at that altitude.
Any explanations?
A fairly common somewhat similar example is when a piece of paper falls out of a vehicle on the highway - it doesn't keep up with the vehicle.
Not that I have any better answers than you :)
The report makes interesting reading (in 10-minute-at-a-time chunks). Not as dry as might be expected, well written, mostly in terms I can understand. Only goes off into the arcane a couple of times.
the main thing is that the foam block was light in weight and once it hit the airstream, it was slowed in much the same way as that cigarette pack... you'll also note that both items spun after their release... this also contributes to the slowdown in much the same way that a coin dropped from a major height will also spin and not cause the damage one might imagine when it hits the ground...
another thing to consider, too, about the force of the impact is that spin... the speed of the spin added additional total speed to that section of the foam block that impacted the wing area... if that leading edge of the foam achieved a spinrate of sufficient quantity, it could easily have contributed 100mph or more to the impact velocity in addition to the speed differential already gained by the foam block slowing...
and finally, note that those tiles are not all that strong... one can easily put their finger right into them with little trouble...
if you haven't been by [caib.us ], yet, it may be a good idea to drop by there for the reports... other places like www.space.com have a lot of info in their forums, too... i know that space.com has numerous nasa employees posting there... they are not, however, posting in any official capacity...
Upon take off there is a great amount of things going on. So lets say the shuttle is moving a 500 miles per hour or even a little slower in the initial 20 feet. Then add the foam falling at 30 miles per hour thats around 530 miles per hour thats gonna ruin something if it hits, even if it were at 300 miles per hour in the first 20 feet. Another thing to take into account is the downward pressure, maybe a vaccum like pressure, that accelorates the foam up.
Something you can look at is a regular car wreck for an example. Your driving at 45 miles per hour and a deer is standing out in the road and you whack that sucker and blammo, smear of deer. The deer was not going fast, just standing there. However you hit it at 45 and it weighed 120 lbs your car weighed 2000 lbs (if you drive an america car) so now you have a screwed up car. The deer was not moving, but you were.
It makes sence that when the foam hit the wing that it would cause the damage it did. The things I am not sure of would be the downward pressure coming from the rockets lighting up. If there are any nasa folks that could shed some light on this that would be neato.
You also have to take into account that there are many things in life no matter how you plan for it they just happen. Someone has control and knows whats going on, I aint him though.
Any typo are to be likened to the nearest word you can relate it to.
Me + Typing = not good
"So, in my mind, at the instant the foam broke off it would have been travelling at the same speed as the fuel tank; and, therefor, at the same speed as the shuttle. "
what you are fogetting is that the foam was optimised to stay on the rocket booster and when it deployed from its planned position effectively
the algorythm changed ...
I think we all know what poop can result from that :-)
Consider this, stick your hand out the window of you car at 60 mph. It's difficult to hold it straight and requires strength to do so. Imagine tossing something out - gone.
That's less than half a percent of shuttle speed. I don't know what the atmosphere is like at that altitude, but I think it is more dense than half a percent of sea level.
-- the foam was traveling with the Shuttle at about 1,568 mph
-- the velocity of the foam debris slowed from 1,568 mph to about 1,022 mph
-- the Orbiter hit the foam with a relative velocity of about 545 mph
In essence, the foam debris slowed down and the
Orbiter did not,so the Orbiter ran into the foam. The foam
slowed down rapidly because such low-density objects have
low ballistic coefficients, which means their speed rapidly
decreases when they lose their means of propulsion.
Basically everything was still going real, real fast (yeah, that's a technical term), but the orbiter was going faster than the foam.
Basically everything was still going real, real fast (yeah, that's a technical term)
I thought all the real technical terms got one or more words bleeped out of the middle...
If you were worried about litter, you could perform the car experiment with starch packing foam. :) It melts into harmless starch goo as soon as it gets wet.
Toss one out the front seat window, and see if a back-seat passenger with their hand out the window can catch it... then ask them if it hit their hand very hard. As long as you weren't travelling 1000+ mph at the time, they shouldn't be injured.
I can feel Newtons law of relativity coming in here
I is a college graduate, but I majored in history. I've never heard of Newton's Law of Relativity. What is it?
lawman
I've never heard of Newton's Law of Relativity. What is it?
For each increase in price there is a corresponding decrease in the amount of fig filling.
I was thinking along those same lines:
Every +1 increase of visiting relative creates a
-12 availability of fig newtons
Think of the force of the thrust that was jetting out the base of the shuttle. Think of this as fast moving air. If all that air is moving so fast out of the rockets than it must create a vaccum further up. All the air on either side of the boosters would be drawn down, creating an almost suction effect up the body of the craft. The foam might have been effected by this and almost sucked down to it's impact point.
Mack.
