NASA: DEBRIS NOT TO BLAME

New York Post ^ | 2/06/03 | ANDY GELLER and FRANCI RICHARDSON

[kattracks]

February 6, 2003 -- NASA yesterday all but ruled out the possibility that the shuttle Columbia disaster was caused by a chunk of foam insulation that struck the left wing during liftoff.

Agency experts are now focusing on other theories - including the possibility the wing's heat-protecting tiles were damaged by orbiting space junk.

[Fitzcarraldo]

What caused the insulation to break off in the first place?

[kattracks]

Maybe this.

The report went on to speculate as to why the foam dropped off. As it turned out, to be environmentally friendly, NASA had eliminated the use of Freon in foam production, Mr. Katnik reported. The Marshall Space Flight Center in Huntsville, Ala., later concluded that the absence of Freon led to the detachment of the foam.

[Fitzcarraldo]

Don't know about you, but to me those OMS pod tiles look awful beat up. There are some really nasty gouges and pits. Here is a medium res view, click on link for hi-res.

Click here for hi-res image (700K)

[NoControllingLegalAuthority]

I cannot take NASA's "investigation" seriously. They have already ruled out a cause before the pieces of wreckage are gathered? I thought investigations were to gather the evidence BEFORE drawing conclusions.

[leadpenny]

Jay Barbree coming up now on Imus. MSNBC

[Falcon4.0]

By my calculations of 1/2 mass X velocity squared, the 2.67lbs foam with an impact speed of 1500 feet per second gives you a force of 3375000lbs or 1687.5 tons of force.
Sounds like a resonable explination for tile damage to me.

[Check6]

I repeat: It is sickening to see the culpable NASA administrator begin to have success in the disinformation campaign designed to save his own miserable skin.

[leadpenny]

Imus was reading from a NY Times article earlier and, according to some NASA expert, the shuttle was going a little over 1500 MPH but the relative speed of the foam piece hitting the Columbia wing was something like 700 MPH. FWIW.

[Straight Vermonter]

What you are forgetting is that at the moment it broke off the was traveling at the same speed as the shuttle. Your equation should take into account not the speed of the shuttle but rather the relative speed of the shuttle to the foam.

[Fitzcarraldo]

Imus was reading from a NY Times article earlier and, according to some NASA expert, the shuttle was going a little over 1500 MPH but the relative speed of the foam piece hitting the Columbia wing was something like 700 MPH.

Good point. Look at what happens in tornadoes where the wind speed gets up to 250 MPH. Straw driven straight into tree trunks, etc.

[Flyer]

Speaking after a memorial service for the seven Columbia astronauts, Corrigan said the program should be suspended until safety issues are resolved.

It will take decades and major leaps in technology before all the safety issues are resolved. Present day space travel is dangerous. Very dangerous. And some brave people are willing to take that risk.

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[Falcon4.0]

I thought that they were reffering to both forward velocities.
But, even with an impact speed of 700 MPH the force would be 790.5 tons.

[dtel]

By ruling out, I believe they mean they are not fixating on it as the cause, as some on here are wont to do.
It is acknowledged and duly noted, but the search goes on for either verification or the discovery of something else that could cause the problem.
It hasn't even been a week yet, be patient.

[Falcon4.0]

Thanks, but I was using what I thought was the impact speed.
The foam would not carry much inertia and loose speed radiply. Anyway you slice it it's alot of force.

[leadpenny]

Thank you. I figured I was splitting hairs anyway.

The youngest FReepers will be telling their grand children 50 years from now how they saw the last Shuttle, with an EFT covered in styro-foam, lift off in Jan of 2003. Whatever we see go into space from hear on out will not look the same. IMO.

[Cboldt]

By my calculations of 1/2 mass X velocity squared, the 2.67lbs foam with an impact speed of 1500 feet per second gives you a force of 3375000lbs or 1687.5 tons of force. Sounds like a resonable explination for tile damage to me.

First, your incorrect calculation of 0.5 x m x v**2 has a math error.

Second, you missed an important factor (I'll point it out below).

Third, Force is mass time acceleration, your equation is for kinetic energy. The amount of damage caused will certainly be affected by the amount of kinetic energy the object has, but this object did not give up all of its kinetic energy to the orbitor. Also, the amount of damage is sometimes dependent on the RATE the kinetic energy is given up.

OK, first, 1500*1500 = 2,250,000, times 2.67 is 6,007,500, and half of that is 3,003,750. But, this number is not a proper engineering calculation for kinetic energy. A common mistake made is to take a weight figure (2.67) and equate that to "mass." The two units (weight and mass) are not equivalent for calculating kinetic energy.

In order to convert between them (weight and mass), one uses the acceleration due to gravity, and using the units of choice, that unit is 32.2 feet per second per second. An object that exerts 2.67 pounds of force when resting on the earth has a mass of 0.0829 lb*sec*sec/ft (2.67 divided by 32.2). This same object is weightless in space, and would exert a heavier force if resting on Jupiter, etc.

Using the correct calculation of kinetic energy: 0.5 times 0.0829 lb*sec*sec/ft times 1500 ft/sec times 1500 ft/sec gives this moving object 93,300 foot-pounds of kinetic energy.

One can "figure" the units without using numbers, by the way, and it is a good thing to do to determine whether the calculation is giving an answer in the units you expect (e.g., are we looking for force, pressure, temperature, or something else?). In this case, the sec*sec in the numerator cancels the sec*sec in the denominator, the ft*ft in the numerator divided by the ft in the denominator leaves just ft in the numerator, so the final answer is expressed in ft-lb.

Check out The Physics Classroom.

[Cboldt]

Physics classroom URL went missing on me.

Link here -> The Physics Classroom

[dtel]

Thanks for the info and link.

[OldFriend]

I suspect the computers were not programmed to deal with a roll outside their parameters. When they tried to compensate for the leftward roll it went too far, exposing the shuttle to the intense heat and we know the rest.

Just this uninformed, uneducated guess from an old lady freeper.