06 Jul 2003, 14:02, JIM HOLSONBACK (1:123/140), wrote to ALL:

Hi JIM.

 JH> Recently, I saw in newspaper a writeup about experiments done by 
 JH> NASA - they made a compressed Nitrogen canon, firing a piece of 
 JH> lightweight insulation (BIR somewhat less than 1.5 pounds), and fired 
 JH> the insulation piece at a test article of shuttle wing leading edge at 
 JH> something like 530 miles per hour.  The test article(s) did sustain 
 JH> some damage.
...................

 JH> Unfortunately, I didn't see anything about the rationale for the 
 JH> 500+ mph impact.  In any event, it is clear that the shuttle was 
 JH> moving out smartly, and the lightweight insulation must have slowed 
 JH> down a lot due to air friction before it struck the wing of the 
 JH> orbiter.

 JH> If anyone has seen more of the scientific details of the Shuttle
 JH> testing, I'd like to hear about them.

That is the only test that I have read about also, and I share the same
question.  I _think_ I can rationalize that the shuttle was at max
acceleration on a trajectory from 0 MPH to 17,000 MPH, and with NASA
knowing the split second timing from the breakaway to impact, they probably
calculated the change-of-speed of the shuttle itself during that
approximate three seconds from breakaway of the foam until impact time.

They might not have even needed to calculate for air resistance.  If at
that point in time the shuttle was accelerating at ~200MPH per second, that
2.8 seconds to impact would give about 530 MPH increase in shuttle speed
relative to the speed of the piece of foam.


     Good luck...  M.

--- Msged/386 TE 06 (pre)