To: spunkets; snopercod; wirestripper
Regarding photos of LH wing structure after impact, does anyone have a link?
I missed the press conf today and would like to believe that this is not the cause of the accident. However, let's look at some estimates of impact energy for ice on the wing area.
"The videos that NASA has are much clearer"
Yes, I posted those links in the thread a bit later.
It sounds like you want to discuss the momentum of the object. Regardless of whether or not the object is 10 kg or 100 kg, the velocity at separation from the stack is identical.
The force of impact changes depending upon the mass.
p=mv
f = ma
assume
foam mass = 4 kg
ice mass = 20 kg
v = relative velocity of impact
p(ice) = 20kg * v
p(foam) = 4 kg * v
Note mass ratio between ice vs. foam determines the ratio of the momentum of the two objects.
You are correct regarding the momentum of the object.
since force of impact = mass of object x acceleration of object into wing
f(ice)=20kg x a
f(foam)=4kg x a
The force of impact is also dependent on the same variable.
If the object is primarily ice and is a circular object about 50 cm in diameter and 5 cm thick...
the volume of that cylinder would be pi x r^2 x h
that's 3.14 x 0.25 x 0.05 = 0.0393 cubic meters
The density of ice is 917 kg/cubic meters
The mass of the ice was about 36 kg!
From Snopercod's posting of the tile map for OV-102, it appears that the forward ET-orbiter attachment bipod is about 7500 cm from the LH main landing gear door.
Let us assume that the video frame rate is 29.9 frames per sec. Movement of the object from one frame to the next correlates to 1/30th of a second (or 0.0333 sec).
Let us also assume that the object moves in one frame from the bipod to the LH main landing gear door (roughly 200 inches) about 500 cm.
The velocity of the object is 500 cm/0.033 sec = 15151 cm/sec = 5965 in/sec = 500 fps = 0.09 miles/sec = 338 mph!
Only NASA or the contractor knows if a 35 kg object going 340 mph can destroy tile in the area of the LH MLG door assembly.
(Snopercod...regarding shuttle engineers... you really do need to move to California... and don't get Hollised in the process :) )
225 posted on
02/05/2003 10:42:22 PM PST by
bonesmccoy
(Defeat the terrorists... Vaccinate!)
To: bonesmccoy
I have been looking for the pics they showed today.
No luck so far.
To: bonesmccoy
Let us assume that the video frame rate is 29.9 frames per sec. Movement of the object from one frame to the next correlates to 1/30th of a second (or 0.0333 sec).
someone said that the Frames Per Second was 97 (or something like that), not 29.
232 posted on
02/05/2003 10:54:33 PM PST by
XBob
To: bonesmccoy
Better late than never department: I just caught on to your reference to Ken Hollis. Yup, I worked with him in the firing room. CMPS. IIRC, he got fired for speaking publicly about his job.
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