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To: sd-joe
the brick's acceleration vector was opposite to that of the craft. at mach 3, that would mean a 2000 mph wind (pause here with me and stick your hand out the sunroof of my corvette) would be acting on the debris in an opposite direction to that of the craft.

now... that was a good sized chunk of whatever it was... and i would guess it would accelerate to some substantial velocity with a 2000 mph wind on it in 40 meters, then striking a body traveling in the opposite direction... the relative difference in velocities could be significant.

momentum... mass (we don't know) X velocity (we don't know).

but... my guess is that even a couple pounds of whatever it was, would be cranking with whatever mass it had... and very well could have raised some serious havoc.

i've seen 200 mph winds stuff a 2X4 through a car.

182 posted on 02/03/2003 6:32:42 PM PST by glock rocks (i only engineer zeroes and ones.)
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To: glock rocks
"would mean a 2000 mph wind"

No, the "wind" starts out at the 1000 mph speed of both the rocket and the "brick" at the time of separation, and decreases relative to the brick as the brick accelerates due to the wind. At the same time that it is accelerating due to the wind, it is decelerating due to gravity (the rocket is going pretty much straight up).

Now the "brick" in relation to the shuttle, starts out at the same speed, accelerates due to wind and decelerates due to gravity. The big unknown is how much "wind" acceleration there is in the short time before it hits the wing. We are talking a small fraction of a second here I believe. Even a fairly high acceleration would not result in a great speed change in a very small time span.

Also the wind acceleration is a function of density and surface area. A large flat but light surface (like a car hood or sail) would accelerate much more than a dense, small, round object.

All that being said, the speeds and forces involved here are pretty impressive. However, the shuttle is not as fragile as some make it out to be. It is constructed to handle this incredible environment.

225 posted on 02/03/2003 7:03:34 PM PST by sd-joe
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To: glock rocks; sd-joe
i've seen 200 mph winds stuff a 2X4 through a car.

Yeah. and the tiles are sufficiently fragile 300mph raindrops have enough energy to blow them away. The same raindrops are accelerated by the flow around the airframe. This has happened at least twice in the history of the program. Each time they were sure the borosilicate glass coated tiles and the carbon-carbon tiles, both used in the areas of highest heat, would fare ok. Didn't happen.

The whole scheme operates at the knife edge of engineering risk in many areas because of the energies involved. Every cost tradeoff includes the acceptance of risk, and sometimes they don't get it right. Sad when all your eggs are in one basket.

People who say there is no effective bailout at mach 18 are ignoring the issue. The shuttle engineering is intended to return shuttle, payload, and crew, at a comfortable acceleration. Payload and crew safety are on opposite sides of the balance. If you give up shuttle, payload, and comfort, I think you will find some solutions have already been posed and ignored in the history of NASA. I would accept 10g acceleration loads and a 10% chance, for example, if I knew the alternative was 100% likely to come down in pieces. Which is the absolute consequence when the shuttle starts to tumble at mach 18.

400 posted on 02/04/2003 6:27:30 AM PST by no-s
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