At 09:45 AM 2/23/01 -0500, Trei, Peter wrote:
>I'll speculate that Jim posted this as a demo that 'amateur' rocketry
>can reach orbit. If you read the article, you'll find it does nothing of
>the kind. This is suborbital - in fact, the rocket goes almost 350km
>straight up and down (they're testing scramjet configurations during
>re-entry).
A significant portion of a solid rocket motor's weight is the casing and
nozzle. The casing allows the gases from the burning propellent to
generate enough pressure that when they exit the nozzle their moving a very
high velocity. One of the brightest recent ideas in rocketry comes from
Technanogy (http://www.technanogy.net): if you reduce the size of the
propellent grains the velocity of the gasses at the burning surface can go
from sub-sonic to supersonic without the need for a nozzle (perhaps even a
casing). Goodbye nozzle and casing, hello single-stage to orbit. Thrust
vectoring, if desired, would be accomplished by other well-known means.
Technanogy has built a pilot plant to manufacture 40 nm aluminum
powder. The technology's efficacy was verified by a series of test at
Aerospace Corp. and they have secured a grant to retrofit a large number
Sidewinders. They claim that the change should dramatically increase range
with minimal weapon system changes. If successful they hope to apply their
approach to orbital vehicles.
steve
