launch

On Tuesday, November 19, 2002, at 09:34 AM, Brad Walsh wrote:

>> To this end I believe NASA should devote at least 50% >of the budget to
>> reusable launch vehicle development.
>
> And/or to developing the Space Elevator concept, using carbon nanotube
> technology.

Space elevators certainly deserve some long term R&D (actually, I've
done a tiny bit of this myself on NASA's dime), but the probability of
success isn't all that high even in the long term. It only takes one
fatal problem to make a system unusable, and there are several candidate
fatal problems for space elevators. They include:

-- strength of materials. For example, measured carbon nanotube
strength is much less than the early theoretical calculations predicted.
-- atmospheric interference
-- safety

This isn't to say we shouldn't work on it, we should. But we certainly
shouldn't count on it.

The dinosaurs were destroyed by an asteroid because they weren't
space-faring. It's almost as if Gaia then thought "Well, dinosaurs
worked pretty well, but space-faring is necessary. Maybe I'll should
try mammals this time." Humanity is now developing systems to detect and
deflect asteroids, and could build orbital space colonies to spread
beyond Earth to insure life would survive a planetary catastrophe.

Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html