Re: SpaceX Aims For 2009 Re-usability Demo

Pat Flannery <flanner@xxxxxxxxxx> wrote:

Jochem Huhmann wrote:
This would be a good point to finally try active cooling. Let the fuel
tank heat up and design in pressure-controlled valves that vent residual
(vaporized) fuel over the skin of the stage, cooling it and protecting
it from the plasma. I have always thought that this is the best way to
get anything mainly consisting of large and nearly empty fuel tanks
intact through reentry.


But you are going to have to keep it stable as far as orientation goes
during reentry, and that's probably going to mean spinning it up so a
nose-mounted heatshield/active cooling system stays pointy-end first as
it comes in...given it's shape that may not be easy.

I'm not sure that spinning it up makes things any better - because the
tail is going to be very heavy what with the engines and thrust
structures back there. You could end up fighting some nasty coupling
and precession issues.

Since the only expensive things on it are the guidance electronics and
engine, it might be smarter to mount the electronics back at the tail
end of the stage near the engine, and just have that section come down
via parachute while the propellant tankage is allowed to burn up. That
would certainly save a lot of weight on the parachute system.

I've often though the same thing.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL
.

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