In article ,
Chuck Stewart wrote:
chemical fuels, if you picked carefully. I would guess that ClF5/NH3
would be non-contaminating. (Don't know if anyone's tried that particular
combination; ammonia is notorious for being difficult to burn well because
it's so stable, but ClF5 is notorious for being so ferociously active that
it gives smooth combustion with anything it gets its hands on.)

Including the telescope?

That's definitely a combination you want to run fuel-rich. :-)

Handling ClF5 is, shall we say, a "zero defects" kind of operation. Never
mind fuels; the stuff is hypergolic with all normal fire-extinguishing
agents...

(The recommended firefighting procedure for a ClF5 fire is to take cover
at a safe distance. Quickly.)
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |