"John H" wrote in message
...
I was watching a repeat of the post landing briefing and Mike Linebaugh was
talking about purging residual hypergolics from the orbiter after
landing... are those LH2 and LO2 and I assume its whats left over from
liftoff in parts of the pumps, pipes? whatever... wouldnt they just
evaporate or sublime or whatever they do out in space? or if they are in a
closed system they might still be present? Or is he talking about whats
left over in the re-entry engines.


It is what is left over in the "re-entry" engines -- called the Orbital
Maneuvering System. The small jets that control attitude -- called the
Reaction Control System -- are also hypergolic.

Danny Deger