Electronic components suitable for use in vacuum?

[wavley]

As far as epoxy goes, I know that in the past we used some Armstrong A-12 on parts for NASA's WMAP probe, it may be a good place to look.  And yes, we had a valve fail once, that's why we know it takes two weeks to melt. As far as the amp goes, I can't take credit for designing it, I just build them, but I do help perform experiments to make them better.

[aziltz]

According to wikipedia (which may be dodgy), the pressure at 100km above sea level is still 10^(-3) Torr, which is a much lower quality vacuum than ours.  The interstellar vacuum, even, is not infinite, really - there are always some bits of dust or molecules about, and even in their absence (i.e. in the spaces between them), quantum mechanics predicts a finite minimum energy density (the "vacuum energy").

i am so glad you dropped quantum mechanics just now.