Space hardware must be free of contamination and be able to withstand radiative behavior of temperature and the very thin atmosphere of space. 100Km straight up is the Karman line. This is where the atmosphere becomes too thin to support lift. Satellites generally fly at about 300 Km above the earth, which for vacuum folks is about 10-6 torr. Cascade TEK’s SVO hi-vac ovens can reach 10-6 and often into the 10-7 torr range.