Testing Things We Put Into Space
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.
Vacuum bake outs simulate the space like atmosphere and temperature conditions the satellite component will see. It is also critical to outgas any contaminates at the molecular level. A high-vac bake out will generally accomplish this. Also, with a very thin atmosphere, temperature transfer is radiative versus convection. (The same temperature performance that occurs in a vacuum oven).
Some of the more popular tools of the vacuum bake out trade include:
- A RGA (Residual Gas Analyzer) identifies the type of contaminates outgassing.
- A QCM (Quartz Crystal Monitor) shows the rate of outgassing.
Cascade TEK is accredited to perform NASA MSFC-SPEC-548 “Specification For Vacuum Baking Of Electrical Connectors For Space Applications.” In this specification, the vacuum bake cycle is 340°F + 10°F, -15°F and a vacuum range of 5 x 10-4 torr or better. The duration is 48 hours, not to exceed 100 hours. Although this NASA spec is designed for connectors, it serves as a good guideline for other flight hardware components.
Thermal hi-vac systems are expensive and sensitive instruments. Cascade TEK’s SVO-10 Turbo is available on a as needed basis for our customers to perform the necessary bakeouts.