Micro-Space has begun Vacuum Environment testing of our operational communications modules. This will be a long process, for - although we have done production and research high vacuum work for decades (including a variety of thin film coatings and multilayer structures) – we have never done vacuum environment testing for spacecraft systems and will have to add a number of elements to our vacuum chambers.

Beyond the obvious concern of venting of batteries (and liquid electrolytic capacitors, if they were used), plus vaporization of necessary lubricants in mechanical systems, the primary vacuum effect on electronics is to expand the thermal control problems. With the loss of air convection for heat distribution at even moderate vacuum, temperature gradients become more severe. With the loss of all gas thermal conductivity in high vacuum (10 exp - 4 Torr) only radiation and conduction in solids remain to remove heat from hot components.

Heat sinks of course need to be redefined, since they are not cooled by air, and if not positioned to radiate heat directly into space, they accomplish little or nothing. The classic black heat sink is also a mistake, since white paint radiates heat in the infrared as well as any other color, but the white surface absorbs less solar radiation if sunlight can't be completely blocked from the radiator structure.

These problems are reduced with today's low power electronic components. Legacy space systems have a bigger problem since the new, low power products are not “Space Qualified”. In fact, many of these will have a higher ionizing radiation sensitivity, which will call for redundant systems and components as well as error correction techniques. The short operational life of a Google Lunar Lander of course reduces the problems seen with a ComSat. Military satellites, like military aircraft, tend to have such a high “Power Density” in the electronics that cooling is a huge problem.