The CPU Shack Updated Aug 12 2012
Many CPUs have been used in space craft, space stations and other such probes.
Such CPUs must be highly reliable, and very durable. The temperatures in space, even
with heaters, can vary widely. The radiation that a system is exposed too can be immense.
So when designing one of these systems designers don't always use the latest and greatest
microprocessor. They use a chip that has been tried and tested. That they KNOW will work.
A CPU for use in space must first be MIL-STD-883 (usually Class M or S, ground based is B). This means it has met the over 100 tests
that the Department of Defense has developed to insure reliable operation.
These tests include: thermal, mechanical, AC electrical and DC electrical tests as well as sampling
requirements for individual wafer inspections.
Most CPUs that pass come from the center of a wafer. This eliminates edge defects and
generally makes for a more radiation resistant device.
Also note that MOST spacecraft use many CPUs. Either for redundancy or to split tasks.
Being able to separately control EACH component of a spacecraft is very important.
This would be impossible if one CPU controlled them all. With each sub-system powered
by its own CPU the sub-systems can be better controlled for power management and
fault tolerance. (for example if one CPU dies it only would disable one instrument, not the whole spacecraft)
More:
http://www.cpushack.com/space-craft-cpu.html
