[LINK] "Why NASA’s Orion Spacecraft Flew Old, Slow Computers Into Orbit"

[rfmcdonald]

Universe Today's Elizabeth Howell explains why new spacecraft like NASA's Orion use older computers. Their failure modes are well-known, it turns out, and combine capability with durability generally.

It’s funny to think that your smartphone might be faster than a new spaceship, but that’s what one report is saying about the Orion spacecraft. The computers are less-than-cutting-edge, the processors are 12 years old, and the speed at which it “thinks” is … slow, at least compared to a typical laptop today.

But according to NASA, there’s good reasoning behind using older equipment. In fact, it’s common for the agency to use this philosophy when designing missions — even one such as Orion, which saw the spacecraft soar 3,600 miles (roughly 5,800 kilometers) above Earth in an uncrewed test last week and make the speediest re-entry for a human spacecraft since the Apollo years.

The reason, according to a Computer World report, is to design the spacecraft for reliability and being rugged. Orion — which soared into the radiation-laden Van Allen belts above Earth — needs to withstand that environment and protect humans on board. The computer is therefore based on a well-tested Honeywell system used in 787 jetliners. And Orion in fact carries three computers to provide redundancy if radiation causes a reset.

“The one thing we really like about this computer is that it doesn’t get destroyed by radiation,” said Matt Lemke, NASA’s deputy manager for Orion’s avionics, power and software team, in the report. “It can be upset, but it won’t fail. We’ve done a lot of testing on the different parts of the computer. When it sees radiation, it might have to reset, but it will come back up and work again.”