The Orion, which took itsfirst unmanned test flightDec. 5,launching from Cape Canaveral, Florida and orbitingfor four and a half hours before splashing into the Pacific Ocean, isNASA’s latest human-rated spacecraft project, and probably the most ambitious ever. Itsultimate goal, like the Apollo program 45 years ago, is to take humans to places they’ve never gonebefore. In 1969, that meantthe Moon. This time, the destination isMars, and the Orion might takea crew there by 2021.
Given the grand scope of this project, one might think that the NASA engineersbuilding the shuttle would pull out everytechnological stop, drawing in the newestsuper-fastcomputing power. Right?
Not quite, Orion project manager Matt Lemketold The Space Reviewin a recent interview. In fact, the computer hardwareonboard the Orion eschews the cutting-edge, favoring gear that has been tried and tested for years. The three onboard Honeywell-built flight computers each run on two IBM PowerPC 750X single-core processors—dinosaur chips that have been around since 2002, and were used inApple computers until the company switched to Intel chips in 2006. The computers are “not any faster than your smartphone,” Lemke said.
This isn’t due to budget constraints; the December flight cost $375 million, and the Orion program will receive $1.2 billion funding in fiscal 2015. Rather, it’s because these old-codger computers are actually the best for the job. That’s because while speed might be prioritizedin the consumer sector—where customers can or must buy a replacement if something goes wrong—reliability takes precedencewhen it comes to computing in space.
And the Honeywell computers are nothing if not solid. They are adapted from the onboard computers used by Boeing 747 aircraft and outfitted to resist the intense vibrations and radiation of a long space flight.
The radiation shielding is perhaps the most important. High-energy rays in space can altera computer’s memory, causing glitches that could be catastrophic. That’s the main reason to have three onboard computers—if one or even two crash, the system can still correct itself.
And of course, hardware from 2002 still makes the equipment the Apollo mission had at hand in 1969 seem prehistoric. Back then, the onboard computer clocked in at one megahertz and had about 36 kilobytes of memory. An iPhone 6 is athousand times faster, with 30,000times thememory.
Still, Apollomade it to the Moon. When it comes to space travel, sometimes old and steady beats fast and sexy.
