The Space Shuttle's five1 general-purpose computers played a critical role in each flight: controlling the engines, monitoring thousands of sensors, displaying data to the astronauts, and navigating the Shuttle. Each computer consisted of two 60-pound aluminum-alloy boxes: the box on the right is the CPU, a 32-bit processor that executed 420,000 instructions per second. These computers were designed before microprocessors became popular, so the processor was built from multiple boards crammed...