Ken Oyadomari’s work space at NASA Ames Research Center in Mountain View, Calif., looks like a triage tent for smartphones. Parts from dozens of disassembled devices are strewn on workbenches. A small team of young engineers picks through the electronic carnage, carefully extracting playing card-size motherboards—the microprocessing heart of most computers—that will be repurposed as the brains of spacecraft no bigger than a softball. Satellites usually cost millions of dollars to build and launch. The price of Oyadomari’s nanosats, as they’ve become known, is around $15,000 and dropping.