Milner, whose parents named him after the Russian cosmonaut Yuri Gagarin, studied physics at Moscow State University before helping to start a series of Internet companies. Thanks in part to a prescient investment in Facebook, Milner has accumulated a fortune worth $3.2 billion, according to the Bloomberg Billionaires Index. Starting in 2012, he set upon an ambitious second career as a scientific patron.

As part of this “hobby,” as he described it, Milner has funded a series of rich scientific prizes in physics, math, and life sciences. Last July, he announced that he would spend $100 million on Breakthrough Listen over the next decade, reinvigorating what had been a mostly dormant search for extraterrestrial life.

Milner was inspired in part to launch the new Breakthrough Starshot after seeing a postage-stamp-size spacecraft built by KickSat, a Kickstarter-funded research project that began its first mission in 2014. Though KickSat’s spaceships don’t have engines or the cameras needed by Milner’s butterfly ships, they were created with a very modest budget that included a roughly $75,000 Kickstarter campaign. Zachary Manchester, the creator of KickSat, has joined the Breakthrough Starshot team. “This is a glimpse of the future,” Milner said as he extracted one of KickSat’s computer-chip-like spaceships from his jacket pocket.

Milner and Worden are hesitant to discuss timing, but they say that the mission is achievable within a generation, assuming that advances in lasers and chips continue apace. Worden estimated that the program will eventually cost somewhere around $10 billion, about what the European Organization for Nuclear Research spent to build the Large Hadron Collider.

If all goes well, Milner looks forward to seeing a picture of a planet that could support life. “It could be a very expensive picture,” he said, offering a wry smile, “but maybe the most precious picture ever taken.”

First « 1 2 » Next