Last July, Milner committed $100 million to support the expansion of a University of California, Berkeley-based search for extraterrestrial intelligence (SETI) program that enables astronomers at observatories around the world to "listen" for radio signals and bursts of laser light. His new commitment will fund research and engineering programs designed to prove the feasibility of the concepts behind his Breakthrough Starshot project — which calls for sending fleets of tiny robot spacecraft into interstellar space — within a generation.
A former physicist, Milner envisions thousands of ships he calls "nanocrafts" speeding at a hundred million miles an hour to star systems light-years away. The tiny spacecraft would carry huge lightweight "sails" — "each no more than a few hundred atoms thick," Milner said — propelled by the pressure from light beams created by phased arrays of earth-bound lasers generating hundreds of millions of kilowatts at a time.
"We hope to demonstrate the lightweight payload and sail technologies within a decade," said Avi Loeb, a Harvard University astrophysicist who heads Milner's advisors for Breakthrough Starshot, told the Chronicle. "Interstellar travel is challenging, but based on these technical advances, we believe there is a path forward without obvious show-stoppers....If we are lucky, it's a couple of decades."
"The limit that confronts us now is the great distance between us and the stars," said cosmologist Stephen Hawking, who serves on the board of directors for the project. Milner's commitment, he added, should lead Earth-bound space explorers to "transcend our limits."