SAN FRANCISCO (Reuters) - Billionaire Internet investor Yuri Milner announced another $100 million initiative on Tuesday to better understand the cosmos, this time by deploying thousands of tiny spacecraft to travel to our nearest neighboring star system and send back pictures.

If successful, scientists could determine if Alpha Centauri, a star system about 25 trillion miles away, contains an Earth-like planet capable of sustaining life.

The catch: It could take years to develop the project, dubbed Breakthrough Starshot, and there is no guarantee it will work.

Tuesday’s announcement, made with cosmologist Stephen Hawking, comes less than a year after the announcement of Breakthrough Listen. That decade-long, $100 million project, also backed by Milner, monitors radio signals for signs of intelligent life across the universe.

Breakthrough Starshot involves deploying small light-propelled vehicles to carry equipment like cameras and communication equipment. Scientists hope the vehicles, known as nanocraft, will eventually fly at 20 percent of the speed of light, more than a thousand times faster than today’s spacecraft.

“The thing would look like the chip from your cell phone with this very thin gauzy light sail,” said Pete Worden, the former director of NASA’s Ames Research Center, who is leading the project. “It would be something like 10, 12 feet across.”

He envisions sending a larger conventional spacecraft containing thousands of nanocraft into orbit, and then launching the nanocraft one by one, he said in an interview.

Slideshow ( 7 images )

The idea has precedents with mixed results.

Two years ago, Cornell University’s KickSat fizzled after the craft carrrying 104 micro-satellites into space failed to release them. The plan was to let the tiny satellites orbit and collect data for a few weeks.

Worden acknowledges challenges, including the nanocraft surviving impact on launch. They would then endure 20 years of travel through the punishing environment of interstellar space, with obstacles such as dust collisions.

“The problems remaining to be solved - any one of them are showstoppers,” Worden said.

Governments likely would not take on the research due to its speculative nature, he said, yet the technology is promising enough to merit pursuing.

If the nanocraft reach the star system and succeed in taking photographs, it would take about another four years to transmit them back to Earth.

A onetime physics PhD student in Moscow who dropped out to move to the United States in 1990, Milner is one of a handful of technology tycoons devoting time and money to space exploration. He is known for savvy investments, including in social network Facebook Inc and Chinese smartphone company Xiaomi.