The Russian philanthropist and entrepreneur Yuri Milner, alongside a panel of esteemed theoretical physicists, including Stephen Hawking, announced today an ambitious plan to send a team of small, ultra-lightweight robots to earth’s closest star system, Alpha Centauri, which is 4.37 light-years away.

“For the first time in human history, we can do more than just gaze at the stars,” Milner said of the $100 million initiative called Breakthrough Starshot, during an event at the One World Observatory in Lower Manhattan. “We can actually reach them.”

These probes, which Milner (named Yuri after cosmonaut Yuri Gagarin, who 55 years ago today became the first human to go into space describes as “sailboats,” are nanocrafts that could reach Alpha Centauri after a twenty-year journey.

These gram-scale nanocrafts will be pushed through space by a light beam, which consists of phased arrays of lasers. The light beam has the capability of being scaled to a 100 gigawatt level.

The nanocrafts are built with two main components: A StarChip — gram-scale wafer, carrying cameras, photon thrusters, power supply, navigation and communication equipment, and constituting a fully functional space probe — and a Lightsail — thin and lightweight metamaterials, which can enable the fabrication of meter-scale sails no more than a few hundred atoms thick and at gram-scale mass.

This, Milner says, is the “Silicon Valley approach to space flight.” He also said the goal is to mass-produce the StarChips at the cost of an iPhone.

The plan is to send these nanocrafts 600,000 miles into space, while moving at a fifth of the speed of light. These will be a thousand times faster than today’s spacecraft technology, and a million times faster than a car.

The first version of the StarChip, which can be mass produced.

Milner acknowledges that there are still challenges ahead and also encouraged scientists from around the world to work them out together. With this in mind, the Breakthrough Starshot initiative also has a research grant program, with the goal that further scientific and engineering research could solve these 19 challenges:

This announcement coincides with the 35th anniversary of the first orbital mission of NASA’s space shuttle program.

Artist rendering of the nanocrafts.

Until today, the details concerning the space exploration initiative were largely a mystery. More than 27,000 people tuned into the live-streamed event, the predictions in the comments section beforehand ranging from “are we building a Death Star??” to “alien life confirmed.”

Speculation that the focus of the project would be on the search for extraterrestrial life was made by media outlets prior to the event. Milner and Hawking teamed up in July 2015 to unveil Breakthrough Listen, a 10-year $100 million funded SETI search. Breakthrough Listen is considered the “biggest scientific search ever undertaken for signs of intelligent life beyond Earth.”

Milner, a trained physicist worth an estimated $3 billion with a track record of making good predictions, is bankrolling Breakthrough Listen, which has plans to survey 1,000 of the closest stars to Earth while listening “for messages from the 100 closest galaxies.” Milner also funds a related project, Breakthrough Message, which is a competition to craft the best message to send to aliens.

This “path to the stars,” Breakthrough Initiative hopes, will also help astronomers come across a Earth-like planet existing within the “habitable zones” of the Alpha Centauri’s three star system. But, perhaps most intriguingly, Nobel-prize winning astronomer Saul Perlmutter coyly noted today that he’s never thought that planets were where we’ll find extraterrestrial life first. They could very well be in the stars.

Photos via GifGrabber, Screenshot