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Stephen Hawking and a Russian billionaire want to send tiny, light-powered spacecraft to Alpha Centauri

Stephen Hawking and a Russian billionaire want to send tiny, light-powered spacecraft to Alpha Centauri


And they want to make it there in just 20 years

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Russian venture capitalist Yuri Milner, along with physicist Stephen Hawking, has announced a $100 million initiative for exploring Alpha Centauri, the star system nearest to our own. The new project is called Breakthrough Starshot, and the goal is to explore the technologies needed to create small, light-powered spacecraft capable of reaching Alpha Centauri in just 20 years.

The project will be led by Pete Worden, the former director of NASA's AMES Research Center. Facebook founder and CEO Mark Zuckerberg will join Hawking and Milner on the project's board of directors.

Breakthrough Starshot’s ultimate goal is to determine the feasibility of sending "ultra-light, ultra-compact spacecraft" to Alpha Centauri. The idea is to use vehicles that are like the space versions of sailboats. These spacecraft are called lightsails because they use light for propulsion, and they’re not new: one was even launched by Bill Nye and the Planetary Society last year. Lightsail spacecraft typically use the Sun’s light or solar wind for propulsion, but Milner’s proposed version would instead use a giant laser array to propel the spacecraft toward Alpha Centauri.

Starshot's spacecraft would use lasers and lightsails

Starshot's sails would measure a few meters wide, a few hundred atoms thick, and have very little mass. They would tow even smaller spacecraft behind the sails, too, which Milner calls these the "StarChips." Part of the goal of Starshot is to find a way make these StarChips wafer thin while still including things like cameras, sensors, a power supply, communication and navigation equipment, and photon thrusters for maneuvering. Milner says that advancements in nanotechnology will make developing these StarChips possible.

Alpha Centauri is the closest neighboring star system, but it’s more than four light years — or 25 trillion miles — away. To get a sense of scale, consider Voyager 1, which has been traveling at 40,000 miles per hour for almost 40 years. It’s still less than .0005 percent of the distance to Alpha Centauri. Future Starshot spacecraft would need to move at more than 134 million miles per hour in order to travel to Alpha Centauri in just 20 years.

Starshot is really just a research project; the actual mission would be much more expensive

"Significant engineering challenges" must be overcome before anything resembling Starshot's proposed mission gets off the ground, according to Breakthrough Initiatives, which is the overarching investment program run by Milner. The scale of Starshot's ambitions significantly exceeds any projects currently in operation. It’s not just the problem of the unheard-of speeds required to get spacecraft to Alpha Centauri in such a short amount of time. Nor is it simply developing the lightsails and chips. The vehicles would also require significant infrastructure. For instance, to get the tiny spacecraft, dubbed nanocrafts, off the ground, a "mothership" would need to be built and launched to high-altitude orbit. Plus, the laser array meant to propel the crafts hasn’t yet been developed — and it, too, would need to be built in an especially dry, high-altitude location on Earth in order to work.

Then there's the matter of cost. Breakthrough Initiatives calls Starshot a "$100 million research and engineering program," but the actual price tag of a mission would be much higher. In the accompanying press release, Breakthrough Initiatives admits as much, saying that the proposed mission would require a budget "comparable to the largest current scientific experiments." Those experiments run in the billions of dollars.

This is not the first time that Milner and Hawking have collaborated on a space venture. Just last year Milner devoted $100 million to increasing the search for extraterrestrial life (SETI) with a project called "Breakthrough Listen." That project going to allow researchers to study the 1 billion stars nearest to Earth as well as 100 galaxies outside our own Milky Way.

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