Stephen Hawking and a Russian billionaire want to send tiny light-propelled “nanocrafts” to Alpha Centauri

Talk about “shooting for the stars.”
Talk about “shooting for the stars.”
Image: European Southern Observatory
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Innovation in space exploration requires bright minds and deep pockets. A new ambitious space project, announced today (April 12), boasts the best of both those worlds.

The legendary physicist Stephen Hawking is combining powers with the Russian entrepreneur and billionaire Yuri Milner to launch ”Breakthrough Starshot,” a $100 million initiative to aid in the search for life elsewhere in the universe. Its lofty goal sounds straight out of science fiction: Starshot aims to send thousands of tiny spacecrafts, called “nanocrafts,” to Alpha Centauri—the closest solar system to our own.

Hawking and Milner aren’t the only famous names involved. The initiative is led by Pete Worden, the former director of NASA’s AMES Research Center. Facebook creator and CEO Mark Zuckerberg is on the project’s board.

With standard spacecraft technology, it would take around 30,000 years to reach Alpha Centauri, which is four lightyears (25 trillion miles) away. Starshot, however, would use a very different technology. Instead of a traditional chemical propellant, the nanocrafts are powered by light. In theory, the nanocrafts could travel at roughly one-fifth of the speed of light, allowing them to—again, theoretically—reach the faraway star system in just 20 years.

They’d be equipped with even tinier cameras that could record images of potentially habitable planets within the Alpha Centauri system. It would then take about four years for the nanocrafts to send that data back to Earth. If all goes according to plan, humans could be looking at images of these alien worlds in just three decades or so.

Each nanocraft, each only a few grams in size, would consist of two main components. The first is the “StarChip,” a microcomputer processor that the project has predicted it can build in the future based on Moore’s Law—a theory positing that computer processing power will double every two years. Some scientists have criticized the theory, but Hawking and Milner will hope it holds true in order for them to develop such tiny machines with such immense computer power.

The second component is the “Light Beamer,” a phased array of lasers that would push the nanocrafts through space when pointed at their sails. As Rachel Feltman writes in the Washington Post, though, designing computers and lasers powerful (and small) enough to send these spacecrafts through space at the desired speeds is a long shot.

The key here is that this is really all only a theory—nothing similar has every been attempted before. Still, other scientists are similarly fascinated by the prospect of light travel. In 2018, NASA will launch a small satellite powered by the photons from the sun pelting its ultrathin sail. That space vessel, however, will only venture as far as a near-Earth asteroid. The nonprofit research organization Planetary Society, led by scientist Bill Nye “The Science Guy,” is also developing solar sailing technology with the LightSail project.

Milner, a physicist by training, launched the Breakthrough Initiatives last year. Among its other ambitious projects is “Breakthrough Listen,” another $100 million initiative to scan the skies for evidence of extraterrestrial life using radio telescopes.

Hawking and Milner made the announcement on the 55th anniversary of the first human spaceflight, made by Russian cosmonaut Yuri Gargarin in 1961.

Image by European Southern Observatory on Wikimedia, licensed under CC-BY-4.0.