Breakthrough Starshot program to make stamp-sized solar-powered spaceships capable of interstellar travel

The most famous cosmologist in the known universe, Dr Stephen Hawking, together with a much-moneyed mob of investors headed by Russian tech billionaire Yuri Milner and including Facebook creator Mark Zuckerberg, have just launched an extraordinary plan to send tiny spaceships deeper into the universe than mankind has ever stretched before: operation Breakthrough Starshot.

Powered by solar sails, the nucleus of the nano craft envisaged by the Breakthrough Starshot project will be a single microchip, little more than 1cm across. With scientists’ ever-growing capability to shrink super-sophisticated technology, these spacechips will collect and transmit vast amounts of data during their missions, which, all going to plan, will see them reach Alpha Centauri in the space of 20 years (a trip that would take spacecraft using today’s technology around 30,000 years).

Alpha Centauri is the solar system next-door to our own. As far as intra-galactic community etiquette goes, thus far we’ve thought it safe enough to have the music on quite loud after 9pm, even on a school night, since our interstellar neighbour is 40 trillion kilometres (4.37 light years) away, and if anyone lives there, they appear to be quite heavy sleepers. However, us Earthlings might just be about to awaken them, by sending a ball over the fence. A very small ball, perhaps, but one that can travel at 60,000 kilometres a second (which is roughly 135 million miles per hour, or one-fifth the speed of light).

In many respects, Dr Stephen Hawking is an unlikely candidate to encourage the lobbing of such a ball. Until relatively recently, the charismatic former Cambridge don has urged a much more cautionary line on communicating with aliens. If we end up attracting the attention of an alien race who turn out to be vastly superior to us, he has warned, we risk coming out of any ensuing relationship a little like Native Americans emerged from the scenario after Europeans rocked up in the New World.

Hawking’s last collaboration with Yuri Milner reflected this somewhat careful approach to making potential contact with extraterrestrial beings. Last year, with $100-million of Milner’s money, the pair announced the Breakthrough Listen initiative, which will spend 10 years searching a million stars and a hundred galaxies with it ear cupped, listening for signals broadcast by alien civilizations—but not necessarily letting them know about our presence. The second stage of this project is the Breakthrough Message initiative, which will potentially open up a dialogue with any lifeforms that might be out there, but no cosmic communiqués have yet been broadcast.

Meanwhile, Dr Hawkings has apparently had a rethink about his apocalyptic approach to making contact, and realised that our species is stuck between the third rock from the Sun, and potentially a very hard place. ‘Earth is a wonderful place, but it might not last forever,’ he commented this week. ‘Sooner or later, we must look to the stars. Breakthrough Starshot is a very exciting first step on that journey.’

And that first step is being taken thanks to the passion and punching power of 54-year-old Yuri Milner, a billionaire businessman and noted philanthropist named after the Russian cosmonaut who was the first person to travel in space. Around a year ago, Milner began consulting scientists such as Harvard University astrophysicist Avi Loeb, about the serious potential of interstellar travel. Loeb came up with the concept of miniaturising the mission vehicle and propelling it with laser-powered light sails, and he’s now the new chairman of Breakthrough Starshot’s advisory board. Loeb leant on earlier work completed by Philip Lubin, a physicist at the University of California, who is also part of the project team.

Milner has conceded that it will take a lot more investment—some estimates place the cost at around trillion dollars—and up to two decades of work before the project can achieve lift off, but he’s confident that interstellar travel is possible, and if we can make one tiny space-spanning information-sourcing craft, we should be able to create a cloud of them. Which would be good, because these are definitely one-way missions, and the ultimate destiny of each individual spaceship is very uncertain.

After hurtling through our own solar regions, sending quickfire reports and images back to Earth as it travels, the proposed craft will then set off to the twin-star system of Alpha Centauri. Once there it will transmit data (which will take up to four years to reach controllers) until, devoid of any brakes, it will continue careering into the unknown, to keep exploring long after it’s gone beyond earshot of everyone on Earth.