It’s four-and-a-quarter light-years to the closest planets beyond the solar system, which orbit the star Proxima Centauri. At the speed of the fastest probe ever launched, it would take about 80,000 years to get there. But one project plans to cover that distance in about 20 years — and not with one probe, but potentially with hundreds. But there’s a catch: Each probe would be the size of a postage stamp.

Breakthrough Starshot was established in 2016. Teams of scientists and engineers are studying the challenges of launching such tiny probes.

Each one would be powered by a “sail” covering a few square yards. High-powered lasers on Earth would beam light at them. The pressure of the light would accelerate the probes to about 20 percent of the speed of light within hours of launch.

A probe would carry everything it needed to conduct its mission, including cameras and its own laser to transmit information to Earth. It would have a thin coating to protect it from collisions with grains of dust.

There are lots of challenges to overcome. Today’s lasers are nowhere near powerful enough to propel the probes, for example. And at a large fraction of lightspeed, a probe would have a good view of its target planets for only seconds.

If technology continues to improve at its current pace, though, it’s possible that the first probes could be launched in a few decades — zooming toward our closest planetary neighbors.

Script by Damond Benningfield