Itâs a theoretical concept, but realistic enough that NASAâs Innovative Advanced Concepts program has given Davoyanâs group $175,000 to show that the technology is feasible. âThereâs rich physics in there,â says Davoyan, a mechanical and aerospace engineer at UCLA. To create propulsion, he continues, âyou either throw the fuel out of the rocket or you throw the fuel at the rocket.â From a physics perspective, they work the same: Both impart momentum to a moving object.
His teamâs project could transform long-distance space exploration, dramatically expanding the astronomical neighborhood accessible to us. After all, weâve only sent a few robotic visitors to scope out Uranus, Neptune, Pluto, and their moons. We know even less about objects lurking farther away. The even smaller handful of NASA craft en route to interstellar space include Pioneer 10 and 11, which blasted off in the early 1970s; Voyager 1 and 2, which were launched in 1977 and continue their mission to this day; and the more recent New Horizons, which took nine years to fly by Pluto in 2015, glimpsing the dwarf planetâs now famous heart-shaped plain. Over its 46-year journey, Voyager 1 has ventured farthest from home, but a pellet-beam-powered craft could overtake it in just five years, Davoyan says.
He takes inspiration from Breakthrough Starshot, a $100 million initiative announced in 2016 by Russian-born philanthropist Yuri Milner and British cosmologist Stephen Hawking to use a 100-gigawatt laser beam to blast a miniature probe toward Alpha Centauri. (The star nearest our solar system, it resides âonlyâ 4 light-years away.) The Starshot team is exploring how they could hurl a 1-gram craft attached to a lightsail into interstellar space, using the laser to accelerate it to 20 percent of the speed of light, which is ludicrously fast and would reduce travel time from millennia to decades. âIâm increasingly optimistic that later this century, humanityâs going to be including nearby stars in our reach,â says Pete Worden, Breakthrough Starshotâs executive director.
