New Horizons was the fastest spacecraft ever launched. Even so, it took almost a decade for it to reach Pluto, on the edge of the solar system. Yet one researcher is looking at ways to develop a probe that would fly all the way to the next star system in only about twice that amount of time — propelled by a beam of light. Sending a probe to another star would require enormous amounts of energy. It can’t be done with standard rockets, and nuclear-powered craft may be centuries in the future, if they’re built at all. But Philip Lubin of the University of California at Santa Barbara is looking at another approach. Instead of carrying heavy rockets and fuel, his probe would be powered by a laser on or near Earth. The radiation pressure would accelerate the probe to a good fraction of the speed of light. The laser could be powered by sunlight. That would provide almost unlimited energy and allow the laser to operate around the clock, giving the probe a non-stop “push.” Lubin received a NASA
