Optical communications technologies don’t work too well in dusty, polluted air, but the vacuum of space holds more promise, so NASA wants to test a laser communications system in orbit.

It’s one of three projects selected by NASA for a trial run, with the other two being a solar sail and a deep space atomic clock. Laser communication systems have been tested in space before, but not on the scale of the planned Laser Communications Relay demonstration mission, which will run for three years.