asteroids. >> the power of what lucy is able to do by having so many targets, we can construct all these comparisons between all the different varieties and the diversity that we see in the trojans, the unexpected diversity, the different colors, the different collisional histories. it's really a repository of fossils, as we like to say, of things that happened at the earliest stages of solar system evolution. >> reporter: the spacecraft, a little more than 14 meters from tip to tip, is powered by two giant solar arrays that will expand outward like chinese folding fans. they'll carry lucy farther away from the sun than any other solar-powered spacecraft. lucy will never return to earth, but she won't be the last to visit the asteroids. nasa plans to send more. china and russia are teaming up on an asteroid mission in 2024. and the uae in 2028. kristin fisher, cnn.