A planned U.S. mission to investigate three ice-covered moons of Jupiter will demand fast-paced research, fabrication and realistic non-nuclear testing of a prototype nuclear reactor within two years, says a Los Alamos National Laboratory scientist. The roots of this build and test effort have been under way at Los Alamos since the mid-1990s, said David Poston, leader of the Space Fission Power Team in Los Alamos’ Nuclear Design and Risk Analysis Group.