The Death Star in "Star Wars" reeled in space ships with "tractor beams." So did Captain Kirk's USS Enterprise on "Star Trek." Now NASA's Goddard Space Flight Center in Greenbelt, Maryland, aims to develop a real tractor beam, but on a much smaller scale. Here's the concept: Unmanned space probes might use laser beam technology … Continue reading It's not 'Star Trek,' but NASA wants a 'tractor beam'