One day, small spacecraft could fly around Earth, using devices called electron beams to remove hulking, derelict spacecraft from orbit without ever having to touch. It may sound like science fiction, but aerospace engineers from ÍÃ×ÓÏÈÉú´«Ã½ÎÄ»¯×÷Æ· say they could be ready to test the idea in space in just five to 10 years.