Nasa examines 'tractor beams' for sample gathering

US space agency Nasa has funded a study of "tractor beams" to gather samples for analysis in future missions.

The $100,000 (£63,000) award will be used to examine three laser-based approaches to do what has until now been the stuff of science fiction.

Several tractor-beam ideas have been published in the scientific literature but none has yet been put to use.  Full Read