Lasers Could Blast Astronauts to Mars, Protect Earth from Asteroids

The same laser system being developed to blast tiny spacecraft between the stars could also launch human missions to Mars, protect Earth from dangerous asteroids and help get rid of space junk, project leaders say. Last month, famed physicist Stephen Hawking and other researchers announced Breakthrough Starshot, a $100 million project that aims to build prototype light-propelled "wafersats" that could reach the nearby Alpha Centauri star system just 20 years after launch. The basic idea beh