LOS ANGELES, May 14 : NASA's Psyche probe was headed for a close encounter with Mars on Friday and a planned gravity boost to set the spacecraft on its final course to the solar system's largest known metallic asteroid, thought to be the remnant core of an ancient protoplanet.The Psyche probe, named for the a

A NASA spacecraft chasing a rare metal asteroid is swinging past Mars for a gravity boost. The Psyche spacecraft will slingshot past the red planet at more than 12,000 mph Friday.

NASA's Psyche spacecraft will slingshot past Mars on Friday, on its way toward a rare metal-rich asteroid.