CAPE CANAVERAL, Fla. (AP) – A NASA spacecraft chasing a rare metal asteroid swings past Mars this week for a gravity boost, snapping thousands of pictures as practice for the main encounter in 2029. Named Psyche, like the asteroid it's after, the robotic explorer will slingshot past the red planet at 12,333 mph (19,848 kph) on Friday 15 May. It will be an especially close flyby, with Psyche passing within 2,800 miles (4,500 kilometers) of Mars , equivalent to the distance between the US east