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. It will be an especially close encounter, with Psyche passing within 2,800 miles. Then it will be on to the asteroid belt between Mars and Jupiter that is home to its enticing target. All of the spacecraft’s science instruments will be on for the flyby. Cameras will snap thousands of pictures. The spacecraft is named Psyche like the asteroid it’s after. The spacecraft should reach the metal-rich asteroid in 2029.