Mariner 4NASA attempts a second unmanned launch to Mars, successfully putting Mariner 4 on course for its nine-month cruise to the red planet. Intended to take the first-ever close-up pictures from the vicinity of another planet, Mariner 4’s main engineering objective is to simply survive the trip. The main problem encountered en route is a flaky star tracker (intended to lock onto specific stars and keep Mariner 4 in the correct orientation).