Project Mercury, a nationwide team effort led by NASA, recorded and studied the physiological and psychological effects of astronauts in space. NASA selected McDonnell to design, develop and build the first crewed spacecraft Jan. 12, 1959. Before the final splashdown, May 16, 1963, McDonnell had delivered 20 vehicles, and the spacecraft had compiled 53 hours 55 minutes and 25 seconds of crewed space flight time.