At the same time, Command Module Pilot Alfred Worden orbited the Moon, operating the sensors in the SIM bay of the service module. This suite of instruments collected data on the Moon and its environment using a panoramic camera, a gamma-ray spectrometer, a mapping camera, a laser altimeter, a mass spectrometer, and a lunar subsatellite deployed at the end of the moonwalks. The lunar module returned safely to the command module and, at the end of Apollo 15’s 74th lunar orbit the engine was fired for the journey home. During the return trip Worden performed the first spacewalk in deep space. The Apollo 15 mission splashed down safely on August 7 despite the loss of one of its three parachutes.