Apollo 15 was the first of the Apollo ‘J’ missions capable of a longer stay time on the Moon and greater surface mobility. There were four primary objectives falling in the general categories of lunar surface science, lunar orbital science, and engineering-operational. The mission objectives were to explore the Hadley-Apennine region, set up and activate lunar surface scientific experiments, make engineering evaluations of new Apollo equipment, and conduct lunar orbital experiments and photographic tasks.
Apollo 15 was the ninth crewed mission in the US Apollo program, and the fourth mission to land on the Moon. Apollo 15 saw the first use of the Lunar Roving Vehicle.
Al’s Apollo 15 Transposition, Docking and Extraction of the Lunar Module
The mission launched on July 26, 1971, and splashed down on August 7, with the lunar surface exploration taking place between July 30 and August 2. Commander David Scott and Lunar Module Pilot James Irwin landed near Hadley Rille and explored the local area using the rover, allowing them to travel further from the lunar module than had been possible on previous missions. They spent 181⁄2 hours on the Moon’s surface on extravehicular activity (EVA), and collected 170 pounds (77 kg) of surface material.
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 Al Worden performed the first deep space spacewalk.
Al Worden’s Deep Space EVA
The Apollo 15 mission splashed down safely on August 7 despite the loss of one of its three parachutes.
Al Worden often recounted: “I could see fuel leaking as we descended, which disintegrated the first parachute on contact. I also watched as holes started to appear in the second. Thankfully we splashed down before another chute failed.”
The mission accomplished its goals but was marred by negative publicity the following year when it emerged that the crew had carried unauthorized postal covers to the lunar surface, some of which were sold by a West German stamp dealer. The members of the crew were reprimanded for poor judgment, and did not fly in space again. Apollo 15 is also remembered for the discovery of the Genesis Rock, and for Scott’s use of a hammer and a feather to validate Galileo’s theory that absent air resistance, objects drop at the same rate due to gravity.