Apollo 15 was the fourth mission to land astronauts on the Moon.
The prime crew men of the Apollo 15 lunar landing mission, aboard the NASA Motor Vessel Retriever (MVR), talk with the assigned lead Underwater Demolition Team (UDT) swimmer for recovery operations of the mission. The crewmen were in the Gulf of Mexico to take part in water egress training. From left to right are U.S. Navy Lieutenant Fred W. Schmidt; astronauts Alfred M. Worden, command module pilot; James B. Irwin, lunar module pilot; and David R. Scott, commander.