Apollo 15 was the forth manned landing on the Moon. The mission took place in July & August 1971.
David Scott and James Irwin descended to the Moon's surface after a night's rest in orbit around the Moon. They spent three days on the Moon's surface and carried out three EVAs. This extended time was possible in part because of improved spacesuits.
This was the first mission to use the Lunar Rover, a lightweight vehicle. When tested after landing, the front wheel steering was not working, but the back worked OK. The men could never go further on the Rover than they would be able to walk back if it broke down - but it still extended their range considerably.
After unloading the Rover they first carried out a sampling trip. Then they set up a similar scientific station to those of Apollos 12 and 14. This allowed for triangulation. The second and third days included a lot more sampling trips. These were mostly to test theories based on the reults of the earlier Apollo landings.
Before lift off the Rover was driven some distance from the Lunar Module so that its cameras could capture Falcon's lift off.
While in orbit, Alfred Worden operated a variety of cameras and some experiments to determine the makeup of the Moon's crust.
During the descent to Earth, one of the three paracutes did not open, but the landed safely, if a little fast, on the remaining two.