Apollo 15 entered lunar orbit on July 29, 1971. The next day, astronauts David R. Scott and James B. Irwin separated their Lunar Module (LM) Falcon from Alfred M. Worden, who remained in orbit aboard the Command Module (CM) Endeavour. Scott and Irwin touched down at the Hadley-Apennine site and conducted four spacewalks, including three excursions using the Lunar Roving Vehicle, for a combined total of 19 hours. They deployed an experiment package and collected 170 pounds of rock and soil samples to return to waiting scientists on Earth. In the meantime, Worden conducted an expanded set of observations and photography of the lunar surface from orbit. After their 67-hour lunar surface stay, Scott and Irwin prepared to rejoin Worden in orbit.