The mission accomplished its goals and also saw the collection of the Genesis Rock, thought to be part of the Moon's early crust, and Scott's use of a hammer and a feather to validate Galileo's theory that when there is no air resistance, objects fall at the same rate due to gravity regardless of their mass.

The mission received 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.

In 1962, NASA contracted for the construction of fifteen Saturn V rockets to achieve the Apollo program's goal of a crewed landing on the Moon by 1970; at the time no one knew how many missions this would require.

[20] Scott was born in 1932 in San Antonio, Texas, and, after spending his freshman year at the University of Michigan on a swimming scholarship, transferred to the United States Military Academy, from which he graduated in 1954.

Irwin had been born in 1930 in Pittsburgh, and had attended the United States Naval Academy, graduating in 1951 and serving in the Air Force, receiving a master's degree from Michigan in 1957.

Geologist Farouk El-Baz trained the prime crew's command module pilot, Ken Mattingly to inform his planned observations from lunar orbit.

[ALSJ 2] Scott was determined that his crew bring back the maximum amount of scientific data possible, and met with Silver in April 1970 to begin planning the geological training.

The CAPCOM was accompanied by a geologist unfamiliar with the area who would rely on the astronauts' descriptions to interpret the findings, and familiarized the crew members with describing landscapes to people who could not see them.

The Site Selection Committee had narrowed the field down to two sites—Hadley Rille, a deep channel on the edge of Mare Imbrium close to the Apennine mountains or the crater Marius, near which were a group of low, possibly volcanic, domes.

[39] The expanded mission meant that Worden spent much of his time at North American Rockwell's facilities at Downey, California, where the command and service module (CSM) was being built.

[41] The demands of the training strained both Worden's and Irwin's marriages; each sought Scott's advice, fearing a divorce might endanger their places on the mission as not projecting the image NASA wanted for the astronauts.

Scott explained the choice of the name Endeavour on the grounds that its captain, James Cook, had commanded the first purely scientific sea voyage, and Apollo 15 was the first lunar landing mission on which there was a heavy emphasis on science.

Boeing received the contract for three rovers on a cost-plus basis; overruns (especially in the navigation system) meant the three vehicles eventually cost a total of $40 million.

This was a concern not only because an important piece of equipment, providing information on distance and rate of approach, might not work properly, but because bits of the glass cover were floating around Falcon's interior.

[61] As well as preparing the Lunar Module for its descent, the crew continued observations of the Moon (including of the landing site at Hadley) and provided television footage of the surface.

[ALFJ 13] After analyzing the problem, the crew and Houston decided the probe instrumentation umbilical was likely loose or disconnected; Worden went into the tunnel connecting the command and lunar modules and determined this was so, seating it more firmly.

But the time schedule allowed Scott to open the lander's top hatch (usually used for docking) and spend a half hour looking at their surroundings, describing them, and taking photographs.

After concluding this stop, they returned to the lander to drop off their samples and prepare to set up the Apollo Lunar Surface Experiments Package (ALSEP), the scientific instruments that would remain when they left.

[80][ALSJ 6] Although Scott had eventually been successful at drilling the holes, he and Irwin had been unable to retrieve a core sample, and this was an early order of business during EVA 3, their third and final moonwalk.

The core proved one of the most important items brought back from the Moon, revealing much about its history, but the expended time meant the planned visit to a group of hills known as the North Complex had to be scrubbed.

[ALSJ 6] Once the astronauts were beside the LM, Scott used a kit provided by the Postal Service to cancel a first day cover of two stamps being issued on August 2, the current date.

[ALSJ 3][82] Scott then performed an experiment in view of the television camera, using a falcon feather and hammer to demonstrate Galileo's theory that all objects in a given gravity field fall at the same rate, regardless of mass, in the absence of aerodynamic drag.

This was Joe Allen's idea (he also served as CAPCOM during it) and was part of an effort to find a memorable popular science experiment to do on the Moon along the lines of Shepard's hitting of golf balls.

His task was complicated by the lack of a working mission timer in the Lower Equipment Bay of the command module, as its circuit breaker had popped en route to the Moon.

[85] At approximately 171,000 nautical miles[ALFJ 1][86] (197,000 mi; 317,000 km) from Earth, it was the first "deep space" EVA in history, performed at great distance from any planetary body.

Upon landing in the North Pacific Ocean, the CM and crew were recovered and taken aboard the recovery ship, USS Okinawa, after a mission lasting 12 days, 7 hours, 11 minutes and 53 seconds.

It is remembered still for its combination of competent enthusiasm, magnificent machinery, finely honed science and the grandeur of a very special site in the cosmos beside a meandering rille and graceful, massive mountains – Hadley Base.

[ALFJ 8] Despite the successful mission, the careers of the crew were tarnished by a deal they had made before the flight to carry postal covers to the Moon in exchange for about $7,000 each, which they planned to set aside for their children.

Van Hoeydonck claims to have had a different understanding of the agreement, by which he would have received recognition as the creator of a tribute to human space exploration, with rights to sell replicas to the public.

[ALSJ 13] The halo area of the Apollo 15 landing site, created by the LM's exhaust plume, was observed by a camera aboard the Japanese lunar orbiter SELENE and confirmed by comparative analysis of photographs in May 2008.