Fourth crewed Moon landing
Apollo 15 (July 26 – August 7, 1971) was the ninth crewed mission in the Apollo program and the fourth Moon landing. It was the first J mission, with a longer stay on the Moon and a greater focus on science than earlier landings. Apollo 15 saw the first use of the Lunar Roving Vehicle.
The mission began on July 26 and ended 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 18 ;templatestyles src="Fraction/styles.css" / ;1⁄2 hours on the Moon's surface on four extravehicular activities (EVA), and collected of surface material.
At the same time, Command Module Pilot Alfred Worden orbited the Moon, operating the sensors in the scientific instrument module (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, Worden performed the first spacewalk in deep space. The Apollo 15 mission splashed down safely on August7 despite the loss of one of its three parachutes.
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. The members of the crew were reprimanded for poor judgment, and did not fly in space again.
Background.
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. In 1969 Apollo 11 succeeded in landing on the Moon with the sixth SaturnV, so nine rockets remained available for a hoped-for total of ten landings. These plans included a heavier, extended version of the Apollo spacecraft to be used in the last five missions (Apollo 16 through 20). The revamped Lunar Module would be capable of up to a 75-hour stay, and would carry a Lunar Roving Vehicle to the Moon's surface. The service module would house a package of orbital experiments to gather data on the Moon. In the original plan Apollo 15 was to be the last of the non-extended missions to land in Censorinus crater. But in anticipation of budget cuts, NASA cancelled three landing missions by September 1970. Apollo 15 became the first of three extended missions, known as J missions, and the landing site was moved to Hadley Rille, originally planned for Apollo 19.
Crew and key Mission Control personnel.
Crew.
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. Serving in the Air Force, Scott had received two advanced degrees from MIT in 1962 before being selected as one of the third group of astronauts the following year. He flew in Gemini 8 in 1966 alongside Neil Armstrong and as command module pilot of Apollo 9 in 1969. Worden was born in 1932 in Jackson, Michigan, and like his commander, had attended West Point (class of 1955) and served in the Air Force. Worden earned two master's degrees in engineering from Michigan in 1963. 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. Both Worden and Irwin were selected in the fifth group of astronauts (1966), and Apollo 15 would be their only spaceflight. All three future astronauts had attended Michigan, and two had taken degrees from there; it had been the first university to offer an aeronautical engineering program.
The backup crew was Richard F. Gordon Jr. as commander, Vance D. Brand as command module pilot and Harrison H. Schmitt as Lunar Module pilot. By the usual rotation of crews, the three would most likely have flown Apollo 18, which was canceled. Brand flew later on the Apollo–Soyuz Test Project and on STS-5, the first operational Space Shuttle mission. With NASA under intense pressure to send a professional scientist to the Moon, Schmitt, a geologist, was selected as LMP of Apollo 17 instead of Joe Engle.
Apollo 15's support crew consisted of astronauts Joseph P. Allen, Robert A. Parker and Karl G. Henize. All three were scientist-astronauts, selected in 1967, as the prime crew felt they needed more assistance with the science than with the piloting. None of the support crew would fly during the Apollo program, waiting until the Space Shuttle program to go into space.
Mission Control.
The flight directors for Apollo 15 were as follows:
During a mission the capsule communicators (CAPCOMs), always fellow astronauts, were the only people who normally would speak to the crew. For Apollo 15, the CAPCOMs were Allen, Brand, C. Gordon Fullerton, Gordon, Henize, Edgar D. Mitchell, Parker, Schmitt and Alan B. Shepard.
Planning and training.
Schmitt and other scientist-astronauts advocated for a greater place for science on the early Apollo missions. They were often met with disinterest from other astronauts, or found science displaced by higher priorities. Schmitt realized that what was needed was an expert teacher who could fire the astronauts' enthusiasm, and contacted Caltech geologist Lee Silver, whom Schmitt introduced to Apollo 13's commander, Jim Lovell, and to its Lunar Module pilot, Fred Haise, then in training for their mission. Lovell and Haise were willing to go on a field expedition with Silver, and geology became a significant part of their training. Geologist Farouk El-Baz trained the prime crew's command module pilot, Ken Mattingly to inform his planned observations from lunar orbit. The crew's newly acquired skills mostly went unused, due to the explosion that damaged the Apollo 13 spacecraft, and caused an abort of the mission. Apollo 14's CMP, Stuart Roosa, was enthusiastic about geology, but the mission commander, Shepard, less so.
Already familiar with the spacecraft as the backup crew for Apollo 12, Scott, Worden and Irwin could devote more of their training time as prime crew for Apollo 15 to geology and sampling techniques. 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. Schmitt's assignment as Apollo 15's backup LMP made him an insider, and allowed him to spark competition between the prime and backup crews. The cancellation of two Apollo missions in September 1970 transformed Apollo 15 into a J mission, with a longer stay on the lunar surface, and the first Lunar Roving Vehicle (LRV). This change was welcomed by Scott, who according to David West Reynolds in his account of the Apollo program, was "something more than a hotshot pilot. Scott had the spirit of a true explorer", one determined to get the most from the J mission. The additional need for communications, including from planned experiments and the rover, required the near-rebuilding of the Honeysuckle Creek Tracking Station in Australia.
Geology field trips took place about once a month throughout the crew's 20 months of training. At first, Silver would take the commanders and LMPs from the prime and backup crews to geological sites in Arizona and New Mexico as if for a normal field geology lesson, but closer to launch, these trips became more realistic. Crews began to wear mock-ups of the backpacks they would carry while hiking near the Rio Grande Gorge, and communicate using walkie-talkies to a CAPCOM in a tent. 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. Considering himself a serious amateur, Scott came to enjoy field geology.
The decision to land at Hadley came in September 1970. 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. Although not ultimately his decision, the commander of a mission always held great sway. To David Scott the choice was clear, as Hadley "had more variety. There is a certain intangible quality which drives the spirit of exploration and I felt that Hadley had it. Besides it looked beautiful and usually when things look good they are good." The selection of Hadley was made although NASA lacked high resolution images of the landing site; none had been made as the site was considered too rough to risk one of the earlier Apollo missions. The proximity of the Apennine mountains to the Hadley site required a landing approach trajectory of 26 degrees, far steeper than the 15 degrees in earlier Apollo landings.
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. He undertook a different kind of geology training. Working with El-Baz, he studied maps and photographs of the craters he would pass over while orbiting alone in the CSM. As El-Baz listened and gave feedback, Worden learned how to describe lunar features in a way that would be useful to the scientists who would listen to his transmissions back on Earth. Worden found El-Baz to be an enjoyable and inspiring teacher. Worden usually accompanied his crewmates on their geology field trips, though he was often in an airplane overhead, describing features of the landscape as the plane simulated the speed at which the lunar landscape would pass below the CSM.
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 consulted Director of Flight Crew Operations Deke Slayton, their boss, who stated what was important was that the astronauts do their jobs. Although the Irwins overcame their marital difficulties, the Wordens divorced before the mission.
Hardware.
Spacecraft.
Apollo 15 used command and service module CSM-112, which was given the call sign "Endeavour", named after HMS "Endeavour", and Lunar Module LM-10, call sign "Falcon", named after the United States Air Force Academy mascot. 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. Apollo 15 took with it a small piece of wood from Cook's ship, while "Falcon" carried two falcon feathers to the Moon in recognition of the crew's service in the Air Force. Also part of the spacecraft were a Launch Escape System and a Spacecraft-Lunar Module Adapter, numbered SLA-19.
Technicians at the Kennedy Space Center had some problems with the instruments in the service module's scientific instrument module (SIM) bay. Some instruments were late in arriving, and principal investigators or representatives of NASA contractors sought further testing or to make small changes. Mechanical problems came from the fact the instruments were designed to operate in space, but had to be tested on the surface of the Earth. As such, things like the 7.5 m (24 ft) booms for the mass and gamma ray spectrometers could be tested only using equipment that tried to mimic the space environment, and, in space, the mass spectrometer boom several times did not fully retract.
On the Lunar Module, the fuel and