The Lunar Roving Vehicle (LRV) is a battery-powered four-wheeled rover used on the Moon in the last three missions of the American Apollo program (15, 16, and 17) during 1971 and 1972. It is popularly called the Moon buggy, a play on the term "dune buggy".
Built by Boeing, each LRV has a mass of without payload. It could carry a maximum payload of , including two astronauts, equipment, and cargo such as lunar samples, and was designed for a top speed of , although it achieved a top speed of on its last mission, Apollo 17.
Each LRV was carried to the Moon folded up in the Lunar Module's Quadrant 1 Bay. After being unpacked, each was driven an average of , without major incident. These three LRVs remain on the Moon.
History
The concept of a lunar rover predated Apollo, with a 1952–1954 series in Collier's Weekly magazine by Wernher von Braun and others, "Man Will Conquer Space Soon!". In this, von Braun described a six-week stay on the Moon, featuring ten-ton tractor-trailers for moving supplies.
In 1956, Mieczysław G. Bekker published two books on land locomotionBekker, Mieczyslaw G.; Theory of Land Locomotion, U. Michigan Press, 1956, and The Mechanics of Vehicle Mobility, U. Michigan Press, 1956 and 1962. while he was a University of Michigan professor and a consultant to the U.S. Army Tank-Automotive Command's Land Locomotion Laboratory. The books provided much of the theoretical basis for future lunar vehicle development.
In 1959, Georg von Tiesenhausen conceived the lunar rover as a four-wheel-drive vehicle with noninflated, flexible wheels.
Early lunar mobility studies In the February 1964 issue of Popular Science, von Braun, then director of NASA's Marshall Space Flight Center (MSFC), discussed the need for a lunar surface vehicle, and revealed that studies had been underway at Marshall in conjunction with Lockheed, Bendix, Boeing, General Motors, Brown Engineering, Grumman, and Bell Aerospace.von Braun, Wernher; "How We'll Travel on the Moon," Popular Science, February 1964, pp. 18–26. Saverio Morea was named LRV Manager at MSFC in 1961.
Beginning in the early 1960s, a series of studies centering on lunar mobility were conducted under Marshall. This began with the lunar logistics system (LLS), followed by the mobility laboratory (MOLAB), then the lunar scientific survey module (LSSM), and finally the mobility test article (MTA). In early planning for the Apollo program, it had been assumed that two Saturn V launch vehicles would be used for each lunar mission: one for sending the crew aboard a Lunar Surface Module (LSM) to lunar orbit, landing, and returning, and a second for sending an LSM-Truck (LSM-T) with all of the equipment, supplies, and transport vehicle for use by the crew while on the surface. All of the first Marshall studies were based on this dual-launch assumption, allowing a large, heavy, roving vehicle.Young, Anthony; Lunar and planetary rovers: the wheels of Apollo and the quest for Mars; Springer, 2007, pp. 30–57;
Grumman and Northrop, in late 1962, began to design pressurized-cabin vehicles, with electric motors for each wheel. At about this same time, Bendix and Boeing started their internal studies on lunar transportation systems. Mieczysław Bekker, now with General Motors Defense Research Laboratories at Santa Barbara, California, was completing a study for NASA's Jet Propulsion Laboratory on a small, uncrewed lunar roving vehicle for the Surveyor program. Ferenc Pavlics, originally from Hungary, used a wire-mesh design for "resilient wheels," a design that would be followed in future small rovers.Bekker, Mieczyslaw G., and Ferenc Pavlics; "Lunar Roving Vehicle Concept: A Case Study"; GMDRL Staff Paper SP63-205, May 1963.
In early 1963, NASA selected Marshall for studies in an Apollo Logistics Support System (ALSS). Following reviews of all earlier efforts, this resulted in a 10-volume report. Included was the need for a pressurized vehicle in the weight range, accommodating two men with their expendables and instruments for traverses up to two weeks in duration. In June 1964, Marshall awarded contracts to Bendix and Boeing, with GM's lab designated as the vehicle technology subcontractor."Molab," Encyclopedia Astronautics. Bell Aerospace was already under contract for studies of Lunar Flying Vehicles.Courter, Robert; "What It's Like to Fly the Jet Belt," Popular Science, Nov. 1969, pp. 55–59, 190.
Even as the Bendix and Boeing studies were underway, Marshall was examining a less ambitious surface exploration activity, the LSSM. This would be composed of a fixed, habitable shelter–laboratory with a small lunar-traversing vehicle that could either carry one man or be remotely controlled. This mission would still require a dual launch with the moon vehicle carried on the "lunar truck". Marshall's Propulsion and Vehicle Engineering (P&VE) lab contracted with Hayes International to make a preliminary study of the shelter and its related vehicle."Lunar Shelter/Rover Conceptual Design and Evaluation," NASA CR-61049, Nov. 1964. Because of the potential need for an enclosed vehicle for enlarged future lunar explorations, those design efforts continued for some time and resulted in several full-scale test vehicles.
With pressure from Congress to hold down Apollo costs, Saturn V production was reduced, allowing only a single launch per mission. Any roving vehicle would have to fit on the same lunar module as the astronauts. In November 1964, two-rocket models were put on indefinite hold, but Bendix and Boeing were given study contracts for small rovers. The name of the lunar excursion module was changed to simply the Lunar Module, indicating that the capability for powered "excursions" away from a lunar-lander base did not yet exist. There could be no mobile lab—the astronauts would work out of the LM. Marshall also continued to examine uncrewed robotic rovers that could be controlled from the Earth.
From the beginnings at Marshall, the Brown Engineering Company of Huntsville, Alabama, had participated in all of the lunar mobility efforts. In 1965, Brown became the prime support contractor for Marshall's P&VE Laboratory. With an urgent need to determine the feasibility of a two-man self-contained lander, von Braun bypassed the usual procurement process and had P&VE's Advanced Studies Office directly task Brown to design, build, and test a prototype vehicle."Brown Builds Concept Of Lunar Vehicle," BECO Views, Vol. 9, Jan. 1966, p. 1. While Bendix and Boeing would continue to refine concepts and designs for a lander, test model rovers were vital for Marshall human factors studies involving spacesuit-clad astronauts interfacing with power, telemetry, navigation, and life-support rover equipment.
Brown's team made full use of the earlier small-rover studies, and commercially available components were incorporated wherever possible. The selection of wheels was of great importance, and almost nothing was known at that time about the lunar surface. The Marshall Space Sciences Laboratory (SSL) was responsible for predicting surface properties, and Brown was also prime support contractor for this lab; Brown set up a test area to examine a wide variety of wheel-surface conditions. To simulate Pavlics's "resilient wheel," a four-foot-diameter inner tube wrapped with nylon ski rope was used. On the small test rover, each wheel had a small electric motor, with overall power provided by standard truck batteries. A roll bar gave protection from overturning accidents.
In early 1966, Brown's vehicle became available for examining human factors and other testing. Marshall built a small test track with craters and rock debris where several different mock-ups were compared; it became obvious that a small rover would be best for the proposed missions. The test vehicle was also operated in remote mode to determine characteristics that might be dangerous to the driver, such as acceleration, bounce-height, and turn-over tendency as it traveled at higher speeds and over simulated obstacles. The test rover's performance under one-sixth gravity was obtained through flights on a KC-135A aircraft in a Reduced Gravity parabolic maneuver; among other things, the need for a very soft wheel and suspension combination was shown. Although Pavlics' wire-mesh wheels were not initially available for the reduced gravity tests, the mesh wheels were tested on various soils at the Waterways Experiment Station of the U.S. Army Corps of Engineers at Vicksburg, Mississippi. Later, when wire-mesh wheels were tested on low-g flights, the need for wheel fenders to reduce dust contamination was found. The model was also extensively tested at the U.S. Army's Yuma Proving Ground in Arizona, as well as the Army's Aberdeen Proving Ground in Maryland.
Lunar Roving Vehicle Project
During 1965 and 1967, the Summer Conference on Lunar Exploration and Science brought together leading scientists to assess NASA's planning for exploring the Moon and to make recommendations. One of their findings was that the LSSM was critical to a successful program and should be given major attention. At Marshall, von Braun established a Lunar Roving Task Team, and in May 1969, NASA approved the Manned Lunar Rover Vehicle Program as a Marshall hardware development. The project was led by Eberhard Rees, Director of Research and Development at Marshall, who oversaw the design and construction of the rover, with Saverio Morea acting as project manager.
On 11 July 1969, just before the successful Moon landing of Apollo 11, a request for proposal for the final development and building the Apollo LRV was released by Marshall. Boeing, Bendix, Grumman, and Chrysler submitted proposals. Following three months of proposal evaluation and negotiations, Boeing was selected as the Apollo LRV prime contractor on 28 October 1969. Boeing would manage the LRV project under Henry Kudish in Huntsville, Alabama. Kudish was replaced the following year in 1970 by LRV Project Manager Earl Houtz. As a major subcontractor, the General Motors Defense Research Laboratories in Santa Barbara, California, would furnish the mobility system (wheels, motors, and suspension); this effort would be led by GM Program Manager Samuel Romano andFrom the Moon to the Balloon, New Jersey's Amazing Aviation History, HV Pat Reilly, 1992. Ferenc Pavlics. Boeing in Seattle, Washington, would furnish the electronics and navigation system. Vehicle testing would take place at the Boeing facility in Kent, Washington, and the chassis manufacturing and overall assembly would be completed at the Boeing facility in Huntsville."Lunar Roving Vehicle," MSFC press release, 29 October 1969; Marshall Star, 3 November 1969.