60 Years Ago: The First Flight of the Lunar Landing Research Vehicle

[NASA]

President John F. Kennedy’s national commitment to land a man on the Moon and return him safely to the Earth before the end of the decade posed multiple challenges, among them how to train astronauts to land on the Moon, a place with no atmosphere and one-sixth the gravity on Earth. The Lunar Landing Research Vehicle (LLRV) and its successor the Lunar Landing Training Vehicle (LLTV) provided the training tool to simulate the final 200 feet of the descent to the lunar surface. The ungainly aircraft made its first flight on Oct. 30, 1964, at NASA’s Flight Research Center (FRC), now NASA’s Armstrong Flight Research Center (AFRC) in California. The Apollo astronauts who completed landings on the Moon attributed their successes largely to training in these vehicles.

The first Lunar Landing Research Vehicle silhouetted against the rising sun on the dry lakebed at Edwards Air Force Base in California’s Mojave Desert.

In December 1961, NASA Headquarters in Washington, D.C., received an unsolicited proposal from Bell Aerosystems in Buffalo, New York, for a design of a flying simulator to train astronauts on landing a spacecraft on the Moon. Bell’s approach, using their design merged with concepts developed at NASA’s FRC, won approval and the space agency funded the design and construction of two Lunar Landing Research Vehicles (LLRV). At the time of the proposal, NASA had not yet chosen the method for getting to and landing on the Moon, but once NASA decided on Lunar Orbit Rendezvous in July 1962, the Lunar Module’s (LM) flying characteristics matched Bell’s proposed design closely enough that the LLRV served as an excellent trainer. 

Two views of the first Lunar Landing Research Vehicle shortly after its arrival and prior to assembly at the Flight Research Center, now NASA’s Armstrong Flight Research Center, in California.

Bell Aerosystems delivered the LLRV-1 to FRC on April 8, 1964, where it made history as the first pure fly-by-wire aircraft to fly in Earth’s atmosphere. Its design relied exclusively on an interface with three analog computers to convert the pilot’s movements to signals transmitted by wire and to execute his commands. The open-framed LLRV used a downward pointing turbofan engine to counteract five-sixths of the vehicle’s weight to simulate lunar gravity, two rockets provided thrust for the descent and horizontal translation, and 16 LM-like thrusters provided three-axis attitude control. The astronauts could thus simulate maneuvering and landing on the lunar surface while still on Earth. The LLRV pilot could use an aircraft-style ejection seat to escape from the vehicle in case of loss of control.

Left: The Lunar Landing Research Vehicle-1 (LLRV-1) during an engine test at NASA’s Flight Research Center (FRC), now NASA’s Armstrong Fight Research Center, in California’s Mojave Desert. Right: NASA chief test pilot Joseph “Joe” A. Walker, left, demonstrates the features of LLRV-1 to President Lyndon B. Johnson during his visit to FRC.

Engineers conducted numerous tests to prepare the LLRV for its first flight. During one of the engine tests, the thrust generated was higher than anticipated, lifting crew chief Raymond White and the LLRV about a foot off the ground before White could shut off the engines. On June 19, during an official visit to FRC, President Lyndon B. Johnson inspected the LLRV featured on a static display. The Secret Service would not allow the President to sit in the LLRV’s cockpit out of an overabundance of caution since the pyrotechnics were installed, but not yet armed, in the ejection seat. Following a Preflight Readiness Review held Aug. 13 and 14, managers cleared the LLRV for its first flight.

Left: NASA chief test pilot Joseph “Joe” A. Walker during the first flight of the Lunar Landing Research Vehicle (LLRV). Right: Walker shortly after the first LLRV flight.

In the early morning of Oct. 30, 1964, FRC chief pilot Joseph “Joe” A. Walker arrived at Edwards Air Force Base’s (AFB) South Base to attempt the first flight of the LLRV. Walker, a winner of both the Collier Trophy and the Harmon International Trophy, had flown nearly all experimental aircraft at Edwards including 25 flights in the X-15 rocket plane. On two of his X-15 flights, Walker earned astronaut wings by flying higher than 62 miles, the unofficial boundary between the Earth’s atmosphere and space. After strapping into the LLRV’s ejection seat, Walker ran through the preflight checklist before advancing the throttle to begin the first flight. The vehicle rose 10 feet in the air, Walker performed a few small maneuvers and then made a soft landing after having flown for 56 seconds. He lifted off again, performed some more maneuvers, and landed again after another 56 seconds. On his third flight, the vehicle’s electronics shifted into backup mode and he landed the craft after only 29 seconds. Walker seemed satisfied with how the LLRV handled on its first flights.

Left: Lunar Landing Research Vehicle-2 (LLRV-2) during one of its six flights at the Flight Research Center, now NASA’s Armstrong Flight Research Center, in California in January 1967. Right: NASA astronaut Neil A. Armstrong with LLRV-1 at Ellington Air Force Base in March 1967.

Walker took LLRV-1 aloft again on Nov. 16 and eventually completed 35 test flights with the vehicle. Test pilots Donald “Don” L. Mallick, who completed the first simulated lunar landing profile flight during the LLRV’s 35^th flight on Sept. 8, 1965, and Emil E. “Jack” Kluever, who made his first flight on Dec. 13, 1965, joined Walker to test the unique aircraft. Joseph S. “Joe” Algranti and Harold E. “Bud” Ream, pilots at the Manned Spacecraft Center (MSC), now NASA’s Johnson Space Center (JSC) in Houston, travelled to FRC to begin training flights with the LLRV in August 1966. Workers at FRC assembled the second vehicle, LLRV-2, during the latter half of 1966. In December 1966, after 198 flights workers transferred LLRV-1 to Ellington AFB near MSC for the convenience of astronaut training, and LLRV-2 followed in January 1967 after completing six test flights at FRC. The second LLRV made no further flights, partly because the three Lunar Landing Training Vehicles (LLTVs), more advanced models that better simulated the LM’s flying characteristics, began to arrive at Ellington in October 1967. Neil A. Armstrong completed the first astronaut flights aboard LLRV-1 on Mar. 23, 1967, and flew 21 flights before ejecting from the vehicle on May 6, 1968, seconds before it crashed. He later completed his lunar landing certification flights using LLTV-2 in June 1969, one month before peforming the actual feat on the Moon.

Left: Apollo 11 Commander Neil A. Armstrong prepares to fly a lunar landing profile in Lunar Landing Training Vehicle-2 (LLTV-2) in June 1969. Middle: Apollo 12 Commander Charles “Pete” Conrad prepares to fly LLTV-2 in July 1969. Right: Apollo 14 Commander Alan B. Shepard flies LLTV-3 in December 1970.

All Apollo Moon landing mission commanders and their backups completed their lunar landing certifications using the LLTV, and all the commanders attributed their successful landings to having trained in the LLTV. Apollo 8 astronaut William A. Anders, who along with Armstrong completed some of the early LLRV test flights, called the training vehicle “a much unsung hero of the Apollo program.” During the flight readiness review in January 1970 to clear LLTV-3 for astronaut flights, Apollo 11 Commander Armstrong and Apollo 12 Commander Charles “Pete” Conrad, who had by then each completed manual landings on the Moon, spoke positively of the LLTV’s role in their training. Armstrong’s overall impression of the LLTV: “All the pilots … thought it was an extremely important part of their preparation for the lunar landing attempt,” adding “It was a contrary machine, and a risky machine, but a very useful one.” Conrad emphasized that were he “to go back to the Moon again on another flight, I personally would want to fly the LLTV again as close to flight time as possible.” During the Apollo 12 technical debriefs, Conrad stated the “the LLTV is an excellent training vehicle for the final phases. I think it’s almost essential. I feel it really gave me the confidence that I needed.” During the postflight debriefs, Apollo 14 Commander Alan B. Shepard stated that he “did feel that the LLTV contributed to my overall ability to fly the LM during the landing.”

Left: Apollo 15 Commander David R. Scott flies Lunar Landing Training Vehicle-3 (LLTV-3) in June 1971. Middle: Apollo 16 Commander John W. Young prepares to fly LLTV-3 in March 1972. Right: Apollo 17 Commander Eugene A. Cernan prepares for a flight aboard LLTV-3 in October 1972.

David R. Scott, Apollo 15 commander, stated in the final mission report that “the combination of visual simulations and LLTV flying provided excellent training for the actual lunar landing. Comfort and confidence existed throughout this phase.” In the Apollo 15 postflight debrief, Scott stated that he “felt very comfortable flying the vehicle (LM) manually, because of the training in the LLTV, and there was no question in my mind that I could put it down where I wanted to. I guess I can’t say enough about that training. I think the LLTV is an excellent simulation of the vehicle.” Apollo 16 Commander John W. Young offered perhaps the greatest praise for the vehicle just moments after landing on the lunar surface: “Just like flying the LLTV. Piece of cake.” Young reiterated during the postflight debriefs that “from 200 feet on down, I never looked in the cockpit. It was just like flying the LLTV.” Apollo 17 Commander Eugene A. Cernan stated in the postflight debrief that “the most significant part of the final phases from 500 feet down, … was that it was extremely comfortable flying the bird. I contribute (sic) that primarily to the LLTV flying operations.”

Left: Workers move Lunar Landing Research Vehicle-2 from NASA’s Armstrong Flight Research Center for display at the Air Force Test Flight Museum at Edwards Air Force Base. Right: Lunar Landing Training Vehicle-3 on display outside the Teague Auditorium at NASA’s Johnson Space Center in Houston.

In addition to playing a critical role in the Moon landing program, these early research and test vehicles aided in the development of digital fly-by-wire technology for future aircraft. LLRV-2 is on display at the Air Force Flight Test Museum at Edwards AFB (on loan from AFRC). Visitors can view LLTV-3 suspended from the ceiling in the lobby of the Teague Auditorium at JSC.

The monograph Unconventional, Contrary, and Ugly: The Lunar Landing Research Vehicle provides an excellent and detailed history of the LLRV.

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