The Lunar Roving Vehicle, or “moon buggy”, was used in several Apollo missions to the Moon.
Moon Buggy on display at Marshall Space Flight Center, AL
When the Nazis surrendered in May 1945, one of the US Army’s first priorities was to hunt down and capture as many of the German technical staff as possible, particularly in the fields of rocketry and jet engines, and the Americans managed to find the greatest prize of all: Dr Wernher von Braun, the V-2’s designer, and much of his team. Von Braun was packed to the US, where he agreed to work on American rocketry.
In July 1958 the National Aeronautics and Space Administration (NASA) was created to oversee the American space effort, and in 1960 the Army’s Redstone Arsenal was incorporated into NASA as the George C Marshall Space Flight Center.
The Mercury series developed all of the basic systems that were necessary for spaceflight. The Gemini series, using the Titan II ICBM as a launch vehicle, would create and test all of the systems necessary for a mission to the Moon, including orbital maneuvering, rendezvous and docking, and navigation. Finally, Apollo, which utilized the immense Saturn V rocket as its launch vehicle, would use all of these new systems to put humans on the Moon. All of this space hardware was tested at Marshall, culminating in the Apollo 11 moon landing in July 1969.
In the first Moon landing, in July 1969, Neil Armstrong and Buzz Aldrin spent less than 24 hours on the lunar surface and were actually outside the Lunar Module for just 2 hours, only long enough to gather some rock samples and plant a flag. To American political officials, the entire Moon program had been geo-political in nature—it was purely a way to beat the Soviets, and now that the Moon had been reached, that mission was, as far as they were concerned, accomplished.
NASA, however, had been planning for a much more ambitious program, with opportunities for serious scientific research to be conducted over a series of ten manned landings. With each of these missions, up to Apollo 20, the sojourns on the lunar surface would get longer and the scientific agenda would become more extensive.
This would necessitate a way for astronauts to move around more easily. Even before the first Apollo missions, NASA had already planned designs for some sort of motorized “moon buggy” that could carry the astronauts ever further from their landing site and allow them to explore wider areas of interest.
Officially known as the Lunar Roving Vehicle (LRV), the moon buggy had to withstand a number of brutal conditions. The Moon had no atmosphere to hold heat, so during the nighttime temperatures dropped down to -200F. By contrast, in direct sunlight during the day the vehicle’s components could reach 200F, almost hot enough to boil water. The airless Moon was essentially a vacuum, and the gravity was only one-sixth that of Earth. All of the LRV’s systems had to be as least complex mechanically as possible, since even a failure as simple as a flat tire could be disastrous.
So, the LRV was designed with simplicity in mind. The first issue was propulsion. On the airless Moon, there was no oxygen for combustion and it would not be practical to carry its own supply, so an ordinary gas-powered engine would not work. Instead, the buggy would be driven by a small electric motor on each wheel that was powered by a central battery pack containing two 36v silver-zinc potassium-hydroxide batteries. This system could move the LRV at around 10mph, and could operate even in a total vacuum. The battery pack had enough electricity to run for about 60 miles before it went dead (there was no system for recharging the batteries).
The tires were made from a steel and titanium wire mesh that would distribute the vehicle’s weight and provide a good traction on the powdery lunar surface. The airless tires eliminated any risk of a leak or a flat which could disable the vehicle. The wheels were capable of easily crossing craters or gaps up to 24 inches wide and 12 inches deep. Steering consisted of front-wheel drive, rear-wheel drive, or both.
The LRV was equipped with a color TV camera and a radio that could communicate with both the lunar lander and with flight controllers in Houston. There was storage space for about 1000 pounds of equipment and lunar rock samples. The vehicle was steered by means of a T-shaped joystick, and the navigational system was capable of recording each move of the wheel, providing a “backtrack” system that always allowed the driver to reverse course back to the Lunar Module. For safety, the buggies were never driven further than walking distance from the LM in case there was some kind of breakdown.
The buggy was also designed to be foldable, and was stored in a compact compartment in the side of the Lunar Module during launch. The entire ten-foot vehicle folded into a package the size of a small coffee table, and could be unfolded on the lunar surface by a space-suited astronaut, with the tug of two steel cables.
The moon buggy’s first mission was Apollo 15, launched in July 1971. LRVs were also used in Apollo 16 and 17.
NASA was meanwhile already making ambitious plans to begin construction of a two-ton pressurized wheeled vehicle that could support two astronauts for as long as two weeks on the lunar surface. But with the geo-political goals of the Moon project already accomplished, the US Government was reluctant to continue to spend money on the Apollo program, and in August 1971 the Nixon Administration ended the moon program, canceled the planned Apollo 18, 19 and 20 missions, and slashed NASA’s funding.
A total of four functional LRVs were built. Three of them, from Apollo 15, 16 and 17, remain on the surface of the Moon. The fourth was used for spare parts. In addition, a number of static models were constructed for engineering and for tests.
Today, the engineering model moon buggy used for vibration testing is on exhibit at the Marshall Space Flight Center in Huntsville AL. Other test models can be seen at Johnson Space Center in Houston, at Kennedy Space Center in Titusville FL, at the Smithsonian Air and Space Museum in DC, and at several other museums. There are also a number of replica LRVs on exhibit.