The Apollo missions were monumental achievements, not just for landing humans on the Moon, but also for enabling them to explore its surface extensively. A key element in this exploration was the Lunar Roving Vehicle (LRV), often referred to as the “Moon buggy.” This electric vehicle allowed astronauts to drive separately from the Lunar Module, significantly expanding their exploration range and scientific discoveries.
Driven across the lunar terrain during the final three Apollo missions (15, 16, and 17), the LRV was instrumental in transforming lunar exploration. On Apollo 15, astronauts David Scott and Jim Irwin were the first to experience driving on the Moon. They covered a remarkable 27.8 kilometers in just over three hours of driving time. The distances covered and the time spent driving increased with each subsequent mission. Apollo 16 saw John Young and Charles Duke traverse 26.7 km, while Apollo 17, with astronauts Gene Cernan and Harrison Schmitt, achieved the longest distance of 35.9 km in four and a half hours. This extended mobility, driving in what was essentially a separate car on the Moon, was crucial for collecting a wider variety of lunar samples and conducting more comprehensive scientific experiments.
The LRV was a marvel of engineering, designed to operate in the harsh lunar environment of low gravity and vacuum. Despite having a mass of only 210 kg, it was capable of carrying an additional 490 kg of payload, including astronauts and equipment. Its frame, constructed from lightweight yet strong aluminum alloy tubing, measured 3.1 meters in length with a 2.3-meter wheelbase and stood 1.14 meters tall. The ingenious design allowed it to be folded and stowed in the Lunar Module’s quad 1 bay for the journey to the Moon. It featured side-by-side foldable seats with adjustable footrests and Velcro seatbelts, ensuring astronaut comfort and safety during lunar drives.
The wheels of the LRV were specifically engineered for lunar conditions. They consisted of a spun aluminum hub and a tire made of zinc-coated woven steel strands, providing both flexibility and durability. Titanium chevrons covering half the contact area enhanced traction on the loose lunar soil. Each wheel was independently driven by a 0.25 hp electric motor, powered by two 36-volt silver-zinc batteries. These batteries also supplied power to the steering motors and a utility outlet for equipment like cameras and communication relays, essential for astronauts driving independently on the Moon.
Controlling the LRV was intuitive, using a T-shaped hand controller. Forward motion, steering, and braking were all managed through this single control. The vehicle’s navigation system was equally advanced for its time, employing a directional gyro, odometer, and computer to track direction and distance relative to the Lunar Module. A sun-shadow device provided a backup manual heading reference, vital for astronauts navigating across the featureless lunar landscape in their separate vehicle.
Deploying the LRV on the Moon was a carefully orchestrated process. Astronauts utilized a system of pulleys and reels to lower the folded rover from the Lunar Module. The deployment sequence was largely automated, with the wheels unfolding and locking into place as the rover was lowered. This ingenious deployment mechanism ensured that astronauts could quickly and efficiently get their “separate car” ready for lunar exploration.
Despite a compressed development timeline of just 17 months and initial cost overruns, the Lunar Roving Vehicle proved to be an unparalleled success. Developed by Boeing and Delco, four LRVs were built, with three being successfully driven on the Moon. The LRV’s reliability and flexibility were crucial to the scientific achievements of Apollos 15, 16, and 17. As Harrison Schmitt of Apollo 17 aptly stated, without the Lunar Rover, the major scientific discoveries of these missions and our current understanding of lunar evolution would not have been possible. The ability for astronauts to drive in separate cars, venturing further and wider across the lunar surface, revolutionized lunar exploration and cemented the LRV’s place in space exploration history.
References
- Baker, David, Lunar Roving Vehicle: Design Report, Spaceflight, 13, 234-240, July 1971.
- Boeing LRV Systems Engineering, Lunar Rover Operations Handbook, Doc. LS006-002-2H, Huntsville, Alabama, 19 April 1971.
- Burkhalter, Bettye, and Michael Sharpe, Lunar Roving Vehicle: Historical Origins, Development and Deployment, History of Rocketry and Aeronautics, AAS History Series, 22, 227-261, 1998.
Apollo home page Apollo 15 lunar surface mission Apollo 16 lunar surface mission Apollo 17 lunar surface mission
Lunar Rover Operations Handbook Lunar Roving Vehicle – Air and Space Museum The Human Rover Challenge – NASA
