The Lunar Rover

The words

1. Chassis

   The rover’s chassis was a hinged aluminum frame. Its three sections folded for storage against the lunar module, then opened to support the astronauts, equipment and wheels.

   NASA: the rover’s structure and systems (opens a new tab)

2. Dead Reckoning

   Estimating position from direction and distance traveled.

   The rover’s computer combined wheel-travel measurements with heading information. Its display showed the astronauts their estimated direction and distance back to the lunar module.

   Did you know?

   Young and Duke favored a simple display showing the way back to the lander. Their suggestion replaced a more complex plan to display map coordinates.

   NASA: the rover’s structure and systems (opens a new tab) · Lunar Surface Journal: rover navigation (opens a new tab)

3. Ferenc Pavlics

   Ferenc Pavlics belonged to General Motors’ rover development team. NASA’s history of the wheel design draws on his engineering work and later recollections of how the lunar vehicle took shape.

   NASA Glenn: the lunar rover’s wheel design (opens a new tab)

4. First Drive

   Scott and Irwin used the first crewed lunar rover during Apollo 15 in 1971. Their drives extended surface exploration beyond the distances practical for carrying equipment and samples on foot.

   Did you know?

   For the first time, a lunar-module liftoff was shown on television back on Earth. The pictures came from the rover’s camera, left on the surface.

   NASA: Apollo 15’s first rover journeys (opens a new tab)

5. General Motors

   General Motors’ Defense Research Laboratories developed the rover’s mobility system as a major subcontractor to Boeing. Its engineers turned NASA’s mission needs into requirements for wheels suited to the lunar terrain.

   NASA Glenn: the lunar rover’s wheel design (opens a new tab)

6. Grand Prix

   During Apollo 16, Charles Duke filmed John Young driving the rover over uneven ground near the lander. The astronauts called this demonstration of its driving ability the Grand Prix.

   NASA: Apollo 16’s Grand Prix drive (opens a new tab)

7. Harmonic Drive

   Each rover wheel had its own electric motor connected through a harmonic drive. This compact reduction gear slowed the motor’s rotation as it transmitted power to the wheel.

   NASA: the rover’s structure and systems (opens a new tab)

8. Mesh Wheels

   The rover’s flexible wire-mesh wheels were developed for travel over lunar soil. NASA selected this design after comparing it with a competing hoop-spring wheel and testing how both handled the terrain.

   NASA Glenn: the lunar rover’s wheel design (opens a new tab)

9. Odometer

   The odometer measured the rover’s travel from wheel movement. Combined with heading information, that distance fed the navigation computer’s estimate of the way back to the lunar module.

   NASA: the rover’s structure and systems (opens a new tab)

10. One Horsepower

    Each wheel had a motor rated at one-quarter horsepower. Together, the four electric motors gave the rover a nominal combined rating of one horsepower.

    Smithsonian: rover systems and display model (opens a new tab)

11. Piano Wire

    The rover’s tires were woven from zinc-coated piano wire, a steel wire material. Their flexible mesh construction suited a vehicle that had to carry astronauts across the Moon’s uneven surface.

    Smithsonian: rover systems and display model (opens a new tab) · NASA Glenn: the lunar rover’s wheel design (opens a new tab)

12. Rooster Tail

    Spinning rover wheels could throw a curved spray of lunar dust behind them. During Apollo 16’s Grand Prix drive, Duke filmed these rooster tails rising as Young bounced over uneven ground.

    NASA: Apollo 16’s Grand Prix drive (opens a new tab)

13. Rover

    The Lunar Roving Vehicle was a battery-powered vehicle for two astronauts and their equipment. Used on Apollo 15, 16 and 17, it expanded the reach of their geological exploration.

    Did you know?

    The Smithsonian’s vehicle labeled No. 4 was a non-operable display mockup made chiefly from surplus parts. NASA transferred it to the museum in 1975.

    Smithsonian: rover systems and display model (opens a new tab)

14. Seat Belt

    The rover’s seats had Velcro seat belts to hold the suited astronauts in place. The restraints were part of a seating arrangement built for travel over uneven lunar ground.

    NASA: the rover’s structure and systems (opens a new tab)

15. Walkback Limit

    Mission planners limited rover excursions so astronauts could return to the lander on foot if the vehicle failed. The available supplies in their spacesuits helped determine that historical planning boundary.

    NASA: Apollo 15’s walkback planning (opens a new tab)