1971

Lunar Rover

The moon missions represented a pinnacle of engineering achievement and they were amazing to the billions of people who watched the spectacle. Humans had never before traveled so far, so fast, in such harsh conditions, for so long. But then on the Apollo 15 mission in 1971, engineers took it one step further. Astronauts unpacked a spindly electric moon buggy from their lunar lander, unfolded it, and then drove up to 3 miles (5 km) away from their spacecraft. The utter audacity of it was breathtaking.

The lunar rover was surprisingly simple because engineers focused on weight and reliability. It consisted of a folding, three-part aluminum frame, four electric wheel motors (0.25 hp each) and brakes, two batteries and a power controller, a simple suspension system, and four-wheel electric steering. The entire vehicle weighed only 462 pounds (209 kg). One horsepower (745 watts) doesn’t seem like much, but the top speed was 8 mph (13 kph), and the low moon gravity made everything lighter.

A dish antenna allowed television transmissions back to Earth. Astronauts would park, align the antenna toward Earth and then mission control could control the camera while the astronauts carried out their explorations.

What if something went wrong? Each wheel motor could be disabled individually. There were two batteries in case one failed, and two steering systems as well. But what if the vehicle failed completely? The excursions were designed so the astronauts always had enough time to walk back to the LEM before their life support backpacks ran out of consumables. But what if a life support backpack failed? There was backup oxygen in each backpack, and then a hose that could connect the astronauts together to share the cooling system in the working backpack.

Engineers had thought of every failure mode and had a way around it. So while it looked audacious to drive three miles away from their only way home, the astronauts were safe. Engineers had created good equipment, and if something did go wrong, there was a backup plan.

SEE ALSO Apollo 1 (1967), Lunar Landing (1969), Space Suit (1969), Apollo 13 (1970), Lithium Ion Battery (1991).

Apollo 15 was the first mission to use the LRV. Powered by battery, the lightweight electric car greatly increased the range of mobility and productivity on the scientific traverses for astronauts.