Before Astronauts Drove On the Moon, NASA Thought About Giving Them Bikes

Science nerds around the world are currently going nuts over Curiosity, the one-ton rover NASA just landed on Mars. But Curiosity isn't the only rover with an August birthday (or landing day). In August 1971, the Apollo 15 crew became the first to drive on another body in the Lunar Roving Vehicle.

Lunar rovers weren't new when NASA started thinking about how astronauts could cover more ground on the Moon. As early as 1964, engineers at NASA's Manned Spaceflight Centre started looking at a variety of pressurized lunar roving vehicles. It made sense: give the astronauts something they can live in so they get the most out of their time on the surface. Grumman aircraft, the company behind the Apollo Lunar Module (LM), built a prototype but it was far too heavy for the lift capability of the Saturn V. Pressurized vehicles were abandoned in the short term but retained as a long-term goal. The possibility of eventually combining a landing spacecraft with a rover were incredibly appealing.

So NASA looked at smaller options. One possibility was a bike, a suggestion from MIT mechanical engineer and bike nut David Gordon Wilson. He argued bicycles were smaller, lighter, and wouldn't need the power sources rovers did. The idea never gained much traction. A prototype electric bicycle similarly never went beyond the initial test stage. No, the best type of rover NASA decided would mimic a car. It would be stable and give the astronauts storage.

On October 28, 1969, NASA eventually awarded the $19.6 million contract for the lunar rover to Boeing won the contract. The company's design had to meet three goals: performance, schedule and cost. The lunar rover had to meet the demands of performing in the lunar environment, it absolutely had to be delivered in time for Apollo 15's July 1971 launch, and the final cost had to adhere to the figure laid out in Boeing's original proposal. The contractor was also responsible for building 1-G vehicles for astronaut training and other necessary test and training units. In short, it had to be cheap, fast, and perfect.

The final design was an open vehicle made of lightweight aluminum with four reinforced open spun aluminum covered with strand woven steel mesh zinc for tires. Titanium chevrons covering 50 percent of the tires were fixed on top to reduce the spray of lunar dust. Front and rear wheel steering by individual steering motors gave the rover a tight turning radius thanks to individual steering motors. The astronauts drove the rover with a T-handle in the centre of the crew console, a simple design to operate while wearing heavy gloves.

But one of the most attractive features on the rover was its inclusion of television equipment. Onboard cameras could televise the astronauts' activities, and the vehicle's most distinctive appendage – the umbrella-shaped gold mesh high-gain S-band antenna – beamed back a live feed from the onboard color TV camera. There was also ample storage space on board. Extra film for the astronauts' Hasselblad 70mm cameras were underneath the right-hand seat while the area behind the seats kept all the other equipment used for exploration, sampling and storage.

On July 31, Apollo 15 Commander David Scott and LM Pilot Jim Irwin unpacked the lunar rover at their landing site at the moon's Hadley region. Apollo 16 and Apollo 17 also took lunar rovers to the Moon. In every case, the vehicle allowed astronauts to travel miles from the LM instead of feet, but no one really pushed it to its limits. There were other factors limiting how far the rover could drive, namely the amount of supplies and oxygen the astronauts had. If the rover broke down they would have to walk back to the LM, a bad situation if oxygen was running low.

Despite mission limitations, every astronaut who used the lunar rover on a mission agreed that it was an asset to their exploration. They also agreed that it was fun. Apollo 17 Commander Gene Cernan was the most daring of all rover drivers, pushing its speed up to 11.2 miles per hour. For now, at least, he retains the off-world speed record.