44 Years Ago, NASA Put A Foldable Electric Car On The Moon

Forty four years ago, on this day 31-July in 1971, NASA’s LRV (Lunar Roving Vehicle), better known as the ‘moon buggy,’ was first deployed for use on the moon. What was less said however, was that one of NASA’s biggest achievement was actually the brainchild of a former Nazi engineer, Wernher von Braun, a rocket engineer who developed the V2 rockets used to attack Britain.

After the end of World War 2, the United States’ Central Intelligence Agency was in competition with the other two victors of World War 2 - Soviet Union and the United Kingdom – to gather military intelligence from the Axis forces and to deny post-war Germany of any means to rebuild its military strength.

Wernher von Braun and his team of engineers surrendered to the Americans and the CIA was very interested with the von Braun and his team had to offer.

He was among the group of 1,500 Nazi engineers and scientists brought over to the US under the CIA’s Operation Paperclip to extract useful technical know-how.

Von Braun was subsequently employed by NASA, which later became a key-part of President John F. Kennedy’s efforts to upstage the Soviets – whom by then had become a Communist country and is no longer friends with the US - in a race to space.

The Americans were worried that if the Soviets gained control of space, it could allow them to launch attacks from there.

Von Braun was a strong advocate of space programmes, and harboured dreams of setting up manned space stations. Later, he headed the programme to develop the Saturn V rockets used to launch NASA’s space programmes.

By February 1964, von Braun, in his position as Director of NASA's Marshall Space Flight Center, mooted the idea for a lunar rover.

To protect themselves from cosmic radiation, extreme temperatures and space’s vacuum, astronauts had to wear the bulky protective suit, which limited their body’s movement. A limited supply of oxygen also meant that they couldn’t walk too far away from their lunar landing module (Lunar Module, LM)

It quickly became clear without a motorised vehicle, it would not be possible for astronauts to travel far enough across the moon’s surface to conduct experiments, gather soil samples, and return to their Lunar Module.

On 11-July 1969, shortly before Apollo 11’s Neil Armstrong and Buzz Aldrin made their maiden landing on the moon on 20-July 1969, von Braun sent out a request of proposal for a Lunar Roving Vehicle to Chrysler, Boeing, Bendix, and Grumman. Boeing’s USD 19 million proposal was selected, but cost overruns later escalated the project to USD 38 million.

On the upside, Boeing delivered the rover on 14-March 1971, two weeks ahead of the deadline. Boeing’s LRV took just 17 months to develop with no major faults reported – the shortest and most successful for any major component in the Apollo programme.

Boeing built eight test units of the LRV before the final approved unit was delivered to NASA. In total, three LRVs were sent to the moon under the Apollo 15, 16 and 17 programme.

Although designed by Boeing, the actual task of building the LRVs was sub-contracted to General Motors.

A Foldable EV!

The electric-powered LRV weighed just 210 kg, but since astronauts had to haul a lot of moon rocks back to earth, it was designed to carry up 490 kg of payload. That’s more than its own weight! A typical car can only carry a payload of half its own weight.

However since the moon’s gravity is only 1/6 that of Earth’s, the LRV weighs just 35 kg on the moon, and the 490 kg payload becomes just 82 kg.

To navigate across the rough lunar surface, the LRV had a ground clearance of 355 mm, that’s 122 mm more than a Ford Ranger XLT. The suspension on both ends are double horizontal wishbone with upper and lower torsion bars and a damper unit between the chassis and upper wishbone.

But the Apollo Lunar Module is not exactly a Honda Jazz – it doesn’t have Ultra Seats and it is rather tight inside. So the LRV’s length is keep to just 3.1 metres long – shorter than a Perodua Axia, and just 1.14 metres tall. And they had to make it foldable to fit inside the Lunar Module.

The LRV’s tubular aluminium frame chassis could be folded into three sections for a more compact fit. The suspension itself can be rotated by 135 degrees when folded.

Upon setting foot on the moon, astronauts only need to release two nylon tapes and a D-handle to unfold the LRV. Pretty neat.

Power comes from a pair of 36V silver-zinc batteries, giving it a total driving range of around 92 km. That’s not too bad considering that a modern electric car like a Mitsushi i-MiEV has a real world driving range of around 120 km (with air-conditioning and headlamps switched on).

The maximum speed is 14 km/h. On moon’s low gravity surface, that’s fast enough unless you are not concerned of accidently launching yourself into orbit.

As the LRV’s power-source is the most important component, the batteries were designed with system redundancy in mind. Only one set of battery is needed to power the LRV, but the LRV was fitted with two sets of batteries.

As the Apollo astronauts have no intention of taking the LRV back to Earth with them (they had rocks to carry home with them remember?), the batteries are non-rechargeable types.

Like any proper off-road vehicle, it’s all-wheel drive. Each wheel is driven by a 0.25 hp DC series-wound motor. To disperse heat in space’s vacuum, the motor drive units are hermetically sealed with nitrogen at 7.5 psi to transfer heat from the drive motors to the drive assembly’s outer wall.

Unlike a normal buggy, the LRV doesn’t have steering wheel. A more compact joystick-like hand control is adopted instead.

Push forward to drive, left or right to turn. Pulling the control backwards will engage the cable operated drum brakes on each wheel. Flicking a switch will engage reverse. Pull the handle past spring-loaded catch and it engages the parking brake.  

There’s also four-wheel steering, giving the LRV a remarkably tight turning circle of 3.1 metres. To put that into context, a Mitsubishi Mirage’s turning circle is 4.6 metres.

Did Goodyear Built The Lunar Roving Vehicle’s Tyres?

There is an often perpetuated myth that Goodyear made the tyres for NASA’s LRV. Some of Goodyear’s own press materials credited itself for pioneering space tyres, linking its innovative wire-mesh tyres with NASA’s Lunar Roving Vehicle.

This is incorrect as NASA’s own achieved materials show that the LRV’s tyres were developed General Motors’ Defense Research Laboratories (GM DRL) and not Goodyear.

In fact, Goodyear’s US corporate website's own accounts of its brand’s history only said that Goodyear tyres were the first tyres to be used on the moon – when it was fitted to the hand-pulled, unpowered MET (Modularized Equipment Transporter) used on the Apollo 14. There was no mention of any Goodyear tyres used on the Lunar Roving Vehicle.

NASA’s own records (below) showed that Goodyear was one of the partners asked to develop a tyre for the LRV, along seven other companies, but it was not selected for the project. It end, it was GM’s design that was selected by NASA.

The LRV's aluminium hub wheels and zinc wire mesh tyres were developed by GM. It had titanium chevron-pattern tread covering 50 percent of the surface contact area. There’s an inner frame which acts as a bump stop to prevent excessive deflection of the wire mesh under high impact.

Somewhere along the way, the later generation of Goodyear staffs and their colleagues from public relations and creative agencies confused Goodyear’s involvement in NASA’s hand-pulled Modularized Equipment Transporter with that of the electric-powered all-wheel drive Lunar Roving Vehicle, and credited itself for developing the LRV’s wire mesh tyres.

It is worth noting that the computers used by astronauts in the Apollo space programme had less than 1/10 of the computing power available on many of today’s smartphones.