Feature Electric vehicles have generated plenty of discussion over the last decade or so. However, it was 53 years ago this week that one of the battery-powered machines first carried humans around the Moon.

The Lunar Roving Vehicle (LRV or "Moon buggy") featured in the last three Apollo lunar landing missions: 15, 16, and 17. The four-wheeled vehicle was designed to extend the area astronauts could explore on the Moon, with the proviso that those same astronauts must not venture beyond walking distance from the Lunar Module in the event of a breakdown - a restriction relaxed a little during Apollo 17. Not that there was ever a breakdown.

The vehicle's development time was rapid once the request for proposals was made - shortly before the Apollo 11 mission. Original lavish plans for a pressurized cabin and a vehicle capable of extended excursions were ditched as it became clear that each Apollo mission would consist of just one Saturn V launch. The LRV, therefore, had to fit into the weight and size constraints afforded by the existing Apollo hardware.

In NASA's history of the project, the original cost of the LRV was a princely $19 million, with the first LRV due for delivery by April 1, 1971. As it turned out, the cost ballooned to $38 million, and four LRVs were produced, although the last was used for spares after the Moon landing missions were cut back.

Other models were built, including an engineering model, a trainer, and a pair of 1/6 gravity models for testing the deployment mechanism. The 210 kg LRV was stored folded on one side of the LM descent stage with the chassis facing outwards. The rover would be lowered to the lunar surface via a set of reels and tapes before deployment, much of which was automatic. Switch on the power, and the vehicle was ready to go.

Or it was supposed to. In his book Forever Young, John Young, who commanded Apollo 16, recalled testing the LRV's deployment at Northrop Grumman's Bethpage facility. He said: "We pulled the cord to deploy the LRV automatically ... and it fell in a heap of wreckage on the floor."

The pace of development was breathtaking. It took 17 months to develop the LRV, including feedback from the astronauts, several of whom would be driving the vehicle on the surface of the Moon. Young recalled feedback from him and Apollo 16 Lunar Module Pilot Charlie Duke, resulting in a change to the centrally mounted hand controller used to steer the LRV. He said: "To turn we had to yaw the hand controller right or left. In a pressure suit, this was very difficult and tiring, so we got the technicians to put a center top grip on the stick that we could roll right or left depending on which way we wanted the vehicle to steer."

Each wheel of the LRV had its own electric motor, powered by two 36-volt silver-zinc potassium hydroxide non-rechargeable batteries. Both sets of wheels could turn in opposite directions, giving a steering radius of 3.1 meters, or be decoupled so only one set was used for steering.

But what was it like for that first drive on the Moon?

David Scott, who commanded Apollo 15, wrote in his book Two Sides Of The Moon: "Driving the rover was actually more like flying an airplane, albeit with four wheels, than driving a car."

Despite describing the LRV as "a brilliant piece of engineering," Scott also recalled some of the challenges. The ride was, obviously, a bit bumpy: "No part of the lunar surface was totally flat or even." Bending the bulky Apollo lunar suits into a seated position to drive the LRV was also challenging. And then there was the dust - while the LRV had good traction and power, according to Scott, the wire mesh wheels would throw up plenty of dust.

Scott recalled: "It all made for a ride like a cross between a bucking bronco and a small boat in a heavy swell."

Young said: "The rover was a fun ride. It was really some machine. Occasionally the back end broke loose a bit, steering-wise, but it wasn't a problem."

Young was an enthusiastic LRV driver: "Driving the rover when it skidded was no problem. I never did have the feeling we were going to turn over. One time I had a couple of wheels off the ground and was going sideways. I wasn't too impressed with that!"

Young and Duke's 17 km/h (10.5 mph) record was overhauled on the subsequent Apollo 17 mission, according to the Guinness World Records, when Eugene Cernan took the LRV to 18 km/h (11.18 mph). The recordkeepers noted: "Cernan and Schmitt's speed was assisted by the fact that they were going downhill with a heavy cargo of Moon rocks."

Three LRVs remain on the Moon and are highly unlikely to ever turn a wheel again, not least because, unlike modern EVs, the batteries were not rechargeable.

Still, it has been over half a century since the first EV took a trundle on the Moon, which is worthy of raising a glass, even if range anxiety had quite a different meaning in those days. ®

https://www.theregister.com//2024/08/03/moon_buggy_feature/