One Small Drive For Mankind

Andrew Miles documents a space oddity.

A pleasant Saturday evening drive ahead. (c) Thisdayinaviation.com.

As a professor of ignorance based within the university of life, complex issues such as remembering which side the fuel filler flap is on (even with the pointy arrow!) can, dependant upon time of day, prove vexing. How on Earth therefore does one design and build a car not for this planet? Fortunately, Boeing (with assistance) employing credible professors, engineers wielding planet sized brains along with some good ole fashioned guesswork created the LRV, Lunar Roving Vehicle.

First mooted in the early 1960’s space race, original ideas proved either unwieldy or too small for an astronaut to drive. Once plans had been refined, the role of the LRV (soon nicknamed Moon Buggy) was more pick up than sports car. Distilled down to transporting two men, equipment and a payload bordering 500Kg (more on weights, momentarily) with a potential forty mile radius from home: the LM, or Lunar Module.

The main parties chosen were Boeing as main contractor, GM’s Defence Research Laboratories and a collection from Bendix. A seventeen month delivery date was stipulated – 1st April 1971. Testing occurred earthbound, then airborne to ascertain low-g characteristics. Checklists included bounce height, acceleration and braking, roll over tendencies along with new tyres fitted initially without, then with added guards. Oh, and left hand drive.

“Clem and Wilbur search avidly for the dark side of the Heath.” (c) Hemmings.com via the GM Archive.

The LRV’s chassis, hinged centrally, in order to be folded into the LM, consisted of 2,219 aluminium alloy tubes. A 3 metre frame and wheelbase of 2.3 metres, two seats, again from foldable aluminium with nylon webbing seats. Equipment included: Velcro safety belts and footrests to prevent astronauts floating off into the abyss and even an armrest (but no ash tray). Suspension consisted of double horizontal wishbones with both upper and lower torsion bars.

Power derived from two 36 volt silver-zinc potassium hydroxide non-rechargeable batteries which offered a range of fifty seven miles although to ease any first mission fears strict instructions were not to stray too far from the LM. Generated motor power, all 0.25hp was fed to each of the four wheels (with four wheel steer giving a minute turning circle) but now our focus turns to the tyres.

Hungarian born Ferenc Pavlics is credited with developing the resilient wheel with a 32″ diameter, nine inch wide tyre consisting of zinc coated woven steel strands with titanium Chevroned tread for cutting through the lunar dust. Non-bursting and immensely strong they more than proved their worth. Pavlics had left his homeland after the 1956 revolution, finding work with GM. NASA awarded him for his Apollo missions success in 1971.

Controlling the LRV was simplicity itself. A t-bar positioned between the seats could be moved forward for speed, toggling left and right corresponding to relevant steering inputs. A button and pull back for reverse with the parking brake applied when fully retracted.

And now to weight. On Earth, the LRV weighed 210Kg; the moon has one sixth gravity which reduced the unladen weight to just 34. Another weight factor being the actual deployment of the LRV to moon surface. A system of pulleys and braked reels of cloth tape helped that process.

With the chassis side out, one astronaut inside the LM and with one outside, the LRV could be lowered, wheels automatically folding out and chassis locked into place within ten minutes (when practised on Earth), the moon’s more hostile environment engendered a two minute more delay. Instruments on a rectangular frame displayed speed, heading, power reserve and temperatures; dust the enemy of both man and machine.

Whilst deployed, problems encountered were mercifully few. Eugene Cernan’s hammer handle hit the wheel arch extension, breaking it. A duct tape repair was no match for abrasive moon dust thus their return journey covered everything in grey dust, causing Houston a few heart murmurs as LRV temperatures rose. On returning to the LM, an LRV dust down with a more industrial repair was had. Utilising table light clamps and, of all things, maps with again prodigious use of duct tape, the repair not only worked but survived; the scarred maps a feature of the NASA museum.

The first use of the LRV was from the Apollo 15 mission on 31st July 1971. Always driven by the mission commander, David Scott discovered that the front steering gear had failed*, yet the LRV coped admirably. Three sorties were made, the longest at 7.75 miles travelling a total of 17 miles for the mission. Apollo 16 delivered LRV 2 which managed 16.2 miles of lunar travel with the third and final outings from Apollo 17 managing the most; a single traverse of 12.5 miles with 22.3 in total.

The combined travel times of all three LRV’s a shade under eleven hours. The total cost of the project being $38m. A fourth LRV remained earthbound for spares along with other mock-ups for training purposes which, once the Apollo programme was cancelled grounded them forever. As were those three buggies, parked up and abandoned. Their batteries discharged, what use returning? Anorthosites and other lunar deposits took up the once vital space.

‘Tyre’ close up. Image: Wikipedia

Boys, however professionally trained, will of course be boys. Encouraged by technicians back home to test the vehicles, Cernan holds the Lunar Land Speed record at 11mph, whereas Charles Duke is reported to having spun 180°. Footage of LRV’s getting air exists as the vehicle easily bounces whilst seemingly under some form of control, leaving interrupted tracks forever more on that faraway surface.

The future may witness modern LRV’s with a Japanese undertaking. Toyota, in partnership with the Japanese Aerospace Exploration Agency (JAXA) have plans to take a Lunar Cruiser (what, no Mitsuoka Buddy?) later this decade. Pictures seen reveal a huge craft which dwarves the fifty years old LRV’s. Quite how such behemoth would be delivered may need extra brain power. As for those three left behind: rust won’t be a problem – starting them after many moo…sorry, so long might prove otherwise .

This video shows astronauts having fun with the LRV

* The steering gear failure was temporary, being fixed during the mission. The text has been changed to reflect an error of attribution in the initial draft, which suggested the failure was drivetrain related.

Author: Andrew Miles

Beyond hope there lie dreams; after those, custard creams?

4 thoughts on “One Small Drive For Mankind”

  1. Good morning Andrew, and Happy Boxing Day to you! Even though I do recall the (diminishing) excitement surrounding the Apollo missions I had largely forgotten about the LRV, so thank you for reminding us of them. There was another ‘moon buggy’ that tapped into the zeitgeist surrounding the Apollo missions:

    From the James Bond 007 movie, ‘Diamonds are Forever’ (not ‘Moonraker’ as I would have guessed).

    The impenetrable algorithm that automatically chooses ‘related’ articles has today chosen the Chevrolet Vega, Mercedes-Benz R-Class and Citroën SM. Go figure!

  2. Good morning Andrew and thanks for another article from “left field”. Am I the only one who thinks that the Americans just had to show off their driving abilities on the lunar surface. And the commentary- oh dear!

  3. Another great article Andrew, thank you. My brother is a space fan, he has models of all the Apollo craft and of course the moon buggy. He has a degree in Astro Physics, far cleverer than me. Me, being interested in vehicles of all types and engineering, thought the moon buggy was a great feet of engineering, 50 years ago.

  4. Great article. I never knew this contraption folded, but it makes perfect sense of course, as there is so little space in the spacecraft. Enjoyed reading this.

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