On July 20, 1969, astronaut Neil Armstrong took one small step for man and one giant leap for mankind by walking on the moon. It was quite the feat but a small step nonetheless because traversing the surface proved more difficult than predicted. To move around efficiently and effectively, astronauts needed something with four wheels. So NASA and Boeing improvised the development of a collapsible, all-electric two-seater called the Lunar Roving Vehicle (LRV) to accompany astronauts on the final three Apollo launches. In December 1972, the last men on the moon parked one of the three original LRVs and left it some 740 feet from their landing site, where it sits today.
How much fun it must’ve been, skipping along at 11 mph on a rock with one-sixth the gravity of our planet—in complete silence. Since the final Apollo mission, however, no human has set foot on the moon, let alone driven on it. We were beginning to lose hope that we’d ever see another vehicle—manned or unmanned—kick up lunar dust. That’s about to change, though, thanks in part to Audi.
The German automaker has teamed up with Berlin-based engineering company Part-Time Scientists (PTS) to send two Lunar Quattro rovers to the moon in 2018. The mission’s goal is to return to the Apollo 17 landing site in the Taurus-Littrow Valley to see what shape the abandoned LRV is in.
“This mission is a great challenge. And to solve this challenge, the most important technical competencies of Audi are needed: lightweight design, electrification, and digit-alization,” says Alexander Schmidt, one of Audi AG’s lead development engineers for the effort. “There is no repair shop that the rover can drive into for a service, so it needs to work without a hitch throughout the whole mission.” PTS first launched the project about eight years ago in an effort to chase down Google’s Lunar XPrize, which offers $20 million to $30 million to the first privately funded team to operate a lunar rover on the moon. But when Audi became a sponsor and engineering partner in 2015, priorities shifted and the prize money was no longer the impetus.
“The main commercial objective of the mission with Audi is to demonstrate that it’s possible to privately develop technology for space purposes and showcase that you can land them on the moon,” says Robert Böhme, CEO of Part-Time Scientists. “The scientific goal is to analyze Apollo 17 artifacts, specifically the LRV, which has been sitting on the surface of the moon unsheltered for 45 years. It’s actually very interesting be-cause a lot of people want to send long-term infrastructure to the moon—a city on the surface of the moon—and the best way of powering it would be solar power. If the LRV is completely covered in lunar dust, you would need to hire somebody to clean solar panels regularly.”
Even before Audi became part of this 239,000-mile trip to the moon, PTS had developed a landing shuttle dubbed ALINA as well as prototype versions of rovers that are millennia more advanced than the Apollo LRV model, which was more of an afterthought than a deliberate automotive design. “There was an empty pie-shaped cargo volume on the underside of the lunar lander, and someone had the brilliant idea of designing and building a rover that could be folded up and stuffed into that space,” says Peter Visscher, vice president of space, robotics, and defense engineering for Argo, which is working with the Canadian Space Agency to launch lunar rovers of its own. The quickly constructed LRV weighed 462 pounds (or 76 pounds on the moon), could haul several hundred pounds of bagged scientific samples, and could climb and descend grades up to 25 degrees. It wears materials from the ’60s that would never make it on a modern lunar rover, including nylon, plastic, and even duct tape.
“Originally we were using standard industrial hard aluminum until Audi introduced us to its 3D-printed aluminum,” says Böhme as he describes the Lunar Quattro rover’s construction. “You’re taking aluminum powder that you can blend with other materials to create your own flavor of material. We created a very special brand of aluminum and started building new structures. Eighty percent of the rover’s parts are now 3D-printed, aluminum-based parts. They worked really, really well in tests and didn’t break at all, which was a really big surprise for us.” Schmidt says Audi engineers were able to make the rovers bigger and stronger but also lighter,” shaving some 25 pounds from the Lunar Quattro’s initial PTS design.
The Lunar Quattro’s lithium-ion batteries are well protected inside the rover, insulated by the swiveling solar panel. It has three cameras: two stereo cameras that acquire 3D images and a third high-resolution camera that generates extremely detailed panoramic images. The only similarity between the Lunar Quattro rovers and the LRV is electric propulsion, necessitated by the fact that combustion engines won’t work on the atmosphere-free moon. PTS turned to Audi for its e-tron electrical expertise and Quattro know-how in order to improve the rover drivetrains, which use small motors mounted in each funky-looking aluminum wheel. Each wheel moves independently of one another—essential when you’re very slowly crossing cratered terrain that has been barraged by meteorites for some 4.5 billion years.
Audi deferred to PTS when it came time to fit the drivetrain with seals to keep out lunar dust, also known as regolith. “It’s 1,000 times finer than the finest grain of sand that you can find here on Earth. And it is very, very sharp,” Böhme says. “When Apollo astronauts took off their suits, they realized that lunar dust had gotten into their air-tight suits. And not just their suits but also under their skin, which really freaked them out. If the regolith gets into our rover’s gear subsystem, the gears will go down in only a few seconds.” PTS uses a specialized seal with specific opening and exit paths, allowing dust to enter one end of the seal before being tumbled around and shooed back out the other end—or at least that’s the hope. Even after testing in a bed filled with simulated regolith, Audi and PTS won’t be unquestionably sure everything will function without fault until the Lunar Quattro rovers reach the moon. “It isn’t practical or even possible to completely reproduce the lunar environment on Earth, so we can only perform limited testing,” Visscher says. It’s an ever-evolving learning experience for both Audi and PTS. Even now, as engineering development winds down and planning for the upcoming launch intensifies, the two companies continue to teach one another.
For example, PTS explained to Audi the rovers would need a special coating of PSBN, the white, nonconductive silicate paint you’ve seen on just about every spacecraft ever. Although cars on Earth are designed and tested to operate at minus 40 to up to 130 degrees Fahrenheit, temperature swings on the moon can be much more severe, with 575-degree fluctuations that occur almost instantaneously. In theory, the rover could heat up to 275 degrees and cool down to minus 180 degrees in just a few seconds. “PSBN has tiny mirrors in it,” Böhme says. “It has a very high UV reflectance, reflecting 95 percent of invisible light, which is important for us because then the sun doesn’t heat the spacecraft up so much. After explaining this to Audi engineers, they actually realized this could be an incredible thing for street cars as well.”
You’re taking aluminum powder that you can blend with other materials to create your own flavor of material. … Eighty percent of the rover’s parts are now 3D-printed, aluminum-based parts.
Even though we love the idea of an RS 7 painted in PSBN, we’re left wondering what real, long-term effects this trip to the moon will have on Audi. What happens after the pair of Lunar Quattro rovers is packed into the detachable nose of a SpaceX Falcon 9 rocket, lifted into orbit around the moon, and directed through a hopefully carefree mission? “In the future we have to think beyond our current frontiers,” Schmidt says.
Could there be some starry-eyed future in which we drive Audis on the moon? “The question really isn’t if these things will happen but when,” Visscher says.“It is very likely we will see multiple robotic vehicles driving on the moon by the mid-2020s and manned vehicles by the mid-2030s. Of course, these will be driven by professionally trained rover operators and astronauts. But there are plans being discussed among international space agencies to develop a lunar village where humans from several countries will live and work, and one of the key elements of this concept will be vehicles. Compared to the LRV, the next generation of manned rovers will be considerably larger. Expect a multiwheeled vehicle that bears some resemblance to an RV and has six or eight wheels, not four. A pressurized cabin will allow the occupants to remove their space suits, and the rover will have to carry life-support systems, radiation protection, and power systems.”
As space travel becomes more routine and entities in both the private and public sectors look to stake their claim on the moon, there will likely be opportunities for tourists to visit Earth’s sole natural satellite. It won’t happen in the next few years, and it would cost a small fortune, but it’s possible that one day you won’t need to be a professional astronaut to stand (or drive) on the surface. Audi’s connection with Part-Time Scientists shows a keen interest in advanced technologies and interstellar exploration. So is it possible the automaker could one day build manned vehicles to be driven on the moon? Perhaps the Lunar Quattro rovers are only one small step for Audi as it looks to take one seriously giant leap.