General Motors was the first company to ever put a car on the moon, and it promises to do so again by 2025, in partnership with Lockheed Martin. The new rover dubbed the Lunar Mobility Vehicle (LMV) is fully electric and offers seating for two, fully-autonomous drive capability, and a top speed of just about 12 mph. But how do you design and prototype for off-world missions in one-sixth Earth’s gravity, on a giant sandbox made of blasted rock and glass with no atmosphere? You turn to the folks that developed the latest Hummer EV, apparently.
A Hummer on the Moon?
As surprising as it sounds, the 1,000-hp, massive new Hummer EV was the engineering launch point for GM’s next lunar vehicle. Why? Well the Hummer EV’s development was accomplished from design to production in record time for GM, and with tight deadlines for the lunar vehicle, the automaker wants to replicate that optimization for its LMV again. But there are also a number of engineering concepts that will carry over from Hummer, as well.
The Hummer EV went from a blank sheet to production launch in just two years, from 2019 to 2021, and managed to introduce 17 new features to relaunch the Hummer brand as a design leader within the company, while also utilizing off-the-shelf parts from within where they fit. This was all thanks to new virtual tools utilized in the design process, where the new EV was completely engineered in a virtual environment before the first prototypes ever rolled off a production line.
Using know-how developed for motorsports applications, including a room-sized virtual environment simulator, the Hummer team was able to craft a new vehicle with fine-tuned driving dynamics from scratch and in record time. Now, that room-sized motorsports simulator has been recalibrated to the South Pole of the moon, allowing for accurate development and testing of a new lunar surface drive system.
That lunar drive system sounds a little like a baby Hummer, at least on paper. The Hummer’s electric all-wheel drive setup that allows for electronic torque vectoring here on Earth will be reengineered for utilization on the moon, along with a rear-steer wheel setup like on the Hummer EV. The goal is to make the lunar vehicle as stable and safe as possible, checking for roll ratio, tuning the ride dampening, and honing in the speed and performance limitations to help navigate the brutal, dusty, pot-marked and rocky lunar surface long before the thing ever leaves Earth.
GM’s rover will also adapt off-the-shelf structural Ultium battery cells in the all-electric design, which will have to survive lunar weather, where daytime temperatures reach up to 260 degrees Fahrenheit and nighttime temperatures drop to almost -300 degrees Fahrenheit. GM says it will send up one of its battery cells to space later this year for more testing. Inside GM’s design center, some mockups of the new rover even displayed Hummer and Ultium battery branding, but it was strongly suggested that final branding on the design is still very much up in the air.
Racing Simulator… On the Moon!
The high-tech simulator used for Hummer and now lunar vehicle development started life as a piece of equipment from a U.K. company called Ansible, which specializes in motion rigs and simulation machines known as Driver in the Loop (DIL) systems, and company reps simply added that it “wasn’t cheap.” However, GM pointed out there’s an immeasurable value added in fuel, tire and equipment savings for the racing and Hummer development programs that utilize the virtual tech. Now having the ability to simulate a realistic lunar environment, where vehicle properties can be tweaked and tested in real time here on Earth, avoids potentially costly flaws before it becomes a problem in the real world, or, um, on other worlds.
The virtual testing rig at GM headquarters is the size of a theater room, with an external control booth with at least five operators, and featuring its own massive server room of glowing blue computer stacks. Inside the simulation room are three massive reflective walls painted by multiple projectors for a near-270-degree field of view. In the middle of the room is the rig, which you have to climb up into in its resting starting position, before controllers activate and the rig motions into a floating, neutral driving position.
The controls feed through a C8 Corvette steering wheel, and the motion rig itself is only an ambiguous shell of a roof, dashboard and hood. The operator sits in a Tahoe’s seat, accelerating and braking with two standard vehicle pedals. These pedals and wheel are far from what will end up on the actual rover, the controls of which are still going through various form factors before a final design is decided. The goal of the simulator is to provide an accurately detailed off-road environment like that of the lunar South Pole, with the ability to tweak vehicle parameters like top speed, turning angle, torque, suspension travel, and other driving dynamics that need to be tuned to one-sixth Earth gravity on the highly abrasive, rocky and disorienting lunar surface. Eventually, the simulator will be used to help give astronauts an idea of what driving on the moon is like, though none have had a go in it yet.
The simulation itself is bizarre. Journalists were warned before entering the simulator that the lunar surface is incredibly disorienting, and not to trust the horizon, for it could actually be the crest of a massive crater canyon the vehicle may not be able to navigate out of. Pushing the go pedal leads to a very slow, calm start, nothing like the instant torque of an EV on Earth, to avoid kicking up too much of the abrasive lunar surface. Even virtually, you can feel the suspension hard at work over what’s called the lunar regolith, a fancy word for the unconsolidated debris of tiny sharp rocks and glass shards that have collected over the surface from millions of impacts. Stopping is a chore, and reaction time almost doesn’t matter. The system is designed to slowly bring the vehicle to a stop—locking the brakes up only results in a long slide, again kicking up dangerous material.
The images used for the simulation come from mapping of the actual lunar South Pole, which doesn’t cover every rock, nook, and cranny. While the greater structure of the moon is accurate to five square meters, averages from other real lunar data are used to extrapolate stuff like how many rocks litter the surface, and their average size, disparity, and concentration to create a more accurate simulation.
The Lunar Mobility Vehicle (LMV)
“This is no moon buggy,” GM engineer Brent Deep told a group of journalists at a preview event of the new Lunar Mobility Vehicle (LMV) in GM’s design center in Warren, Michigan last week. Technically, GM and Lockheed Martin refer to their joint project as the Lunar Mobility Vehicle (LMV). Not yet in its final “production” spec, MotorTrend was offered an early view into the design process of the LMV, and met with some of its design team.
As we’ve established, GM and Lockheed Martin’s LMV will utilize GM’s Ultium cylindrical battery cells, powering a four-corner motor system offering full-time all-wheel drive. GM says it hasn’t finalized its design yet, with at least four prior mockups showing off different iterative designs. Models we saw feature leaf spring suspension, seats inspired by a fire engine, adjustable mesh wheels, and a modular loading bay that will house various tools, attachments, pods, and potentially even feature a mobile base in future iterations. The mesh wheels are a particularly interesting design, with some models featuring a sliding wheel hub that can stretch the mesh wheel structure to be wide and soft, like letting air out of a regular tire, or taller and rigid, to kick up less dust.
The latest design iteration featured no seatbacks, to better accommodate the life support units on the backs of astronauts. The carbon fiber seats feature hip-level mounting points, and one design showed an ability for the seat bottom to lift and tilt forward like a recliner, to improve astronaut ingress. One model also featured a front bumper that incorporated a step, and most models were driven with the use of a T-shaped handle controller located between the two seats, with side mounted screen readouts which would allow either astronaut to pilot the LMV. Designers have to keep in mind the thick shoes and gloves of the astronaut suits which limit dexterity, so a traditional wheel and pedal setup was immediately ruled out. A top rail that extends over the astronauts’ helmets features a light bar and communication module.
GM says the three previous lunar rovers used during the NASA Apollo missions averaged around 6 kph, or just about 4 mph, with a max speed of about 12 kph (7.5 mph). GM’s new LMV is capable of speeds up to 20 kph (12.4 mph), but will likely be limited on the actual lunar surface. The rear loading area of the LMV can also be used for tool attachments, with renderings of a crane, an excavator, as well as semi-rigid, posable mounting arms for assisting astronauts in their various missions. Some models featured magnetic cargo mounting points, and a solar panel mounted over the top bar. Some versions showed the astronaut seats completely folded away for more cargo utility, for the LMV’s planned autonomous missions.
Commercial Lunar Autonomy
General Motors will have a Level 5 autonomous vehicle in production by 2025, and it’ll be on the moon. The real potential for the new LMV has surprisingly little to do with ferrying astronauts around. Future NASA Artemis missions will only have astronauts on the surface for a couple of weeks out of the year, at least on the early missions, so GM and Lockheed Martin have come up with an autonomous platform that can operate free of human direction for the rest of the year.
In fact, so far, most of GM and Lockheed Martin’s development of this new LMV has been done without too much input, financing, or assistance from NASA. The plan instead is to offer a commercial vehicle platform for the moon that NASA will then hire for its missions. When NASA isn’t using it, Lockheed Martin’s deep space division plans to offer up the LMV as a commercial vehicle for other off-world projects and missions. The LMV is not designed to be disposable; design longevity promises a testbed platform for scientists 52 weeks out of the year, and they plan to make the most of it (to the highest bidder).
The LMV’s first mission will be recon. Arriving before any astronauts, the autonomous rover will be able to scout the lunar surface, identify points of interest, and test the wear of materials from the harsh conditions that can then inform future missions. GM plans to develop and build multiple variants after the first touchdown in 2025, expanding the capabilities and mission opportunities for decades ahead. There are even already plans within the project for exploring Mars, but they need to get the moon missions right, first.