Credit: Guy Norris/AW&ST

At first glance, there seems to be little to link a windswept ranch in Colorado with the surface of the Moon, but it is here at the base of the Rocky Mountains that space startup Lunar Outpost is putting prototypes of its large-scale Eagle lunar terrain vehicle through their off-road paces.

Viewing the test area from the rim of a nearby mesa, however, it is surprisingly easy to imagine a lunar-like terrain duplicated in the ranch’s rugged hills, cliffs, gullies and slopes. Moreover, the topography resembles the challenging lunar south pole region for which the lunar terrain vehicle (LTV) is being designed.

“A lot of people’s perception of the Moon is from the Apollo era,” says Justin Cyrus, co-founder and CEO of Lunar Outpost. “Unlike the maria and those kind of nice, flatter areas, the lunar south pole is not like the equatorial regions. It’s hills, it’s mountains, it’s ravines, it’s these permanently shadowed craters and tall cliffs. So it’s important that these vehicles be able to handle those types of environments.”

Work at the autonomous testing facility involves two prototype rovers and comes 17 months after Lunar Outpost won a commercial LTV concept design contract as part of NASA’s Artemis program. Under the effort, for which Intuitive Machines and Venturi Astrolab also received competitive contracts, the agency is seeking to establish a sustainable human presence on the Moon to prepare for human exploration of Mars.

Unlike the single-use Lunar Roving Vehicles of the Apollo era, the 21st-century LTVs are intended as a critical long-term element of the exploratory infrastructure. NASA is expected to select a finalist, or finalists, to place LTVs on the Moon for astronaut exploration, groundwork development and scientific research. Planned to be autonomous or optionally drivable, the LTVs also are expected to be available commercially when not in use by NASA, which estimates it will spend $4.6 billion on task order LTV activities through 2039.

Located 160 mi. south of Lunar Outpost’s headquarters in Golden, the rural Colorado test area includes terrain ranging from crater-pockmarked plains to rocky outcrops—all of which the rover is expected to encounter on the Moon.

“Each serves a different purpose,” Cyrus says. “The lunar test facility is for the more extreme obstacles—the craters, the berms, the rocks—that we want to be able to drive over, while the test site toward the back [of the ranch] has some obstacles we don’t want to drive over. There are large ravines and cliffs. We want the vehicle to be able to recognize those and make sure that it is always in a safe position.

“The good news is the vehicle has never driven itself into a ravine,” he continues. “It’s never totaled itself, which is great, but we have learned a heck of a lot doing the long-distance testing at the back of the property and the slope testing that it has done there.”

Following completion of the preliminary design review (PDR) in late May, further refinement of the Eagle is continuing under a series of design and analysis cycles. These are based on lessons learned through tests on the first two vehicles, dubbed the Raven and Falcon, and to be incorporated into as many as seven more Eagle LTV prototypes that Lunar Outpost expects to construct between now and critical design review (CDR) in late 2026 or early 2027. Development work is being conducted collectively by the Lunar Dawn team, which includes partners General Motors, Goodyear, Leidos and MDA Space.

NASA, meanwhile, says it will evaluate the task order proposals received from each LTV vendor and select the demonstration mission by year-end. The first winning LTV is planned to travel to the Moon in late 2029 or early 2030 on Artemis V, the fifth planned mission of the program and the first crewed flight of the Blue Moon lander—made by a team led by Blue Origin and including Astrobotic, Boeing, Draper, Honeybee Robotics and Lockheed Martin.

Resembling a large sports utility vehicle in overall size, but with the wide wheelbase of a Humvee for stability and a low center of gravity for the Moon’s one-sixth gravity, the Falcon has been tested on extended trial runs in the hilly spaces of the ranch. “Falcon goes up to about a 15-deg. slope on shale rock and loose gravel, so it has a lot of slip induced on the vehicle,” Cyrus says. “We have to make sure our torque and our motor control are properly calibrated to be able to handle high slopes and to make sure our vehicle is efficient when going up long slopes over notable periods of time.

“It has also navigated 20-deg. slopes, no problem, and we tested it on up to 35-deg. slopes in high-fidelity simulations, and we were still very safe,” he adds. “That’s the huge benefit of having a lower center of gravity. Our goal is to find issues and problems, develop, iterate and put ourselves in a situation where we are not getting surprises once we hit the more flight-ready models.

“Over the last two years, and especially over the past year with the NASA LTV vehicle program, we have done a pretty good job of getting real hardware out into relevant environments,” Cyrus notes. “We do tests at the component level, and we have many different subsystems we test with, and then we bring it up to the full-scale vehicle. These are still very early in the life cycle, and a lot will change between PDR and CDR based off astronaut feedback and our continuous testing.”

Astronaut feedback follows Lunar Outpost’s involvement in NASA’s LTV feasibility study. In late 2024, each company delivered a static mockup of their vehicle to Johnson Space Center for rover evaluation inside the agency’s Active Response Gravity Offload System test facility. The facility provides an analog environment that can subject astronauts in pressure suits to simulated reduced gravity. In other areas, Lunar Outpost is learning from the evolution of its own vehicles.

“While Raven was our first prototype, the motors we have on it are much more flight-like, so they’re sized for the lunar environment,” Cyrus says. “The Falcon motors, on the other hand, are very oversize for what you’d need in the lunar environment, but it gives us a good idea of the drive dynamics we’d see on the Moon. That’s why Falcon can go up these 20-deg. slopes, where Raven can’t.”

Confidence in key aspects of the design, such as the 36-in. metallic mesh tires developed with Goodrich, has also grown through early tests at NASA’s Marshall Space Flight Center. Dubbed “quarter-car” tests, the evaluation included running a tire complete with its attached suspension, bearings and seals, for hundreds of kilometers in a thermal vacuum chamber on a bed of simulated lunar regolith. Lunar Outpost has also been testing rover mobility and durability in a regolith facility at the Colorado School of Mines close to its headquarters in Golden.

With the large metallic tires, “we’ve driven the vehicle up sheer rock faces at over 25 deg.,” Cyrus says. “We’ve driven it up lunar regolith at over 20 deg., and we tested it out here at the ranch time and time again. It’s very capable. It gives us good traction and allows us to absorb those shocks.”

The large tires and suspension contribute to the Eagle’s high ground clearance. “It’s more like a trophy truck suspension,” adds Cyrus, an off-road vehicle enthusiast, referring to a special class of modified high-ground-clearance racing trucks. “The exact clearance is still being iterated on, but it will be well over 40 cm [16 in.]. That’s the minimum clearance we would have, and realistically, it’s going to be quite a bit higher than that.”

Testing of other systems, such as the Eagle’s autonomous 360-deg. electro-optical camera and lidar sensor suite, also has unearthed lessons—some more unusual than others.

“This summer, swarms of grasshoppers have interrupted the autonomous functionality—it thought the crickets were dust,” Cyrus says. “You don’t want electrostatically levitated dust interrupting your guidance, navigation and control [(GNC)] system, and obviously, you don’t have blowing dust like that on the lunar surface, but you do here down at the ranch. So we now have a specific grasshopper software fix, which helps better identify things that are not lunar-like. That way, we can test the more lunar features.

“We are testing out all sorts of different sensors..., including some of the new advancements in radar as well to help mitigate the lunar dust effects on other sensors,” he adds. “We can operate completely with just the visual cameras and the lidar, but we just got through PDR, and we’re still testing. The most important thing is that they are reliable, so the vehicle doesn’t have to have too much maintenance over time.”

A potentially competitive feature of the LTV contest is each company’s proposed solution to meeting NASA’s requirement for autonomous navigation on the Moon—including the ability to localize within 10 m (33 ft.) over 10 years. “We have a suite of software that allows us to localize anywhere on the Moon,” Cyrus says. “That’s a very difficult thing to do, especially without supporting infrastructure.”

Without giving further details, he adds: “We’ve tried to drive our autonomy stack and our localization stack and our whole GNC system to be totally nonreliant on any external infrastructure, which is a pretty unique capability that we’re building.”

Another key challenge is power. The rover is being designed to survive and even operate during the two-week lunar night that sees temperatures as cold as -280F and in daytime temperatures of up to 260F. Initially in 2023, before Leidos replaced Lockheed Martin on the Lunar Outpost team, the planned battery power system was based on GM’s Ultium cell technology, which relies on a nickel-cobalt-manganese-aluminum chemistry and requires 70% less cobalt than the cells used in the car company’s Chevrolet Bolt EV.

It is unclear if this is still the baseline, however. “We ended up swapping to a new chemistry over the course of Phase 1, just for reliability purposes, and we wanted to make sure that this is the safest and most reliable thing possible,” Cyrus says. “With batteries on the Moon, you can’t have a high risk. If you lose a cell, it needs to be mitigated to that cell. If you lose a pack, it needs to be mitigated to that pack, and you still must be able to operate.”

Main vehicle power is produced by large, deployable, dual-sided solar panels stowed above the rear flatbed. The dual-sided design means solar power is collected regardless of the vehicle’s direction.

“One thing we’ve learned from all of the mission operations on our early rovers is that power is key,” Cyrus says, referring to the company’s smaller Mobile Autonomous Prospecting Platform (MAPP) design, which landed on the Moon in March aboard Intuitive Machines’ IM-2 Athena. Although the lander tipped over on touchdown, preventing the MAPP from deploying, Lunar Outpost says the vehicle was operating as planned. A second version of the MAPP, dubbed the Lunar Voyager 2, is due to travel to the Moon in early 2026 as part of the Intuitive Machines-3 Nova-C lunar lander mission.

While smaller rovers must collect as much data as possible before dying during the long lunar night, power is “key for LTV for different reasons,” Cyrus says. “It allows us to not only drive farther and accomplish more science while we’re on the lunar surface, but also accommodate more payloads. We can still charge up and perform all our operations at hand, even with a completely full bed.”

The Eagle is designed to carry loads of 2,400 kg (5,300 lb.) plus another 3,000 kg in an unpowered trailer. “That is pretty substantive for a planetary rover, and you need a lot of power to do that,” he notes. The bed also mounts an MDA Space-developed, roughly 1-m-long robotic arm dubbed Skymaker.

Designed to accommodate a full range of anthropometric astronaut sizes, from a 1% female to a 99% male, the vehicle’s open driving position is accessed by forward-mounted, lighted steps. The vehicle is controlled by rectangular driving handles large enough to accommodate astronaut gloves and a set of oversize switches. Tools and equipment for experiments, sample collection and support are contained in slide-out container drawers or externally on quick-connect attachments inspired by Molle panels used by off-road enthusiasts.

“Why reinvent the wheel?” Cyrus says. Large fenders, specialized coatings and electrodynamic dust shields are designed to mitigate the buildup of lunar dust, while side- and top-mounted radiators reject excess thermal energy to space.

“We are starting another design cycle right now,” says Forrest Meyen, co-founder and chief science officer. “In between these design cycles, we’re taking our current iteration of our software and autonomy code, and we’re deploying it in the field and getting real feedback to kind of complement and correlate our simulations. By having these design and analysis cycles, we set a snapshot of where the vehicle is at a certain point in time, and then we continue the progression and refinement of the next vehicle.”

The rapid vehicle iteration also helps “refine our own assembly integration and test plans, which we’re going to use for the flight vehicle,” Meyen says. “So it demonstrates the readiness of our supply chain and capability for manufacturing tolerances and at scale. With each prototype, we basically refine that product one step further.”

As for the future of the Artemis program, Meyen says Lunar Outpost remains confident despite recent uncertainty. “What we’ve seen is NASA prioritizing human exploration, and we’ve seen the budgets be focused on that, which is exactly where we specialize,” he says. “So we’re confident in the direction of the Artemis program and how it continues that march to the Moon. We also have a broader vision that goes well with NASA’s vision, which they call the Moon to Mars directorate. The Moon is a huge objective for NASA, and it’s a key steppingstone to get to Mars, and through this program and others, we’re demonstrating capabilities that will be highly valuable to both destinations.”

Quelle: AVIATION WEEK