Prometheus

Built for the terrain that ends every other vehicle.

The lunar south pole is the hardest driving environment humans have ever faced: powdered, abrasive regolith; slopes strewn with ejecta blocks; temperature swings from +120 °C in sunlight to −170 °C in shadow; a 14-day night; and no atmosphere to cool a motor or cushion an impact. Prometheus is designed from first principles for exactly that — and to NASA's Lunar Terrain Vehicle reference requirements: two crew, 8-hour sorties, 20 km minimum range per charge, survival through the lunar night, and ten years of crewed and remote operations.

Every subsystem below was downselected through a weighted trade study — the same discipline we applied to Cosmos. Where flight-proven hardware exists, we baseline it. Where it doesn't, we develop it.

PROM-R-001 · Concept rendering — 6×6 configuration, superelastic tires, ceramic thermal-control skin

Propulsion

Electric is not just the best answer — on the Moon it is effectively the only answer. No atmosphere rules out combustion; consumable-based systems trade poorly against a 10-year service life. The real question is the drive topology. Six independent in-wheel motors give per-wheel torque vectoring, which is decisive on slopes and in soft regolith: slip is detected and corrected at each contact patch individually, the way Curiosity and Perseverance do it on Mars.

Drive motors — build, buy, or partner

The honest answer to "who sells the best lunar in-wheel motor" is: nobody sells one. Every terrestrial drive unit — however brilliant — assumes air or oil cooling, elastomer seals and wet lubricants, all of which fail in vacuum at −170 °C. The best electromagnetics in the world live in EV drive units; the only vacuum-proven drivetrains live in space actuation houses. Prometheus takes one from each.

Supplier ground rule: US manufacturers only. There is no absolute NASA ban on foreign hardware, but ITAR export controls on a crewed lunar vehicle, Buy American provisions, and plain proposal optics all cut the same way. That rules out Mercedes (whose quad-motor electric G 580 is arguably today's best electric off-roader), Porsche, Land Rover, Slovenia's Elaphe and Chinese-owned Protean — noted, admired, excluded.

Energy storage

One battery pack feeds the whole vehicle — drive, avionics, life support and heaters — exactly as specified. The sizing driver is not range; it's surviving the 14-day lunar night, when the pack must keep itself and the avionics above minimum temperature for 336 hours with no sun.

Wheels

The best wheel NASA has ever developed is the superelastic tire from NASA Glenn and Goodyear: a non-pneumatic mesh woven from nickel-titanium shape-memory alloy. Where the Apollo wire-mesh wheel deformed permanently past ~5% strain, nitinol springs recover from up to 10% strain — the tire can be crushed flat to the axle and snap back to shape. That is the difference between a wheel that survives one rock strike and one that survives ten years of them.

Structure & outer shell

Carbon fiber alone is the wrong answer, and it's worth being precise about why. For micrometeoroid protection, what matters is shocking the impactor into vapor at the first surface — aluminum bumpers do this better than CFRP, which fails in brittle, delaminating modes under hypervelocity impact. The proven architecture is a stuffed Whipple shield: a sacrificial outer bumper, a standoff gap, ceramic/aramid stuffing (Nextel + Kevlar), and a structural rear wall. Full protection from large impactors isn't physically achievable for any vehicle — the design standard is probabilistic: no penetration of crew-critical zones over vehicle life at >99% confidence, which is how ISS modules are specified.

Cabin architecture — pressurized or not

Your instinct about regolith is exactly the failure mode NASA worries about. Every pressurized hatch that opens on the surface becomes a dust airlock problem: charged, barbed regolith particles embed in seals and abrade them with each cycle. There is a clean way around it — the suitport, where suits dock backward through the rear bulkhead and never enter the cabin — but it belongs on a larger vehicle. The trade below is why Prometheus Block 1 flies unpressurized.

Crew station & seating

An F1 driving position is built around a soft human in a carbon tub. Our crew is inside a semi-rigid pressure suit with a hard upper torso and a life-support backpack — a reclined F1 posture is nearly impossible to enter in a suit and wrecks sightlines over the nose. The fighter-jet reference is much closer, with one lunar twist: in 1/6 g, standing for hours is easy, which is why several LTV concepts use a stand-up "chariot" station.

Displays, data & telemetry

Cockpit displays on the Moon fight three enemies: raw sunlight with no atmosphere to soften it, gloves with no capacitive touch, and radiation flipping bits in commercial silicon. The answer is layered — nothing safety-critical lives only on a screen.

Homeward — the guardian layer

Baked into the flight software, exactly as you specified: Prometheus continuously solves the return problem. Every few seconds it recomputes the energy and consumables needed to reach the landing site or base camp over real terrain — slopes, temperature, motor efficiency, suit O₂ state — and compares it against what's on board.

The rule is simple: the vehicle must always be able to get home with 10% energy and consumables to spare. When the margin trends toward the floor, Homeward advises; when it reaches it, Homeward turns the vehicle around and drives — crew aboard or not. The same autonomy stack handles remote science traverses between crews, which is how the vehicle earns its keep for ten years, not ten days.

What one-sixth gravity actually does

Mass stays; weight divides by six. A 2,400 kg Prometheus presses on the regolith with the force of a 400 kg Earth vehicle — roughly 650 N per wheel. That's the whole game: traction is proportional to weight, but inertia is proportional to mass. The vehicle is easy to get stuck-free and hard to stop; it brakes, corners and absorbs rock strikes like a fully loaded truck while gripping like a golf cart. This is why torque vectoring and compliant tires beat raw power — the limit is almost never motor torque, it's slip at the contact patch. It's also why Apollo crews reported the LRV going airborne over bumps at 10 km/h: less weight means less suspension force is needed to launch you. Suspension travel is sized long and soft, and Homeward caps speed over rough terrain automatically.

Range is sized to the reserve rule, not the brochure. NASA's LTV floor is 20 km per charge and 8-hour sorties. Prometheus targets 50 km nominal: a 20 km science radius means 40 km round trip, plus slope and thermal penalties, plus the 10% Homeward floor — with margin left for the sortie after this one.

Everything else we have to develop

The subsystems above are the headline trades. A NASA-credible proposal has to close all of these too — this is the honest bill of work.

Development roadmap