Toyota proposes rover design for future moon mission

TOKYO—Toyota's latest high-tech concept vehicle is quite a moonshot. Literally.

Japan's biggest auto maker is hard at work building a six-wheeled, pressurized, hydrogen-powered moon rover it hopes to have traversing the rocky lunar surface in a decade.

The vehicle—called Lunar Cruiser as an extraterrestrial shoutout to the brand's Earth-bound Land Cruiser—will be the ultimate test of Toyota's talent in making durable, reliable vehicles. One slip-up on the moon, and there's no roadside assistance—or return—for the rover's hapless crew.

More importantly, the Lunar Rover symbolizes Toyota President Akio Toyoda's quest to conquer new horizons as he reinvents Toyota Motor Corp. into a new mobility company. The rover will brim with the technologies of tomorrow, from its fuel cell powertrain to its autonomous driving system.

The gambit is partly an outgrowth of Toyota's Five Continents Drive, the multiyear, worldwide test drive that wrapped up this year. Now that the five continents are conquered, people in the company are calling the gray, lifeless orb circling the Earth the "sixth continent"—albeit one without roads, bombarded by radiation and completely hostile to human survival.

"We have now found a new 'road,' which is the moon. And for this new road, we will be able to make a new vehicle," said Takao Sato, project head of Toyota's Lunar Exploration Mobility Works and a former interior design engineer who worked on the Prius hybrid. "This is a dream for us."

The Lunar Cruiser is pushing Toyota's technology and know-how to the limits.

It also will be the most costly Toyota ever built. Sato said it is too early to even think about estimates, but he joked that this much is true: It will be way more expensive than any Bentley.

While Tesla CEO Elon Musk used his rocket company SpaceX to launch a Roadster into orbit around the sun, Toyota might be the first manufacturer to have a wheeled vehicle for humans on the surface of another heavenly body since General Motors worked on the first moon buggies.

Apollo to Artemis

Toyota is proposing its rover for an international moon mission led by NASA and joined by the Japan Aerospace Exploration Agency and other groups. Toyota floated the idea of building the mission's lunar rover last year.

The Lunar Cruiser would be the size of two microbuses and powered by a hydrogen fuel cell system. A retractable solar panel would help generate electricity for on-board use.

Unlike the open-top buggies used under the Apollo missions of the 1970s, Toyota's rover will have an enclosed cabin. The pressurized compartment—complete with sleeping and toilet space—allows travelers to take off their spacesuits. It is designed for two astronauts but can fit four in an emergency.

Specifications come from NASA and Japan's space agency, JAXA. They call for a rover capable of traveling 1,000 kilometers (621 miles) on full tanks of oxygen and hydrogen for a total mission range of 10,000 kilometers (6,210 miles) over 42 days.

The rear will be occupied by the fuel cell system and the hydrogen and oxygen storage tanks. On Earth, Toyota's Mirai fuel cell sedan can draw oxygen straight from the atmosphere, but on the moon, where there is no usable oxygen, astronauts will have to bring their own.

And because the moon's night is the equivalent of two weeks on Earth, electricity generated by a giant solar panel will be stored in batteries to run on-board electronics during the long darkness.

Three antennas—including a large dish on the roof—keep the rover connected to mission control, allowing it to be driven remotely and to send high-definition map data and imagery to Earth.

The plan is to launch two rovers to the moon in 2029 as part of the NASA-led Artemis project.

Unearthly challenges

Artemis is an international project that aims to return humans to the moon by 2024.

NASA will spearhead the rocket and lunar-lander technologies while NASA and Europe's agency are expected to focus on the Gateway space station envisioned as orbiting the moon.

Japan is pitching the rover, and Toyota hopes for a decision from the international consortium on whether to use its proposal by year's end, Sato said. Part of the competition might be various rover concepts floated by NASA, but the U.S. agency has signaled its interest in collaborating with the Japanese.

The rover's mission is to roam the polar regions in search of large deposits of water, in either liquid or solid form. The plan calls for leaving the rover on the moon for five years. Each year, the rover will search a different location for about six weeks.

Its fuel—hydrogen and oxygen—will be dropped off in tanks until the rover finds sufficient H20 on the surface. Then it can make its own fuel through electrolysis. Fuel cells have been a go-to technology for space missions from the 1960s Gemini project through Apollo and the space shuttles. In human-operated craft, the heat and water emissions can be used to help keep the crew alive.

Lunar travel brings challenges completely alien to Toyota's engineering team.

The vehicles have to endure radiation that could fry sensors, extreme heat that would bake rubber or plastic components and fast-flying space debris that could puncture the airtight cabin.

"We must protect against all that," Sato said. "It's like making a bulletproof vest for the vehicle."

The moon is a hard place to drive. It has a dusty, rocky surface that can demand as much as 10 times the energy needed to traverse Earth, and the craters have slopes as steep as 20 degrees.

The Lunar Cruiser must also be self-driving to provide rest and work time for the astronauts. This presents its own challenges in a moonscape lacking roads or high-definition maps.

And most importantly, it must not break down.

In announcing the choice of Lunar Cruiser as its name, Toyota said it wanted the vehicle to hark back to the Land Cruiser, one of the Toyota brand's most rugged, reliable nameplates.

"The Land Cruiser is built with the mindset, quality, durability and reliability to 'bring you home alive,' a quality that the company would like to carry over to the manned lunar rover, which must run in an even more severe environment and set of circumstances," Toyota said.

The design calls for each wheel to have its own 40-kilowatt motor, smaller than the 110-kW motor in the Mirai. But on the moon, where gravity is much weaker, it takes a lot less energy to move the vehicle that's expected to weigh about 3.5 tons.

The rover's fuel cell stack will have about the same power output as the system in the Mirai, although the hydrogen tank will be 10 times bigger.

Sato said 40 kW should be enough to power the vehicle, so a fail-safe system is designed to always deliver that much to the motors, even if part of the setup malfunctions.

Toyota has about 114 people working on mock-ups of the rover and the cabin. But the team is expected to expand to more than 300 as the rover nears production.

Toyota is still deliberating where to build the flight vehicles. They could be assembled in Japan or simply have Japan-built components shipped for final assembly closer to the U.S. launch site.

True new mobility

The idea of building a moon rover was generated during a 2017 companywide campaign to brainstorm new mobility-for-all ideas. Of the 107 ideas submitted, just two were selected: the moon rover and the e-Palette autonomous electric boxcar unveiled in 2018.

To create the Lunar Cruiser, Toyota will partner with a wide range of suppliers, some old—but many new. Tire giant Bridgestone Corp. has been tapped to work on the wheels, which swap rubber for a cylindrical stainless steel design inspired by camel feet.

Many suppliers are new to Toyota because they are in the aerospace sector. Sato declined to name them but said Toyota is talking with about 70 companies in Japan, the U.S. and elsewhere.

One thing probably not landing on the moon will be the Toyota brand name.

In media renditions of the moon rover, the word Toyota is emblazoned in all capital letters along the side and front. But the real-life version won't be as brazen, Sato said. "It's going to be a huge, planetwide team that is cooperating," Sato said. "This is not something that only Toyota is making."