Honda Will Test a Fuel-Cell System in Space

Elon Musk may have called dibs on Mars. But with an eye toward life on the moon, Honda will test a new regenerative fuel-cell system aboard the International Space Station (ISS).

The test will build upon research from Honda’s earthbound hydrogen cars like the Clarity and new 2025 CR-V fuel-cell SUV, which use a circulative renewable-energy system. The system will produce a continuous stream of oxygen, hydrogen, and electricity on the ISS—or, someday, perhaps a moon base.

On 4 April, Honda announced it would test its high-differential-pressure water electrolysis system on board the ISS, although the company hasn’t yet revealed the launch date. The test will be part of a collaboration with Sierra Space, a Colorado-based commercial space company, and the Alabama-based aerospace company Tec-Masters.

Late last year, Honda established a new space-development division within its U.S. subsidiary to develop technologies and better collaborate with the U.S. space industry. Sierra Space will transport Honda’s system to the ISS aboard its Dream Chaser spaceplane. The 9-meter craft—about one-quarter the length of the retired space shuttle orbiters—can haul five tonnes of pressurized cargo and a half-tonne of unpressurized cargo, and then land at any compatible commercial runway around the world.

Honda’s Fuel-Cell System on the ISS

Here’s how Honda’s fuel-cell system will work: Using electricity sourced from ISS solar panels, the system will electrolyze onboard water into hydrogen and oxygen, to test and validate the technology in a space-based environment. As envisioned for the moon’s surface, the fuel cell would generate electricity during the two-week lunar day. During lunar night, the system would use that electricity to produce breathable oxygen. The only by-product of the fuel-cell reaction is water, which is recycled into the electrolysis system. Voilà!—an efficient closed-loop energy cycle. Matt Damon would be proud.

The process is similar to how a home solar system operates on Earth, where daytime solar electricity is harnessed, and excess energy is stored in home batteries to provide nighttime power.

“Honda envisions the circulative renewable-energy system to be part of the infrastructure for humanity’s sustained habitation on the moon, utilizing the available resources of sunlight and water,” the company said in a press release

Honda will use Sierra Space’s spaceplane to carry its fuel-cell system to the International Space Station.Sierra Space

A bit like the system itself, Honda says its technology trickle-down works in both directions. As the automaker strives to make hydrogen power viable for transportation, equipment, or stationary storage, it has dramatically reduced the weight and boosted the energy density and durability of fuel cells. That helps address a critical need to reduce transportation costs in space and lunar development. Enabling high-pressure hydrogen storage in smaller containers means less need to transport and manage large numbers of tanks. And testing its system in the microgravity environment of space will help verify efficiency and reliability.

“The technical improvements valued in space are many of the same improvements Honda values on Earth,” Honda spokesman Marcos Frommer says.

In February, Honda unveiled a next-generation fuel-cell module at the International Hydrogen and Fuel Cell Expo, in Tokyo. The module triples the previous version’s volumetric density, at 0.5 kilowatts per liter for the 300-liter fuel cell, allowing a much smaller footprint. The module, which succeeds a unit developed in tandem with General Motors, can generate 150 kW.

A new fuel-cell power generator, also unveiled in Tokyo in February and scheduled for mass production next year, is a stationary storage system that can produce up to 1,000 kW by combining four 250-kW units in parallel—the same unit that drives the new US $51,395 CR-V Fuel Cell SUV. It’s designed to provide clean backup power for factories or offices, and can start up within 10 seconds of being needed.

Hydrogen’s upsides include energy density that’s three times as dense as gasoline, and about 160 times as dense as lithium-ion batteries. One kilogram of hydrogen holds 39.6 kilowatt-hours of energy, versus 0.25 kWh for a kilogram’s worth of top lithium-ion batteries. Five-minute refueling times are on par with those of gasoline. Yet companies that include Honda, Toyota, and General Motors have tried and failed to gain a toehold with fuel-cell cars.

Here on Earth, hydrogen has suffered a serious failure to launch. Skeptics see the fuel as a dead end. As EVs and hybrids have come to dominate alternative fuels and charging infrastructure, hydrogen can seem like even more of a moonshot. It hasn’t helped that the United States’ hydrogen-fueling infrastructure is as desolate as the moon. There are only about 50 public hydrogen stations in the United States. All but one are in California, the only state where you can buy a fuel-cell car. Other experts, including the International Energy Agency, insist that hydrogen from renewable sources can and must play a critical role in reducing greenhouse emissions and mitigating climate change between now and 2050.

Like a stubborn explorer, Honda isn’t listening to skeptics. Honda will offer about 300 units of its hydrogen CR-V this year, joining similarly fractional supplies of the Toyota Mirai and Hyundai Nexo. As the first plug-in hybrid fuel-cell car, the Honda can travel 29 miles (about 46 kilometers) on a 17.7-kWh battery, before switching to a 4.3-km tank of onboard hydrogen, for a total range of about 290 miles (about 466 km). The company insists hydrogen still has clear advantages over batteries, especially for large vehicles or industrial equipment that demand long hours of operation. For two core company areas of development, stationary storage and heavy machinery, infrastructure becomes less of an issue.