How Oxygen Can Be Produced on the Moon

 

The sphere created by Sierra Space can simulate lunar-like temperature and pressure conditions.

The engineers stepped into a massive spherical chamber to meticulously examine the equipment. In front of them stood a strange, silver metallic device, entangled in colorful wires. They hoped this peculiar machine would one day produce oxygen on the Moon.

Once the engineers exited the chamber, testing began. The box-like machine gradually consumed layers of grayish dust and soil particles known as regolith, a chemically similar substitute for actual lunar soil. Within moments, the dust melted into a thick, molten substance. At one stage, its temperature soared past 1,650 degrees Celsius. After adding some reactants, oxygen molecules started bubbling out of the mixture.

Brant White, a program manager at the private company Sierra Space, stated, “We’ve tested everything we can here on Earth. Our next step is to go to the Moon.”

This testing by Sierra Space began in the summer at NASA’s Johnson Space Center. This is just one of several technologies researchers are developing to support future lunar bases, ensuring astronauts’ needs are met.

Future astronauts will need oxygen to breathe. To send spacecraft from the Moon to Mars or other distant destinations, they’ll need rocket fuel, which also requires oxygen.

The lunar settlers may also need metals, which they could extract from the regolith scattered across the Moon’s surface. However, much depends on the development of nuclear reactors capable of efficiently extracting these resources.

“This could save billions of dollars in mission costs,” explained Brant White. Without such technologies, additional metals and large quantities of oxygen would need to be transported from Earth to the Moon, a process that is challenging and costly.

Fortunately, the Moon’s regolith is rich in metal oxides. However, while the science of extracting oxygen from metal oxides is well understood on Earth, making it work on the Moon is a much bigger challenge.

In July and August of last year, Sierra Space conducted experiments in the spherical chamber, creating a vacuum to simulate space conditions. This year, they mimicked the Moon’s temperature and pressure.

Sierra Space reported that their device had to be progressively improved to handle the extremely coarse and abrasive lunar dust and soil particles. According to Brant White, this dust infiltrates everything.

Another critical factor that cannot be adequately tested on Earth or even in orbit is the Moon’s gravitational force, which is about one-sixth that of Earth’s. Testing the machine’s effectiveness on the Moon itself, under low-gravity conditions, using actual lunar soil, will take Sierra Space several more years—likely not before 2028, or even later.

Paul Burke of Johns Hopkins University emphasized that without proper countermeasures, lunar gravity could pose a significant challenge to some oxygen extraction technologies.