Within a giant domain, the engineers distributed their equipment. In front of them stands silver metal wiping into colorful wires — a box they hope to one day make from oxygen on the moon.

Once the team cleared the field, the experiment began. The box-like machine was now taking in small amounts of dusty regolith—a mixture of dust and sharp gravel with a chemical composition that mimicked real lunar soil.

Soon, it was a regolith globe. A layer of it is heated to temperatures exceeding 1650 degrees Celsius. As some reactants were added, molecules containing oxygen began to come out.

“We’ve tested everything we can on Earth now,” says Brant White, program manager at Sierra Space Corporation, a private company. “The next step is going to the moon.”

The Sierra Space Experiment unfolded at NASA’s Johnson Space Center this summer. It’s far from the only technology that researchers are working with, as they develop systems that could power astronauts living on a future moon base.

These astronauts will need oxygen to breathe but also to make rocket fuel for spacecraft that might start from the Moon and head to destinations farther afield — including Mars.

The inhabitants of the moon base may also require minerals and can even harvest these from the dusty gray debris that dresses the moon’s surface.

Much depends on whether or not we can build reactors capable of extracting such resources effectively.

The alternative – bringing a lot of spare oxygen and minerals to the Moon from Earth – “could save billions of dollars in mission costs,” Mr. White explains.

Fortunately, lunar regolith is full of metal oxides. But while the science of extracting oxygen from metal oxides, for example, is well understood on Earth, doing so on the Moon is much more difficult. Not least because of the circumstances.

The massive spherical chamber that hosted the Sierra space tests in July and August of this year caused a vacuum and also simulated the Moon’s temperatures and pressures.

The company says it’s had to improve how the machine works over time so it can better combat the highly abrasive and revealing texture. “It gets everywhere, wearing all sorts of mechanisms,” Mr. White says.

The crucial thing, which you can’t experience on Earth or even in orbit around our planet, is lunar gravity — which is roughly one-sixth that of Earth’s. It may not be until 2028 or later that Sierra Space can test its system on the Moon, using real regolith in microgravity conditions.

Paul Burke at Johns Hopkins University says the moon’s gravity could be a real problem for some oxygen extraction technologies unless engineers design it.

In April, he and his colleagues Published paper They detail the results of computer simulations that showed how various oxygen extraction processes can be hampered by relatively weak gravitational pull. The process under investigation here was molten Regolith electrolysis, which involves using electricity to split lunar minerals containing oxygen, in order to directly extract the oxygen.

The problem is that such technology works by forming bubbles of oxygen on the surface of the electrodes deep within the molten artery itself. “It’s the consistency of, say, honey. It’s very sticky,” says Dr. Burke.

“Those bubbles will not rise as quickly – and may actually be delayed in detaching from the electrodes.”

There can be ways around this. One may shake the oxygen making machine device, which may shake the bubbles free.

The additional fake electrodes may make it easier for the oxygen bubbles to break off. Dr. Burke and his colleagues are now working on ideas like this.

Sierra Space technology, a thermal process, is different. In their case, when oxygen-containing bubbles form in the regolith, they do so freely, rather than on the surface of the electrode. This means there is less chance of tripping, says Mr White.

Emphasizing the value of oxygen for future lunar expeditions, Dr. Burke estimates that, per day, an astronaut requires the amount of oxygen found in approximately one or three kilograms of regolith, depending on the astronaut’s fitness levels and activity.

However, life support systems at the moon base will likely recycle the oxygen that the astronauts breathe. If so, it wouldn’t be necessary to process so much Regolith just to keep the lunar population alive.

A real use case for oxygen extraction techniques, Dr Burke adds, is in providing oxidation for rocket fuel, which could enable ambitious space exploration.

Obviously, the more resources that can be manufactured on the moon, the better.

Sierra Space’s system requires adding some carbon, although the company says it can recycle most of this after each oxygen production cycle.

Together with colleagues, Palak Patel, a doctoral student at MIT, came up with a pilot Regolith electrolysis systemTo extract oxygen and minerals from lunar soil.

“We really look at it from the point of view of, ‘Let’s try to reduce the number of rerun assignments,'” she says.

In designing their system, Ms. Patel and her colleagues addressed the problem described by Dr. Burke: that low gravity can hinder the separation of oxygen bubbles that form on the electrodes. To counter this, they used a “Sonicator,” which bursts bubbles with sound waves in order to dislodge them.

Ms Patel says future resource extraction machines on the Moon could derive iron, titanium or lithium from Regolith, for example. These materials may help Moon resident astronauts make 3D-printed replacement parts for the Moon base or replacement components for damaged spacecraft.

The usefulness of lunar regolith does not stop there. Ms. Patel notes that, in separate experiments, she melted simulated regolith into a tough, dark, glass-like material.

She and his colleagues have been working out how to turn this material into strong, hollow bricks, which might be useful for building structures on the moon. Imposing black monolithHe says. Why not?