[Blue Origin] released footage from inside the machine, which is housed at the Space Resources Centre of Excellence in Los Angeles, showing bubbles of oxygen emerging from the melted regolith.

The reactor relies on electrolysis – a chemical process that uses direct electric current to split compounds into their basic elements.

The Moon dust is melted to 1,600C and then a current passes through, which separates the metal and silicon ions from the oxygen ions to which they were bound.

The positive metal and silicon ions migrate to one electrode and the negative oxygen ions to the other, where the gas bubbles out and can be collected to be used as air or propellant. Metals sink to the bottom.

The process can separate oxygen from metals such as iron, aluminium, and silicon.

Electrolysis of molten regolith seems pretty neat!