… The type of dust that attracted the engineers to Hawaii is called “tephra,” a fine, powder-like material that is ejected during a volcanic eruption. Tephra works well in the prototype chemical processing units because it mimics the dust found on the moon.
A NASA-developed rover called SCARAB showed how a prospecting rover could dig beneath the dusty lunar surface to process soil in order to extract oxygen. A similar rover on the moon could look for water ice and volatile gases such as hydrogen, helium and nitrogen in the permanently shadowed craters of the moon’s poles.
Larger systems could produce oxygen from greater quantities of moon soil. Roxygen (developed by NASA) and the Precursor In Situ Resource Utilization Lunar Oxygen Testbed, or PILOT (developed by Lockheed Martin) both feature a hydrogen reduction system that can produce and store oxygen from soil.
“We’re trying to make the lunar outposts more self-sustaining,” explained Tom Simon, head of the OPTIMA program at NASA’s Johnson Space Flight Center, which is overseeing the development of the PILOT and ROxygen test units. “We want to produce oxygen, but we also want to extract oxygen from the regolith so that we can combine it with what’s left of the residual hydrogen from the descent tanks and make water. Our goal is to never send a tank of oxygen or a tank of water to the moon.”
During this field test, a robotic excavator, similar in size and weight to those currently exploring the planet Mars, showed how soil could be extracted and delivered to the ROxygen system. Also tested was an excavator that uses a bucket drum to collect and deliver soil to the PILOT system.
“It’s one thing to test these instruments in the laboratory,” said Hamilton, “but that really doesn’t tell you how it will perform during a lunar mission. Our challenge is to replicate those conditions as closely as possible to ensure that the test results will be a true reflection of how these instruments will perform on the moon.”
Advanced Life Support
NASA’s lunar exploration plan says that on-site lunar resources could generate about one to two metric tons of oxygen per year, enough to support four to six people annually. Since it takes about 100 kilograms (kg) of soil to get 1 kg of oxygen, team leaders are looking at electrostatic and magnetic separation techniques to possibly concentrate the soil and increase the production rate. Next June, for example, testing will begin on a process that could potentially draw as much as 10 or 20 kg of oxygen out of every 100 kg of soil. …