Thediscovery of water on the moon announced this week has scientists andspaceflight buffs pumped for a return of humans to the otherwise dusty planet.But in addition to water, anyone who goes there will be looking for someoxygen.
IfNASA or any space agency is to set up moon bases,they'll need oxygenand water for breathing, drinking and to create fuel for return flights.Carrying all that stuff up there would be prohibitively expensive if long-termresidency is the goal.
NASA hadoffered $250,000 in prize money in a contest to spur technology aimed atgetting oxygenfrom moon dirt, but it expired in June 2009 after 2 years with no winners.
Nowscientists from NASA and Case Western Reserve are designing and testingcomponents of an oxygen generator that would extract the element from silicondioxide and metal oxides in the lunar dirt. They have designed sifters neededto produce a consistent supply of oxides.
Testingthe setup is tricky, however, because gravity here is a lot stronger thanthere, and tools and machines work differently.
SoKatie Fromwiller, a senior civil engineering student, and Julie Kleinhenz, anassistant research professor of aerospace and mechanical engineering, spent twodays flying in high gravity-depleting arcs off the Texas coast last month aboardthe "vomit comet," a research plane that simulates reduced gravity.
Insidethe plane, the pull of gravity approximated the moon's weak gravity ? aboutone-sixth what we feel on Earth ? during the rapid drop in each arc. (Theriders felt twice the pull of the Earth's gravity on the way back up. Duringtwo runs, they floated in zero gravity.)
"Itwas as if they were working on the moon, 20 seconds at a time," said DavidZeng, Frank H. Neff Professor and Chair of Civil Engineering from the CaseSchool of Engineering and one of the principal investigators of the study.
NASAengineers were testing other components of the oxygen generator on the sameflight.
NASA,Kleinhenz explained in a statement, has plans to build a system that includes arover that would dig, carry and dump moon soil into a hopper or holding vessel.Sifters would separate particles by size, collecting those that can beconverted most efficiently. The particles can also be separated by composition.For example, an electrostatic charger can be used to isolate iron oxides fromother soil materials.
Thewanted particles would then be blown into a reactor with hydrogen and heated to2,000 degrees Fahrenheit. At this time, the oxygen released from the oxideswould attach to the hydrogenand be collected.
Whilein flight, the pair tested two kinds of devices, a vibro-sieve and a sifter. Asthe plane reached lunar gravity, Fromwiller switched on a vibration table thatshook a sieve, similar to a perforated pan used to pan for gold. As on Earth,the process worked.
Kleinhenzworked a sifter that operates much like a flour sifter. It, too, was able toseparate particles in low gravity.
Zengand his team are continuing to analyze data produced over the two days.Ultimately, NASA will decide which kind of device to use in the oxygengenerator.