Moon dust particles gave Apollo mission astronauts tough time
Washington | September 27, 2008 1:35:06 PM IST
Fine as flour and rough as sandpaper, moon dust gave Apollo astronauts a tough time by causing 'lunar hay fever', problems with space suits, and dust storms in the crew cabin.
Larry Taylor, director, Planetary Geosciences Institute, University of Tennessee and other scientists will present their research on lunar dust at the joint Oct 9 meeting of the Geological Society of America (GSA), Soil Science Society of America (SSSA) and American Society of Agronomy (ASA), among others.
NASA will use these findings to plan a safer manned mission to the Moon in 2018. The trouble with moon dust stems from the strange properties of lunar soil. The powdery grey dirt is formed by micrometeorite impacts which pulverise local rocks into fine particles, according to a release of the Geological Society of America.
The energy from these collisions melts the dirt into vapour that cools and condenses on soil particles, coating them in a glassy shell.
These particles can wreak havoc on space suits and other equipment. During the Apollo 17 mission, for example, crewmembers Harrison "Jack" Schmitt and Gene Cernan had trouble moving their arms during moonwalks because dust had gummed up the joints.
"The dust was so abrasive that it actually wore through three layers of Kevlar-like material on Jack's boot," Taylor said.
To make matters worse, lunar dust suffers from a terrible case of static cling. UV rays drive electrons out of lunar dust by day, while the solar wind bombards it with electrons by night.
Luckily, lunar dust is also susceptible to magnets. Tiny specks of metallic iron are embedded in each dust particle's glassy shell. Taylor has designed a magnetic filter to pull dust from the air, as well as a "dust sucker" that uses magnets in place of a vacuum.
He has also discovered that microwaves melt lunar soil in less time than it takes to boil a cup of tea. He envisions a vehicle that could microwave lunar surfaces into roads and landing pads as it drives, and a device to melt soil over lunar modules to provide insulation against space radiation. The heating process can also produce oxygen for breathing.
But the same specks of iron that could make moon dust manageable also pose a potential threat to human health, according to Bonnie Cooper at NASA's Johnson Space Center.
"Those tiny blebs of pure iron we see on the surface of lunar grains are likely to be released from the outside edges of the particle in the lungs and enter the bloodstream," she said.
Preliminary studies suggest that the inhalation of lunar dust may pose a health hazard, possibly including iron toxicity. Members of NASA's Lunar Airborne Dust Toxicity Advisory Group, Cooper, Taylor, and colleagues are studying how moon dust affects the respiratory system.
They plan to set a lunar dust exposure standard by 2010, in time for NASA engineers to design a safer and cleaner trip to the Moon.St/jg
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