posted December 23, 2004
This NASA painting of the lunar landscape shows a concept for a pilot plant to produce liquid oxygen
The VAMPS process starts with traditional mining or construction equipment and Experiments with a bucket wheel excavator designed at NORCAT in Sudbury, Canada. Shown from
audience with an updated report on lighting conditions (e P S R D article: The Moon's Dark, Icy Poles ).
Distribution of temperatures inside a large flat-floored crater in a lunar
polar region were calculated by
Ashwin Vasavada (UCLA), an
expert in thermal modeling of
planetary surfaces. During the
long lunar night the surfaceamerican dream
everywhere cools to less that 80
Kelvin, with some areas less than
词根大全
50 Kelvin. But even during the
hottest part of the lunar day, some
portions of a crater like this remain
very cold, reaching no more than
80 Kelvin. The regions can trap
volatiles like H 2O, CO, and CO 2,
and might be important sources
for propellant to drive commerce
throughout the inner solar system.
Courtesy of Ash Vasavada, Univ.
of California, Los Angeles.
Permanently dark areas could collect volatile materials otherwi scarce on the Moon. The most important of the is
water. The neutron detector onboard the Lunar Prospector mission showed clearly that there is an enrichment of hydrogen
(H) in polar regions, but could not determine whether it was in the form of H 2O, molecular hydrogen
(H 2), elemental
教育在线网hydrogen, or some other form. The Clementine mission rigged an innovative radar experiment that suggested the prence
excitingof water ice, but obrvations of portions of the south pole using the huge radio telescope in Arecibo, Puerto Rico did not
detect ice. The issue remains highly controversial, but leaves the rest of us lots of room to speculate on the nature of the
hydrogen in polar regions.
If the hydrogen is in the form of H 2O ice, it could be an enormously important resource that could drive commercial
development of the Moon, as Brad Blair and his colleagues discusd at the Roundtable. Before any commercialization
除此之外英语翻译can take place, however, cosmochemical prospectors have a lot of work to do. As I noted in my talk at the meeting, we
know very little about the nature of the surface in the permanently shadowed areas of the Moon. The ground up rock
covertmight be finer grained than the regolith (fragmental surface materials on the Moon) we sampled at the Apollo landing
北京朝阳外国语学校
sites, including that at the Apollo 16 site in the ancient highlands.
More important, if water condend onto silicate grains at the cold temperatures in the shadows it would not be in the
form of the familiar crystalline ice. It would be amorphous, lacking any long-range order to the H and O atoms--sort of andonated
candy boyicy glass. In contrast to crystalline ice, this structure is quite accommodating to gas such as tho in comets (carbon
dioxide, carbon monoxide, methane). When amorphous ice (also called amorphous solid water) is heated above about 120
Kelvin, it changes to the crystalline form, releasing the trapped gas. This is one of the reasons why comets spew gas and
dust. Thus, if we tried to mine the ice to make hydrogen and oxygen for propellant, heating the icy regolith might cau
rapid loss of the water we were trying to mine. Heat is also relead as amorphous ice transforms to crystalline ice, which
could cau a runaway effect-catastrophic loss of a precious resource, at least locally.
But all that is speculation at prent. We need to conduct experiments on regolith with ice in it, with and without other
gas. This needs to include understanding what happens when the regolith is gardened by the rain of tiny meteorites that
continuously strike the Moon. Most important, we need to characterize the permanently shadowed places thoroughly from
orbit and with robotic landers equipped with sophisticated analytical instruments. NASA is planning such missions during
the next five years. A talk by James Powderly and colleagues at Honeybee Robotics (in collaboration with scientists at the
Johnson Space Center, Ames Rearch Center, Jet Propulsion Laboratory, Boeing, the Army Corps of Engineers, and Los
Alamos National Laboratories) highlighted one well-tested concept for sampling the icy, cryogenic regolith in polar
andriodregions. Called the Subsurface Analyzer and Sample Handler (SASH) it is basically a drill equipped with instruments to
