The
confirmation of Martian water ice by the Phoenix Mars Lander may hint at the
planet's potential for supporting life — or at least human life.
NASA
scientists have quietly
developed technologies such as microwave beams for future explorers to
extract water from the moon or Mars, even as the Phoenix team focuses on
finding out more about the Martian climate and history of water.
"If
there is an outpost, there's a need for water, and we don't want to bring water
from Earth," said Edwin Ethridge, a materials scientist at NASA's Marshall
Space Flight Center in Huntsville, Ala.
Water
could provide more than just an extraterrestrial drink: the right equipment
could break down water for oxygen and even fuel for a human mission. That could
lighten the load and cost of any future mission heading for the moon or Mars.
Mining
with microwaves
Ethridge
spends most of his time working
on the Ares rockets slated to return NASA astronauts to the moon. So
perhaps it's no surprise that he devotes his spare moments to tinkering with a
device that can beam microwaves down to help extract underground water ice.
"One
of the chief advantages of microwaves is that it will penetrate the soil, and
so would greatly minimize if not eliminate requirement to dig," Ethridge
told SPACE.com.
Eliminating
the need to dig would also reduce the chance for dust to
cause problems with astronauts and their equipment. Microwaves could also
work better on the moon given its near-vacuum environment and super-insulating
lunar dust.
Ethridge
worked with colleague Bill Kaukler, also at NASA Marshall and a materials scientist at the
University of Alabama in Huntsville, to run demonstration tests on simulated
lunar permafrost. They found that they could remove 98 percent of water ice
through sublimation, or converting the frozen water directly into a gas, and
could also capture 99 percent of the extracted water.
Shaken,
not stirred
Recent
missions have shown that any water found on the moon or Mars will likely remain
locked away in ice, whether on the surface or underground. Adjusting the
frequency of microwaves can allow them to penetrate deeper to reach any such
frozen reservoirs.
The
use of water-mining technology during the planned moon missions could serve as
a "test bed for Mars and any other extraterrestrial body that has
water," Ethridge noted.
No
one has uncovered solid evidence of water ice on the moon yet, but lunar
orbiters have detected concentrations of hydrogen at the poles that strongly
suggest the presence of untapped ice. A study earlier this year also confirmed
the presence
of water inside ancient moon samples brought back by Apollo astronauts.
"At
the poles, there are craters that have been permanently shadowed for billions
of years," Ethridge said. Many lunar scientists suspect that water ice
survives in those permanently shadowed regions away from sunlight.
No
one has to wonder that about Mars, where the Phoenix Mars Lander directly
detected water ice after scraping away at the polar surface. Mars orbiters
have also detected concentrations of hydrogen on the red planet, all the way
from the poles to near the equator.
"It
absolutely amazed me about Mars that they just had to scratch the surface and
found water ice that is stable," Ethridge said.
Drink
your (Mars) milkshake?
There
could be an ocean of frozen water under Phoenix, but tapping it would still
require energy resources that a Mars mission might not have.
"As
far as humans go, if you want to form a colony on Mars or establish a station,
you'd want to dig a well and pump liquid up from the surface," said Peter
Smith, the principal investigator leading the Phoenix Mars Lander mission at
the University of Arizona in Tucson.
Liquid
water would much more easily enable any human mission, but remains an elusive
and perhaps unlikely find. Phoenix still needs to run further tests on its
water ice sample.
"We're
trying to figure out its past," Smith noted. "Our job is to figure
out if this ice has melted and gone through a liquid phase."
Squeezing
out the drops
Meanwhile,
Ethridge continues to plow ahead with his study to make the microwave
extraction process more efficient. He and Kaukler hope to shrink the energy
requirements for their current 1 kilowatt system.
"One
of the early landers on the moon probably won't have that power," Ethridge
pointed out. "We're working on a smaller power type demonstration."
Most
scientists agree that the current Martian climate remains too cold for water to
exist in liquid form. Still, some hold out the chance for flowing water
somewhere underground, perhaps in the form of hot springs.
"I
think that's the big discovery yet to be made that's going to enable humans to
go to Mars and sink a well," Smith said.
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