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View Full Version : Space Radiation Threats To Astronauts Addressed In Federal Research Study (Forwarded)


Andrew Yee[_1_]
October 27th 06, 09:17 PM
Office of News Services
University of Colorado-Boulder
Boulder, Colorado

Contact:
Daniel Baker, (303) 492-4509
Jim Scott, (303) 492-3114

Oct. 25, 2006

Space Radiation Threats To Astronauts Addressed In Federal Research Study

A better understanding of solar storms and how best to protect astronauts
from space radiation is needed as NASA pushes toward manned missions to the
moon and Mars in the coming decades, according to a new National Research
Council report.

Researchers have been stepping up studies on radiation biology and space
shielding in recent years, said the University of Colorado at Boulder's
Daniel Baker, chair of the committee that issued an NRC report this week
titled, "Space Radiation Hazards and the Vision for Space Exploration." The
report probes the physical risks and technology obstacles of extended space
journeys and is tied to a 2004 presidential mandate to return to the moon by
2020 and then send human travelers on to Mars, said Baker, director of
CU-Boulder's Laboratory for Atmospheric and Space Physics.

Baker, an internationally known space weather expert, said the report
brought together space physicists and radiation biologists, amplifying
common interests between the groups. "This was an important step," he said.
"One of the benefits of this report is that we are beginning to lower the
error bar on the health impacts of space radiation to astronauts, and are
looking hard at other challenges like more accurate solar forecasting and
improved space engineering techniques."

Astronauts are regularly exposed to high doses of radiation, including
galactic cosmic rays -- thought to come from distant supernova explosions --
as well as energetic particles from the sun and charged particles trapped in
Earth's magnetic field, he said.

Potential health effects include leukemia and other cancers, and
degenerative tissue effects like cataracts, heart disease, digestive
diseases and respiratory diseases, according to the report. Radiation also
can cause damage to the central nervous system and cause acute risks like
vomiting and nausea, said Baker.

"One concern is that astronauts could become ill from space radiation
effects and vomit in their space suits, which could be extremely serious,"
he said.

The report noted that a violent solar storm that occurred in August 1972
between the Apollo 16 and Apollo 17 missions could have been extremely
hazardous to astronauts had they been on the moon. The radiation exposure
levels would have varied depending on whether the astronauts were exploring
the lunar surface or were inside the landing vehicle, which would have
offered more protection, said the report.

"We know that this storm was large enough that it could have had potentially
fatal consequences to astronauts had they been on the moon at that time,"
said Baker.

The report also addresses the issue of "storm shelters" to protect
astronauts from harmful radiation, which can be built both inside spacecraft
or on the surface of the moon and Mars, Baker said. Such shelters could
include cylindrical "cocoons" of thick shielding material for astronauts to
crawl in or shelters lined with thick tanks filled with water, since water
is not only essential for space travel but also contains large amounts of
hydrogen, a proven buffer for mitigating harmful radiation, he said.

Plastic polymers containing large amounts of hydrogen also might be a
potentially useful building material for shielding, according to the report.
"There is always the possibility that a spacecraft can be blasted by
significant doses of radiation, and we need to take that into account when
designing spacecraft," he said.

Soils on the moon and Mars also could be used to build efficient shelters
from solar storms, especially if astronauts were on extended expeditions
putting them hours away from base camps or space vehicles, Baker said. The
report recommends creating a "color-coded alert system" for intense solar
events that could be transmitted quickly to astronauts roaming alien soils,
he said.

A workshop on the issues -- co-sponsored by NASA, the National Science
Foundation and the National Research Council -- was held Oct. 16 to Oct. 20
in Wintergreen, Va. In September, NASA selected 12 radiation biology
proposals for funding that target reduction of health and safety risks for
astronauts, said Baker.

The National Research Council is a federal organization created by the
National Academy of Sciences in 1916 to bring together the American science
and technology community to advance knowledge and advise the federal
government.

[NOTE: The report is available for online viewing at
http://newton.nap.edu/catalog/11760.html ]