Space Radiation Health Project
Sun emits radiation that can cause cellular damage to
humans in space.|
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leave Earth's protective atmosphere, they will encounter harmful
space radiation -- galactic cosmic rays (GCR), particles of high
energy and high charge (HZE), protons, and secondary particles including
neutrons. Space radiation ionizes, or deposits energy, as it traverses
through material and living tissue. Space radiation differs drastically
from the x-rays or gamma rays that we experience on Earth by producing
more complex types of DNA or cellular damage that may lead to adverse
health risks even at low doses.
The Space Radiation
Health Project (SRHP), based at the NASA Johnson Space Center (JSC), is one facet of NASA's overall Space Radiation Health Program and
leads the overall integration and implementation of spaceflight
safety. NASA's Office of Biological and Physical Research (OBPR)
tasks its Bioastronautics, Fundamental Space Biology, and Microgravity
Sciences Divisions to understand and quantify the space radiation
environment and its effects on astronauts. Under the direction of
the Bioastronautcs Division, the JSC Space Radiation Health Project
coordinates and integrates a radiobiology research program; develops
and maintains a database of risk prediction models; and seeks to
develop technology leading to countermeasures that will prevent,
reduce, and ameliorate harmful radiation effects.
NASA has teamed
with the Department of Energy (DOE) to construct the NASA Space
Radiation Laboratory (NSRL), a high-energy, heavy-ion irradiation
facility at the Brookhaven National Laboratory (BNL) in Upton, N.Y.
Using this new NSRL facility, scientists from several universities
and medical centers across the nation will be able to simulate the
space radiation environment to investigate radiation-caused chromosomal
damage and mutations; potential radiation damage to eye, skin, and
brain tissues; and radiation effects on the formation of cataracts
and tumors. In addition, new methodologies for assessing the radiation
protection from spacecraft shielding and potential new dietary and
pharmacological measures to counteract harmful radiation effects
will be analyzed.
Risk Modeling Tool
NASA has developed,
and continues to refine, mathematical models of the space radiation
environment, radiation transport, and DNA damage and repair for
projecting astronaut risks. These models agree with physical measurements
in Earth and Mars orbit to an accuracy of ±20% and are used
both as a science application and an engineering design tool for
space radiation shielding studies. Results from experimental studies
at the NSRL will be used to improve the NASA computational risk
model. In concert with estimations and standards for the biological
effects of radiation, these models are used to estimate the amount
of time an astronaut can safely live and work in space.
to mitigate radiation risk include limiting the time and duration
of radiation exposure (carefully scheduling spacewalks) and designing
shielding for spacecraft and spacesuits. Countermeasures that may
hold promise for the future include paramaceutical radioprotectants
and gene therapy to repair or eliminate damaged cells.
leave our home planet for exploration missions and safely return,
we aim to see that lives on Earth benefit from the research and
technology that enabled their leap into the cosmos.