Plastics may effectively block cosmic rays
US: Lighter materials like plastics can provide effective shielding
against the radiation hazards faced by astronauts during extended space
travel, a U.S. study said Tuesday.
The finding, based on observations made by the Cosmic Ray Telescope
for the Effects of Radiation (CRaTER) on board the U.S. spacecraft known
as Lunar Reconnaissance Orbiter, could help reduce health risks to
humans on future missions into deep space, researchers from the
University of New Hampshire and the Southwest Research Institute said.
According to the researchers, aluminum has always been the primary
material in spacecraft construction, but it provides relatively little
protection against high-energy cosmic rays and can add so much mass to
spacecraft that they become cost- prohibitive to launch. “This is the
first study using observations from space to confirm what has been
thought for some time -- that plastics and other lightweight materials
are pound-for-pound more effective for shielding against cosmic
radiation than aluminum,” lead author Cary Zeitlin of the University of
New Hampshire said in a statement.
“Shielding can't entirely solve the radiation exposure problem in
deep space, but there are clear differences in effectiveness of
different materials,” Zeitlin said.
The plastic-aluminum comparison was made in earlier ground- based
tests using beams of heavy particles to simulate cosmic rays, and the
researchers found that the shielding effectiveness of the plastic in
space is very much in line with what they discovered from the beam
experiments.
“So we've gained a lot of confidence in the conclusions we drew from
that work,” said Zeitlin. “Anything with high hydrogen content,
including water, would work well.”
The researchers used the CRaTER instrument to gauge the radiation
dose of cosmic rays after passing through a material known as
tissue-equivalent plastic, which simulates human muscle tissue.
AFP |
