Current Issue March 2014 magazine cover  Save 47% off the cover
price!   The Invisible Killers   Other forms of radiation
populate deep space and may pose a danger to astronauts: X-rays,
alpha-rays, beta-particles, gamma-rays, and neutrons. All
contain excess energy and, in an attempt to stabilize
themselves, throw off mass or energy. The high energy of these
particles enables them not only to travel at or near light speed
but also to penetrate shields and burrow deep into human tissue.
Sim City In the space between here and Mars, the distribution of
cosmic rays is not dense enough to induce acute radiation
sickness. But what if the exposure consisted of a low, steady
level of ionizing radiation over a two- or three-year mission in
deep space? Would that cause subtler health problems? Scientists
estimate that an astronaut in a conventional spacecraft on a
900-day Mars mission might encounter as much as 130,000
millirem—a dose equivalent to what you’d be exposed to living
370 years on Earth.  To help build a