Radiation Risk Predicted for Astronauts on Space Station

An accurate method predicts the doses of radiation that astronauts will receive aboard the orbiting European laboratory module, Columbus, recently attached to the International Space Station (ISS).

The radiation environment close to Earth consists mainly of particles trapped in the Earth's magnetic field, particles that arrive from deep space called Galactic Cosmic Rays (GCRs), and particles expelled from the Sun during solar eruptions. These components vary with time, mainly due to the unpredictable activity of the Sun, which influences the Earth's magnetic field. In turn, the Earth's field determines the extent of the trapped particles and how well Earth is shielded from incoming GCRs.

Beyond the Earth's magnetic field, spacecraft and their occupants are exposed to the full force of the GCRs and the solar eruptions. Missions to the Moon and Mars venture into this harsher and unpredictable radiation environment for periods of many months or even years.

A new software package accurately simulates the physics of radiation particles passing through spacecraft walls and human bodies. Such techniques will be essential to use for calculating the radiation doses received by astronauts on future voyages to the Moon and Mars.

The project, funded by European Space Agency's (ESA; Paris, France; www.esa.int) General Studies Program and the Swedish National Space Board (SNSB; Solna, Sweden), was initiated by Christer Fuglesang of ESA's European Astronaut Corps. The ESA simulation is called Dose Estimation by Simulation of the International Space Station (ISS) Radiation Environment (DESIRE). "The project was designed to provide a European capability in accurately predicting radiation doses onboard Columbus,” stated Petteri Nieminen, ESA's technical officer on the study.

To predict accurately the radiation risk faced by astronauts, scientists and engineers must tackle three separate problems: How much radiation is hitting the space vehicle? How much of that radiation is blocked by the available shielding? What are the biologic effects of the radiation on the astronauts?

To provide the environmental information, ESA is flying a standard radiation monitor on a number of its spacecraft, including Proba-1, Integral, Rosetta, GIOVE-B, Herschel, and Planck. Known as the Standard Radiation Environment Monitor (SREM), it measures high-energy radiation particles. It was developed and manufactured by Oerlikon Space (Zurich, Switzerland) in cooperation with Paul Scherrer Institute Villigen PSI, Switzerland) under a development contract from ESA.


Related Links:
European Space Agency
Oerlikon Space
Paul Scherrer Institute