  Cosmic radiation is a critical factor for astronauts' safety in the context
of evaluating the prospect of future space exploration. The Radiation
Assessment Detector (RAD) on board the Curiosity Rover launched by the Mars
Scientific Laboratory mission collected valuable data to model the energetic
particle radiation environment inside a spacecraft during travel from Earth to
Mars, and is currently doing the same on the surface of Mars itself. The
Martian Radiation Experiment (MARIE) on board the Mars Odyssey satellite
provides estimates of the absorbed radiation dose in the Martian orbit, which
are predicted to be similar to the radiation dose on Mars' surface. In
combination, these data provide a reliable assessment of the radiation hazards
for a manned mission to Mars. Using data from RAD and MARIE we reexamine the
risks for a crew on a manned flight to Mars and discuss recent developments in
space exploration.
