What is "biosentinel"

BioSentinel is a planned low-cost CubeSat spacecraft on an astrobiology mission that will use yeast to detect, measure, and compare the impact of deep space radiation on DNA repair over long time beyond low-Earth orbit.

Selected in 2013 for a 2018 launch, the spacecraft will operate in the deep space radiation environment throughout its 18-month mission. This will help scientists understand the health threat from cosmic rays and deep space environment on living organisms and reduce the risk associated with long-term human exploration, as NASA plans to send humans farther into space than ever before.