Yassen Abbas, a young graduate trainee at ESA’s Life, Physical Science and Life Support Laboratory, explains his work to design an experiment for deep space that will investigate the susceptibility of living cells to cosmic radiation. Today’s astronauts orbiting close to Earth are protected from most space radiation by our planet’s atmosphere and magnetic field. In future, astronaut missions are planned to Mars and beyond. 

But heading farther out to space would increase crews’ radiation exposure from both solar and cosmic radiation. Concern is greatest around the 1% of cosmic radiation nuclei the size of an iron atom or more – known as ‘high-ionising high-energy particles’ or HZE for short – which can slice right through DNA. The most serious class of damage is termed ‘double-strand breaks’, leading to loss of genetic information and potentially triggering cancer.

However cells do have an ability to repair double-strand breaks, and the experiment – intended as a passenger on a future deep space mission, or else a dedicated CubeSat – would apply fluorescent markers to osteosarcoma cells – a type of bone cancer –selected because of their rapid growth characteristics. The more cells per sample, the higher the chance of observing a radiation event. The proposed experiment would include a camera to trace the progress of the repair process, returning images to the ground in real time.