Solar cell development for Mars exploration missions

The time frame of those Aurora missions does not allow the early development of alternative technologies. Indeed, fuel cells and radioisotope thermoelectric generators (RTG) for instance require too many technology developments within Europe and/or too stringent political issues due to the nuclear issues at launch. It was considered much more affordable to further develop, improve and optimise current power conversion efficiency of solar cells for Mars exploration missions which lead to the activity considered here.

The Mars surface environment is very different to that of Earth. Dust storms, the increased distance from the Sun and large temperature range have a great impact on the spectral response of solar cells. This activity intends to assess typical solar flux conditions for Martian surface missions. Taking these outputs into account, a behavioural analysis of suitable solar cell candidates is then performed with respect to relevant solar flux conditions.

Different types of solar cells are investigated for possible enhancements through simulations. In this context, testing is performed to estimate the impact of material properties and physical structure of each candidate on the electrical performance. The main outcome of this activity is the down-selection of the most appropriate solar cell material/structure for given Martian conditions (both typical/clear sky and worst/dust storm case will be analysed).

This activity is directly applicable to ExoMars which can benefit significantly from this work. Within the next few years, it is deemed essential to implement this activity within this robotic mission that will make full use of new solar cells to increase the rover’s life span, daily operational time (especially for the power-demanding locomotion system and drill system) and mechanism capabilities.