The original idea for the Lens R&D extended temperature Sunsensors was born when ESA was working on their Mars rover.

In order to allow sterilisation and avoid biocontamination, the sensors should be able to withstand high temperatures and be vented (non-hermetic)

During the night time on Mars the sensors should be able to cope with very low temperatures though.

This set of requirements is met by carefully balancing the CTE of the different materials used and development of a dedicated glue.

Although ESA decided not to go with our sensors, the development was continued and resulted in the a sensor that has shown to be capable of surviving the a full qualification program as specified in ECSS-E-ST-03. with temperature cycles between -125°C and +125°C.

Based on this qualification, a team of CNES and DLR have now selected our BiSon64-ET as the prime attitude sensor for their MMX rover.

This rover is to rove Phobos, one of the moons of Mars.

Due to the distance to the earth and the large amount of propulsion needed to bring something to Mars, the weight is limited. Due to the distance to the Sun there is not an abundance of power available to heat-up the rover during the day and generate energy to store. Therefore, the rover consists of a thermally isolated box and some extending components. This in turn leads to large temperature excursions on those components.

Due to the extreme temperatures experienced during this mission there are not many components that can be used outside of the temperature controlled compartment. Next to this they will have to determine the direction of the Sun with an as high as possible accuracy either requiring a fine Sunsensor or a startracker. As startrackers have a much higher accuracy than Sunsensors but a much more limited temperature range and a much higher power demand, the logical choice was for our extended temperature Sunsensor BiSon64-ET.

Nevertheless we are very proud that our sensor has been selected for this daring mission that will cause our sensor to boldly go where no Sunsensor has gone before.