European Space Agency

BiSon64 production optimisation


The objective of the project was to increase the attractiveness of the BiSon64 sunsensor for use as a coarse sunsensor on board of mega constellations by showing production repeatability and finding a way to reduce production costs by reducing the calibration efforts.


Find a product specification that will allow for the lowest total cost of ownership while still meeting project requirements


The product can be used as a course sunsensor without uploading any calibration data or performing any temperature correction.


The BiSon64 sunsensor is an analogue fine sunsensor which provides two axis attitude information with a guaranteed accuracy of 3.5° over temperature and lifetime without uploading any calibration data.

System Architecture

The BiSon64 sunsensor uses a radiation hardened four quadrant photodiode and a sapphire membrane.


To produce 3 batches of sunsensors and attempt to improve the accuracy in-between batches while searching for ways to simplify the calibration.

Current status

The project has been closed and showed that the sensors can be produced with an increased accuracy. Next to this it has been shown that the specified accuracy of 3.5° can be met without performing any sensor specific compensation, thus simplifying the use on board of a spacecraft significantly and saving significant costs in the field of configuration control and verification.

Status date

Monday, July 17, 2017 - 08:18