Astrometry of celestial bodies is strategic in various scientific or engineering applications. We have designed an experiment with OPS-SAT1 to assess the feasibility of optical astrometry with simple CubeSat hardware. OPS-SAT1 is a 3U CubeSat designed and operated by ESA/ESOC in Darmstadt with an imager and an ADCS by Berlin Space Technology. Then, there is an entry barrier: can we at least see stars and process their images on board? We will present the scope of our experiment and the first pictures we have got from OPS-SAT1, with a special focus on the ADCS and imager requirements. Acknowledgement: special thanks to ESA's OPS-SAT team for the great support in providing the first pictures.