The possibilities to investigate astrophysical compact objects are strongly limited. Due to the small size of these objects it is hardly possible to resolve their geometry. The CubeSat mission ComPol will investigate the black hole binary system Cygnus X-1. The goal is to improve its physical model by measuring the polarization of the hard X-ray spectrum. The information about the polarization can be extracted from the kinematics of the Compton scattering. A Silicon drift detector (SDD) is used as a scatterer. The SDD is stacked onto a CeBr3 calorimeter to be able to measure the full kinematics.
The talk will give an overview of the underlying physics, the detector setup and the project schedule.