The CyanoSat project aims at developing a hyperspectral sensor for satellite earth observation missions to detect cyanobacteria and other water quality parameters. This paper outlines the development of the imaging subsystem, a f/4.5 three mirror anastigmat telescope with a 2x3 degree field of view. The telescope is an all-aluminium design comprising of a single spherical and two aspheric mirrors designed to fit within the constrains of a 3U CubeSat volume including the payload electronics. While the assembly and testing are ongoing the opto-mechanical design and tolerance analysis during the design phase defined an integration sequence able to keep the alignment of each mirror within the accuracy needed to meet initial imaging requirements.