Adams, DavidContent, RobertLawrence, JonMcGregor, HelenHorton, AnthonyIreland, MikeSpitler, LeeZhelem, RossGreiner, JochenKlose, SylvioLaux, UweTrenti, Michele2025-06-102025-06-1097815106534120277-786Xhttp://www.scopus.com/inward/record.url?scp=85146658285&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733757935SkyHopper is a proposed CubeSat mission to simultaneously observe 4 bands in the wavelength range from 0.8 to 1.7 micron. The light is captured by a telescope with a 100 mm x 200 mm primary and a field of view of 0.6° x 2.6°. A preliminary definition (phase B) of the optical telescope assembly for the mission is now completed. It is designed to make high precision intensity measurements of every object in the field of view. This brought a series of constraints to avoid stray light. Different optical designs were studied. A Kösters prism is used to split the light into 4 bands on a 2k x 2k detector. The telescope design is based on a 3 mirror anastigmat with additional lenses to provide good image quality in the final focal plane for all bands and also in the intermediate focal plane and the pupil plane where cold stops are needed. Aberrations and vignetting of the prism had to be removed. Science applications include exoplanet transits in front of low-mass stars, rapid Infrared follow-up of Gamma Ray Bursts and exploring the Cosmic Infrared Background.The Secondary mirror (M2) is supported by a secondary support ring, visible in dark blue in Figure 9. The absolute location of M2 on the support ring is unimportant, as the alignment is done via temporary adjustment stages at the truss mounts.enPublisher Copyright: © 2022 SPIE.CubeSatSpace OpticsTelescope202210.1117/12.263169685146658285