SkyHopper CubeSat: A Multi-Band NIR Telescope for Precise Intensity Measurements

Abstract

SkyHopper 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. Show more