Space Telescopes based on Satellite Tandem Flights

Due on the recent progress in satellite control engineering, tandem flight arrangements of mini-satellites are currently in discussion and under consideration for future space missions. CubeSat technologies offer an interesting possibility for space-born telescope payloads based on this approach. In such scenario, two small satellites will fly at a constant distance of few meters up to 100 meters. Thereby, the front satellite will carry the telescope optics and the second satellite the detector system. Related formation flight requirement were addressed in the NetSat-Mission, composed of four 3U-CubeSats, launched 2020. Space technology challenges concern in particular orbit control by an appropriate propulsion system as well as precision attitude pointing towards the joint target, and could be transferred from the NetSat-mission to the proposed Tandem Mission. This will allow space-based telescopes with a long focal length even placed on board of small or miniature CubeSat-type satellites. Cost effective Kirkpatrick Baez type X-ray telescopes represent an important application here as they have longer focal lengths compared to the previously used astronomical observatories using Wolter I type X-ray mirrors.