In-orbit testing of GEO feeder links with TELEO
Jean‐Christophe Richard, Sylvain Poulenard, Xavier Gnata, Laurent Coret, Thomas Anfray, Michael Crosnier, Thibault Marduel, Ludovic Zurawski, Sarah Montigaud, F. Lacoste, Julien Sommer, Géraldine Artaud, Bouchra Benammar, Étienne Samain, T. Lanz, Erick Bondoux, Aurélie Montmerle-Bonnefois, Cyril Petit, Nicolas Védrenne, Armin Schimpf, Hisham Forrière
Abstract
Airbus has initiated in 2018 a program, with the support of CNES, to develop terabits per second optical feeder links for its future GEO telecommunication satellites [1]. This program includes a flight demonstration called TELEO hosted on a commercial satellite BADR-8 launched in May 2023, and arrived at its final GEO orbit in September 2023. TELEO was developed in the frame of the CNES DYSCO project, based on several building blocks whose development had started previously in the ESA ARTES FOLC2 activity. TELEO is a technological demonstrator dedicated to in-orbit testing of optical uplink and downlink, and mitigation techniques for error free telecom links [2]. TELEO payload includes a fully representative prototype of a laser terminal called TOP-M with a 260 mm diameter tele-scope [3], a 5 W optical amplifier [4] and an optical transceiver capable of 10 Gbaud downlink non-return to zero differ-ential phase shift keying (NRZ-DPSK) and 10 Gbaud uplink NRZ on-off keying (OOK) [5]. The first TELEO tests enabled Airbus team to check the performances of the TOP-M, in particular its sub-system pointing accuracy, targeting the micro-radian performance needed for future larger aperture terminal (up to 500 mm). Once the payload has been fully commis-sioned, TELEO becomes an in-orbit test bed to assess Earth-Space optical links under various atmospheric conditions, including uplink optical power monitoring before and after fiber injection as well as telecom tests at 10 Gbaud uplink and downlink. TELEO ground segment deployment started in 2023. It is currently composed of the mission control center (MCC) in Toulouse and three optical ground stations (OGS), the baseline being the French optical ground station (FrOGS, CNES) [6], [7] in Calern north of Grasse, equipped with various building blocks designed and prototyped by Airbus partners (Bertin Alpao and OGS technologies) in the frame of CO-OP activity (French recovery plan under CNES supervision). As an opportunity, the ground segment has been completed with two other ground stations: the A-OGS at ESA facility in Tenerife, in order to have a back-up for the TELEO payload commissioning before further tests, in the frame of CREOLA ARTES activity, and ONERA’s Research OGS FEELINGS [8], located in a peri-urban area 25 km south of Toulouse, which aims to improve the atmospheric channel assessment and its mitigation with respect to state of the art (MADIRAN project funded by DGA). This paper gives an overview of the results obtained during the first year of the TELEO in-orbit demonstration program, focusing both on the optical payload and ground-GEO link performances, and highlights the activities moving forward.