ESA GNC Conference Papers Repository

The first SGEO platform used as bus for the Hispasat 36W-1 mission has successfully achieved its on-ground test campaign including AOCS verification and validation activities at various stages. It is launched end of January 2017 and will perform a transfer to GEO using a bi-propellant thruster system followed by orbital relocation and on-station operation using electric propulsion. This paper will present innovative flight results from the first in-orbit experiences with focus on the LEOP operation phase. In a first part, the paper will focus on the performance of the early mission phase including the sun acquisition and the transfer to geostationary orbit including the chemical propulsion burns and the various slew manoeuvres, as well as first perigee crossings. In a second part, the paper will concentrate on the station relocation performed using an innovative strategy based on electrical propulsion and applying complex attitude profiles in order to maximize the thrust taking into account operational constraints and performing critical momentum control at the same time. In a last part, the GPS experiment flying on-board SGEO will be described showing first performances in GEO. The GPS receiver is using a medium gain antenna pointed towards the earth on-station and is expected to track up to 5 GPS satellites once on-station and thus provide valuable PVT information. Throughout the paper, in-orbit results will be compared to analysis, simulation predictions and ground testing and suggestions for further improvements will be made if applicable. It has to be noted that the paper content may slightly differ depending on actual results and main areas of interest.