ESA GNC Conference Papers Repository

A Formation Flying Astronomical Survey Telescope (FFAST) mission that will cover much of the sky with relatively high energy X-rays is planned. In the FFAST mission, a precise distance must be maintained between the Mirror Spacecraft (MSC) and the Detector Spacecraft (DSC). These controls are conducted to measure the range and LOS between the 2 spacecraft via a relative navigation sensor, known as FF Image Navigation Equipment (FINE). To focus on the desired observation area effectively, a new guidance control law to maintain the phase of the relative circular orbit is derived. To verify the proposed relative guidance and navigation system, a Rendezvous and Docking Operation Test System (RDOTS) of JAXA is used as a motion emulator. This paper describes the result of a hardware-in-the-loop simulation test used to validate the efficacy of the new guidance & navigation system with the FINE ground test model.