Viewing any geostationary satellite is a challenge but I don't think that the operation of the thrusters will result in any signature that would help to see that TDRS satellite move. Hydrazine is a monopropellant that provides hot gas propulsion. The gas is clear. There is no orange flame. Unless you have an IR telescope, the satellite looks the same whether the thrusters are firing or not. I got the following info from http://shuttle.nasa.gov/sts-70/orbit/payloads/tdrs/index.html Jeff Barker email@example.com ----------------------------------------- TDRS Propulsion and attitude control The TDRS propulsion subsystem is a monopropellant hydrazine system which provides impulse for attitude control, unloading momentum wheels, and velocity corrections for positioning and stationkeeping. The propulsion subsystem propellant maximum capacity is 1300 lb. The system provides for a 10-year operational life and a 7-year maximum storage life. The combines storage and operational life is 11 years. The propellant budget is predicated on several use and efficiency factors, including orbit insertion error correction and lifetime attitude control and stationkeeping. The propulsion subsystem consists of the following components: 2 propellant tanks 2 redundant groups of 12 thrusters 6 latching isolation valves 3 fill and drain valves 2 filters pressure and temperature instrumentation thermal management plumbing mounting brackets To prevent firing of the TDRS thrusters in the orbiter payload bay, the propulsion system is equipped with arm/disarm functions in the ordnance arming unit.