Today’s update on GOCE was provided by the Spacecraft Operations Manager, Christoph Steiger, at ESOC, Darmstadt, Germany.
Following depletion of fuel last Monday, GOCE’s orbit has decayed by about 5.5 km in the last days. As of today, the spacecraft is at an altitude of roughly 218.5 km. As expected at this early stage of the decay, drag levels are rather low and the spacecraft is behaving as expected. GOCE’s attitude and orbit control system is now in the so-called Fine Pointing Mode, the normal operational mode during orbital decay.
Standard operations activities like spacecraft monitoring & control and orbit determination & prediction are proceeding routinely, albeit with improved ground station coverage and augmented team profiles (i.e. extra folks on duty – Ed.) for the operations teams at ESOC.
We are keeping a close eye on the performance of the spacecraft subsystems as it descends. Some special assessments are now being done on a regular basis for the star sensors and the coarse Earth-Sun sensor, which are expected to yield novel information on the performance of these units at extremely low altitudes. We are also using acceleration data from GOCE’s super-precise Gradiometer to assess the environmental conditions – the drag level – experienced by the spacecraft during the orbital decay.