Posted on 10 November 2013 by Daniel
Spacecraft doing great: GOCE at 133 km
Update from GOCE Operations Manager Christoph Steiger at ESOC Less than 10 hours before re-entry, we have just had another ground contact with GOCE at 15:37 CET using KSAT’s Svalbard station. The spacecraft is now at an altitude of just 133km, with the decay rate around 1.5 km per hour (and increasing quickly). The average drag level is well over 200 mN (milliNewton). The spacecraft is still doing great, with good attitude control. The Gradiometer has been switched off by us, as the accelerometers were saturated at these high drag levels. The scientific GPS receivers of GOCE keep working very well. Temperatures close to the front of the spacecraft keep increasing steadily: the central computer...
Posted on 10 November 2013 by Daniel
Sunday morning update from ESOC
ESA’s Christoph Steiger, the GOCE Spacecraft Operations Manager at ESOC, sent in this update earlier this morning. Less than 1 day before the predicted re-entry into the atmosphere, the spacecraft is still functioning well and we are proceeding with our standard spacecraft operations activities. GOCE is at roughly 147 km altitude this morning; the drop rate is greater than 1 km per hour and increasing. Drag levels are now too high to be measured by the accelerometers. Based on the results of our orbit determination, early this morning they are around 165 mN average drag. Temperatures of units and subsystems close to the front of the spacecraft keep increasing (by about 13...
Posted on 9 November 2013 by Daniel
Saturday GOCE status update from ESOC
This sent in just a couple hours ago by ESA’s GOCE Operations Manager Christoph Steiger, at ESOC. This morning GOCE was at an altitude of around 160 km. As expected, the drag levels have increased very much, with the average now around 90 mN (milliNewton). Despite the extreme environmental conditions, we had a problem-free acquisition of signals from the spacecraft this morning (meaning that the ground station found GOCE pretty much in the orbital position it was predicted to be). The attitude control of the spacecraft is performing very well. Data from the Gradiometer is now only usable for part of the orbit, when drag levels are below 80 mN and the...
Posted on 4 November 2013 by Daniel
GOCE at 192 km: Update from ESOC
This update sent in from GOCE Operations Manager Christoph Steiger at ESOC this morning. This morning, GOCE is at an altitude of roughly 192 km, with atmospheric drag levels at an average of 24 mN (milliNewton) and peaks up to 35 mN. The spacecraft is still fully functional with good attitude control. Our routine spacecraft monitoring and tracking activities are proceeding as planned. Today, GOCE is expected to drop by about 4 km. The atmospheric drag and the resulting altitude decay rate are going to increase significantly over the coming days, as GOCE gets lower and lower.
Posted on 31 October 2013 by Daniel
GOCE at 205km: Update from ESOC
This update provided by GOCE Operations Manager Christoph Steiger at ESOC. GOCE is now at an altitude of roughly 205 km, having lost about 19 km since depletion of fuel on 21 October. The atmospheric drag has increased substantially during the orbital decay, from an average of about 8 mN (milli Newton) to above 15 mN. The spacecraft behaviour is as expected, with the attitude control system continuing to work fine. We keep doing our routine spacecraft operations activities; no major problems have been encountered so far. The recent rise in solar activity has contributed to a noticeable increase in drag. Interesting days may lie ahead, as several coronal mass ejections (CMEs)...
Posted on 15 October 2013 by Daniel
GOCE fuel update
ESA’s Christoph Steiger, Spacecraft Operations Manager at ESOC, provides this update today on GOCE fuel consumption. Currently, the window for fuel depletion spans from now until 27 Oct. Our ‘best guess’ would be for early next week. Some insight on the technical matters behind this: the pressure in the system is going to drop below the minimum operating pressure of the ion propulsion engine (2.5 bar) this Friday, after which the engine might continue working for a few more days. Below 2.5 bar, the pressure everywhere in the system (high and low pressure section) will be the same, such that we can compare pressure measurements from various sensors, allowing us...