GOCE
Artist's view of GOCE. Its sleek, aerodynamic design led it to be dubbed the 'Ferrari of space' | |||||||||
| Mission type | Gravitational research | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Operator | ESA | ||||||||
| COSPAR ID | 2009-013A | ||||||||
| SATCAT no. | 34602 | ||||||||
| Website | http://www.esa.int/GOCE | ||||||||
| Mission duration | Planned: 20 months Final: 4 years, 7 months, 3 days | ||||||||
| Spacecraft properties | |||||||||
| Manufacturer | Thales Alenia Space EADS Astrium | ||||||||
| Launch mass | 1,077 kg (2,374 lb) | ||||||||
| Dry mass | 872 kg (1,922 lb) | ||||||||
| Dimensions | 5.3 m × 2.3 m (17.4 ft × 7.5 ft) | ||||||||
| Power | 1,600 watts | ||||||||
| Start of mission | |||||||||
| Launch date | 17 March 2009, 14:21 UTC | ||||||||
| Rocket | Rockot/Briz-KM | ||||||||
| Launch site | Plesetsk Cosmodrome | ||||||||
| Contractor | Eurockot Launch Services | ||||||||
| End of mission | |||||||||
| Disposal | Orbital decay | ||||||||
| Declared | 21 October 2013 UTC | ||||||||
| Last contact | 10 November 2013, 22:42 UTC | ||||||||
| Decay date | 11 November 2013, 00:16 UTC | ||||||||
| Orbital parameters | |||||||||
| Reference system | Geocentric | ||||||||
| Regime | Sun-synchronous | ||||||||
| Perigee altitude | 254.9 km (158.4 mi) | ||||||||
| Apogee altitude | 254.9 km (158.4 mi) | ||||||||
| Inclination | 96.7 degrees | ||||||||
| Epoch | 28 June 2010 | ||||||||
| Transponders | |||||||||
| Band | S band | ||||||||
| Frequency | 2 GHz | ||||||||
| Bandwidth | up to 1.2 Mbit/s download up to 4 kbit/s upload | ||||||||
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Insignia for the GOCE mission | |||||||||
The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) was the first of ESA's Living Planet Programme heavy satellites intended to map in unprecedented detail the Earth's gravity field. The spacecraft's primary instrumentation was a highly sensitive gravity gradiometer consisting of three pairs of accelerometers which measured gravitational gradients along three orthogonal axes.
Launched on 17 March 2009, GOCE mapped the deep structure of the Earth's mantle and probed hazardous volcanic regions. It brought new insight into ocean behaviour; this in particular, was a major driver for the mission. By combining the gravity data with information about sea surface height gathered by other satellite altimeters, scientists were able to track the direction and speed of geostrophic ocean currents. The low orbit and high accuracy of the system greatly improved the known accuracy and spatial resolution of the geoid (the theoretical surface of equal gravitational potential on the Earth).
The satellite's unique arrow shape and fins helped keep GOCE stable as it flew through the thermosphere at a comparatively low altitude of 255 kilometres (158 mi). Additionally, an ion propulsion system continuously compensated for the variable deceleration due to air drag without the vibration of a conventional chemically powered rocket engine, thus limiting the errors in gravity gradient measurements caused by non-gravitational forces and restoring the path of the craft as closely as possible to a purely inertial trajectory.
After running out of propellant, the satellite began dropping out of orbit and made an uncontrolled re-entry on 11 November 2013.