GOCE

Gravity Field and Steady-State Ocean Circulation Explorer
Artist's view of GOCE. Its sleek, aerodynamic design led it to be dubbed the 'Ferrari of space'[1]
Mission typeGravitational research
OperatorESA
COSPAR ID2009-013A Edit this at Wikidata
SATCAT no.34602
Websitehttp://www.esa.int/GOCE
Mission durationPlanned: 20 months
Final: 4 years, 7 months, 3 days
Spacecraft properties
ManufacturerThales Alenia Space
EADS Astrium
Launch mass1,077 kg (2,374 lb)
Dry mass872 kg (1,922 lb)
Dimensions5.3 m × 2.3 m (17.4 ft × 7.5 ft)
Power1,600 watts
Start of mission
Launch date17 March 2009, 14:21 (2009-03-17UTC14:21) UTC[2]
RocketRockot/Briz-KM
Launch sitePlesetsk Cosmodrome
ContractorEurockot Launch Services
End of mission
DisposalOrbital decay
Declared21 October 2013 (2013-10-22) UTC[3]
Last contact10 November 2013, 22:42 UTC[4]
Decay date11 November 2013, 00:16 UTC[5]
Orbital parameters
Reference systemGeocentric
RegimeSun-synchronous[6]
Perigee altitude254.9 km (158.4 mi)[6]
Apogee altitude254.9 km (158.4 mi)[6]
Inclination96.7 degrees
Epoch28 June 2010[6]
Transponders
BandS band
Frequency2 GHz
Bandwidthup to 1.2 Mbit/s download
up to 4 kbit/s upload
GOCE mission insignia
Insignia for the GOCE mission
SMOS →

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.[1]

  1. ^ a b "GOCE completes its mission". European Space Agency. Retrieved 11 November 2013.
  2. ^ "GOCE launched and in orbit". European Space Agency. 17 March 2009. Retrieved 10 October 2013.
  3. ^ "ESA's GOCE mission comes to an end" (Press release). European Space Agency. 21 October 2013. No. 33-2013. Retrieved 10 July 2017.
  4. ^ Scuka, Daniel (11 November 2013). "ESOC update – 23:50CET". European Space Agency. Retrieved 28 December 2016.
  5. ^ Scuka, Daniel (11 November 2013). "GOCE re-entry region". European Space Agency. Retrieved 28 December 2016.
  6. ^ a b c d "GOCE giving new insights into Earth's gravity". European Space Agency. 29 June 2010. Retrieved 29 June 2010.