VEGA plays role in rectifying GOCE anomaly

4 October 2010 – VEGA staff based at ESA’s European Space Operations Centre (ESOC), have played a key role in rectifying a fault on the Gravity field and steady-state Ocean Circulation Explorer (GOCE) mission.

The anomaly occurred in early July 2010, preventing the spacecraft from sending both on-board software generated telemetry and scientific data to the ground. During the fault period, GOCE’s status was only visible through a limited set of hardware-generated telemetry parameters. Experts from ESA and industry identified that the fault was related to a communication link between the processor module running the on-board software and the telemetry module in charge of formatting and sending data to the radio frequency system for transmission to the ground.

During the attempts to identify the anomaly and recover the spacecraft, VEGA staff working alongside ESA personnel were part of the Flight Control Team responsible for operating and monitoring the spacecraft subsystems as normal. This included many "in the blind" and complex procedures such as performing attitude change manoeuvres and operating the Ion Propulsion System.

VEGA also had the role of operating the ground station equipment for failure investigation purposes. In particular, VEGA ensured the ground station could receive GOCE’s signal and provide a good link with the satellite both for telemetry reception and commanding in the challenging conditions caused by the on-board failure.

GOCE’s recovery came after the ESOC team applied software patches which gained access to troubleshooting information via the slow trickle of data that was still reaching the GOCE ground stations. This information enabled the team to develop an understanding of the state of all the onboard systems

Despite this anomaly, since becoming operational in early September 2009, GOCE has already delivered two-thirds of the gravity data expected from the mission and given scientists an enormous amount of data that will help redefine our understanding of the Earth’s gravity field. Moreover, the mission has been extended to the end of 2012 as it uses less fuel than anticipated.

Further information
For further information, please contact Karen Rogers on karen.rogers@vega.co.uk.