GOCE successfully completes early orbit phase

Mar 20, 2009
The sleek aerodynamic design of GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) immediately sets it apart from most other satellites. This unique five-metre long spacecraft has none of the usual moving parts. The satellite together with its sensor, system of supporting instrumentation and control elements actually form a single composite gravity-measuring device. Credits: ESA - AOES Medialab

ESA's GOCE satellite was formally declared ready for work at 01:00 CET on 20 March. During the critical Launch and Early Orbit Phase beginning with separation from its booster on 17 March, GOCE was checked out to confirm that all of its control systems are operating normally.

The end of the Launch and Early Phase (LEOP) came overnight after was switched to Fine Pointing Mode. This means that all of its systems are working normally and the is ready for full commissioning of its scientific instruments. With the end of LEOP, normal communications between the satellite and the ground are now being provided by ESA's ESTRACK station at Kiruna, Sweden.

"Everything is working well and we have a healthy satellite. Today, we will end round-the-clock staffing in the Main Control Room and move the Flight Control Team to regular work-day operations in the Dedicated Control Room," said Flight Operations Director Pier Paolo Emanuelli speaking this morning at ESA's European Space Operations Centre (ESOC), Darmstadt, Germany.

Satellite-to-satellite tracking in operation

This video is not supported by your browser at this time.
March 16, 2009 MP3 audio recording of the GOCE Flight Operations Director initiating the 'GO/NO-GO' roll call in the Main Control Room at ESOC, the European Space Operations Center. The roll call confirms that all supporting teams at ESOC are ready for GOCE launch. Credit: ESA

A major aim of this week's LEOP work was to bring the Satellite-to-Satellite Tracking Instrument (SSTI) - a highly accurate GPS () receiver - into full operation. Emanuelli confirmed that it is working normally.

"Switching on the SSTI was especially important, as this meant the satellite could start performing its own autonomous orbit determinations. SSTI identifies GOCE's position very accurately, and we need this functioning before we can bring the satellite into its final drag-free operations mode," he said.

First science data sets already received

In addition to providing realtime for flight control, SSTI is one of GOCE's two payload instruments and it is a very accurate scientific tool for recording and reconstructing the satellite's actual orbit. The first SSTI data have already been successfully received at the Payload Data Ground Segment at ESA's Earth Observation Centre (ESRIN), Frascati, Italy.

This video is not supported by your browser at this time.
Although the GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) gradiometer is highly accurate, it is not possible to map the complete gravity field at all spatial scales with the same quality. To overcome this limitation the position of the GOCE satellite is tracked by GPS relative to GPS satellites at an altitude of 20 000 km - this procedure is known as satellite-to-satellite tracking. The gradiometer is used to measure small scales of the gravity field whilst GPS is used to obtain large-scale data. Credits: ESA - AOES Medialab

"Receiving initial science data from SSTI so soon has been an excellent first step and, now that the SSTI is operating, we are already proceeding with commissioning of the scientific payload," said GOCE Mission Manager Rune Floberghagen, who worked in ESOC's Main Control Room alongside the Mission Control Team during LEOP to monitor progress.

"GOCE is operating very well, and we are already looking forward to commissioning our other main instrument, the Electrostatic Gravity Gradiometer, starting in mid-April. It's going to be a very busy but tremendously exciting time as we begin science operations," said Floberghagen.

In the coming weeks, the mission is expected to achieve a number of crucial milestones, including switching on the electric ion propulsion, switching into Drag-Free Attitude Control mode and lowering the orbit to the planned altitude of about 260 km.

Source: European Space Agency

Explore further: The source of the sky's X-ray glow

add to favorites email to friend print save as pdf

Related Stories

GOCE satellite: Critical operations ongoing

Mar 19, 2009

(PhysOrg.com) -- After liftoff 17 March, ESA's GOCE spacecraft is performing very well, having achieved an extremely accurate injection altitude of 283.5 km, just 1.5 km lower than planned. The Mission Control ...

GIOVE-B spacecraft in good health

Apr 30, 2008

A second test satellite for Galileo, Europe's rival to the US Global Positioning System, is "in good health" despite a hiccup that emerged after it was placed in orbit last Sunday, the European Space Agency ...

Launch of GOCE Satellite delayed

Sep 08, 2008

(PhysOrg.com) -- The preparatory activities for the launch of ESA's GOCE satellite from the Plesetsk cosmodrome in northern Russia had to be stopped yesterday afternoon (Sunday 7 September) by Eurockot due ...

Artemis provides communications for Jules Verne ATV

Mar 14, 2008

ESA's Artemis data relay satellite, controlled from Fucino (Italy) and with its mission control centre and Earth terminal located at Redu (Belgium), is providing communications between the Jules Verne ATV ...

ESA's Earth Explorer gravity satellite on show

Jul 19, 2007

GOCE, ESA’s first satellite dedicated to measuring the Earth’s gravity field, has been presented to the press today in Turin, Italy, before being shipped to ESTEC – the space agency’s research and ...

Recommended for you

The source of the sky's X-ray glow

11 hours ago

In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft X-ray glow blanketing the sky comes from both inside and outside the solar system.

End dawns for Europe's space cargo delivery role

21 hours ago

Europe will close an important chapter in its space flight history Tuesday, launching the fifth and final robot ship it had pledged for lifeline deliveries to the International Space Station.

Giant crater in Russia's far north sparks mystery

Jul 26, 2014

A vast crater discovered in a remote region of Siberia known to locals as "the end of the world" is causing a sensation in Russia, with a group of scientists being sent to investigate.

NASA Mars spacecraft prepare for close comet flyby

Jul 26, 2014

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

Bacteria manipulate salt to build shelters to hibernate

Jul 25, 2014

For the first time, Spanish researchers have detected an unknown interaction between microorganisms and salt. When Escherichia coli cells are introduced into a droplet of salt water and is left to dry, b ...

How do we terraform Venus?

Jul 25, 2014

It might be possible to terraform Venus some day, when our technology gets good enough. The challenges for Venus are totally different than for Mars. How will we need to fix Venus?

User comments : 0