Subscribe free to our newsletters via your
. 24/7 Space News .




PHYSICS NEWS
Successful Launch For GOCE
by Staff Writers
Bonn, Germany (SPX) Mar 20, 2009


As well as irregularities in the mean sea level, GOCE examines the effects of seismic activity on the Earth's gravity field. Credit: ESA.

At 15:21 CET on 17 March 2009, the new environmental satellite GOCE (Gravity field and steady-state Ocean Circulation Explorer) was successfully launched into Earth orbit from the Plesetsk Cosmodrome in northern Russia. The Rockot launch vehicle brought the satellite into a near-polar orbit with an inclination of 96.5 degrees at an altitude of 260 kilometres.

From this orbit, GOCE will map the Earth's gravity field over a 20-month period, with a level of accuracy never seen before. The expected results will be especially important for oceanography, geophysics and ocean level studies.

Through GOCE, European space exploration will also contribute to the implementation of EU climate and environmental policies. Germany provides 22% of the funding for the European Space Agency's (ESA) Earth Observation Envelope Programme (EOEP) of which the 300 million euro GOCE mission forms part.

GOCE is the first in a series of highly specialised satellites that will allow ESA to provide accurate data about processes taking place in the atmosphere, in oceans and on land, which could lead to new insights into global environmental change.

GOCE has an eye for detail
Gerold Reichle, Executive Board member of the German Aerospace Center (Deutsches Zentrum fur Luft- und Raumfahrt; DLR) and responsible for its Space Agency (Raumfahrt-Management), emphasises the mission's strategic importance: "Seen against the backdrop of massive climate change and the far-reaching impact it could have on the world we live in, GOCE serves to underline the strong commitment of the German and European space sector to long-term climate research. Not only has the space sector played a substantial role in the discovery of global climate change, it also provides the most important instruments used to investigate its effects. This will enable politicians and society as a whole to take the necessary decisions in order to safeguard the basic conditions for human survival."

GOCE will provide environmental researchers with a global, homogenous and accurately detailed picture of the Earth's gravity field, enabling them to establish the surface circulation of the oceans for the first time. Sea level changes around Australia and South America can then, for instance, be compared to those in the North Sea and in the Mediterranean.

In this way, oceanographers hope to be able, for example, to answer the question of whether several small circulations have the same effect on heat transport within the global circulation system as a few large ones. Using the data provided by GOCE, it will also be possible to directly derive inch-perfect sea level data from GPS readings.

In the field of geophysics, GOCE's gradiometry promises a glimpse into the Earth's interior. This is expected to significantly enhance our understanding of the Earth's continental and oceanic crust. In addition, GOCE data can be used to determine the topography of the sea floor and the thickness of the polar sea ice, and to reconstruct the density of the large ice sheets.

European Earth science satellite programmes out in front
Speaking about the high-tech equipment on board the latest ESA satellite, Gerold Reichle adds: "GOCE shows how advanced European engineering is. European collaboration has enabled the development of world-class innovative high technologies."

The satellite will measure the Earth's gravity field with a spatial resolution of 100 kilometres and record gravity anomalies with a precision of one millionth of the Earth's gravitational pull (10-6 g). The geoid will be mapped with an accuracy of one to two centimetres. In order to meet these ambitious goals, GOCE is pushing the limits of what is technically feasible today.

The closer a satellite is to the Earth, the stronger the gravity signals are. For this reason, GOCE orbits at an altitude of about 260 kilometres, the lowest orbit ever for a scientific satellite.

An ion engine known as the Drag-free System will compensate for the drag forces experienced by the satellite due to the residual atmosphere at this low altitude, which would otherwise cause it to lose height quickly. The attitude control system will ensure the instruments are correctly aligned with respect to the Earth.

A GPS receiver on board GOCE allows continuous and inch-perfect determination of the satellite's position. This receiver is primarily used to map out the large-scale structures in the Earth's gravity field.

In addition, the satellite is also the first to feature a gravity gradiometer, which is based on the principle of differential acceleration measurement. Equipped with three pairs of such accelerometers, this instrument represents state-of-the-art technology.

Forty-one European companies, led by Thales Alenia Space in Italy, have worked together to produce the satellite. EADS Astrium (Friedrichshafen) is the main German contractor for the satellite platform. The magnetic-field-based attitude control elements used to fine-tune the satellite's orientation (by Zarm Technik GmbH) and the solar cells (by RWE Space Solar in Heilbronn) have also been made in Germany.

The gradiometer was built at Thales Alenia Space in France and the acceleration sensors by the French firm Onera.

Launch and mission sequence
The launch and mission are just as much a collaborative European effort as the development and construction of the satellite itself. Eurockot, the operating company behind the Rockot launch vehicle, is a German-Russian joint venture between EADS Astrium (51%) and Khrunichev Space Center (49%).

The rocket lifted off from Plesetsk, 800 kilometres north of Moscow; the launch, separation from the launch vehicle and subsequent flight were monitored by the European Space Operations Center (ESOC).

Raw data will be received and stored at the Command and Data Acquisition Facility (CDAF) in Kiruna, in northern Sweden. Researchers will also monitor the condition of the satellite from here. The Kiruna ground station is optimally located for satellites in a near-polar orbit.

The data will be processed and archived at ESA's Earth observation headquarters in Italy and at the decentralised GOCE High-Level Processing Facility (HPF). The German GOCE Project Office (GOCE-Projektburo), funded by the DLR Space Agency, is located at the Technical University of Munich.

The Project Office is headed by Professor Reinhard Rummel, the initiator of the GOCE project. Its function is to co-ordinate the approximately 20 German GOCE user groups and to keep them informed about the mission in order to ensure that German science benefits from it to the greatest extent possible.

.


Related Links
ESA - GOCE
The Physics of Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








PHYSICS NEWS
ESA's Gravity Satellite Moves To Launch Pad
Paris, France (SPX) Mar 12, 2009
With liftoff just five days away, ESA's GOCE spacecraft - encased in the protective half-shells of the launcher fairing - has been transported from the cleanroom and installed in the launch tower at the Plesetsk Cosmodrome in northern Russia. The so-called Upper Composite, which comprises the Gravity field and steady-state Ocean Explorer (GOCE) satellite joined to the Breeze-KM Upper Stage ... read more


PHYSICS NEWS
NASA Moon Mission Brings Divergent Passions Together

Russia picking moon rocket design

Third Meeting Of ISECG

China To Land Probe On Moon At Latest In 2013

PHYSICS NEWS
Online Poll For NASA's Mars Rover Naming Contest Opens March 23

Mars Rovers Take Stock On Goals And Routes

Opportunity's New Software Working Fine - sol 1811-1817

Spirit Makes Slight Progress on New Route - sol 1831-1837

PHYSICS NEWS
ATK Delivers Final Hardware For Ares I-X Test Flight

Discovery astronauts begin space walk

Space tourism from Sweden to start in 2012: company

Forum To Explore Why We Should Go To Moon And Mars

PHYSICS NEWS
China Able To Send Man To Moon Around 2020

China To Launch 15 To 16 Satellites In 2009

Macao Donates 14 Million Yuan To Mainland Space Program

Scholarships Established For Aerospace Research

PHYSICS NEWS
Space Station Construction Visible In Backyard Telescopes

Space station's solar wings unfurled

Discovery astronauts complete second spacewalk

ISS, Discovery crews meet, get down to business

PHYSICS NEWS
ILS And SES Announce Three New Proton Launches

ESA postpones Herschel-Planck launch

Ariane 5 To Launch Biggest Ever Commercial Telcomm Satellite

Atlas V Launch Postponed

PHYSICS NEWS
Finding Twin Earths Is Harder Than We Thought

Starlight, Star Bright

Keck Teaming Up With Kepler To Find Other Earths

Kepler Mission Rockets To Space In Search Of Other Earths

PHYSICS NEWS
Iran Says First Satellite Successfully Completes Mission

Talks to bring iPhone to China ongoing: China Mobile

Fujitsu launches world's first colour e-book

NEWSKY Communication Network Presented For The First Time




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement