Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

September launch for ESA's gravity mission GOCE

29.05.2008
A new launch date has been set for GOCE. The change of date is due to precautionary measures taken after the malfunction of an upper-stage section of a Russian Proton launcher. Now confirmed not to affect GOCE's Rockot launcher, the most advanced gravity mission to date is scheduled for lift-off on 10 September 2008.

As a consequence of the new launch date, the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite is currently undergoing final flight reconfiguration at ESA-ESTEC in the Netherlands. Shipment to the Plesetsk launch site in northern Russia will take place in July - from where the sleek five-metre long GOCE spacecraft will be carried into its unusually low orbit on a modified

SS-19 Russian Intercontinental Ballistic Missile (ICBM) launcher. The adaptation of the SS-19, called 'Rockot', uses the two original lower stages of the ICBM in conjunction with an upper-stage called Breeze-KM for commercial payloads.

Up until early March this year, GOCE was well on its way to being launched at the end of May. However, as a result of the failure on 15 March of a Proton Breeze-M upper-stage, all launches using Breeze were suspended pending investigations by the Russian State Commission. Although GOCE's Breeze-KM upper-stage is different to the larger Proton Breeze-M, they do share some common elements. The investigations have led to the conclusion that it is safe to use the Breeze-KM as is, resulting in the Russian State Commission clearing GOCE for launch.

Since August last year, the high-tech GOCE spacecraft has been undergoing extensive testing at ESA's test facilities in the Netherlands. The programme included a wide range of qualification tests to ensure that the satellite could withstand the rigours of launch as well as the harsh environment of space. One such series of tests was carried out in the Large Space Simulator where, under vacuum, the extreme heat of the Sun is simulated by lamps and mirrors - subjecting the satellite to 1400 W of power over each square metre of the side of the satellite that faces the Sun.

As well as being designed to fly in an orbit as low as is technically feasible to retrieve the strongest possible gravity signal, the sleek arrow-shaped satellite is ultra-stable to ensure that measurements taken are of true gravity and not influenced by any movement of the satellite. GOCE, therefore, has none of the moving parts often seen on other spacecraft. Since GOCE is designed to orbit the Earth with one side always facing the Sun, one side only is equipped with solar panels.

Due to its low altitude and inclination, once a year the GOCE satellite will experience an eclipse period of 135 days with one eclipse of up to 28 minutes per orbit. A peculiarity of orbital dynamics is that one is free to choose the eclipse period to fall either between October and February or, between April and August by launching either in the morning or in the evening of the launch day.
Now launching in September, it is best to have the eclipses in the April to August time frame. The May launch would still have gone for the eclipse season in winter. The difference in the two configurations is that, as seen from the Sun, the satellite either flies clock- or anti-clockwise around the Earth. This has impact on the satellite configuration and some units have to be moved from one side of the satellite to the other. Thanks to the flexibility of the satellite design, this is a relatively simple operation. Therefore, modifications to accommodate this new flight configuration are about to be carried out at ESA in the Netherlands. When GOCE has been reconfigured, the spacecraft will be transported by aircraft from the Netherlands to Arkhangelsk in Russia, and from there by train to the launch site in Plesetsk for final testing.

Once launched, GOCE will begin to map global variations in the gravity field with unprecedented detail and accuracy. This will result in a unique model of the geoid, which is the surface of equal gravitational potential defined by the gravity field – crucial for deriving accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change. GOCE-derived data is also much needed to understand more about processes occurring inside the Earth and for use in practical applications such as surveying and levelling.

Danilo Muzi | EurekAlert!
Further information:
http://www.esa.int

More articles from Earth Sciences:

nachricht Novel method for investigating pore geometry in rocks
18.06.2018 | Kyushu University, I2CNER

nachricht Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Controlling robots with brainwaves and hand gestures

20.06.2018 | Information Technology

Electron sandwich doubles thermoelectric performance

20.06.2018 | Power and Electrical Engineering

Intelligent maps will help robots navigate in your home

20.06.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>