14 DAY TRIAL // Understanding the gravitational pull that our planet exerts is of tremendous importance for the field of space exploration, as well as for determining the best orbits to place satellites in. Due to its uneven nature, the Earth is exerting various degrees of pull over various areas, and this is the main reason why GOCE was constructed. The European Space Agency's (ESA) spacecraft, designated Gravity Field and Steady-State Ocean Circulation Explorer (GOCE), surveys minute variations in the planet's gravitational pull over areas that are otherwise extremely hard to study. One such example is the Himalayas mountain chain, which was recently targeted by the sensitive probe.
The satellite, launched back on March 17, 2009, is the most sensitive and accurate scientific instrument of its kind in orbit. The data it has been relaying back for all these months is being processed by an international team of experts that also includes scientists from the Technische Universitaet Muenchen (TUM), in Germany. They say that GOCE datasets confirm the fact that some of the existing models, aimed at explaining the gravitational field certain regions of the globe exert, need to be thoroughly revised. Based on the new knowledge, investigators hope to be able to construct additional models to understand natural phenomena, such as earthquakes and ocean circulation patterns.
“It is becoming clear that we are receiving good information for the regions that are of interest from a geophysical point of view,” the chairman of the GOCE Gravity Consortium, professor Reiner Rummel. The expert, who is also a geodesist at the TUM, presented the preliminary results collected from the satellite's data, at the General Assembly of the European Geosciences Union. The event was held in Vienna on May 7. He also explained that telemetry readings gave mission controllers reasons to believe that the spacecraft would be able to endure more in space than initially estimated.
“We hope we can continue to measure for even three to four years,” Rummel told scientists. GOCE is a remarkable spacecraft because it orbits the planet at a height of only 255 kilometers. This means that it has the lower orbital altitude of all other scientific spacecrafts. Another implication is that its state-of-the-art ion thrusters need to fire continuously, in order to adjust GOCE's flightpath, and to prevent the delicate space probe from smashing into the ground. Measuring gravitational variations while being propelled is possible for the satellite due to its smooth ion engine, which provides a bump-free ride.