One year ago today, GIOVE-A began transmitting Galileo navigation signals. This satellite is the first flight element in ESA’s in-orbit validation program for Galileo.

Carried into space from the Baikonour Cosmodrome in Kazakhstan by a Soyuz launch vehicle on 28 December 2005, GIOVE-A then successfully completed the initial tasks in its mission – orbit injection, deployment of its solar arrays and the commissioning and check-out of its various payload systems – before commencing the transmission of navigation signals.

This signal transmission has secured the use of the frequencies allocated to the Galileo system by the International Telecommunication Unit (ITU), achieving the primary mission for which the satellite was constructed.

The navigation signal has been broadcast continuously to fulfill the other important objectives of the GIOVE mission:

• verification of the critical technologies for the Galileo satellites, including the on-board Rubidium Atomic Frequency Standard (RAFS) clocks, the navigation signal generator and the chain of equipment that comprises the navigation payload
• characterisation of the novel features of the Galileo signal design, including the verification of user receivers and their resistance to interference and multi-path reception in realistic static and dynamic conditions, aiming to better estimate the effect on navigation services and future applications
• characterisation of the radiation environment of the Medium Earth Orbit (23 260 km altitude) planned for the Galileo constellation, to better understand this particular environment – particularly the radiation doses and electro-magnetic fields that could affect the design of the operational system

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January 13th, 2007 | Earth Sciences and Geomatics, General Science | 1 comment

The worldwide disruption of fuel supplies and accompanying price spikes caused by Hurricane Katrina convinced the Swedish government that it is high time to give fossil fuels the heave-ho, according to Mona Sahlin, minister for sustainable development. She announced on October 1 that the government has set a new policy target to eliminate Sweden’s dependence on fossil fuels by 2020.

Sweden is the second-highest per capita consumer of energy in Europe, and some critics argue that boosting the efficient use of existing energy resources will do more to reduce fossil fuel use than setting a radical target that is not likely to be met.

The new target to break Sweden’s reliance on fossil fuels by 2020 will be achieved with a focus on renewable energy, through tax incentives and market-based mechanisms, Sahlin says. Beginning on January 1, homeowners who convert to renewable-energy heating systems will receive a tax break. The green certificate system, which already requires commercial electricity suppliers to purchase a certain percentage of their electricity from renewable sources, will be extended to 2030. Drivers of “environmentally friendly” cars, such as hybrids and cars that run on ethanol, will enjoy tax relief, get free parking in some cities, and be exempt from Stockholm’s congestion charge.

Prime Minister Göran Persson is genuinely interested in breaking Sweden’s dependence on fossil fuels, says Stefan Edman, one of Sweden’s most respected environmental authors and chair of a commission that is recommending further measures to meet the target.

“Sweden could reach the target in the heating sector, but it will be much more difficult for transportation,” Edman says. Since 1975, oil consumption for heating homes and businesses has dropped by 70%. Transportation now accounts for roughly half of Sweden’s fossil-fuel consumption. In a government report released last June, Edman proposed more than 20 measures to cut fossil-fuel use for transportation.

Sweden would have a greater impact on cutting global emissions of CO2 if it simply used its existing energy resources more efficiently, responds Per Kågeson, director of Nature Associates, a consultancy. He says that large-scale conversion to ethanol could lead to more clearing of rainforests and ultimately elevate greenhouse gas emissions in countries outside of Sweden; for example, Brazil supplies 80% of Sweden’s ethanol. It could also mean the end of Swedish biofuel exports. Countries that rely on Swedish biofuel are likely to switch to fossil fuels if exports decline, Kågeson says.

Source: ES&T Online News.

January 11th, 2007 | Earth Sciences and Geomatics, Environment | 3 comments