BERLIN (Reuters) - Europe launched four more Galileo satellites on Tuesday, taking the number in orbit to 22 and moving a step closer to having its own navigation system, lessening its dependence on the U.S. Global Positioning System, or GPS.
The satellites blasted off from Europe's spaceport in French Guiana aboard an Ariane 5 rocket at 3.36 PM local time (1836 GMT) and headed for an orbit of around 24,000 kms (14,900 miles) above Earth, according to the European Space Agency (ESA).
The Galileo system is eventually to have a total of 30 satellites, weighing about 700 kgs (1,543 pounds) each, which are equipped with antennae and sensors and powered by two 5-square-metre (53.8 square foot) solar wings.
Since the EU decided to go ahead with Galileo 17 years ago, the programme has suffered some setbacks, including delays, financing problems, two satellites being put into the wrong orbit and questions about whether Europe really needs a rival system to GPS.
The EU aims to use Galileo to tap into the global market for satellite navigation services, which it estimates will be worth 250 billion euros ($296 billion) by 2022. Also, it says that around 6 to 7 percent of the $16 trillion EU economy depends on the availability of global navigation satellite signals.
The EU has an agreement with the United States that allows the combined use of GPS and Galileo, which will allow for more accurate positioning than with only one system.
Chipmakers including STMicroelectronic, Qualcomm and Broadcom have announced Galileo-ready chips for smartphones and the automotive sector.
That means that once the next four Galileo satellites are launched in July 2018, new smartphones drawing data from both the U.S. and the European satellites will achieve an accuracy of 30 cm (1 ft), compared with around 5 m (16.4 ft) with GPS only.
The remaining Galileo satellites are due to be launched by the end of 2020.
Russia and China have also launched their own global positioning systems, Glonass and Beidou, to underpin their defence industries and civilian commerce.
India is working on a similar system but suffered a setback in August when its eighth navigation satellite imploded shortly after lift off.
(Reporting by Maria Sheahan; Editing by Hugh Lawson)