In the first step towards ending Indias dependence on the US-controlled Global Positioning System (GPS), the first of seven satellites that will form the Indian Regional Navigation Satellite System, or IRNSS, is expected to be launched by December 2012, Indian Space Research Organisation (ISRO) scientists have said. The IRNSS will be composed of seven geostationary satellites to watch over the country from 36,000 km above the earths surface two satellites each would be positioned in the north and south, with three in the middle, according to Pradeep V Khekale, a senior scientist with ISROs Space Applications Centre (SAC) in Ahmedabad. Khekale is the programme manager for GAGAN, or GPS-aided Geo Augmented Navigation, a system that improves GPS accuracy for users in India, and is involved in developing the applications for IRNSS. Currently, only the United States and Russia have functional independent satellite-based navigation systems, although China has recently launched two satellites for its own system. The first satellite launch is expected within a year, and all seven satellites for IRNSS are expected to be launched within three years, said Chirag Dewan, a senior scientist at SAC. The payloads for the IRNSS would weigh approximately 2,000 kilograms, and would need Geosynchronous Satellite Launch Vehicles, or GSLVs, to launch them. Khekale added that the two-frequency INRSS would be more accurate than the single frequency GPS. IRNSS is generating a lot of interest, excitement and focus at the SAC now, especially after the successful launch of the RISAT-1 just a few weeks ago, said Shailendra Singh, a Radio Frequency engineer at SAC who was part of the RISAT mission, the payload for which was developed here.