The Indian Regional Navigational Satellite System (IRNSS) is an autonomous regional satellite navigation system being developed by the Indian Space Research Organisation (ISRO) which would be under total control of Indian government. The requirement of such a navigation system is driven by the fact that access to Global Navigation Satellite Systems, GPS, is not guaranteed in hostile situations. The IRNSS would provide two services, with the Standard Positioning Service open for civilian use and the Restricted Service, encrypted one, for authorized users (military).
The first satellite of the proposed constellation, developed at a cost of 1,600 crore (US$291.2 million), is expected to be launched during 2012-2013 while the full constellation is planned to be realized around 2015. A goal of complete Indian control has been stated, with the space segment, ground segment and user receivers all being built in India. Three satellites will be in geostationary orbit over the Indian Ocean. Missile targeting could be an important military application for the constellation.
India plans to start launching satellites by the end of 2013, at a rate of one satellite every six months. This will make the IRNSS optimally functional by 2015. India also launched 3 new satellites into space to supplement this. Indian Regional Navigational Satellite System (IRNSS-1) will be the first of the total seven satellites of the IRNSS constellation. It will have a lift off mass of 1380 kg and operate a navigation payload and a C-band ranging transponder and employ an optimised I-1K bus structure with a power handling capability of 1600W and is designed for a nominal mission life of 7 years.
Source: Indian Military Page in facebook