The Indian Regional Navigation Satellite System or IRNSS with an operational name of NAVIC (Navigation with Indian Constellation) is an Indian developed Navigation Satellite System that is used to provide accurate real-time positioning and timing services over India and region extending to 1500 km around India. The fully deployed NAVIC system consists of 3 satellites in GEO orbit and 4 satellites in GSO orbit, approximately 36,000 km altitude above earth surface. However, the full system comprises nine satellites, including two on the ground as stand-by. The requirement of such a navigation system is driven because access to foreign government-controlled global navigation satellite systems is not guaranteed in hostile situations, as happened to the Indian military depending on American GPS during the Kargil War. The NAVIC would provide two services, with the Standard Positioning Service open for civilian use, and the Restricted Service (an encrypted one) for authorized users (including the military). Once the NAVIC is declared operational after checking the systems – space (satellites), ground (ground stations) and the user-end signal receivers, India will formally join a select group of nations owning their own Navigational Satellite system . The NAVIC constellation of seven satellites are in orbit and is expected to operate from June 2016 onwards.
As part of the project, ISRO opened a new satellite navigation center within the campus of ISRO Deep Space Network (DSN) at Byalalu, in Karnataka on 28 May 2013. A network of 21 ranging stations located across the country will provide data for the orbital determination of the satellites and monitoring of the navigation signal.
A goal of complete Indian control has been stated, with the space segment, ground segment and user receivers all being built in India. Its location in low latitudes facilitates a coverage with low-inclination satellites. Three satellites will be in geostationary orbit over the Indian Ocean. Missile targeting could be an important military application for the constellation. The total cost of the project is expected to be Rs.1420 crore (US$211 million), with the cost of the ground segment being Rs.300 crore (US$45 million). Each satellites costing Rs.150 crore (US$22 million) and the PSLV-XL version rocket costs around Rs.130 crore (US$19 million) . The seven rockets would involve an outlay of around Rs.910 crore (US$135 million). The NAVIC signal has been released for evaluation in Sep 2014.
IRNSS-1A was the first navigational satellite in the Indian Regional Navigation Satellite System series of satellites to be placed in geosynchronous orbit. It was built at ISRO Satellite Centre, Bangalore, costing Rs.125 crore (US$19 million). It has a lift-off mass of 1380 kg, and carries a navigation payload and a C-band ranging transponder, which operates in L5 band (1176.45 MHz) and S band (2492.028 MHz). An optimised I-1K bus structure with a power handling capability of around 1600 watts is used and is designed for a ten-year mission. The satellite was launched on-board PSLV-C22 on 1 July 2013 from the Satish Dhawan Space Centre at Sriharikota.
IRNSS-1B is the second out of seven in the Indian Regional Navigation Satellite System. It was very precisely and successfully placed in its orbit through PSLV-C24 rocket on 4 April 2014. IRNSS-1C IRNSS-1C is the third out of seven in the Indian Regional Navigation Satellite System series of satellites. The satellite was successfully launched using India’s PSLV-C26 from the Satish Dhawan Space Centre at Sriharikota on 16 October 2014 at 1:32 am.
IRNSS-1D is the fourth out of seven in the Indian Regional Navigation Satellite System series of satellites system. It was successfully launched using India’s PSLV-C27 on 28 March 2015 at 5:19 pm.
IRNSS-1E is the fifth out of seven in the Indian Regional Navigation Satellite System series of satellites system. It was successfully launched on 20 January 2016 using India’s PSLV-C31 at 9:31 am. IRNSS-1F IRNSS-1F is the sixth out of seven in the Indian Regional Navigation Satellite System series of satellites system. It was successfully launched on 10 March 2016 using India’s PSLV-C32 at 4:01 pm.
IRNSS-1G is the seventh and final of the IRNSS series of satellites system. It was successfully launched on 28 April 2016 at 12:51pm IST using India’s PSLV-C33. The successful launch of this satellite concludes the setting up of India’s first indigenous Regional Navigation Satellite System.