What is IRNSS?
The Indian Regional Navigation Satellite System or IRNSS is an indigenous 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 IRNSS system consists of 3 satellites in GEO orbit and 4 satellites in GSO orbit, approximately 36,000 km altitude above earth surface. 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 IRNSS 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).
IRNSS would have seven satellites, out of which four are already placed in orbit. The constellation of seven satellites is expected to operate from 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 ₹1420 crore (US$212 million), with the cost of the ground segment being ₹300 crore (US$45 million) and each satellites costing ₹125 crore (US$19 million). The IRNSS signal has been released for evaluation in Sep 2014.
Satellites:
IRNSS-1A
IRNSS-1A the first navigational satellite in the Indian Regional Navigation Satellite System series of satellites to be placed in geosynchronous orbit (GSO) was built at ISRO Satellite Centre, Bangalore, costing ₹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 optimized 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
IRNSS-1B is the second out of seven in the Indian Regional Navigation Satellite System. It has been 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’sPSLV-C26 from the Satish Dhawan Space Centre at Sriharikota on 16 October 2014 at 1:32 am.
IRNSS-1D
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
IRNSS-1E will be the fifth out of seven in the Indian Regional Navigation Satellite System series of satellites system. Its launch is planned in January 2016.
IRNSS-1F and IRNSS-1G
IRNSS-1F will be the sixth and IRNSS-1G will be seventh of the Indian Regional Navigation Satellite System series of satellites. Launch of the both is planned in March 2016 which will become a record for ISRO as it never launched two satellites in a single month ever since its inception.
