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07:49 AM, September 1, 2017
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PSLV-C39 IRNSS-1H mission (Image: ISRO)

Indian Space Research Organization (ISRO) launched Polar Satellite Launch Vehicle (PSLV) carrying a replacement satellite for Indian Regional Navigation Satellite System (IRNSS) failed after reaching sub-geosynchronous transfer orbit Thursday.

The IRNSS-1H constellation or NavIC, program was launched on schedule from the Second Launch Pad late evening Thursday. The launch failed after the heat shield tip or the rocket inside which the satellite is housed did not open. It was scheduled to open 3 minutes and 23 seconds into the flight of the rocket.

The constellation of seven spacecraft would give India a dedicated navigation system serving military and civilian applications reducing the nation’s reliance on systems controlled by foreign governments, Nasa Space Flight portal reported Thursday.

The problems aboard IRNSS-1A began in mid-2016 with the failure of one of its three atomic clocks. The remaining two failed over the following six months.

Without the clocks in operation the satellite cannot produce a sufficiently accurate signal to be used for precise navigation, although it is continuing to broadcast system messages. At launch in July 2013, the spacecraft was expected to provide ten years of service.

IRNSS-1H is a 1,425-kilogram (3142 lb) satellite which is expected to provide ten years of service. It will be stationed in an inclined geosynchronous orbit at longitude of 55 degrees East, where it will replace IRNSS-1A, the portal reported.

The satellite is of the same design as its predecessor, based around ISRO’s I-1K bus, with the same ten-year design life.

Four of the seven satellites in the IRNSS constellation are deployed in inclined orbits, with two each at 55 and 111.75 degrees East.

The remaining three satellites are in equatorial geostationary orbits, at 34, 83 and 129.5 degrees East.

Deployment of IRNSS began in July 2013, with the launch of IRNSS-1A, while the April 2016 launch of IRNSS-1G completed the initial constellation. All seven satellites in orbit were launched by ISRO using PSLV-XL vehicles, the same type of rocket that was tasked with delivering IRNSS-1H to orbit on Thursday.

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