IRNSS-1A


IRNSS-1A is the first navigational satellite in the Indian Regional Navigation Satellite System series of satellites been placed in geosynchronous orbit.

Satellite

The satellite has been developed at a cost of, and was launched on 1 July 2013. It will provide IRNSS services to the Indian public, which would be a system similar to Global Positioning System but only for India and the region around it.
Each IRNSS satellite has two payloads: a navigation payload and CDMA ranging payload in addition with a laser retro-reflector. The payload generates navigation signals at L5 and S-band. The design of the payload makes the IRNSS system inter-operable and compatible with GPS and Galileo. The satellite is powered by two solar arrays, which generate power up to 1,660 watts, and has a lifetime of ten years.

Launch

The satellite was launched from the Satish Dhawan Space Centre on 1 July 2013 at 11:41 PM. The launch was postponed from its initial launch date of 26 June 2013 due to a technical snag in the 2nd stage of the PSLV-C22 launch rocket. ISRO then replaced the faulty component in the rocket and rescheduled the launch to 1 July 2013 at 11:43 p.m.
Scientists from the German Aerospace Centre 's Institute of Communications and Navigation in Oberpfaffenhofen, Germany, have received signals from IRNSS-1A. On 23 July 2013, the German Aerospace Center scientists pointed their 30-meter dish antenna at Weilheim towards the satellite and found that it was already transmitting a signal in the L5 frequency band.

Failure

The three Rubidium atomic clocks on-board IRNSS-1A failed, with the first failure occurring in July 2016. ISRO planned to replace it with IRNSS-1H, in August 2017, but this failed to separate from the launch vehicle, but on 12 April 2018, ISRO launched successfully IRNSS-1I as a replacement for IRNSS-1A.
The cause of failure was traced to one of the feed through capacitor carrying the DC supply to the physics package of clock, malfunctioning due to excessive rise in temperature.