ISRO to launch new navigation satellite IRNSS-1H as replacement after clock failure

The Indian Space Research Organisation (ISRO) is all set to launch a new navigation satellite on August 31. IRNSS-1H will replace IRNSS-1A which failed due to deficiencies in three atomic clocks that are crucial in providing positional information to users on earth, as per the report by The Indian Express. ISRO stated that IRNSS-1H will be launched on board ISRO’s PSLV-C39 rocket. The new satellite will expand the existing seven satellites of NavIC constellation. As per the report ISRO had earlier this year stated that the three rubidium atomic frequency standard (RAFS) clocks on IRNSS 1A – which is the first of seven IRNSS satellites launched on July 1, 2013 – had malfunctioned, further rendering the satellite ineffective.

The report also suggests that the space agency had originally indented for nine satellites in IRNSS (Indian Regional Navigation Satellite System) that cost Rs 1,420 crore. The purpose was to service the needs of the civilian sector and the Indian defence forces who require the global positioning data. Out of nine, the seven satellites were to form the navigation Indian constellation or NavIC, while the rest of two were meant to be the replacements. On each of the IRNSS satellites there are three atomic clocks, out which one acts as the primary timekeeper, while the other two act as backups. The failure of all three clocks on a satellite will render the satellite ineffective in providing positional information.

In the year 1999, the space agency had started working on the IRNSS programme following the Kargil War.