Countdown progresses as ISRO's eighth navigation satellite IRNSS-1H nears launch

New Delhi: The countdown for the launch of navigation satellite 'IRNSS-1H' from Sriharikota later today, to augment the existing seven satellites of the NavIC constellation is progressing well.

The 44.4 metre tall PSLV-C39 in its 41st flight, carrying the 1,425 kg satellite, is scheduled for a lift-off at 1900hrs today from the second launch pad at the spaceport of Sriharikota, about 110km from here.

The Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) had on August 29 cleared the countdown.

The launch vehicle PSLV-C39 will use the 'XL' variant, of PSLV equipped with six strap-ons, each carrying 12 tons of propellant.

The spacecraft was built and tested by ISRO along with a consortium of six small and medium industries.

IRNSS-1H would be a back up navigation satellite for IRNSS-1A one of the seven satellites of the constellation, as its three rubidium atomic clocks on board had stopped functioning.

The Indian Regional Navigation Satellite System (IRNSS) is an independent regional system developed by India on par with the US-based GPS, Glonass of Russia, and Galileo developed by Europe.

The system that offer services like terrestrial and marine navigation, disaster management, vehicle tracking and fleet management, navigation aide for hikers and travellers, visual and voice navigation for drivers, was named 'NavIC' (Navigation with Indian Constellation) by Prime Minister Narendra Modi.

ISRO had launched seven satellites - IRNSS-1G on April 28, 2016, IRNSS-1F (March 10, 2016), IRNSS-1E (January 20, 2016), IRNSS-1D (March 28, 2015), IRNSS-1C (October 16, 2014), IRNSS-1B (April 4, 2014) and IRNSS-1A on July 1, 2013.

According to ISRO officials, the total cost of all the seven satellites was Rs 1,420 crore.

(With PTI inputs)