Chennai: The countdown for the launch of navigation satellite IRNSS-1H from Sriharikota later on Thursday, to augment the existing seven satellites of the NavIC constellation, is progressing well, Indian Space Research Organisation (Isro) officials said.
The 29-hour countdown began on Wednesday at 2pm and scientists are currently involved in filling up the propellants, the officials said, adding that the countdown is progressing well.
The mission readiness review (MRR) committee and launch authorisation board (LAB) had on 29 August cleared the countdown.
The launch vehicle PSLV-C39, carrying the 1,425kg satellite, is scheduled for a lift-off at 7pm from the second launch pad at the spaceport of Sriharikota, about 110km from Chennai.
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 Global Positioning System (GPS), Glonass of Russia, and Galileo developed by Europe.
The system, which offers 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.
The seven navigation satellites launched earlier by Isro are IRNSS-1G (28 April 2016); IRNSS-1F (10 March 2016); IRNSS-1E (20 January 2016), IRNSS-1D (28 March 2015), IRNSS-1C (16 October 2014), IRNSS-1B (4 April 2014); and IRNSS-1A (1 July 2013).
According to Isro officials, the total cost of all the seven satellites was Rs1,420 crore.