The 29-hour countdown for Thursday’s launch of navigation satellite IRNSS-1H to augment the existing seven satellites of the NavIC constellation began on August 30.
To be launched on board PSLV-C39, IRNSS-1H will be a ’back-up’ navigation satellite for IRNSS-1A, one of the seven satellites in the constellation, as its three rubidium atomic clocks on board had stopped functioning.
“The 29-hr countdown operations of PSLV-C39/IRNSS-1H mission have started on Wednesday at 14:00 hrs IST,” the Indian Space Research Organisation said.
The launch is scheduled at 19:00 hrs from the Second Launch Pad of the Satish Dhawan Space Centre at Sriharikota in Andhra Pradesh.
The Mission Readiness Review (MRR) committee and Launch Authorization Board (LAB) had on August 29 cleared the 29-hour countdown.
The launch vehicle PSLV-C39 will use the ‘XL’ version of PSLV equipped with six strap-ons, each carrying 12 tons of propellant.
The over 1,400 kg spacecraft was built and tested by ISRO along with a consortium of six small and medium industries.
The Indian Regional Navigation Satellite System (IRNSS) is an independent regional navigation satellite system developed by India on par with U.S.-based GPS.
The system that offers services like terrestrial and marine navigation, disaster management, vehicle tracking and fleet management, navigation aide for hikers and travelers, 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 INR 1,420 crore.