Photo from ISRO: PSLV-C41/IRNSS-1I Mission scheduled to be launched on April 12

India's space agency Indian Space Research Organisation (ISRO) said that it will launch a navigation satellite. ISRO will launch the satellite on April 12 from its Sriharikota spaceport in Andhra Pradesh.

The 43rd flight of Polar Satellite Launch Vehicle (PSLV-C41) will launch the Indian Remote Navigation Satellite System (IRNSS-1I) from the first launch pad of the Satish Dhawan Space Centre at Sriharikota on April 12 at 4.04 am. - ISRO

The IRNSS-1I is the eighth satellite to join the NavIC navigation satellite constellation in Earth's polar orbit.

Panoramic view of PSLV-C41 on the first launch pad.

IRNSS-1I is expected to replace IRNSS-1A, the first of the seven navigation satellites, that was rendered ineffective after its three rubidium atomic clocks failed. The seven satellites are part of the NavIC navigation satellite constellation.

ISRO launched communication satellite GSAT-6A on March 29 on-board a heavy rocket (GSLV), but lost communication link with it on March 31 when it was on course to its intended slot in the geo-stationary orbit, about 36,000 km above the Earth.

Payload fairing with GSAT-6A is being integrated.

The Master Control Facility (MCF) of ISRO at Hassan in Karnataka has been trying its best to restore link with the 2,000 kg satellite since April 1 but has not succeeded till date.

ISRO Chairman K Sivan had said post the launch that GSAT-6A was a complement to GSAT6, which was already in orbit, and these two satellites combined will provide a platform for development of advanced technologies. This is the first mission for Sivan, who assumed charge of the space agency in January.

Payload fairing with GSAT-6A is being integrated.

In August last year, India's mission to launch its backup navigation satellite IRNSS-1H on board PSLV-C39 ended in a failure after a technical fault on the final leg following a perfect launch.

8TH NAVIGATION SATELLITE IRNSS-1I

The 8th navigation satellite IRNSS-1I will be a replacement in the NavIC constellation for the 1,425 kg IRNSS-1H that failed to eject out of the PSLV rocket on August 31, 2017 to its intended orbit as its heat shield failed to separate even about 20 minutes after it was launched.

The rocket's heat shield should have had separated three minutes into the launch, but failed to.

GSLV-F08 Heat-shield is being closed with GSAT-6A satellites inside.

After a 19-minute wait for the heat shield to separate, ISRO scientists had declared the mission unsuccessful.

The IRNSS-1H satellite was to have been slung into orbit at 507 km above the Earth in the polar orbit.

(With inputs from IANS and PTI)