India to launch 8th navigation satellite IRNSS-1I on 12 April to augment the NAVICC constellation

India’s space agency **ISRO** on 8 April said it will launch a navigation satellite from its spaceport in Sriharikota in Andhra Pradesh on 12 April. [caption id=“attachment_4299291” align=“alignleft” width=“380”] PSLV-C40 on First Launch Pad. Image: ISRO[/caption] “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 12 April at 4.04 am,” the Indian Space Research Organisation (ISRO) said in a statement on its official website. The IRNSS-1I is the eighth satellite to join the NavIC navigation satellite constellation in Earth’s polar orbit. The launch a fortnight after ISRO launched **communication satellite GSAT-6A** on 29 March on board a heavy rocket (GSLV), but **lost communication** link with it on 31 March when it was on course to its intended slot in the geo-stationary orbit, about 36,000 km above the Earth. The Master Control Facility (MCF) of the space agency at Hassan in Karnataka has been trying its best to restore link with the 2,000 kg satellite since 1 April but not succeeded till date. 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 31 August, 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 separated three minutes into the launch, but failed to. 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.