India successfully launches IRNSS-1I navigation satellite

A replacement satellite for NavIC, India’s navigation constellation, was successfully launched April 11 from Satish Dhawan Space Centre SHAR, Sriharikota.

In its 43rd flight, the India Space Research Organization’s (ISRO’s) Polar Satellite Launch Vehicle PSLV-C41 propelled the 1,425-kilogram IRNSS-1I Navigation Satellite into orbit.

All three rubidium atomic clocks on IRNSS-1A have failed. A replacement satellite, IRNSS-1H, was launched on Aug. 31, 2017, but was not successfully deployed. This satellite, IRNSS-1I, is also a replacement satellite for IRNSS-1A.

PSLV-C41 lifted off at 0404 hrs (4:04 a.m.) IST, as planned, from the spaceport’s First Launch Pad. After a flight lasting about 19 minutes, the vehicle achieved a sub-geosynchronous transfer orbit with a perigee (nearest point to Earth) of 281.5 km and an apogee of 20,730 km inclined at an angle of 19.2 degrees to the equator, following which IRNSS-1I separated from PSLV.

After separation, the solar panels of IRNSS-1I were deployed automatically. ISRO’s Master Control Facility (MCF) at Hassan, Karnataka, took over the control of the satellite. In the coming days, orbit maneuvers will be performed from MCF to position the satellite at 55 degrees East longitude in the planned geosynchronous orbit with an inclination of 29 degrees to the equator.

IRNSS-1I is the latest member of the Navigation with Indian Constellation (NavIC) system. NavIC, also known as Indian Regional Navigation Satellite System (IRNSS), is an independent regional navigation satellite system designed to provide position information in the Indian region and 1500 kilometers around the Indian mainland.

A number of ground facilities responsible for IRNSS satellite ranging and monitoring, generation and transmission of navigation parameters, satellite control and network timing have been established in many locations across the country as part of NavIC.