Let us first begin by summarising the IRNSS Framework. There are presently seven Indian Regional Navigation Satellite System (IRNSS) satellites (1A to 1G) in orbit.

  • A, B, F, G are placed in an orbit, which implies they appear to be at a fixed location on top of the planet and they orbit along with the planet.
  • The remaining 3 C, D, E, are situated in fixed orbit-they appear to be at a fixed location on top of the planet on the equator and orbit along with the planet.

The launch of IRNSS-1I will be the 9th direction satellite launch beneath the project which has 7 successful launches and 1 unsuccessful launch.


Details on IRNSS-1I:

  • ISRO is trying to launch one of the backup satellites to switch NavIC navigation satellite constellation’s IRNSS-1A whose 3 rubidium clocks failed
  • PSLV in forty third flight will depart IRNSS-1I which weighs 1425 kg. it’ll replace IRNSS-1A and join the constellation of seven satellites.
  • It will have L5 and S-band exploration payload with rubidium atomic timers.
  • It will be placed in a very sub-geosynchronous transfer orbit and at its nearest point will be 284 km above the planet and at its farthest will be twenty,650 km above the planet.
  • Like all other IRNSS satellites, IRNSS-1I will carry 2 payloads – navigation payload and locomote payload –
  • the former to transmit signals for determinative position, speed and time and
  • The latter for determining the frequency range of the satellite.

Previous attempts at replacement:

  • It is ISRO’S second try at launching a replacement satellite.
  • The past mission in August 2017 where a PSLV carried IRNSS-1H unsuccessful when the heat shield covering the satellite didn’t separate.
  • Except IRNSS-1H, all the launches were successful.


Benefit of IRNSS-1I:

  • IRNSS can assist in terrestrial, aerial and marine navigation, disaster management, vehicle trailing and speed management, integration with mobile phones, actual timing, mapping and geodetical information capture, a terrestrial navigation aid for hikers and travellers, visual and voice navigation for drivers & riders.
  • Navigation satellite signal receivers which can offer positioning and weather alerts to fishermen in deep ocean and additional such devices are going to be fitted in boats in Tamil Nadu and Kerala.
  • This will facilitate in causing alerts to fishermen very important data at times of cyclones.


  • There are three components in the satellites’ receiver – a Bluetooth module, a microcontroller and a chipset. The receiver, developed by ISRO’s Space Applications Centre, Ahmedabad, is also being enhanced to save power in both mobile and the device.

Read in detail about IRNSS here.

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