Issue 74

India Launches Next Gen Navigation Satellite

28 May 2023: India launched a NVS-01 navigation satellite using a Geosynchronous Satellite Launch Vehicle (GSLV) Mk.11 rocket from the Satish Dhawan Space Centre. NVS-01 is the first of India's second-generation NavIC satellites and is equipped with new Indian-developed atomic clocks. Launch Video. Satellite Deployment…

28 May 2023: India launched a NVS-01 navigation satellite using a Geosynchronous Satellite Launch Vehicle (GSLV) Mk.11 rocket from the Satish Dhawan Space Centre. NVS-01 is the first of India’s second-generation NavIC satellites and is equipped with new Indian-developed atomic clocks. Launch Video. Satellite Deployment Video.

– The Navigation with Indian Constellation (NavIC), system is a regional satellite navigation network developed by the Indian Space Research Organisation (ISRO). Also known as the Indian Regional Navigation Satellite System (IRNSS), the system’s first generation consists of seven satellites in geosynchronous orbit — although a total of nine spacecraft have been launched, including replacements.

– IRNSS-1A, the first satellite in the series,

was launched in Jul 2013, with the constellation reaching its full complement following the launch of IRNSS-1G in Apr 2016. After three years in orbit, the atomic clocks aboard IRNSS-1A began to develop faults, and IRNSS-1H was launched as a replacement in Augt 2017. This did not reach orbit after the payload fairing of its carrier rocket failed to separate, so IRNSS-1I was deployed instead in Apr 2018, becoming the final first-generation IRNSS satellite to launch.

– ISRO has confirmed the failure of several other clocks across other satellites in the fleet. ISRO’s annual report for 2020-21 noted that the IRNSS-1G satellite had also been moved to a secondary role, but did not identify the reason for this. NVS-01 is expected to take IRNSS-1G’s slot in the constellation.

-Accurate timekeeping provided by atomic clocks is vital to operating navigation satellites, as the signals they broadcast contain timestamps. Receivers use these timestamps, and the knowledge that radio signals propagate at the speed of light, to calculate distance to the satellites and triangulate their position based on the signals and relative positions of multiple satellites.

-NVS-01 is also over 900kg heavier than the first-generation satellites and incorporates other enhancements to expand the capabilities of the NavIC constellation. These include broadcast of a new L1 signal, in addition to the L5 and S-band signals broadcast by the existing satellites, which will improve interoperability with other satellite navigation systems such as the US Global Positioning System (GPS) network.

NavIC constellation (NVS-01 pending orbit circularization)

NVS-01 launch from the Satish Dhawan Space Centre

NVS-01 prepared for launch

NVS-01 satellite deployment