India’s navigation system gets a boost after ISRO successfully launches NVS-01 satellite

The Indian Space Research Organisation (Isro) on Monday successfully launched NVS-01, a second-generation navigation satellite on board the Geosynchronous Launch Vehicle or GSLV Mk-II, from the Satish Dhawan Space Centre (SDSC) in Sriharikota.

The NVS-01 will augment India’s regional navigation system by providing accurate and real-time navigation, the space agency said.

“GSLV-F12/ NVS-O1 Mission is accomplished: After a flight of about 19 minutes, the NVS-O1 satellite was injected precisely into a geosynchronous transfer orbit,” Isro announced after Monday’s launch.

Watch: ISRO puts 2nd-Gen satellite NVS-01 into orbit | Why It Matters To India

The space agency said, “Subsequent orbit-raising manoeuvres will take NVS-01 into the intended geosynchronous orbit.”

At the end of a 27.5-hour countdown, the 51.7-metre tall, three-stage GSLV Mk-II lifted off at 10.42am from the second launchpad at SDSC, nearly 130km from Chennai. This was GSLV’s 15th flight.

Isro chairperson, S Somanath said that the satellite was placed in the precise orbit and the space agency declared the mission successful.

“Congratulations on the excellent GSLV-F12 mission outcome. The satellite has been placed in a precise orbit. This mission is after the debacle of the GSLV-F10 mission, where we had an issue with the cryogenic state. I am happy that the updates and changes we have made to make the stage more reliable have been a success,” Somanath said in a post-launch press briefing.

Giving an update about the upcoming missions, Somanath said that Isro is now gearing for the launch of Chandrayaan-3, India’s third moon mission. He said that he is confident of a July launch for Chandrayaan-3. HT reported last week that July 12 will be the likely date of the launch.

After the launch of Chandrayaan-3, Isro is also rushing to launch India’s sun mission, Aditya-L1, which is likely to be scheduled for August-September.

To meet the positioning, navigation and timing requirements of the nation, Isro has established a regional navigation satellite system called Navigation with Indian Constellation (NavIC). NavIC was earlier known as the Indian Regional Navigation Satellite System (IRNSS). Isro scientists said that NVS-01 will be a return flight mission for the GSLV launch vehicle, which will carry the next generation NavIC satellite. This satellite will replace the IRNSS-1G satellite launched in 2016.

According to Isro’s mission document, NavIC satellites are used in terrestrial, aerial, and marine transportation, location-based services, personal mobility, resource monitoring, surveying and geodesy, scientific research, time dissemination and synchronization, and safety-of-life alert dissemination.

Read: ISRO launches next-gen satellite for real-time GPS, timing. 7 things to know

The IRNSS-1G satellite was the seventh navigation satellite of the seven satellites constituting the IRNSS space segment. Its predecessors—IRNSS-1A, 1B, 1C, 1D, 1E and 1F—were launched by PSLV-C22, PSLV-C24, PSLV-C26, PSLV-C27, PSLV-C31 and PSLV-C32 in July 2013, April 2014, October 2014, March 2015, January 2016 and March 2016, respectively.

NavIC is designed with a constellation of seven satellites and a network of ground stations operating 24x7. Three satellites of the constellation are placed in geostationary orbit and four satellites are placed in inclined geosynchronous orbit. The ground network consists of a control centre, precise timing facility, range and integrity monitoring stations, two-way ranging stations, etc.

The payload is also carrying an indigenously developed rubidium atomic clock developed by the Space Applications Centre, Ahmedabad, which is an “important technology that only a handful of countries possess”, according to Isro. The clock forms a key part of the satellite navigation system.

NavIC offers two services -- standard position service (SPS) for civilian users and restricted service (RS) for strategic users. These two services are provided in both L5 (1176.45 MHz) and S band (2498.028 MHz). NavIC coverage area includes India and a region up to 1,500km beyond the Indian boundary. NavIC signals are designed to provide user position accuracy better than 20m and timing accuracy better than 50 nanoseconds. The NavIC system operates in the L5 band, which is a protected frequency specifically assigned to the Indian system. The NVS-1 incorporates L1 band signals additionally to widen the services.