Countdown for Isro's 100th mission begins at Sriharikota: Here’s all you need to know about GSLV-F15 NVS-02 launch

Standing at 50.9 meters tall, the GSLV-F15 comes after the successful GSLV-F12 mission

The Indian Space Research Organisation (Isro) is gearing up for its landmark 100th launch from Sriharikota in Andhra Pradesh. On Tuesday, the 27-hour countdown began for Isro's historic 100th mission, which will launch a navigation satellite aboard a GSLV rocket, space agency sources reported.

This would be the first mission under the leadership of Isro chairman V Narayanan, who took office on January 13.

Here’s all you need to know about the GSLV-F15 NVS-02 mission

-The Geosynchronous Satellite Launch Vehicle (GSLV) with indigenous Cryogenic upper stage in its 17th flight, carrying the navigation satellite NVS-02 is scheduled for lift-off at 6.23 am on January 29 from the second launch pad at Sriharikota.

- The navigation satellite is the second in the series of the Navigation with Indian Constellation (NavIC) aimed to provide accurate position, velocity and timing to users in the Indian sub-continent as well as to regions about 1,500 km beyond the Indian land mass.

- Standing at 50.9 meters tall, the GSLV-F15 comes after the successful GSLV-F12 mission, which carried the second-generation navigation satellite NVS-01 into orbit on May 29, 2023.

- NavIC comprises five second generation satellites--NVS-01/02/03/04/05 envisaged to augment NavIC base layer constellation with enhanced features for ensuring continuity of services.

- The NVS-02 satellite designed and developed by the U R Satellite Centre weighs about 2,250 kg. It has navigation payload in L1, L5 and S bands in addition to ranging payload in C-band like its predecessor NVS-01.

- The key applications the satellite would be used for are terrestrial, aerial and maritime navigation, precision agriculture, fleet management, location based services in mobile devices, orbit determination for satellites, Internet-of-Things (IoT) based applications, emergency and timing services, ISRO said.

- NVS-02 satellite was designed, developed and integrated at U R Satellite Centre (URSC) with the support of other satellite-based work Centres. On completion of Assembly and Integrated Testing (AIT), the satellite was subjected to satellite level thermovac test to verify and validate its design and performance in simulated space environment during November-December 2024. The satellite underwent dynamic test during December 2024 thus confirming its suitability to withstand the dynamic loads anticipated during launch.

- A comprehensive pre-shipment review (PSR) of the performance and compliance of the satellite during various phases of its realisation was completed on December 27, 2024. The satellite was flagged off to SDSC-SHAR, the launch port of India on January 5, 2025.