Context: Indian Space Research Organisation (ISRO) is all set to launch its 100th mission – the NVS-02 satellite, aboard the Geosynchronous Satellite Launch Vehicle (GSLV) – in January 2025.
Relevance of the Topic:Prelims: Key facts about NVS-02 Satellite; NAVIC System
About NVS-02 Satellite
- NVS-02 will be the second satellite in the series of 2nd-generation navigation satellites and the 9th satellite in the Navigation with Indian Constellation (NavIC).
- NavIC consists of a constellation of 7 satellites (First-generation Satellites)
- NVS-01 (the first 2nd generation satellite was launched in May 2023)
- Launch vehicle: GSLV Mark II
- NVS-02 will likely have two kinds of payloads - navigation payload and ranging payload.
Payloads of NVS-02
1. Navigational payload:
- Navigational payload transmits signals to users on Earth. It does so using three bands in the spectrum - L1, L5, and S band.
- A Rubidium atomic clock is on-board NVS-02.
- Atomic clocks are highly accurate and stable clocks, with errors of less than 10 nanoseconds.
- The low errors result in providing accurate ranging for position determination.
- The Rubidium atomic clock measures the length of one second by counting the oscillations of rubidium-87 atoms.
2. Ranging payload:
- Ranging payload consists of a transponder.
- This helps the navigation satellite transmit time-stamped navigation signals to the receivers at the ground station.
- This information is then processed at the end-user stage to derive their exact position, speed, and time.
- This helps in providing seamless and non-stop service irrespective of weather conditions on Earth.
Significance of 2nd generation satellites
- 2nd-generation satellites in NavIC will send signals in a third frequency (L1) besides the L5 and S, thus increasing interoperability with other satellite-based navigation systems.
- 2nd-generation satellites have a much more robust encryption system to keep all communications completely secure.
- These satellites will have a longer mission life of more than 12 years. 1st generation satellites have a mission life of 10 years.
What is NavIC?
- NavIC (Navigation with Indian Constellation) is the independent stand-alone navigation satellite system of India. It was earlier known as IRNSS (Indian Regional Navigation Satellite System).
- Features:
- NavIC consists of a constellation of seven satellites. Three satellites are located in the geostationary orbit and the remaining four are located in geosynchronous orbits around the Earth: IRNSS-1A, IRNSS-1B, IRNSS-1C, IRNSS-1D, IRNSS-1E, IRNSS-1F, and IRNSS-1G.
- The first satellite of the seven-satellite navigation system was launched in 2013, and the seventh satellite was launched in 2016.
- NVS-01 replaced IRNSS-1G.
- NVS-02 is also a replacement satellite for one of the satellites in NavIC.
- NavIC provides positioning, navigation, and timing services to users across India and the region extending up to 1,500 km around the country, with position accuracy of better than 20 meters, and timing accuracy of better than 50 nanoseconds.
- Developed by: Indian Space Research Organisation (ISRO).
NavIC offers two types of services
- Standard Positioning Service: Available to all users and provides positioning accuracy of around 20 meters throughout the Indian region and within the primary service area.
- Restricted Service: Encrypted service primarily intended for authorised users such as the military, government agencies, and other security-sensitive applications.
Key objectives of NavIC system will be to aid:
- Precision military activity
- Strategic applications
- Terrestrial, aerial, and maritime navigation
- Precision agriculture
- Geodetic surveying
- Emergency services
- Fleet management
- Location-based services in mobile devices
- Orbit determination for satellites
- Marine fisheries
- Timing services for financial institutions, power grids, and other government agencies
- Internet-of-Things (IoT) based applications.
Satellite navigation systems of other countries:
- Presently, there are four global satellite-based navigation systems.
- United States: Global Position System (GPS)
- Russia: Global Navigation Satellite System (GLONASS)
- China: BeiDou
- European Union: Galileo
- Japan has a four-satellite regional navigation system (Quasi-Zenith Satellite System).
Why NavIC over global competitors?
- NavIC is an independent regional system over the Indian region and does not depend on other systems for providing a position service within the service region.
- GPS and GLONASS are operated by the defence agencies of the US and Russia, respectively.
- There is a possibility that civilian service can be degraded or denied at any given time. E.g., during the 1999 Kargil War, the Indian government requested the US to provide enemy locations, but this request was denied.
- Enhances India's military capabilities by providing accurate real-time navigation data for defence applications like weapon guidance, fleet management and location-based services, reinforces national security and safeguards territorial integrity.
- NavIC signals come to India at a 90-degree angle, making it easier for them to reach devices located even in hard-to-reach areas like congested areas, dense forests, or mountains. In contrast to this, the GPS signals (satellites placed in Medium Earth Orbit) are received over India at lower angles.