The Indian government has acknowledged that NavIC (Navigation with Indian Constellation), India’s indigenous satellite navigation system, is currently not fully operational for navigation services after the number of functional positioning satellites dropped below the minimum required. With only three satellites currently providing Position, Navigation and Timing (PNT) services, NavIC cannot deliver its intended navigation capability, which requires at least four operational satellites.
The setback comes after one of NavIC’s key satellites, IRNSS-1F, lost its final working atomic clock after completing its 10-year design life.
Why Does NavIC Need Four Satellites?
Satellite navigation works by calculating a user’s position using signals received from multiple satellites.
While three satellites can theoretically determine a location under ideal conditions, a fourth satellite is required to accurately calculate the difference between the satellite clocks and the receiver’s clock. Without this fourth satellite, the system cannot reliably provide Position, Navigation and Timing (PNT) services.
This is why global navigation systems such as GPS, Galileo and NavIC rely on multiple satellites operating simultaneously.
What Happened To NavIC?
India has launched 11 NavIC satellites over the years.
However, several satellites have either reached the end of their operational life, lost navigation capability or failed to reach their intended orbit. The latest setback occurred when IRNSS-1F, launched in 2016, stopped providing navigation services after its final onboard atomic clock failed.
As a result, only three satellites are currently capable of delivering full navigation services, while five others continue to support only one-way messaging applications.
Where Is NavIC Used?
NavIC is India’s homegrown alternative to GPS and is designed to provide positioning, navigation and timing services across India and regions extending up to 1,500 kilometres beyond its borders.
The system supports applications including:
- Vehicle navigation
- Maritime operations
- Disaster management
- Public transport tracking
- Fishing vessel safety
- Defence and strategic operations
- Time synchronisation for critical infrastructure
It has also been integrated into thousands of commercial vehicles and railway tracking systems.
Government Working On Strengthening NavIC
The government has said that efforts are underway to restore and strengthen the NavIC constellation.
Future plans include completing the full satellite network, deploying additional satellites, expanding user services and increasing the use of indigenous space-grade atomic clocks to reduce dependence on imported technology.
The long-term objective is to ensure a robust and reliable navigation system capable of supporting both civilian and strategic applications.
Why NavIC Matters
An indigenous navigation system is strategically important because it allows India to reduce dependence on foreign satellite navigation networks such as the US GPS, Europe’s Galileo, Russia’s GLONASS and China’s BeiDou.
A fully operational NavIC ensures greater security, uninterrupted navigation services during emergencies and improved support for defence, transportation and critical infrastructure.
Restoring the constellation remains a priority for India’s space programme.
Summary
The government has confirmed that NavIC is currently not fully functional for navigation because only three satellites are providing Position, Navigation and Timing services, whereas at least four are required for accurate positioning. The setback follows the failure of IRNSS-1F’s atomic clock, although the government is working to strengthen the constellation with additional satellites and indigenous technologies.