Navigation sat NVS-03 ready for launch, 3 more satellites to follow: Space min Jitendra Singh in LS
The Minister of State for the Department of Space informed the Lok Sabha that the NVS-03 navigation satellite is ready for launch, with two more satellites, NVS-04 and NVS-05, to follow at subsequent intervals.
The update was provided in response to a question in Parliament on the status of India's indigenous satellite navigation system, NavIC (Navigation with Indian Constellation), also known as IRNSS (Indian Regional Navigation Satellite System).
The launches are aimed at replenishing the NavIC constellation, which has been operating with a reduced number of functional satellites after one of the constellation's newer satellites, NVS-02, failed to reach its intended orbit due to a propulsion-related fault.
The government reiterated that the three upcoming satellites (NVS-03, NVS-04, NVS-05) are intended to restore full positioning, navigation and timing (PNT) capability to the system.
NavIC / IRNSS — India's regional satellite navigation system
NavIC (Navigation with Indian Constellation), earlier called IRNSS (Indian Regional Navigation Satellite System), is India's indigenous regional satellite navigation system developed by ISRO to provide accurate positioning and timing services over India and a surrounding region extending about 1,500 km beyond its borders. It functions as India's alternative to the US GPS, Russia's GLONASS, the EU's Galileo, and China's BeiDou, but is regional rather than global in coverage.
Key Details
- NavIC's original constellation consisted of seven satellites (IRNSS-1A to 1G), a mix of geostationary (GEO) and geosynchronous (GSO) orbits.
- The system offers two services: Standard Positioning Service (SPS), for civilian use, and Restricted Service (RS), an encrypted service for authorized (including strategic/military) users.
- A minimum of four operational satellites in view is required for the system to independently calculate a user's position (latitude, longitude, altitude) and time; with fewer, only degraded or timing-only service is possible.
NVS-03's readiness for launch is significant because NavIC's operational satellite count had fallen close to or below this four-satellite threshold after earlier satellites aged out or, as with NVS-02, failed to reach operational orbit — directly affecting the system's ability to provide standalone positioning.
NVS series — second-generation NavIC satellites
The NVS series (NVS-01 onward) constitutes the second-generation of NavIC satellites, designed to replace and upgrade the original first-generation IRNSS satellites. They carry indigenously developed atomic clocks and an expanded signal set, including the civilian L1 band (matching the GPS L1 frequency) in addition to the earlier L5 and S-band signals, improving compatibility with common consumer devices such as smartphones.
Key Details
- NVS-01, launched in May 2023, was the first satellite of this second-generation series and carries an indigenous rubidium atomic clock, reducing dependence on imported clock technology.
- NVS-02, launched in January 2025 aboard a GSLV rocket, failed to reach its final orbit after a valve malfunction prevented its onboard engine from firing for orbit-raising.
- NVS-03 (also designated IRNSS-1L) is intended to be launched aboard the GSLV Mk II rocket, ISRO's operational launch vehicle for geosynchronous missions using an indigenous cryogenic upper stage.
NVS-03's launch is a direct replacement/replenishment move following the NVS-02 setback, continuing the second-generation NVS satellite series that adds the L1 civilian band to broaden NavIC's usability in ordinary consumer devices.
GSLV — Geosynchronous Satellite Launch Vehicle
GSLV (Geosynchronous Satellite Launch Vehicle) is ISRO's launch vehicle developed for placing satellites into geosynchronous transfer orbit, primarily used for heavier communication and navigation satellites that first-generation PSLV cannot efficiently carry to such orbits.
Key Details
- GSLV Mk II is a three-stage vehicle using an indigenously developed Cryogenic Upper Stage (CUS), making it the most powerful GSLV variant currently operational (distinct from the larger GSLV Mk III/LVM3 used for heavier payloads).
- NavIC/IRNSS satellites have been launched using both PSLV (for earlier, lighter satellites) and GSLV (for some second-generation NVS satellites).
NVS-03 is slated to fly on a GSLV variant, consistent with the pattern of using GSLV for the heavier second-generation NVS satellites carrying atomic clocks and expanded payload instrumentation.
- NVS-03, NVS-04, and NVS-05 are the next three satellites planned to replenish the NavIC constellation, to be launched over an extended timeline (reportedly spread across roughly the next one to one-and-a-half years).
- Minimum satellites required for standalone NavIC positioning service: 4 in view.
- NVS-01 (2023) carries India's indigenous rubidium atomic clock and added the civilian L1 signal band.
- NVS-02 (launched January 2025) failed to reach its designated orbit due to a valve/propulsion fault, prompting the need for NVS-03 as replenishment.
- NavIC's original operational area extends approximately 1,500 km beyond India's borders.