← Resources · August 03, 2026
Science & Technology GS3 4 min read

2 strategic satellites sit at spaceport as govt nod eludes Isro

What happened
01

Two ISRO satellites, NVS-03 and GISAT-1A, are reported to be ready at the launch site, but their missions are on hold pending formal government/institutional clearance to resume launches.

02

The hold follows two recent PSLV mission setbacks in quick succession: PSLV-C61 (carrying the EOS-09/RISAT-1B earth observation satellite) failed in May 2025, and PSLV-C62 failed in January 2026, prompting a broader pause and review of the launch schedule.

03

NVS-03 is a navigation satellite meant to sustain and expand India's NavIC regional positioning system; GISAT-1A is a geostationary earth-observation satellite intended for continuous imaging of the Indian subcontinent, including near-real-time disaster and hazard monitoring.

04

The delay illustrates how a launch vehicle failure triggers an organisation-wide clearance process before any further missions — irrespective of vehicle type — since root-cause and corrective-action sign-off is required before flight resumption.

05

This comes against the backdrop of ISRO's steadily expanding launch cadence in recent years, making back-to-back vehicle failures and the resulting institutional pause a notable disruption to the schedule.

Navigation vs earth-observation satellites: NVS/NavIC series vs EOS/GISAT series India runs two functionally distinct satellite families relevant here. The NavIC (Navigation with Indian Constellation) system — India's own regional satellite navigation system, akin to GPS — is being sustained by the second-generation NVS series (NVS-01 onward), which carry indigenous atomic clocks and are designed to deliver position accuracy better than 20 metres and timing accuracy better than 50 nanoseconds over India and a surrounding region extending about 1,500 km beyond its borders. GISAT/EOS satellites, by contrast, are earth-observation satellites: GISAT-1A (also catalogued as EOS-05) sits in geostationary orbit for continuous, near-real-time imaging of the subcontinent — used for disaster monitoring, agriculture, and border surveillance — unlike India's other EOS/RISAT low-earth-orbit satellites, which pass over a location periodically rather than continuously. UPSC often tests this navigation-versus-observation distinction, along with which orbit (MEO/geosynchronous for NavIC, geostationary for GISAT, sun-synchronous LEO for most other EOS/RISAT satellites) each series uses.

Launch vehicle families: PSLV, GSLV, and LVM3 ISRO operates three main launch vehicle families with different payload capacities and roles. The Polar Satellite Launch Vehicle (PSLV) is the workhorse four-stage vehicle mainly used for sun-synchronous and polar orbit missions (earth observation, and historically interplanetary missions like Chandrayaan-1 and Mangalyaan). The Geosynchronous Satellite Launch Vehicle (GSLV), using an indigenous cryogenic upper stage, is used for heavier payloads to geosynchronous transfer orbit, including NavIC/NVS satellites. The Launch Vehicle Mark-3 (LVM3, formerly GSLV Mk III) is ISRO's heaviest-lift vehicle, used for the heaviest communication satellites and crewed/Gaganyaan-related missions. A failure on one vehicle family (PSLV, in this case) does not automatically ground the others technically, but institutional launch-clearance reviews and range/safety sign-offs at the same spaceport can still affect the overall schedule.

Governance: Department of Space and the Space Commission India's space programme is governed by a two-tier structure set up in 1972: the Department of Space (DOS), a central government department reporting directly to the Prime Minister, and the Space Commission, an inter-ministerial apex body that formulates space policy and budgets. ISRO functions as the executing/implementing arm under the Department of Space, carrying out programmes as directed by the Space Commission and DOS; the ISRO Chairman also serves concurrently as Secretary, DOS, and as Chairman of the Space Commission. Government "clearance" for resuming launches after a failure typically flows through this DOS/Space Commission oversight structure, following review by an ISRO Failure Analysis Committee that investigates the anomaly and certifies corrective measures before certifying the vehicle fit for re-flight.

Recent PSLV mission history PSLV has flown over 60 missions since its 1993 debut and is regarded as ISRO's most reliable vehicle, but two failures within roughly eight months (PSLV-C61 in May 2025 carrying EOS-09, and PSLV-C62 in January 2026) mark an unusual reliability dip for a vehicle with a historically strong track record, and this is the direct proximate cause of the current launch pause referenced here. [Unverified: exact technical cause of the PSLV-C62 failure]

Key facts & data
  • NVS-03: navigation satellite for the NavIC constellation; NavIC targets position accuracy better than 20 m and timing accuracy better than 50 nanoseconds.
  • GISAT-1A / EOS-05: geostationary earth-observation satellite for continuous imaging of the Indian subcontinent (disaster/hazard monitoring).
  • Two recent PSLV failures cited: PSLV-C61 (May 2025, carrying EOS-09/RISAT-1B) and PSLV-C62 (January 2026).
  • ISRO's three launch vehicle families: PSLV (polar/sun-synchronous orbits), GSLV (geosynchronous transfer orbit, indigenous cryogenic stage), LVM3 (heaviest payloads, crewed missions).
  • India's space governance: Department of Space and the Space Commission, both established in 1972; ISRO functions as the implementing agency under DOS.
  • ISRO Chairman concurrently holds the posts of Secretary, Department of Space, and Chairman, Space Commission.
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