ISRO’s Space Surveillance Phase-III: 52 Satellites for All-Weather Recon
The Cabinet Committee on Security has accorded final approval for Phase-III of India’s most ambitious military space programme yet — a ₹27,400-crore constellation of 52 high-resolution, all-weather surveillance satellites to be launched between 2027 and 2034. Overseen by the newly empowered Defence Space Agency (DSA) and executed jointly by ISRO, DRDO, and private industry, the constellation will deliver persistent, sub-30 cm resolution imagery and real-time moving-target indication over the entire Indo-Pacific theatre — day or night, cloud or monsoon.
Announced by Defence Minister Rajnath Singh on December 9, 2025, the project marks the operational culmination of India’s journey from a “space-support” nation to a genuine space-power capable of independent battlespace awareness.
Constellation Architecture
| Orbit Layer | No. of Satellites | Key Capability | Primary Sensor |
|---|---|---|---|
| LEO Imaging (480–550 km) | 24 | 0.25 m optical + 0.8 m SAR | Cartosat-3 derivative + indigenous X-band SAR |
| MEO Persistent (8,000–12,000 km) | 12 | 1–2 m resolution, 8–10 min revisit | Multi-mode SAR + hyperspectral |
| GEO Stationary (36,000 km) | 4 | Real-time video + missile launch detection | GSAT-7C class with IR payload |
| LEO Electronic Intelligence (ELINT) | 8 | Radar emitter geolocation | EMISAT-2 derivative |
| LEO Communications Relay | 4 | Anti-jam, 400 Gbps laser links | Indian Data Relay Satellite System |
Total mass at launch: ~68 tonnes across 28 PSLV-XL/GSLV-MkIII and 12 private small-launch missions.
Why Phase-III Was Urgent
China’s Yaogan constellation already exceeds 120 operational satellites, giving Beijing near-real-time coverage of the Indian Ocean. The 2025 Galwan-II crisis exposed India’s dependence on periodic Cartosat passes and foreign commercial imagery. Phase-III eliminates that vulnerability forever.
Key operational advantages:
- Revisit time over LAC/LoC: < 8 minutes (vs current 24–48 hours)
- All-weather penetration: X-band SAR defeats monsoon clouds
- Moving target tracking: GMTI radars cue BrahMos-Ultra and Prachand ALCM strikes
- Blue-water coverage: Continuous tracking of PLAN carrier groups from Hainan to Horn of Africa
Private Sector & Indigenisation
For the first time, private industry will build and own 38 of the 52 satellites under the new iDEX–SPARC model:
- Pixxel (hyperspectral payloads)
- Skyroot & Agnikul (dedicated small launches)
- Ananth Technologies & Centum Electronics (on-board processors)
- Tata Advanced Systems & L&T (satellite buses)
This mirrors the explosive private momentum seen in DRDO’s recent SAMANVAY transfers. How SAMANVAY 2025 is catalysing the space-defence nexus.
Strategic Alignment
The constellation is the crown jewel of the 15-Year Defence Roadmap (ICDP 2025–2040), which explicitly lists “space-based ISR dominance” and “AI-enabled autonomous satellite operations” as non-negotiable goals. Full breakdown of the space pillar in ICDP 2025–2040.
It also dovetails with the Army’s new border deterrence architecture — Ashni drone platoons and Gray Eagle UAVs will receive direct satellite feeds for beyond-line-of-sight targeting. Army’s new LAC arsenal explained.
The four GEO birds will double as missile early-warning platforms, closing the gap until dedicated HAVA satellites come online by 2032.
Timeline & Funding
- First six LEO SAR satellites: 2027–28 (PSLV-XL)
- Full 24-satellite imaging layer: 2031
- Complete 52-satellite constellation IOC: December 2034
- Funding: 62 % MoD, 28 % ISRO, 10 % private risk capital
In conclusion, Phase-III is not just a satellite programme — it is India’s declaration of space as the ultimate high ground. By 2035, no adversary movement from Tibet to the Malacca Strait will escape Indian eyes. The era of fighting with one hand tied behind our back is officially over.
