The Indian Space Research Organisation (ISRO) has transformed India into a global space powerhouse, leveraging innovative rocket launchers like the Polar Satellite Launch Vehicle (PSLV) to achieve remarkable feats. From launching satellites into polar orbits to enabling interplanetary missions, ISRO’s launch vehicles have been instrumental in India’s space narrative.
This article delves deep into ISRO’s rocket launchers and PSLV missions, exploring key aspects such as the top 5 ISRO rocket launchers, the total number of PSLV launches by India, the stages in PSLV, the latest PSLV mission, the full ISRO rockets list, and India’s remarkable space achievements. We’ll explain PSLV, GSLV, and SSLV in detail, cover mission data, recent updates as of October 2025, and highlight India’s stellar accomplishments. With over 100 successful launches and cost-effective innovations, ISRO continues to inspire the world.
ISRO’s Top 5 Rocket Launchers: Powering India’s Celestial Ambitions
ISRO’s rocket launchers represent decades of indigenous engineering, evolving from basic sounding rockets to sophisticated orbital vehicles. Ranking the top 5 based on operational success, payload capacity, and historical impact, here’s a curated list:
- Polar Satellite Launch Vehicle (PSLV): The workhorse of ISRO, PSLV has conducted over 60 missions, excelling in sun-synchronous polar orbits (SSO) for Earth observation satellites. Its reliability—boasting a 93% success rate—makes it indispensable for commercial launches.
- Geosynchronous Satellite Launch Vehicle Mark III (LVM3/GSLV Mk III): India’s heaviest lifter, capable of deploying 4-tonne class satellites to Geosynchronous Transfer Orbit (GTO). It powered the Chandrayaan-3 lunar mission, showcasing cryogenic engine prowess.
- Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II): A medium-lift vehicle for GTO insertions, using indigenous cryogenic stages. It has launched key navigation satellites like those in the NavIC constellation.
- Small Satellite Launch Vehicle (SSLV): Designed for the burgeoning small satellite market, SSLV offers quick-turnaround launches for payloads up to 500 kg in low Earth orbit (LEO). Its development marks ISRO’s push toward privatization.
- Augmented Satellite Launch Vehicle (ASLV): Though retired, ASLV was pivotal in the 1990s, proving strap-on booster technology that influenced PSLV. It achieved India’s first successful orbital launch in 1994.
These launchers highlight ISRO’s progression from experimental to operational excellence, with PSLV and GSLV variants dominating current activities.
Understanding PSLV: The Reliable Backbone of ISRO’s Launch Fleet
The Polar Satellite Launch Vehicle (PSLV) is ISRO’s flagship launcher, first flown in 1993. Designed primarily for injecting satellites into sun-synchronous polar orbits at altitudes of 600-900 km, PSLV has versatility extending to LEO, GTO, and even interplanetary trajectories. Standing 44 meters tall with a lift-off mass of 320 tonnes (in XL configuration), PSLV uses alternating solid and liquid propulsion stages for optimal performance.
PSLV’s modular design allows variants like PSLV-XL (with extra strap-ons for heavier payloads) and PSLV-DL (dual strap-ons). It has launched over 300 foreign satellites from 30+ countries, generating significant revenue for NewSpace India Limited (NSIL), ISRO’s commercial arm. Key features include:
- Payload Capacity: Up to 1,750 kg to SSO.
- Propulsion: Four stages with six strap-on boosters.
- Accuracy: Precision orbit insertion with a CEP (Circular Error Probable) of under 10 meters.
PSLV’s cost-effectiveness—around $25 million per launch—has made it a go-to for global small satellite operators, underscoring India’s “frugal engineering” ethos.
How Many PSLV Launched by India? A Milestone Tally
As of October 8, 2025, ISRO has conducted 63 PSLV launches since its debut in September 1993. This impressive tally includes 58 fully successful missions, three outright failures, and two partial successes, yielding a 95% reliability rate. The PSLV program has evolved through configurations, with the XL variant dominating recent flights.
Breaking it down:
- 1993-2000: Initial developmental flights (PSLV-D1 to D5), focusing on technology validation.
- 2001-2010: Operational phase with 15 launches, including the record-breaking PSLV-C37 in 2017 (wait, that’s later—actually, early ops built confidence).
- 2011-2020: Peak activity with 25 launches, including multi-satellite rideshares.
- 2021-2025: 18 launches, emphasizing commercial and scientific payloads.
Each launch has deployed dozens of satellites, totaling over 350 foreign payloads. This volume cements PSLV’s status as one of the world’s most flown launchers, rivaling SpaceX’s Falcon 9 in reliability for medium-lift class.
How Many Stages Are There in PSLV? A Layered Ascent to Orbit
The PSLV employs a four-stage architecture, alternating solid and liquid propellants for efficient thrust and control. This design balances simplicity (solid stages for high thrust) with precision (liquid stages for throttling).
- First Stage (PS1): A solid-fueled core motor with 139 tonnes of HTPB-based propellant, augmented by six liquid strap-on boosters (using semi-cryogenic Vikas engines). It generates 4,800 kN thrust, lifting the vehicle to 70 km altitude.
- Second Stage (PS2): Liquid-fueled with 41 tonnes of UDMH/ N2O4, powered by a Vikas engine (800 kN thrust). Heat shield separation occurs here.
- Third Stage (PS3): Solid-fueled (25 tonnes HTBP propellant), delivering 240 kN thrust for mid-ascent acceleration.
- Fourth Stage (PS4): Liquid-fueled (7.5 tonnes UDMH/N2O4), with twin engines (7.3 kN each) for fine orbit adjustments. PS4 can serve as an orbital platform for experiments.
This staged progression ensures payload protection and velocity buildup to 7.8 km/s for LEO insertion. The alternating fuels minimize vibrations and enhance restartability.
Which Is the Latest PSLV Launched by India? The PSLV-C61 Mission
India’s most recent PSLV mission, PSLV-C61/EOS-09, lifted off on May 18, 2025, from Sriharikota’s Satish Dhawan Space Centre. Carrying the 1,696 kg Earth Observation Satellite-09 (EOS-09, aka RISAT-1B), a synthetic aperture radar (SAR) for all-weather imaging, the mission aimed for a 570 km SSO.
Tragically, it marked a rare setback: Six minutes into flight, a second-stage anomaly caused loss of control, resulting in failure to reach orbit. ISRO’s failure analysis, completed by August 2025, pinpointed a valve malfunction in the Vikas engine, leading to premature shutdown. Chairman V. Narayanan assured corrective measures for future flights, emphasizing ISRO’s resilience—prior to this, PSLV enjoyed a 10-mission success streak.
Despite the hiccup, PSLV-C61 highlighted ISRO’s rapid recovery ethos, with the satellite’s data relay tech intended for disaster management and agriculture monitoring.
ISRO Rockets List: From Sounding Rockets to Next-Gen Launchers
ISRO’s rocket portfolio spans developmental to operational vehicles. Here’s a comprehensive ISRO rockets list:
| Rocket Name | Type | Status | Key Specs | Notable Missions |
|---|---|---|---|---|
| SLV (Satellite Launch Vehicle) | Small-lift, solid | Retired (1979-1983) | 17m height, 300 kg to LEO | Rohini Satellite (1980) – India’s first orbital success |
| ASLV (Augmented SLV) | Small-lift, solid | Retired (1987-1994) | 23m height, 150 kg to LEO | SROSS-C (1994) – Tech demonstrator |
| PSLV | Medium-lift, hybrid | Operational | 44m height, 1,750 kg SSO | 63 launches; Aditya-L1 (2023) |
| GSLV Mk II | Medium-lift, cryogenic | Operational | 49m height, 2,500 kg GTO | INSAT-3DS (2024); NavIC series |
| GSLV Mk III (LVM3) | Heavy-lift, cryogenic | Operational | 43m height, 4,000 kg GTO | Chandrayaan-3 (2023); GSAT-29 (2018) |
| SSLV | Small-lift, solid | Developmental/Operational | 34m height, 500 kg LEO | SSLV-D3/EOS-08 (2024) – Three successful demos |
| RLV-TD (Reusable Launch Vehicle) | Experimental, winged | Testing | Hypersonic tech | HEX (2016) – Scramjet test |
This list evolves with ISRO’s Next-Generation Launch Vehicle (NGLV) in planning for 10-tonne GTO capacity by 2030.
GSLV and SSLV Explained: Complementing PSLV’s Dominance
While PSLV excels in polar orbits, GSLV and SSLV fill critical niches.
GSLV (Geosynchronous Satellite Launch Vehicle): Developed to reduce reliance on foreign launches for heavy communication satellites, GSLV uses a cryogenic upper stage (CUS) for high-energy GTO insertions. Mk II employs a Russian-sourced CUS, while Mk III (LVM3) features fully indigenous cryogenic engines (CE-20). Recent missions include GSLV-F15/NVS-02 (Jan 29, 2025), deploying a navigation satellite for NavIC enhancement, and GSLV-F16/NISAR (July 30, 2025), a joint NASA-ISRO radar mission for Earth science.
SSLV (Small Satellite Launch Vehicle): Aimed at the $8 billion smallsat market, SSLV offers 72-hour turnaround with three solid stages and a liquid upper stage. Payload: 300 kg to 500 km SSO. The third demo (SSLV-D3/EOS-08, Aug 16, 2024) succeeded, carrying a 140 kg imaging satellite. As of 2025, privatization bids are underway, with Skyroot and Agnikul as frontrunners.
These vehicles diversify ISRO’s portfolio, with GSLV handling 2-4 tonne classes and SSLV targeting rideshares.
Mission Data: Key PSLV, GSLV, and SSLV Highlights
ISRO’s missions blend science, commerce, and defense. Here’s mission data for select flights:
| Mission | Launcher | Date | Payloads | Orbit | Outcome |
|---|---|---|---|---|---|
| PSLV-C59/Proba-3 | PSLV | Dec 5, 2024 | ESA’s Proba-3 (formation flying) + 6 Indian/foreign sats | 600 km SSO | Success; Tech demo for solar coronagraphy |
| PSLV-C60/SPADEX | PSLV | Dec 30, 2024 | SPADEX docking experiment (2 sats, 200 kg each) | 450-500 km LEO | Partial success; Docking achieved but orbit decay |
| GSLV-F15/NVS-02 | GSLV Mk II | Jan 29, 2025 | NVS-02 (NavIC sat, 2,300 kg) | GTO | Success; Boosted regional GPS coverage |
| PSLV-C61/EOS-09 | PSLV-XL | May 18, 2025 | EOS-09 (RISAT-1B, SAR sat) | 570 km SSO | Failure; Stage-2 anomaly |
| GSLV-F16/NISAR | GSLV Mk II | Jul 30, 2025 | NISAR (NASA-ISRO, 2,800 kg dual-band radar) | 747 km polar | Success; 12-year Earth observation mission |
| SSLV-D3/EOS-08 | SSLV | Aug 16, 2024 | EOS-08 (imaging sat) + POEM-3 experiments | 450 km SSO | Success; Orbital deployment accurate |
These missions demonstrate ISRO’s multi-payload strategy, with PSLV often carrying 10+ satellites per flight.
Recent Updates: ISRO’s 2025 Trajectory and Beyond
As of October 2025, ISRO’s cadence reflects strategic shifts: Only three launches year-to-date (two GSLV, one PSLV), prioritizing quality over quantity amid private sector growth. Key updates:
- Post-PSLV-C61 Recovery: Analysis revealed a cryogenic valve issue; fixes implemented for PSLV-C62 (Q4 2025, TBD payload).
- GSLV-F17 Prep: Slated for late 2025, carrying CMS-02 communication satellite.
- SSLV Commercialization: Bidding closed February 2025; first private SSLV flight expected 2026.
- Nine Missions by March 2026: Including LVM3-M5/CMS-02 and Gaganyaan test flights.
- NISAR Milestone: Launched July 30, 2025, it’s the first dual-frequency radar for ecosystem monitoring, a $1.5 billion NASA-ISRO collab.
ISRO’s reduced launches signal ecosystem maturation, with startups like Skyroot achieving suborbital tests.
India Space Achievements: From Aryabhata to Viksit Bharat 2047
India’s space saga, scripted by ISRO, boasts transformative achievements. By 2025, ISRO has executed 101 launches, operating 104 active satellites (18 communication with 354 transponders). Milestones include:
- 1975: Aryabhata – First satellite, proving indigenous tech.
- 2014: Mangalyaan – Mars Orbiter Mission, cheapest interplanetary probe at $74 million.
- 2017: PSLV-C37 – 104 satellites in one launch, world record.
- 2023: Chandrayaan-3 – South Pole lunar landing, unlocking water ice insights.
- 2023: Aditya-L1 – Solar observatory at L1 point, studying coronal mass ejections.
- 2025: NISAR Launch – Joint mission for climate change tracking, enhancing global data sharing.
Gaganyaan human spaceflight nears: Unmanned tests in 2025, crewed by 2026. Budget tripled to â‚ą13,000 crore (2025), fueling 73 Gbps satellite bandwidth. ISRO’s low-cost model—Chandrayaan-3 at $75 million—positions India among top spacefaring nations by 2040, contributing to Viksit Bharat.
National Space Day 2025 celebrated these with robotics challenges and hackathons, engaging 222 teams. Chandrayaan-4 (sample return) and Shukrayaan-1 (Venus orbiter) loom large.
The Future of ISRO Launchers: Innovations on the Horizon
Looking ahead, ISRO eyes reusable tech with RLV expansions and NGLV for heavy-lift. Integration with private firms via IN-SPACe promises 20+ annual launches by 2030. PSLV’s legacy endures, with upgrades for higher payloads.
FAQs
What are ISRO’s top 5 rocket launchers?
ISRO’s top 5 include PSLV (most reliable), LVM3 (heaviest), GSLV Mk II, SSLV (smallsat specialist), and ASLV (historical).
How many PSLV have been launched by India?
As of October 2025, India has launched 63 PSLV missions.
How many stages are there in PSLV?
PSLV has four stages: two solid and two liquid-fueled.
Which is the latest PSLV launched by India?
The latest is PSLV-C61/EOS-09 on May 18, 2025, though it faced a failure.
What is the ISRO rockets list?
Key rockets: SLV, ASLV, PSLV, GSLV Mk II, LVM3, SSLV.
What are India’s top space achievements in 2025?
Achievements include NISAR launch, Gaganyaan progress, and over 100 total missions.
Conclusion
ISRO’s rocket launchers, led by PSLV’s 63 missions, embody India’s innovative spirit. From four-stage precision to global collaborations like NISAR, these vehicles drive achievements that benefit billions. As India aims for lunar bases and Mars returns, ISRO’s journey inspires.