Why this matters now
SSLV is tested for: 3 stages SS1 (87 t) + SS2 (7.7 t) + SS3 (4.5 t) all solid + Velocity Trimming Module (VTM) liquid; length 34 m diameter 2 m mass 120 t; 500 kg LEO 500 km / 300 kg SSO; SSLV-D1 launched 7 Aug 2022 EOS-02 (microsat) + AzaadiSAT (student) — FAILED: terminal velocity error placed satellites in unstable orbit + decayed; SSLV-D2 10 Feb 2023 EOS-07 + Janus-1 + AzaadiSAT-2 — success first injection 450 km orbit; SSLV-D3 16 Aug 2024 EOS-08 + SR-0 — success; Aug 2024 commercial transfer: NSIL signed contract with Hindustan Aeronautics Limited + Larsen & Toubro consortium for SSLV production transfer (Rs 511 crore deal), with HAL leading.
Design highlights
- Modular all-solid first 3 stages + liquid VTM (terminal trim).
- SS1: 2 m diameter, 87 t solid — world’s second-largest solid motor after SLS booster, fired in 1 stage.
- SS2 + SS3: 7.7 t + 4.5 t solid.
- VTM: liquid bi-prop for orbit precision injection.
- Launch from SHAR (later possibly Kulasekarapatnam, TN).
- Cost ~Rs 30-35 crore vs ~Rs 130 cr for PSLV.
- Turnaround: 24 hours (target); 72 hours achieved D2; for commercial small-sat market.
Flight history
| Flight | Date | Outcome |
|---|---|---|
| SSLV-D1 | 7 Aug 2022 | Failure — VTM terminal velocity error; EOS-02 + AzaadiSAT placed in 76×356 km elliptical orbit, decayed. |
| SSLV-D2 | 10 Feb 2023 | Success — injected EOS-07 + Janus-1 + AzaadiSAT-2 into 450 km circular. |
| SSLV-D3 | 16 Aug 2024 | Success — EOS-08 microsat 175.5 kg + SR-0. |
D1 failure attributed to accelerometer saturation during 2nd stage separation, leading to incorrect navigation. Software + redundancy fixed for D2.
Commercial transfer
August 2024: NSIL signed Rs 511 crore Technology Transfer Agreement with consortium Hindustan Aeronautics Limited (HAL, lead) + Larsen & Toubro for SSLV production. First private SSLV expected 2026-27. Goal: meet 100+ small-sat constellation market that PSLV is too large + expensive to serve.
Part of broader privatisation under IN-SPACe + Indian Space Policy 2023.
UPSC angle
Know SSLV (Small Satellite Launch Vehicle) — 500 kg LEO 500 km / 300 kg SSO designed 24-hour turnaround <6 person team ~Rs 30 crore per launch; 3 stages SS1 (87 t) + SS2 (7.7 t) + SS3 (4.5 t) ALL SOLID + VELOCITY TRIMMING MODULE VTM liquid bi-prop; length 34 m diameter 2 m mass 120 t; SS1 world’s 2nd-largest solid motor (after SLS booster); SSLV-D1 LAUNCHED 7 AUG 2022 EOS-02 microsat + AzaadiSAT student — FAILED (terminal velocity error placed in 76x356 km elliptical decayed; accelerometer saturation 2nd stage separation); SSLV-D2 10 FEB 2023 EOS-07 + Janus-1 + AzaadiSAT-2 — SUCCESS first injection 450 km orbit; SSLV-D3 16 AUG 2024 EOS-08 175.5 kg + SR-0 — SUCCESS; AUG 2024 COMMERCIAL TRANSFER NSIL signed Rs 511 CRORE TTA with HINDUSTAN AERONAUTICS LIMITED (HAL lead) + LARSEN & TOUBRO L&T consortium for SSLV production; first private SSLV expected 2026-27; goal meet 100+ small-sat constellation market PSLV too large/expensive; part of IN-SPACe + Indian Space Policy 2023 privatisation; launch from SHAR (later possibly KULASEKARAPATNAM TN).
Frequently asked questions
What is SSLV?
Small Satellite Launch Vehicle — ISRO’s 3-stage solid+liquid launcher for 500 kg payloads to LEO. 34 m tall, 120 t mass, ~Rs 30 crore per launch, designed 24-hour turnaround.
When did SSLV first succeed?
SSLV-D2 on 10 February 2023 — placed EOS-07 + Janus-1 + AzaadiSAT-2 in 450 km circular orbit. D1 (7 Aug 2022) failed due to accelerometer saturation.
Who will produce SSLV commercially?
HAL-L&T consortium (Hindustan Aeronautics Limited as lead + Larsen & Toubro). NSIL signed Rs 511 crore Technology Transfer Agreement in August 2024. First private SSLV expected 2026-27.
Why a small launcher when PSLV exists?
To address the small-satellite constellation market — PSLV is too large + expensive (~Rs 130 cr) for individual small-sat customers. SSLV at ~Rs 30 cr + 24-hour turnaround targets commercial demand.