OVERVIEW: The S‑25O is a large, unguided, air-launched 266 mm rocket featuring a fragmentation warhead and radio-proximity (airburst) fuse. Designed for area suppression and soft-target engagement from tactical aircraft.

DETAILS: Developed in the mid-1970s and entering service around 1975, the S‑25O measures approximately 3.76 m in length, weighs around 370 kg, and utilizes a solid-propellant rocket motor with 94 kg of fuel to reach speeds of 505–555 m/s. The main warhead 420 mm in diameter packs 58 kg of explosives and pre-fragmented casing, producing about 6,500 fragments upon detonation via the RV‑25 radio altimeter fuse at 5–10 m altitude. Effective engagement envelopes range from 1.6 km at low altitude to approximately 3.0 km high-altitude release, at launch speeds up to 1,500 km/h.

The S‑25O offers a heavier payload and airburst capability compared to smaller rockets like the S‑13 and S‑24, making it effective in runway disabling, troop concentration, and light fortification suppression roles.

Launched singly from O‑25 rocket pods under combat aircraft, the tail fins deploy post-launch, and the fuse arms before detonation. Proximity airburst enhances area coverage and anti-personnel effectiveness, especially over open or soft targets.

NOTE:
IOC: ~1975
Operators: Soviet Union/Russia, Ukraine
Platforms: Su‑25, Su‑25T/TM, Su‑27, Su‑34, Su‑35 
Conflict used in: Soviet–Afghan War, Russo‑Ukrainian War (2022–present) 

SOURCE:
Weaponsystems.net: https://weaponsystems.net/system/734-S-25 ; Wikipedia “S‑25 (rocket)”: https://en.wikipedia.org/wiki/S-25_%28rocket%29 ; Fenix Insight (S‑25‑O): https://fenixinsight.com/m/2134