Tsyklon-4
| Function | Carrier rocket |
|---|---|
| Manufacturer | |
| Country of origin | Ukraine |
| Size | |
| Height | 39.95 m (131.1 ft) |
| Diameter | 3.0 m (9.8 ft) |
| Mass | 198,250 kg (437,070 lb) |
| Stages | 3 |
| Capacity | |
| Payload to {{{to}}} | |
| Associated rockets | |
| Family | R-36 / Tsyklon |
| Comparable | Zenit |
| Launch history | |
| Status | Cancelled |
| Launch sites | Alcântara ACS Pad |
| First stage – 11K69 | |
| Powered by | 1 × RD-261 + RD-855 Vernier engine |
| Maximum thrust | 2,970 kN (303 tf) |
| Specific impulse | 300.4 s (2.946 km/s) |
| Burn time | 119 seconds |
| Propellant | N2O4 / UDMH |
| Second stage – 11S692 | |
| Powered by | 1 × RD-262 + RD-856 Vernier engine |
| Maximum thrust | 995 kN (101.5 tf) |
| Specific impulse | 314 s (3.08 km/s) |
| Burn time | 162 seconds |
| Propellant | N2O4 / UDMH |
| Third stage | |
| Powered by | 1 × RD-861K |
| Maximum thrust | 76 kN (7.8 tf) |
| Specific impulse | 325 s (3.19 km/s) |
| Burn time | 450 seconds |
| Propellant | N2O4 / UDMH |
The Tsyklon-4, also known as Tsiklon-4 and Cyclone-4, was a Ukrainian carrier rocket which was being developed for commercial satellite launches. Derived from the Tsyklon-3, it had a new third stage, a larger payload fairing, and a modernised flight control system compared to its predecessor. The control system had been developed by JSC Khartron.