Epsilon (rocket)
 Epsilon flight F2 before launch in December 2016 | |
| Function | Launch vehicle |
|---|---|
| Manufacturer | IHI Corporation |
| Country of origin | Japan |
| Cost per launch | US$39 million |
| Size | |
| Height | 24.4 m (E-X) 26 m (Enhanced) 26.8 m (Epsilon S Block1) 27.2 m (Epsilon S) |
| Diameter | 2.5 m |
| Mass | 91 t (E-X) 95.4 t (Enhanced) ~100 t (Epsilon S) |
| Stages | 3–4 |
| Capacity | |
| Payload to LEO (Epsilon 3 stage) | |
| Altitude | 250 km × 500 km (160 mi × 310 mi) |
| Mass | 1,500 kg (3,300 lb) |
| Payload to LEO (Epsilon 4 stage) | |
| Altitude | 500 km (310 mi) |
| Mass | 700 kg (1,500 lb) |
| Payload to SSO (Epsilon 4 stage) | |
| Altitude | 500 km (310 mi) |
| Mass | 590 kg (1,300 lb) |
| Payload to LEO (Epsilon S) | |
| Altitude | 500 km (310 mi) |
| Mass | 1,400 kg (3,100 lb) |
| Payload to SSO (Epsilon S) | |
| Altitude | 700 km (430 mi) |
| Mass | 600 kg (1,300 lb) |
| Launch history | |
| Status | Active |
| Launch sites | Uchinoura |
| Total launches | 6 |
| Success(es) | 5 |
| Failure | 1 |
| First flight | 14 September 2013 |
| Last flight | 12 October 2022 |
| First stage (E-X/Enhanced) – SRB-A3 | |
| Propellant mass | 65.9 t (145,000 lb) |
| Maximum thrust | 2,271 kN (511,000 lbf) |
| Specific impulse | 284 s (2.79 km/s) |
| Burn time | 116 seconds |
| First stage (Epsilon S) – SRB-3 | |
| Propellant mass | 66.8 t (147,000 lb) |
| Maximum thrust | 2,158 kN (485,000 lbf) |
| Specific impulse | 283.6 s (2.781 km/s) |
| Burn time | 105 seconds |
| Second stage (E-X) – M-34c | |
| Maximum thrust | 371.5 kN (83,500 lbf) |
| Specific impulse | 300 s (2.9 km/s) |
| Burn time | 105 seconds |
| Second stage (Enhanced/Epsilon S Block 1) – M-35 | |
| Maximum thrust | 445 kN (100,000 lbf) |
| Specific impulse | 295 s (2.89 km/s) |
| Burn time | 129 seconds |
| Second stage (Epsilon S) – E-21 | |
| Maximum thrust | 610 kN (140,000 lbf) |
| Specific impulse | 294.5 s (2.888 km/s) |
| Burn time | 120 seconds |
| Third stage (E-X) – KM-V2b | |
| Maximum thrust | 99.8 kN (22,400 lbf) |
| Specific impulse | 301 s (2.95 km/s) |
| Burn time | 90 seconds |
| Third stage (Enhanced) – KM-V2c | |
| Propellant mass | 2.5 t (5,500 lb) |
| Maximum thrust | 99.6 kN (22,400 lbf) |
| Specific impulse | 299 s (2.93 km/s) |
| Burn time | 91 seconds |
| Third stage (Epsilon S) – E-31 | |
| Propellant mass | 5 t (11,000 lb) |
| Maximum thrust | 135 kN (30,000 lbf) |
| Specific impulse | ~295 s (2.89 km/s) |
| Burn time | 108 seconds |
| Fourth stage (Optional) – PBS | |
| Maximum thrust | 40.8 N (9.2 lbf) |
| Specific impulse | 215 s (2.11 km/s) |
| Burn time | 1,100 seconds (maximum) |
| Propellant | Hydrazine |
The Epsilon Launch Vehicle, or Epsilon rocket (イプシロンロケット, Ipushiron roketto) (formerly Advanced Solid Rocket), is a Japanese solid-fuel rocket designed to launch scientific satellites. It is a follow-on project to the larger and more expensive M-V rocket which was retired in 2006. The Japan Aerospace Exploration Agency (JAXA) began developing the Epsilon in 2007. It is capable of placing a 590 kg payload into Sun-synchronous orbit.