IHI Aerospace / JAXA · Japan · First flight 2024
Japan's upgraded solid-fuel small satellite launcher, enhanced from the Epsilon series. Shares the SRB-3 booster with H3. Development delayed by a third-stage static fire test failure in 2023.
From SpaceNexus's launch tracker (tracked since Dec 31, 2026); outcomes recorded as each flight lands. Career totals above are the vehicle's full history.
| Height | 27.5 m |
| Diameter | 2.6 m |
| Liftoff mass | 96,000 kg |
| Stages | 3 |
| Engines | SRB-3 + M-35 + KM-V2c |
| Propellant | Solid (HTPB composite) |
| Fairing diameter | 2.6 m |
| Payload to LEO | 1,500 kg |
| Payload to GTO | — |
| Payload to SSO | 600 kg |
| Payload to TLI | — |
| Reusable | No |
| First flight | 2024 (engine test failure, delayed) |
| Last flight | — |
| Variants seen on the manifest | Epsilon S |
A dedicated Epsilon S launch lists at roughly $30 million, about $20,000 per kilogram to low Earth orbit at full payload. Actual contract prices vary with orbit, integration and government requirements.
The next tracked Epsilon S launch is JV-LOTUSat-1 on Dec 31, 2026, 00:00 UTC from Uchinoura Space Center, Japan. Dates move; Mission Control carries the live countdown.
Epsilon S has flown 0 times with 0 successes, 0 failures and 0 partial failures — a 0% success rate.
1,500 kg to low Earth orbit, 600 kg to sun-synchronous orbit.