Eris is a three-stage, hybrid-propulsion small orbital launch vehicle built by Australia's Gilmour Space Technologies, designed to loft small satellites from the Bowen Orbital Spaceport in Queensland.
Eris
Eris is a three-stage, hybrid-propulsion small orbital launch vehicle built by Australia's Gilmour Space Technologies, designed to loft small satellites from the Bowen Orbital Spaceport in Queensland.
Description
Eris is Gilmour Space Technologies' orbital-class small launch vehicle and Australia's first domestically designed and built rocket to attempt orbit. It is a three-stage vehicle standing roughly 23-25 meters tall with a first-stage diameter of 2 meters and a liftoff mass of about 30 tonnes. Its defining feature is Gilmour's proprietary hybrid propulsion technology: four Sirius hybrid rocket motors power the first stage, a single Sirius hybrid motor powers the second stage, and a Phoenix liquid rocket engine powers the third stage. The initial Eris Block 1 variant targets small satellite and rideshare customers, with a payload capacity of approximately 215 kg to a 500 km Sun-synchronous orbit or up to about 305 kg to a low-inclination LEO. Eris launches from the Bowen Orbital Spaceport at Abbot Point in North Queensland, Australia's first licensed orbital launch facility. The rocket's maiden flight, TestFlight 1, lifted off on 30 July 2025 but ended in failure approximately 14 seconds after liftoff when the vehicle lost control, attributed to insufficient/asymmetric first-stage thrust. Gilmour is applying lessons learned toward TestFlight 2, planned for the second half of 2026.
Specifications
| Stages | 3 (Block 1) |
|---|---|
| Height | ~23-25 m |
| First stage diameter | 2 m (tapers to 1.5 m at interstage) |
| Liftoff mass | ~30 tonnes |
| Propulsion | Hybrid: 4x Sirius motors (Stage 1), 1x Sirius motor (Stage 2), Phoenix liquid engine (Stage 3) |
| Payload to SSO (500 km) | ~215 kg (Block 1) |
| Payload to LEO/equatorial | ~300-305 kg (Block 1) |
| Launch site | Bowen Orbital Spaceport, Abbot Point, Queensland, Australia |
| Future variant Eris Block 2 | ~1,000 kg to LEO (planned) |
| Flight heritage | 1 launch attempt as of mid-2026: TestFlight 1 (30 July 2025) failed ~14 seconds after liftoff due to first-stage thrust malfunction; TestFlight 2 targeted for late (Q4) 2026 |