Eris by Gilmour Space Technologies: status and timeline

Milestones

Next · TestFlight 2 orbital attempt

Bowen becomes Australia's first commercial orbital spaceport5 Mar 2024Complete.
Australian Space Agency grants the Eris launch permitNov 2024Complete.
Aviation regulator CASA approval19 Feb 2025Complete.
TestFlight 1 lifts off, falls back after 14 seconds30 Jul 2025+14 mo~~originally May 2024~~Complete.
Suborbital hypersonic test flightTarget 2026Not yet reached.
TestFlight 2 orbital attemptTarget Q1 2027+12 mo~~originally Q1 2026~~Current milestone.

Most important updates

Upcoming

2026Suborbital hypersonic test flight (next)
Q1 2027TestFlight 2 orbital attempt+12 mo~~originally Q1 2026~~

Current obstacles

First flight failed earlyTestFlight 1 cleared the tower but drifted sideways and fell after 14 s; the investigation is complete but findings are not published.
Long delaysFirst launch slipped about 14 months from May 2024 on technical problems, permits and winds; flight 2 has slipped from early 2026.

Physics limits

Hybrids burn less efficientlyFuel only burns where it meets the oxidiser at the grain surface, so mixing is uneven and efficiency is lower than good liquid engines, costing payload.
Big hybrids are hard to scaleThe burning surface grows slowly, so large hybrids need long or multi-port grains to make enough thrust, which can leave unburnt fuel and shake the motor.

How it works

3 parts

Hybrid

A solid fuel grain and a liquid oxidiser

Liquid oxidiser is sprayed down a hollow solid-fuel core and burns along its walls; cutting the oxidiser flow throttles or stops the motor.

Safer to handle

Fuel and oxidiser kept apart

Fuel and oxidiser are stored apart and in different states, so hybrids are safer to handle than solid motors and simpler than liquid engines.

Three stages

Hybrids below, liquid on top

Four Sirius hybrids lift the first stage, one powers the second, and the liquid Phoenix engine finishes the climb to orbit.

Spec sheet

Spec	Eris
Payload to low orbit	Up to 300 kg^R (reported)
Stages	3^R (reported)
First stage	4 Sirius hybrid motors^R (reported)
Third stage	Phoenix liquid engine^R (reported)
Height	23–25 m (reports differ)^R (reported)
Mass at liftoff	About 30 t^R (reported)
TestFlight 1 flight time	14 s^R (reported)

^R reported by the company

Update log

2 updates

Thu 26 Mar

Minor: Gilmour targets end of 2026 for Eris TestFlight 2, after a suborbital hypersonic testPressTest

Wed 30 Jul 2025

Major: Gilmour's Eris, the first Australian-built orbital rocket, falls back 14 seconds after liftoffPressTest

About Gilmour Space Technologies

The team behind Eris

Gilmour Space Technologies

Eris rocket, hybrid rocket motors, Bowen spaceport

Queensland company building Eris, the first Australian-designed orbital rocket, and running Australia's first commercial orbital spaceport at Bowen. Founded by brothers Adam and James Gilmour.

Eris made Australia's first orbital launch attempt in over 50 years on 30 July 2025; it fell after 14 seconds.
Uses hybrid rocket motors (solid fuel, liquid oxidiser) on its first two stages.
Next orbital attempt, TestFlight 2, targeted for end 2026 to early 2027.

gspace.com (opens gspace.com)Company profile →

Headquarters: Australia
Status: Private
Valuation: private
Works in: SpaceflightSmall rockets
Coverage: 1 program · 2 updateslatest 26 Mar 2026checked 11 Oct
Partners: Australian Space Agency
Investors: Blackbird VenturesMain Sequence Ventures
People: Adam GilmourCEO and co-founderJames GilmourCo-founder