Gilmour Space finds oxidizer pump faults behind Eris rocket’s 14-second flight

Gilmour Space Technologies says two independent failure modes in the oxidizer pump system, which feeds the engines the oxidizer that lets their fuel burn, ended the first flight of its Eris rocket in July 2025. The company’s investigation update, released April 24, 2026, lists a second test flight as not before late 2026 or early 2027.

What the investigation found about the 14-second flight

Eris TestFlight1 lifted off from the Bowen Orbital Spaceport in north Queensland on July 30, 2025, local time. The company says the vehicle suffered an in-flight anomaly and was lost within the designated safety area. Gilmour Space, based on the Gold Coast, described the launch as the first by an Australian-made orbital rocket from Australian soil. In its words: “Today, Eris became the first Australian made orbital launch vehicle to lift off from Australian soil.” That statement was reported by ABC News.

The flight lasted 14 seconds. According to Gilmour Space’s investigation, about nine seconds after ignition one of the four first-stage hybrid rocket motors, which burn solid fuel with a liquid oxidizer, lost thrust. A second motor showed similar behavior at roughly 17 seconds. Together the two losses reduced performance and ended the flight early.

The company traced both events to the oxidizer pump subsystem, saying analysis “identified two independent failure modes originating from the oxidiser pump subsystem.” It reports electrical and thermal faults in the electric pump motors and their inverters, the electronics that power them, including components from an external supplier. It has not named the supplier or described the faults in more detail.

Two motors, two failure modes

The finding matters because the faults were separate. Had one design flaw caused both thrust losses, a single fix would have been the obvious remedy. Two independent modes in the same subsystem point to a broader need to requalify the pump, its motors and the electronics that drive them.

Gilmour Space says it is evaluating and implementing design, qualification and process improvements. It has not published what those changes are, or whether components from the external supplier will be replaced. The company has submitted a final report to the Australian Space Agency, coordinated with the Office of the Space Regulator. The report itself is not public, so the conclusions above are the company’s own and have not been independently reviewed.

The investigation also adds detail to the first-day account. The company said then that ignition, liftoff, first-stage thrust, range tracking and telemetry had performed well until the anomaly.

How the flight compared with what the company expected

The flight’s outcome was short but not empty. All four first-stage motors lit and the vehicle left the pad, which the company’s co-founder described in plain terms: “Got off the pad, I am happy.” ABC News also reported that the burn totaled 23 seconds of engine operation across the motors. That fits the investigation’s account: the motors did not all burn for the full 14 seconds, and the flight ended after the second thrust loss.

The central uncertainty is whether the pump fixes will hold across a full first-stage burn. TestFlight1 never reached stage separation or upper-stage flight, so those parts of the vehicle remain unflown. The investigation addresses what went wrong in the first 17 seconds, not how Eris will behave later in an ascent.

Government backing was in place before the launch. ABC reported A$5 million for the Eris launch vehicle, announced the week before, alongside wider support from the Australian government for the Bowen project. The report did not give a total for that wider support.

The second Eris flight is not firmly dated

Immediately after the flight, the company said it hoped to launch again within six to eight months. That window has passed. The investigation update says the next planned missions are “later this year,” without giving a date or mission name.

The company’s missions page is not consistent on timing. One section lists TestFlight2 as no earlier than early 2027. Another says it is planned for no earlier than the end of 2026. Neither is a launch date, and as of October 17, 2026, none has been announced.

The same page lists a separate hypersonic flight test, a suborbital technology and high-speed flight demonstration, as no earlier than the fourth quarter of 2026 and pending approvals. It is a distinct mission from TestFlight2.

Gilmour Space says flight data is already informing vehicle design and operational updates. Other Eris-related items on its pages, such as satellite integration work for ElaraSat, depend on Eris reaching orbit, which it has not yet done.