Australia's First Orbital Rocket Launch: What Went Wrong with Gilmour Space's Eris?

Gilmour Space's Eris Rocket Launch

• 🇦🇺 Gilmour Space became the first Australian company to launch a rocket intended for space with their Eris rocket.
• 🚀 The Eris is a 25m tall, 35-ton rocket designed to carry approximately 100 kg to low Earth orbit, featuring a three-stage design.
• 💡 The first two stages utilize hybrid rocket motors, a unique design combining aspects of solid and liquid rockets.

Hybrid Rocket Technology Explained

• 🧩 Hybrid rockets use a solid fuel with a channel and a liquid oxidizer (like hydrogen peroxide) that burns the fuel when heated.
• ✅ Advantages include solid rocket motor handling and density with the potential for throttling and on/off capability.
• ⚠️ A key challenge is the difficulty in reliably turning hybrid rocket motors back on after initial ignition.

Eris Rocket's First Flight Analysis

• ⏱️ The Eris rocket experienced an engine failure approximately 14 seconds into its flight.
• 📉 Initially, the rocket accelerated, but after one engine failed, thrust was insufficient, leading to a loss of acceleration.
• ⚠️ A second engine failure occurred around 8 seconds into the flight, drastically reducing thrust and causing the rocket to decelerate.
• 🛰️ The attitude control system, using hydrogen peroxide thrusters, successfully kept the rocket stable and prevented a catastrophic breakup, guiding it away from the pad.

Potential Causes for Engine Failure

• ⛽ The hydrogen peroxide tank and its pressure delivery system appeared to function correctly, suggesting issues with individual engine components or valves.
• ⚙️ Possible causes include pump failures, valve malfunctions, or issues with the hydrogen peroxide catalyst system, potentially exacerbated by the rocket sitting for a year.
• 🧪 The behavior of the engines during ground tests versus the vertical flight may have contributed, as fluid dynamics can differ.

Outcome and Future Outlook

• 🔥 Despite the engine failures, the rocket did not explode catastrophically, largely due to the nature of hybrid rocket motors.
• 📈 Gilmour Space reported some successes, including clearing the launch tower and reaching an altitude of 35 meters.
• 🌟 The company is expected to investigate the failures, with hopes for future successful launches into space.