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The engine (shown here without the spike-shaped aerodynamic attachment) was printed from copper. The injector is located on the back. (Image: Robin Wyss \/ Aris Space)<\/p>\nAt D\u00fcbendorf airfield, a group of ETH Zurich students from the Aris space initiative is attempting something that only a handful of nations have ever achieved: design and test an engine powered by controlled detonations. A Rotating Detonation Rocket Engine (RDRE) is a new system that can boost efficiency by detonating the fuel rather than burning it at a steady state, unlike almost all previous combustion systems.<\/p>\n
In a modest hut serving as the control hub, four screens, with operators working out of view at a safe distance from the booster unit, huddle around tables. Footage from several cameras shows the hexagonal copper part, roughly plate-sized and resembling an oversized nut, being placed into a stainless-steel disc attached to a car trailer.<\/p>\n
Aluminum profiles, pipes and tubes, sensor cables, and pressure tanks make up the complex test rig surrounding it. This makes the liquid oxygen vent from the engine, pre-cooling the system, and you can see light everywhere in green under a high-speed camera. Only afterward will the gathered data indicate whether a steady detonation wave has been established. Should this succeed, Aris would be the first student team in the world to ignite a liquid-fueled RDRE.<\/p>\n
The engine (shown here without the spike-shaped aerodynamic attachment) was printed from copper. The injector is located on the back. (Image: Robin Wyss \/ Aris Space)<\/p>\n
The tension is tangible. The silence is punctuated with announcements from the control center: \u201cTemperature: -100 degrees. Pressure: nominal.\u201d Security guards confirm the site is clear. The stage is set.<\/p>\n
The injector, the core of the engine, was created by third-year mechanical engineering student Mattia R\u00f6\u00f6sli. Rocket engines require both fuel and an oxidizer, so the team chose propane and liquid oxygen.<\/p>\n
R\u00f6\u00f6sli\u2019s injector guarantees an exact mixture during injection. The student project Pegasus, funded only through sponsored rates, intends to build and flight-test a bi-liquid RDRE. Industry partners provided materials, services, and funds.<\/p>\n
Expectations run high. RDREs can increase power by 10\u201320% at the same fuel load. Detonation, on the other hand, creates explosive waves that continue to circulate an area, generating extremely high pressures and temperatures unlike those of steady combustion. In this way, more efficient energy use is enabled, and the need for more complex components is reduced, leading to compact, lighter engines.<\/p>\n
The fuel alone can account for as much as 90% of a rocket\u2019s launch mass, so any small increase in efficiency could have huge implications for spaceflight, whether by lowering costs or enabling heavier payloads.<\/p>\n
Yet significant challenges remain. Detonation waves, therefore, move through the annular chamber as fast as 20,000 times per second, forcing materials into extreme compression.<\/p>\n
NASA has tested RDREs on the ground, Poland has tested liquid versions, and Japan is still the only country to have lit one in space. If Pegasus holds even a second of stable detonation, these students will be in the company of an elite group of pioneers.<\/p>\n
R\u00f6\u00f6sli recalls his journey<\/a>: \u201cRockets fascinate me because they fly simply by accelerating fuel backward. The principle is actually quite simple.\u201d<\/p>\n After two years of study, he embraced the unknown: \u201cThere is no one who can tell you exactly how to do it because so much is still unexplored. Working at the forefront of research like this is pretty cool!\u201d<\/p>\n His injector had to blend and dispense gas in less than a millisecond, and it was incapable of causing echoes. This started with sketches, team discussions, and calculations, then moved on to 3D printed prototypes.<\/p>\n \u201cYou don\u2019t need to be exceptionally talented to develop a rocket engine after two years of study. You go step by step and help each other.\u201d<\/p>\n Knowledge transfer within Aris is vital. Every year, teams are built to mentor their successors and impart lessons, occasionally learned the hard way with broken parts. Even Pegasus has assistance from a nearby startup building RDREs. ETH an infrastructure hangar: workbenches, 3D printers, meeting rooms, and testing space.<\/p>\n Safety is paramount. Engines are flow- and pressure-tested before ignition. For months, the team honed in on safe protocols. They met for a briefing, six hours before firing, on test day. To designate their role, each member donned a colored waistcoat: test conductor: blue; safety officer: green; engineer: orange; and data acquisition specialist: yellow. Loaded equipment: cables, gas bottles, fire extinguishers, and snacks to keep the mind alert.<\/p>\n Later the same day, the trailer with the testing stand was taken to the airfield. Military police opened the gates. The team deployed quickly, following checklists and connecting cylinders to fill valves with liquid oxygen. Ice crystals formed instantly.<\/p>\n The engine start sequence initiated at 19:00 CT. Hiss, thud, screech, then fire. But was it a detonation wave? The team checked sensors: no. They refueled and adjusted parameters. At 8:45 p.m., the engine reached a cool -130\u00b0C.<\/p>\n \u201c3, 2, 1, go!\u201d This time, a long, steady stream of fire shot out, buzzing and whistling at high frequencies. R\u00f6\u00f6sli smiled faintly. Confirmation came by radio: \u201cYes! Guys, that was three detonation waves!\u201d Cheers erupted before focus returned to preparations for a third firing.<\/p>\n As dismantling began, pride replaced tension. Gen-Z slang filled the air, and a glow of achievement radiated from the students as they finished. They had done what only a few in the world have accomplished: ignited a spinning detonation rocket engine<\/a> with liquid fuel.<\/p>\n","protected":false},"excerpt":{"rendered":"At D\u00fcbendorf airfield, a group of ETH Zurich students from the Aris space initiative is attempting something that…\n","protected":false},"author":2,"featured_media":70448,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[4],"tags":[37627,19013,41,17],"class_list":["post-70447","post","type-post","status-publish","format-standard","has-post-thumbnail","category-switzerland","tag-engine","tag-rocket","tag-swiss","tag-switzerland"],"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts\/70447","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/comments?post=70447"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts\/70447\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/media\/70448"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/media?parent=70447"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/categories?post=70447"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/tags?post=70447"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}