\n<\/p>\n
Test-firing of a\u00a0resonance igniter built by The Exploration Company in Bordeau France in\u00a0November\u00a02025.\u00a0<\/p>\n
Building a working rocket engine is one thing, igniting the engine\u00a0in a stable and repeatable way\u00a0is an engineering\u00a0feat in itself.\u00a0Resonance ignition produces high\u2011frequency waves inside a shaped cavity. As the waves interact, they resonate and heat the propellants until they ignite.\u00a0This\u00a0type of ignition\u00a0uses\u00a0just\u00a0the\u00a0propellants themselves.\u00a0<\/p>\n
Instead of relying on a spark,\u00a0a\u00a0pyrotechnic device\u00a0or a\u00a0plasma torch, the system creates self\u2011amplifying pressure waves that rapidly increase\u00a0the\u00a0temperature\u00a0of propellant gases.\u00a0<\/p>\n
Propellant\u00a0mixtures\u00a0are injected\u00a0in gaseous form through a \u201cresonance nozzle\u201d into a cavity. If\u00a0the shape\u00a0of the nozzle and the cavity\u00a0are exactly\u00a0right,\u00a0then the propellants bounce back and forth across the cavity and produce standing acoustic waves:\u00a0one wave of gas moving\u00a0in one direction meets\u00a0the wave returning in the opposite direction.\u00a0These waves break into each other at points called nodes,\u00a0resulting in high pressure\u00a0fluctuations\u00a0and\u00a0increasing the temperature of the gas.\u00a0\u00a0<\/p>\n
The Exploration Company\u00a0is investigating this\u00a0phenomenon\u00a0as a novel technique to start their rocket engines, requiring no external ignition devices, just\u00a0a\u00a0resonance nozzle and cavity.\u00a0An advantage of\u00a0resonance\u00a0igniters is that they can be used\u00a0repeatedly,\u00a0they\u00a0use little electricity,\u00a0there is no\u00a0need\u00a0for\u00a0additional\u00a0parts\u00a0and\u00a0they\u00a0are\u00a0therefore\u00a0lightweight. Current\u00a0technologies\u00a0for rocket engines\u00a0use\u00a0spark plugs\u00a0that require\u00a0a\u00a0high voltage,\u00a0glow plugs\u00a0that\u00a0need\u00a0time to warm up, or torch igniters.\u00a0<\/p>\n
The\u00a0first test campaign\u00a0concluded in November\u00a0and\u00a0showed the technology works,\u00a0allowing\u00a0The Exploration Company\u00a0to develop\u00a0know-how\u00a0on the device\u2019s workings\u00a0and better understand the geometry needed for successful,\u00a0rapid\u00a0and repeatable ignition.\u00a0\u00a0<\/p>\n
They tested different setups and analysed modes of ignition. The data from this test campaign will\u00a0help develop another\u00a0version of the device that will be\u00a0included in the\u00a0pre-combustors\u00a0of The Exploration Company\u2019s\u00a0staged-combustion cycle\u00a0high-thrust engine\u00a0programme.\u00a0<\/p>\n
The\u00a0test was conducted within a\u00a0\u20ac9\u00a0M\u00a0contract from the European Space Agency as part of the\u00a0Technologies for High-thrust Re-Usable Space Transportation\u00a0initiative, THRUST!\u00a0<\/p>\n<\/p><\/div>\n
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