Earlier this month, the HELVETIA team of the Swiss ARIS initiative successfully launched their supersonic-sounding rocket at the Spaceport America Cup 22 in New Mexico – supported by Oerlikon, who provided additive manufacturing expertise and production capabilities to develop and 3D print various components for the rocket, including an injector and a nozzle.

The 5.3m long rocket carries avionics, and 4kg of payloads, to an altitude of 30,000 ft. Oerlikon AM helped produce the various rocket parts, including the nozzle (MetcoAdd 718C), injector (AISi10Mg), nose cone tip (AISi10Mg), hatch (PA12), and launch lugs (PA12).

The injector is part of the oxidizer system – with multiple connection points – providing space for various sensors that are important to the propulsion system. Weight is crucial for an efficient launcher, and by additively manufacturing this part using SLM, the weight of the injector was reduced by 1.2kgs, and the complexity of assembly was greatly reduced.

The nozzle for the bi-liquid engine uses regenerative cooling to make longer firing times possible. The additively manufactured nozzle was made with MetcoAdd 718C (Alloy 718) – to withstand the high temperatures and stresses of a launcher firing. Optimal cooling allows the engine to fire for up to 20 seconds.

Regenerative cooling is achieved through 40 cooling channels (ø 1mm²), which split into 80 channels after the throat. Additional film cooling channels (0.6mm²), located at the throat, help to reduce the temperature during test firings.

The complex geometry of the nozzle is nearly impossible to achieve through conventional manufacturing. The additively manufactured nozzle is cheaper, easier and faster to construct, and weighs less – a critical factor in aerospace technology. Using 3D printing technology, Oerlikon’s student-led project was able to produce a nozzle that meets the industry standard.

For comparison, a conventionally manufactured nozzle that the ARIS student project used weighed 11.1kg, while the AM nozzle weighed only 1.6kg.