NASA say it has completed a series of test firings of its first rocket engine part made using 3D printing technology. Custom 3D printers spraying layers of metallic powder using lasers were used to create a rocket engine\'s fuel injector that underwent several hot-fire tests using a mix of liquid-oxygen and gaseous hydrogen, a NASA release reported. Manufacturing this type of injector with traditional processes would take more than a year but the 3D process produced it in less than 4 months, the agency said. NASA\'s Glenn Research Center in Cleveland conducted the successful tests for Aerojet Rocketdyne. \"Rocket engine components are complex machined pieces that require significant labor and time to produce,\" said Tyler Hickman, who led the testing at Glenn. \"The injector is one of the most expensive components of an engine.\" Aerojet Rocketdyne officials said the injector represents a significant advancement in application of 3D printing, also called additive manufacturing. NASA officials hailed the successful test. \"NASA recognizes that on Earth and potentially in space, additive manufacturing can be game-changing for new mission opportunities, significantly reducing production time and cost by \'printing\' tools, engine parts or even entire spacecraft,\" said Michael Gazarik, NASA\'s associate administrator for space technology in Washington.