Now that the 3D printed Rutherford Engine, designed to accompany the Electron launch vehicle, has been qualified for space flight, it’s expected that it will be flown during the Electron’s first test program, scheduled for the later part of this year. Two years of testing and 200 hot fires resulted in the green flight for this unique engine to go to space, special not only because of its construction but also because of its unique electric propulsion cycle which uses brushless DC electric motors and lithium polymer batteries to drive the turbopump. Read more at 3DPrint.com: https://3dprint.com/135721/rocket-labs-electron-rocket/