[Sam Rogers] and colleagues at [AX Technologies] have been testing and developing a small liquid-fueled rocket engine and successfully used vortex cooling to protect a resin 3D printed combustion ...

The VR35K-A is a high-performance liquid oxygen (LOX)/liquid hydrogen (LH2) engine that employs a fuel-rich staged combustion cycle, an innovative turbopump architecture and a VORTEX® combustion ...

In 2023, Sierra Space announced the VR35K-A had completed engine component testing, which allowed the company to advance to the full engine hot fire testing campaign. Next, Sierra Space will continue ...

under contract with Air Force Research Laboratory’s (AFRL), Rocket Propulsion Division, Edwards, Air Force Base in California, marking a major step forward in Sierra Space’s development of ...