ESA - 3D-printed storable-propellant rocket engine design tested

The recent hot firing of a full-scale rocket thrust chamber assembly takes us a step closer to proving 3D-printing for an engine design destined for rocket upper stages, in-orbit transportation applications (kick-stages and space-tugs), microlaunchers, and exploration spacecraft such as a lunar lander and ascent stage on the Moon.

Selected results of hot fire tests of hybrids using 98% HTP and HTPB as

NASA, Aerojet Rocketdyne Test 3D Printed Rocket Engine Component - AmericaSpace

ESA - 3D-printed storable-propellant rocket engine design tested

Rocket Report: A mysterious explosion in China; Firefly tests new engine

NeoFuels

Australian engineers 3D print rocket engine in just 4 months - 3Dnatives

Air Force Research Lab to fund development of Ursa Major's rocket engines - SpaceNews

Rocket Factory Augsburg talks reusability plans and 3D printing

Survey of Low-Burn-Rate Solid Rocket Propellants

ESA - Propulsion activities

Ariane 6: ESA Space Transportation Program - eoPortal

3D Printed Rocket Motor is Fuel Efficient