Abstract: A rocket engine is prepared by fabricating a combustion chamber having an annular wall as a single piece of material. The wall has a first axial region with a first inner diameter, a second axial region with a second inner diameter greater than the first inner diameter, and an inner wall step transition between the first axial region and the second axial region. The combustion chamber is attached to an injector by bonding an annular metallic deposit to the first axial region of the combustion chamber, providing an annular adaptor ring, first welding the adaptor ring to the metallic deposit, and second welding the adaptor ring to the injector.

Abstract: A rocket engine has a combustion chamber formed of an annular wall made of an annular wall material, and an annular insert made of an annular insert material that is of substantially the same thermal expansion coefficient as the annular wall material. The annular insert has an insert outer surface sized to fit within and contact the wall inner surface along less than the wall length. The annular wall and the annular insert are welded together. There is further an attachment between the combustion chamber and an injector. The attachment includes an annular metallic deposit bonded to the combustion chamber, an annular adaptor ring, a weld joint between the adaptor ring and the metallic deposit, and a joint between the adaptor ring and the injector.

Abstract: A rocket engine is prepared by fabricating a combustion chamber having an annular wall as a single piece of material. The wall has a first axial region with a first inner diameter, a second axial region with a second inner diameter greater than the first inner diameter, and an inner wall step transition between the first axial region and the second axial region. The wall is formed by furnishing an oversize blank of the wall material and electrical discharge machining or grinding it to the final size. The combustion chamber is attached to an injector by bonding an annular metallic deposit to the first axial region of the combustion chamber, providing an annular adaptor ring, first welding the adaptor ring to the metallic deposit, and second welding the adaptor ring to the injector.