Liquid rocket engine assemblies and related methods

A liquid rocket engine assembly, comprising:

• a thrust chamber having a first annular recess extending into the thrust chamber and radially inward from an outer surface of the thrust chamber and toward a center longitudinal axis of the liquid rocket engine assembly;
• a nozzle having a first annular protrusion extending radially outward from an outer surface of the nozzle and the center longitudinal axis;
• and
• a joint structure separate and discrete from the thrust chamber and the nozzle, the joint structure attaching the thrust chamber and the nozzle, the joint structure comprising:
• an attachment ring comprising a second annular recess extending into the joint structure and radially outward from the center longitudinal axis, the second annular recess being sized and shaped to receive the first annular protrusion;
• a flange member comprising a second annular protrusion extending radially inward from an inner surface of the joint structure and sized and shaped to be received in the first annular recess of the thrust chamber;
• at least one seal element interposed between the thrust chamber and the nozzle and between the attachment ring and the flange member;
• and
• fasteners extending completely through the attachment ring and the at least one seal element and into the flange member,
• wherein materials of the thrust chamber and of the nozzle comprise different coefficients of thermal expansion.