This document summarizes a paper presented at the 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference about gravitational field propulsion. It discusses the current limits of space propulsion based on momentum conservation and the need for propellant. The paper introduces the concept of generating gravitational fields using man-made devices for propulsion without propellant. It outlines the theoretical concepts of Extended Heim Theory which postulates two additional gravitational-like force fields beyond the four known fundamental interactions. The paper also references experiments at ARC Seibersdorf that claim to generate gravitomagnetic and gravity-like fields, providing potential evidence for novel physical interactions beyond current theories.