Parabilis Space Technologies, Inc. (Parabilis), in collaboration with Utah State University (USU), proposes a low cost, high performance launch vehicle upper stage using oxygen and a novel additively manufactured polymer fuel grain as propellants in response to solicitation T1.01, Affordable Nano/Micro Launch Propulsion Stages. This technology will fulfill the ever-growing mission demands of the CubeSat and NanoSat market by enabling dedicated launch for 5-6 kg class payloads. Comparable launch vehicle stages in this size class are not currently commercially available. The proposed green-propellant system will have significant advancements over alternative technologies in cost, safety, and mission capability. During Phase I, the development team's objectives include preliminary design of an upper stage and the test fire of a demonstration prototype. This innovative stage is designed such that it can integrate directly into NASA Marshall's NanoLaunch 1200 architecture.