Improving Performance of Near-Term Nuclear Electric Propulsion Systems
- Paper number
IAC-07-C4.I.16
- Author
Mr. Roger X. Lenard, Sandia National Laboratories, United States
- Year
2007
- Abstract
Nuclear electric propulsion has been studied seriously for many years. The National Aeronautics and Space Administration’s Jupiter Icy Moons Orbiter (JIMO) program involved a number of teams that performed serious design analyses of a long-range interplanetary probe using nuclear electric propulsion. However, the resultant spacecraft was not able to be launched in a single heavy lift launch system scenario. Consequently, despite the theoretical promise of nuclear electric propulsion, the concept remains a dream unrealized. This paper analyzes the design approaches and assumptions of the JIMO program and assesses their impact on the final design of the spacecraft. The author will assess what changes could have, and should have been made to make the spacecraft more agile and much lighter. The author will also assess the potential for a different thermal-to-electric power system architecture that could dramatically enhance the performance of such spacecraft while using available technologies for the reactor, brayton cycle and other elements of the nuclear power system. The author proposes to use a combined brayton-rankine cycle that addresses many issues associated with the nuclear power system. The primary issues include, weight, efficiency, freeze-thaw considerations for the radiator, power required to pump fluids around the radiator loops and associated pressure drops. The concept employs a brayton cycle system that is direct-coupled to a gas-cooled reactor operating at 1300 K. The brayton cycle exhausts to an ammonia bottoming cycle that generates power and back-side pressure is used to pump the coolant through the radiator. The author will discuss various methods to reduce mass and increase efficiency, including on-going radiator concept development funded, in-part by the author. The author provides insight into various technologies that are used and compares their volume, mass and other specific characteristics to those selected by the various contractor design teams. The author will demonstrate how dramatic mass reductions can be achieved by selecting alternative technologies to those employed in the JIMO program.
- Abstract document
- Manuscript document
IAC-07-C4.I.16.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.