Hybrid rocket propulsion systems for outer planet exploration missions

• Published in: Acta astronautica 2016-11, Vol.128, p.119-130
• Main Authors: Jens, Elizabeth T., Cantwell, Brian J., Hubbard, G. Scott
• Format: Article
• Language: English
• Subjects: Design analysis; Design engineering; Europa; Exploration; Grand Tours; Hybrid propulsion systems; Hybrids; Jupiter; Jupiter satellites; Maneuvers; Missions; Moons; Orbit insertion; Packaging; Planets; Propulsion; Propulsion system design; Propulsion systems; Rocket propulsion; Rockets; Space exploration; Space missions; Spacecraft guidance; Specific impulse; Uranus
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2016.06.036

Outer planet exploration missions require significant propulsive capability, particularly to achieve orbit insertion. Missions to explore the moons of outer planets place even more demanding requirements on propulsion systems, since they involve multiple large ΔV maneuvers. Hybrid rockets present a favorable alternative to conventional propulsion systems for many of these missions. They typically enjoy higher specific impulse than solids, can be throttled, stopped/restarted, and have more flexibility in their packaging configuration. Hybrids are more compact and easier to throttle than liquids and have similar performance levels. In order to investigate the suitability of these propulsion systems for exploration missions, this paper presents novel hybrid motor designs for two interplanetary missions. Hybrid propulsion systems for missions to Europa and Uranus are presented and compared to conventional in-space propulsion systems. The hybrid motor design for each of these missions is optimized across a range of parameters, including propellant selection, O/F ratio, nozzle area ratio, and chamber pressure. Details of the design process are described in order to provide guidance for researchers wishing to evaluate hybrid rocket motor designs for other missions and applications. •Details of the hybrid motor design process are provided.•Comprehensive summary of available test data pertinent to hybrid design process.•Hybrid propulsion systems for missions to Europa and Uranus are presented.•Hybrid motors found to be competitive with existing in-space propulsion systems.