How Propulsion Technology Shaped Beyond-Low-Earth-Orbit Exploration Roadmaps

Stuart Feldman, Erica Hampton, Keithe Baggett, Jason Hundley, and Karin Feldman

Zero Point Frontiers Crop., Huntsville Alabama

This paper will provide an overview of launch and in-space propulsion systems for two different space exploration roadmaps: NASA's Roadmap for Solar System Exploration (1969-1990) and Rockwell's Integrated Space Plan (ISP) (1989-2100). Both plans were generated at dynamic points in U.S. space exploration history: the first developed in the midst of a successful Apollo lunar landing program, and the second during the first decade of the Space Shuttle program. The policies, research and development, technologies, funding and support of each era impacted each plan's development and focus on propulsion systems.

NASA's 1969 Roadmap, developed by the Von Braun team, laid aggressive plans for the continuation of NASA human exploration of the solar system following the completion of the Apollo lunar program. The Saturn V, and Saturn V-derived vehicles, would continue to be used for heavy lift capabilities and a space shuttle would be developed in the mid-1970s, replacing the Apollo/Saturn IB. In-space elements such as the NERVA-derived nuclear shuttle would be developed by the early 1980s. The ISP, developed by Rockwell, was created from several long- term NASA plans and spanned over 100 years. A long-range approach to the space program, the ISP was developed during the post-Challenger 1980s and focused on derivations and capabilities of the Space Shuttle as it existed during that time. The ISP had a gradual buildup to exploration capabilities, including interstellar travel, using in-space technologies like Nuclear Electric Propulsion and Mars cyclers. While there are notable differences between the two roadmaps in terms of assumed development times and mission planning, common propulsion elements and themes like heavy lift launch vehicles, a space shuttle and nuclear propulsion all play critical roles in both plans. This paper will discuss how assumptions about future propulsion technology shaped each roadmap.

Presented at ISDC 2011 - Huntsville. Paper is available.