Human Missions Throughout the Outer Solar System: Requirements and Implementations
- Paper number
IAC-07-D3.1.10
- Author
Dr. Ralph L. McNutt, Johns Hopkins University Applied Physics Laboratory, United States
- Coauthor
Mr. Douglas Fiehler, ASRC Aerospace, United States
- Coauthor
Mr. Jerry Horsewood, United States
- Year
2007
- Abstract
Distance scales and mission times set the top-level engineering requirements for in situ space exploration. Robotic exploration concepts and implemented missions now span a range from the corona of the Sun to greater than 100 AU. In these cases, and all missions in between, transport requirements have been based upon existing launch vehicle capability and delivery (orbital and surface probe) needs at the destination. The emergent use of ion propulsion has likewise been used to enable access to destinations and/or increased payloads but not to shrink flight times significantly. To do so requires both acceleration and deceleration over the cruise segment at significant power levels. To date, the implementation of various planetary gravity assists and long-term mission operations (now thirty years for the Voyager missions) has made for a better cost trade than technology development to decrease flight times, and, therefore, to decrease mission operations costs over the mission lifecycle. Similarly, crewed missions to date have not had mission time limits per se as drivers to implementation. However, the unconstrained cruise times to the outer solar system, as illustrated by the 5 to 30-year cruises of Pioneer 10 and 11,Voyager 1 and 2, Galileo, Cassini-Huygens, and New Horizons, would not be acceptable for either robotic sample returns or human crews. Without significantly increased vehicle masses galactic cosmic ray fluxes provide a human limit for total mission time of ~4 years (2 years out and 2 back) plus ~1 year of exploration at the destination. More restrictive limits on human minimum mass solutions may be driven by tolerance of low gravity for such extended durations, while less restrictive requirements will apply for robotic sample returns. Mass of consumables for humans, e.g., water, oxygen, and food, must also be taken into account, even with reclycing. To bound the problem, flight and propulsion implications for taking a crew of 6 to 10 to the Neptune system and back before the end of this century are considered. A minimum mass solution architecture based upon fission technology will minimize the cost of both the required mission and infrastructure. By fixing the crew and flight time requirements while taking the distances to the four gas giants and their moon systems as a parameter, we deduce the minimum cost path to realizing human exploration of the entire solar system by 2100.
- Abstract document
- Manuscript document
IAC-07-D3.1.10.pdf (🔒 authorized access only).
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