As scientific, commercial, and geopolitical activities accelerate beyond near-Earth, existing delineations of deeper space are proving to be insufficient; often, they are highly technical, inconsistently applied, and inaccessible to many decisionmakers. In this Rand report, the authors build on existing geographical and cartographical precedent to propose four clear astrographic regions — surface environment, near-body space, celestial neighborhood, and deep space — each grounded in durable physical thresholds or established conventions. Designed to be accessible, durable, and generalizable, the framework aims to support discourse among a wide variety of space professionals. The authors also highlight opportunities for further improving this framework, including the incorporation of multibody gravitational boundaries, four-dimensional mapping, and additional space regions and features as space activities continue to evolve.
Key Findings
- Despite advancements in mapping the Earth, the Moon, and even nearby planets, the field of space mapping lacks agreed-upon terms and definitions for depicting and describing the empty space between celestial bodies.
- Existing space depictions have tended to originate in academia and thus prioritize exactness and detail over accessibility, affecting their utility for decisionmakers and space operators.
- The authors offer a novel framework for delineating the astrographic regions for any given gravitational system, following three guiding principles: ensuring a framework that is accessible to policymakers and space planners of all types, durable over the long term, and generalizable across different gravitational systems.
- As interest in cislunar space accelerates, the clear definition and consistent depiction of this region offered in this report will be helpful to support coordination, safety, and future space development.
- Minimum orbit (minorbit) spheres, mass concentrations (mascons), Lagrange zones, reference frames, and Hill spheres are valuable features that future researchers can use to define analogous regions in other gravitational systems.
- The authors anticipate that future work will refine these definitions and incorporate additional concepts not covered in this report.
– Bruce McClintock, Jordan Logue, Jan Osburg, Srikant Kumar Sahoo, Karen Schwindt, Published courtesy of RAND.
