Gravity Poppers: Hopping Probes for the Interior Mapping of Small Solar System Bodies
- Gravity Poppers are small, minimalistic probes that hop around the surface of small solar system bodies, allowing for precise gravity field mapping and interior density reconstruction.
- The concept relies on a mother spacecraft tracking a swarm of poppers from orbit to estimate their trajectories and refine a high-resolution map of the body’s gravity field.
- The Phase I study demonstrated that the Gravity Poppers concept is feasible and has the potential to resolve extremely accurate gravity models, enabling scientists to localize density anomalies such as large boulders on the surface.
- Phase II aims to further develop three core technologies: mechanical design of hopping probes, tracking strategy for detecting probe trajectories, and algorithmic framework for refining gravity models.
- The ultimate goal is to enable robust and affordable mission architectures that can map small body interiors with unprecedented precision, advancing our understanding of the solar system’s smallest bodies.
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Preparations for Next Moonwalk Simulations Underway (and Underwater)
Benjamin Hockman
NASA Jet Propulsion Laboratory
The goal of this effort is to develop a robust and affordable mission architecture that enables the gravimetric density reconstruction of small body interiors to unprecedented precision. Our architecture relies on the novel concept of “Gravity Poppers,” which are small, minimalistic probes that are deployed to the surface of a small body and periodically “pop” so as to perpetuate a random hopping motion around the body. By tracking a large swarm of poppers from orbit, a mother spacecraft can precisely estimate their trajectories and continuously refine a high-resolution map of the body’s gravity field, and thus, its internal mass distribution. Hopping probes are also equipped with minimalistic in-situ sensors to measure the surface temperature (when landed) and strength (when bouncing) in order to complement the gravity field and build a more accurate picture of the interior. The Phase I study focused on feasibility assessment of three core technologies that enable such a mission: (1) the mechanical design of hopping probes to be small, simple, robust, and “visible” to a distant spacecraft, (2) the tracking strategy for detecting and estimating the trajectories of a large number of ballistic probes, and (3) the algorithmic framework by which such measurements can be used to iteratively refine a gravity model of the body. The key finding was that the concept is feasible, and demonstrated to have the potential to resolve extremely accurate gravity models, allowing scientists to localize density anomalies such as “weighing” large boulders on the surface. This Phase II Proposal aims to further develop these three core technologies through continued mission trade studies and sensitivity analysis, case studies for simulated missions, and hardware prototypes demonstrating both hopping behavior and tracking performance.
