PRAXIS mission proposes autonomous in‑situ sampling of planetary rings

NASA’s Jet Propulsion Laboratory, through the work of planetary scientist Marco Quadrelli, has outlined a new mission concept that would, for the first time, bring spacecraft close enough to sample particles from planetary rings. The proposal targets the dense rings of Saturn as well as the more tenuous rings of Uranus and Neptune, and extends to the recently discovered ring systems around small bodies such as the Centaurs Chariklo and Chiron. By collecting and analyzing ring material directly, scientists aim to gain unprecedented insight into the composition, age, and dynamical history of these structures.

The scientific payoff would be significant. Ring particles carry clues about the conditions of the early solar system and the processes that shape planetary environments. A sample from Saturn’s rings could reveal the distribution of ice and dust, while data from the faint rings of Uranus and Neptune would test theories of ring formation and longevity. Measurements of the rings around Chariklo and Chiron could illuminate the evolution of minor bodies and the transition between cometary activity and stable ring systems. The mission would require a spacecraft capable of precise navigation through dense particle fields, a dust analyzer capable of high‑resolution composition studies, and robust shielding to protect instruments from high‑velocity impacts.

If funded, the project would enter a multi‑year development phase, with a launch window potentially in the late 2030s. Quadrelli and his team are preparing a detailed technical and scientific case for submission to NASA’s Decadal Survey, hoping to secure support for a mission that could transform our understanding of ring dynamics and the early history of the solar system.