For centuries, space has fascinated humans like no other. From the sun’s glare to the moon’s surface and even Saturn’s shimmering rings, we have wanted to go up close and see it all. Now, two ambitious NASA-backed projects aim to truly touch Saturn’s rings, venturing into what is known as one of the most dangerous environments in the solar system.Selected under NASA‘s Innovative Advanced Concepts (NIAC) programme, the proposals envision futuristic robotic explorers that could not only sample Saturn’s icy rings for the first time but also deploy thousands of tiny spacecraft to fly through them, unlocking mysteries that have puzzled scientists since the Cassini mission ended in 2017.
The first project
The boom would briefly touch the surface of a moving ring particle, collect material and retract before the spacecraft moves away
The first concept is called PRAXIS or Planetary Rings Autonomous EXploration with In-situ Sampling. It proposes what would amount to the first-ever “touch and go” mission to Saturn’s rings. The project will be led by Dr B. Marco Quadrelli, a Principal and Group Supervisor of the Robotics Modelling and Simulation Group at the Jet Propulsion Laboratory.Despite Cassini revolutionising our understanding of the gas giant, scientists still do not know exactly how the rings formed, how old they are or how the countless ice particles constantly collide, merge and break apart. Those particles range from microscopic grains to chunks the size of houses and are made largely of water ice mixed with rocky material. While Cassini photographed them from close range, it never directly sampled a ring particle.PRAXIS hopes to change that. Instead of flying directly into the planet’s dense rings, the spacecraft would hover safely above them before extending a long, flexible boom inspired by the precision of sport fishing. Guided by artificial intelligence, the boom would briefly touch the surface of a moving ring particle, collect material and retract before the spacecraft moves away.The mission would then repeat the process at multiple locations, including gaps and dense ring regions, allowing scientists to compare samples from across Saturn’s vast ring system.The onboard instruments would immediately analyse the material, measuring particle size, porosity, composition and internal structure, critical clues to understanding whether Saturn’s rings are remnants of a shattered moon, leftover building blocks from planet formation or something completely different.
The second project
It envisions deploying around 10,000 actively steerable femtosatellites, to fly directly through Saturn’s rings
A second NIAC-selected proposal takes a more advanced approach. Led by Michael Rubenstein of Northwestern University, the concept envisions deploying around 10,000 actively steerable femtosatellites, tiny spacecraft each only a few centimetres across, to fly directly through Saturn’s rings, atmosphere and magnetic field.Unlike flagship spacecraft such as Cassini, which had to avoid dense ring regions to reduce collision risk, the femtosat swarm embraces that danger. If thousands of the tiny spacecraft are destroyed by high-speed impacts, the mission can still succeed because the remaining probes would continue collecting data. Together, they would create an unprecedented three-dimensional map of Saturn’s ring composition, atmospheric density and magnetic environment.This distributed approach also offers a major engineering advantage. Rather than risking a single multi-billion-dollar spacecraft, scientists can spread the risk across thousands of inexpensive explorers, immensely increasing the chances of obtaining measurements from environments previously considered inaccessible.While both missions remain in the early concept stage, NASA’s support highlights their credibility and the agency’s growing interest in returning to Saturn after Cassini. If either proposal eventually materialises, humanity will have made another record, that of having touched the rings surrounding Saturn.
