For centuries, space has fascinated humans like no other. From the glare of the sun to the moon’s surface to Saturn’s sparkling rings, we wanted to get up close and see it all.
Now, two ambitious NASA-backed projects aim to 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) program, the proposals envision future robotic explorers that could not only sample Saturn’s icy rings for the first time, but could also deploy thousands of small spacecraft to fly through them, unlocking mysteries that have puzzled scientists since the Cassini mission ended in 2017.
First project
The first concept is called PRAXIS, or autonomous exploration of planetary rings with in situ sampling. It proposes what could amount to the first-ever “touch-and-go” mission to Saturn’s rings. The project will be led by Dr. B. Marco Quadrelli, principal and supervisor of the Robotics Modeling and Simulation Group at JPL.Although Cassini has revolutionized our understanding of the gas giant, scientists still don’t know exactly how the rings formed, how old they are, or how the countless ice particles constantly collide, merge, and break apart.
These particles range from microscopic grains to house-sized pieces, and are largely composed of water ice mixed with rocky material. While Cassini imaged them from close range, it did not directly sample the ring particles.Praxis hopes to change that. Instead of flying directly into the planet’s dense rings, the spacecraft will hover gracefully above them before extending a long, flexible arm inspired by the precision of sport hunting.
Under the guidance of artificial intelligence, the boom will briefly touch the surface of the moving toroid, collect material and retract before the spacecraft moves away.The mission will 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.Instruments on board will instantly analyze the material, measuring particle size, porosity, composition and internal structure, important clues to understanding whether Saturn’s rings are the remains of a shattered moon, building blocks left over from the planet’s formation or something entirely different.
The second project
The second proposal selected by NIAC takes a more advanced approach. The concept, led by Michael Rubinstein of Northwestern University, envisions deploying about 10,000 actively steerable satellites, small spacecraft each only a few centimeters wide, to fly directly through Saturn’s rings, atmosphere and magnetic field.Unlike pioneering spacecraft like Cassini, which had to avoid dense ring regions to reduce collision risks, the femtosquad swarm embraces this risk.
If thousands of small spacecraft are destroyed by high-speed collisions, the mission could still succeed because the remaining probes will continue to collect data. Together, they will create an unprecedented 3D map of Saturn’s ring composition, atmospheric density, and magnetic environment.This distributed approach also provides a significant engineering advantage. Instead of risking a single multi-billion-dollar spacecraft, scientists can spread the risk across thousands of inexpensive explorers, dramatically increasing the chances of obtaining measurements from environments previously considered inaccessible.While both missions are still 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 comes true, humanity will have set another record, touching the rings around Saturn.
