Spacecraft study shows interstellar comet encounter mission within reach

Spacecraft study shows interstellar comet encounter mission within reach
by Clarence Oxford
Los Angeles CA (SPX) Sep 07, 2025

Southwest Research Institute has outlined a mission design capable of intercepting and studying interstellar comets, demonstrating that such encounters are achievable with current technology. The internal study validated the concept against the trajectory of 3I/ATLAS, the third interstellar comet detected to date.

The first known interstellar comet, 1I/'Oumuamua, was discovered in 2017, followed by 2I/Borisov in 2019. The arrival of 3I/ATLAS this year reinforced predictions that future facilities, including the Vera Rubin Observatory, will detect many more interstellar objects over the next decade.

"These new kinds of objects offer humankind the first feasible opportunity to closely explore bodies formed in other star systems," said SwRI Associate Vice President Dr. Alan Stern, who led the project. He noted that a flyby could reveal key insights into the composition and structure of such objects, extending knowledge of planetary formation beyond the solar system.

Because interstellar comets travel on hyperbolic paths at extreme speeds, orbiting them remains out of reach. The SwRI study found, however, that high-speed flybys could be conducted at reasonable cost. Project manager Matthew Freeman explained that a mission designed by the team could have intercepted 3I/ATLAS, gathering groundbreaking data during a head-on encounter.

The research team set out broad scientific goals for such a mission, including characterizing physical properties, probing composition, and studying the coma, the cloud of gas released from the comet. Achieving these objectives would shed light on both formation processes and subsequent evolution.

To evaluate mission feasibility, SwRI developed specialized software to generate synthetic populations of interstellar comets and calculate optimal trajectories. Orbital mechanics expert Dr. Mark Tapley showed that the software produced an intercept path to 3I/ATLAS requiring launch energies comparable to past NASA missions.

"The very encouraging thing about the appearance of 3I/ATLAS is that it further strengthens the case that our study for an ISC mission made," Tapley said. "We demonstrated that it doesn't take anything harder than the technologies and launch performance like missions that NASA has already flown to encounter these interstellar comets."