The Feasibility of a Spacecraft Flyby with the Third Interstellar Object 3I/ATLAS from Earth or MarsOPEN ACCESS
Atsuhiro Yaginuma, Tessa Frincke, Darryl Z. Seligman, Kathleen Mandt, Daniella N. DellaGiustina, Eloy Peña-Asensio, Aster G. Taylor, Michael C. Nolan
Submitted to AAS Journals, draft version July 22, 2025
“We investigate the feasibility of a spacecraft mission to conduct a flyby of 3I/ATLAS, the third macroscopic interstellar object discovered on July 1 2025, as it traverses the Solar System. There are both ready-to-launch spacecraft currently in storage on Earth, such as Janus, and spacecraft nearing the end of their missions at Mars. We calculate minimum ∆V single-impulse direct transfer trajectories to 3I/ATLAS both from Earth and from Mars. We consider launch dates spanning January 2025 through March 2026 to explore obtainable and hypothetical mission scenarios. Post-discovery Earth departures require a challenging ∆V ≳ 24 km s−1 to fly by 3I/ATLAS. By contrast, Mars departures from July 2025 – September 2025 require ∆V ∼ 5 km s−1 to achieve an early October flyby — which is more feasible with existing propulsion capabilities. We discuss how existing spacecraft could be used to observe 3I/ATLAS and how spacecraft at other locations in the Solar System could be repurposed to visit future interstellar objects on short notice.”
