New algorithm exploits orbital precession to slash space tug fuel costs

The new framework rethinks multi-rendezvous space tug missions for active debris removal (ADR). Traditionally, the nodal precession induced by Earth's oblateness is treated as a perturbation to be corrected, requiring expensive propellant. The authors instead treat precession as a resource: they shape an intermediate orbit's size, shape, and inclination to tune the differential precession rate between target debris orbits, reducing fuel demand. This is particularly effective in Sun-synchronous orbits where inclination is the dominant lever.

The algorithm provides three key innovations: an enhanced drift orbit design that is cheaper than prior altitude-only methods; a global per-leg time-budget optimizer that solves coupling between drift time and nodal geometry; and a sequence-recovery test that independently derives a removal order from the debris catalog, matching the published reference. Validated against the ESA Kessler Run competition's solution, the framework matches the benchmark cost with only analytical transfer models and minutes of single-core computation. Cross-validation with flight-dynamics tools bounds fidelity limits, and the constructive nature supports rapid in-orbit replanning after missed maneuvers.