GTOC 9: Results from the University of Colorado at Boulder (team CU Boulder)

This paper describes the strategies and results of the GTOC9 competition for the team from the University of Colorado, Boulder. The goal of the competition was to remove 123 pieces of space debris for the lowest cost, with cost defined in Euros as a function of fuel mass, number of launches, and time into the competition window. The overall strategy for this team was: 1) Find the
set of all possible low-cost chains of debris to visit, 2) Pick from those to define a series of missions that visit most of the debris, 3) Stitch the remaining 20-30 debris onto the existing chains, 4) Add 1-4 more launches to reach the 5-10 debris that remain after stitching, 5) Adjust the dates of each mission slightly to minimize \(\Delta\)V , and 6) Find a series of four maneuvers to transfer from each debris to the next in the fully-integrated dynamics. The final solution removed all 123 pieces of debris with 17 launches for a cost of 1150.8 MEUR.