This work formulates a novel time-expanded p-Median problem to design space-based observer constellations for Cislunar Space Situational Awareness (CSSA). We also derive a Lagrangean relaxation-based algorithm to rapidly obtain near-optimal solutions.

Related publication: Y. Shimane, K. Tomita, and K. Ho, “Cislunar Constellation Design for Space Situational Awareness with Time-Expanded Facility Location Problem,” 2024, [Online]. Available: http://arxiv.org/abs/2408.06238

This work formulates a facility location problem for on-orbit servicing depot in Medium Earth Orbit (MEO), considering low-thrust round-trip servicers.

Related publication: Y. Shimane, N. Gollins, and K. Ho, “Orbital Facility Location Problem for Satellite Constellation Servicing Depots,” J. Spacecr. Rockets, pp. 1–18, Mar. 2024, doi: 10.2514/1.A35691. https://arc.aiaa.org/doi/full/10.2514/1.A35691

With: Mitsubishi Electric Research Laboratories

In this work, an optimization-based station-keeping algorithm for colinear libration point orbits (LPO) based on the xz-plane crossing control technique is conceived. The optimization problem is cast as a sequential second-order cone pro- gram and incorporates an explicit constraint on the perilune pass epoch to en- sure the steered trajectory follows the reference baseline without deviating in phase. The resulting formulation has easily interpretable tuning parameters that may be obtained directly from mission requirements. The algorithm is demonstrated through Monte-Carlo simulations on the Gateway’s Near Rectilinear Halo Orbit (NRHO) in the full-ephemeris dynamics with realistic error models.

Related publication: Y. Shimane, K. Ho, and A. Weiss “Optimization-Based Phase-Constrained Station-Keeping Control on Libration Point Orbit,” in AAS/AIAA Astrodynamics Specialist Conference, 2024. Available: https://www.merl.com/publications/docs/TR2024-109.pdf

With: Mitsubishi Electric Research Laboratories

Autonomous navigation capability in cislunar space is critical for the safe operation of both uncrewed and crewed spacecraft. This project explores the use of horizon-based optical navigation to autonomously navigate and conduct station-keeping for a spacecraft on the 9:2 Near-Rectilinear Halo Orbit (NRHO) in the full-ephemeris model.

Related publication: Y. Shimane, P. Miraldo, K. Berntorp, M. Greiff, P. Elango, and A. Weiss, “High-Fidelity Simulation of Horizon-Based Optical Navigation with Open-Source Software,” in 74th International Astronautical Congress, 2023. Available: https://www.merl.com/publications/docs/TR2023-128.pdf

With: ESA ACT&Friends

We competed in the 12th GTOC competition and ended up 4th place overall!

Related publication: (coming soon!)

The combined use of gravity assist, low-thrust propulsion, and manifold capture for interplanetary transfers is studied. This work makes use of the Sims-Flanagan transcription, incorporating parametrization of arrival to a manifold Poincaré section instead of a celestial body.

Related publication: Y. Shimane and K. Ho, “Gravity‑Assist Low‑Thrust Inter‑System Trajectory Design with Manifold Captures,” J. Astronaut. Sci., 2022. https://doi.org/10.1007/s40295-022-00319-x

With: ESA ACT&Friends

We competed in the 11th GTOC competition and ended up 2nd place overall!

Related publication: M. Märtens, D. Izzo, E. Blazquez, M. von Looz, P. Gomez, A. Mergy, G. Accdiarini, C.H. Yam, J. Hernando-Ayuso, Y. Shimane, “The fellowship of the Dyson ring: ACT&Friends’ results and methods for GTOC 11,” Acta Astronaut., no. February, 2022. https://doi.org/10.1016/j.actaastro.2022.06.025