56 citations · 312 across the 19 of their papers we have counts for
19 papers
Hierarchical Framework for Space Exploration Campaign Schedule Optimization
Nicholas Gollins, Koki Ho
Space exploration plans are becoming increasingly complex as public agencies and private companies target deep-space locations, such as cislunar space and beyond, which require lon…
Analysis of Cooperative and Non-Cooperative Architectures for Multi-Plane On-Orbit Refueling
Kosuke Ikeya, Koki Ho
As many satellite constellations are proposed, deployed, and operated, their maintenance becomes increasingly important to provide satisfactory services; therefore, on-orbit refuel…
Optimizing Multi-Spacecraft Cislunar Space Domain Awareness Systems via Hidden-Genes Genetic Algorithm
Lois Visonneau, Yuri Shimane, Koki Ho
This paper proposes an optimization problem formulation to tackle the challenges of cislunar Space Domain Awareness (SDA) through multi-spacecraft monitoring. Due to the large volu…
Simultaneous Sizing of a Rocket Family with Embedded Trajectory Optimization
Byeong-Un Jo, Koki Ho
This paper presents a sizing procedure for a rocket family capable of fulfilling multiple missions, considering the commonalities between the vehicles. The procedure aims to take f…
Orbital Facility Location Problem for Satellite Constellation Servicing Depots
Yuri Shimane, Nick Gollins, Koki Ho
This work proposes an adaptation of the Facility Location Problem for the optimal placement of on-orbit servicing depots for satellite constellations in high-altitude orbit. The hi…
Regional Constellation Reconfiguration Problem: Integer Linear Programming Formulation and Lagrangian Heuristic Method
Hang Woon Lee, Koki Ho
A group of satellites, with either homogeneous or heterogeneous orbital characteristics and/or hardware specifications, can undertake a reconfiguration process due to variations in…
Multidisciplinary Design Optimization Approach to Integrated Space Mission Planning and Spacecraft Design
Masafumi Isaji, Yuji Takubo, Koki Ho
Space mission planning and spacecraft design are tightly coupled and need to be considered together for optimal performance; however, this integrated optimization problem results i…
Flexibility Management for Space Logistics via Decision Rules
Hao Chen, Brian Gardner, Paul Grogan +1
This paper develops a flexibility management framework for space logistics mission planning under uncertainty through decision rules and multi-stage stochastic programming. It aims…
Hierarchical Reinforcement Learning Framework for Stochastic Spaceflight Campaign Design
Yuji Takubo, Hao Chen, Koki Ho
This paper develops a hierarchical reinforcement learning architecture for multimission spaceflight campaign design under uncertainty, including vehicle design, infrastructure depl…
Space Exploration Architecture and Design Framework for Commercialization
Hao Chen, Melkior Ornik, Koki Ho
The trend of space commercialization is changing the decision-making process for future space exploration architectures, and there is a growing need for a new decision-making frame…
On-Orbit Servicing Optimization Framework with High- and Low-Thrust Propulsion Tradeoff
Tristan Sarton du Jonchay, Hao Chen, Masafumi Isaji +2
This paper proposes an on-orbit servicing logistics optimization framework that is capable of performing the short-term operational scheduling and long-term strategic planning of s…
Framework for Modeling and Optimization of On-Orbit Servicing Operations under Demand Uncertainties
Tristan Sarton du Jonchay, Hao Chen, Onalli Gunasekara +1
This paper develops a framework that models and optimizes the operations of complex on-orbit servicing infrastructures involving one or more servicers and orbital depots to provide…
Deep Reinforcement Learning for Safe Landing Site Selection with Concurrent Consideration of Divert Maneuvers
Keidai Iiyama, Kento Tomita, Bhavi A. Jagatia +2
This research proposes a new integrated framework for identifying safe landing locations and planning in-flight divert maneuvers. The state-of-the-art algorithms for landing zone s…
Bayesian Deep Learning for Segmentation for Autonomous Safe Planetary Landing
Kento Tomita, Katherine A. Skinner, Koki Ho
Hazard detection is critical for enabling autonomous landing on planetary surfaces. Current state-of-the-art methods leverage traditional computer vision approaches to automate the…
Multi-Fidelity Space Mission Planning and Infrastructure Design Framework for Space Resource Logistics
Hao Chen, Tristan Sarton du Jonchay, Linyi Hou +1
To build a sustainable and affordable space transportation system for human space exploration, the design and deployment of space infrastructures are critical; one attractive and p…
Semi-Analytical Model for Design and Analysis of On-Orbit Servicing Architecture
Koki Ho, Hai Wang, Paul A. DeTrempe +2
Robotic on-orbit servicing (OOS) is expected to be a key technology and concept for future sustainable space exploration. This paper develops a semi-analytical model for OOS system…
Satellite Constellation Pattern Optimization for Complex Regional Coverage
Hang Woon Lee, Seiichi Shimizu, Shoji Yoshikawa +1
The use of regional coverage satellite constellations is on the rise, urging the need for an optimal constellation design method for complex regional coverage. Traditional constell…
Event-Driven Network Model for Space Mission Optimization with High-Thrust and Low-Thrust Spacecraft
Bindu Jagannatha, Koki Ho
Numerous high-thrust and low-thrust space propulsion technologies have been developed in the recent years with the goal of expanding space exploration capabilities; however, design…
Optimal Satellite Constellation Spare Strategy Using Multi-Echelon Inventory Control
Pauline C. M. Jakob, Seiichi Shimizu, Shoji Yoshikawa +1
The recent growing trend to develop large-scale satellite constellations (i.e., mega-constellation) with low-cost small satellites has brought the need for an efficient and scalabl…