Current state of the multi-agent multi-view experimental and digital twin rendezvous (MMEDR-Autonomous) framework
Authors: Logan Banker, Michael Wozniak, Mohanad Alameer, Smriti Nandan Paul, David Meisinger, Grant Baer, Trevor Hunting, Ryan Dunham, Jay Kamdar
Organizations: Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, 65409, MO, United States · Purdue University, 610 Purdue Mall, West Lafayette, 47907, USA
As near-Earth resident space objects proliferate, there is an increasing demand for reliable technologies in applications of on-orbit servicing, debris removal, and orbit modification. Rendezvous and docking are critical mission phases for such applications and can benefit from greater autonomy to reduce operational complexity and human workload. Machine learning-based methods can be integrated within the guidance, navigation, and control (GNC) architecture to design a robust rendezvous and docking framework. In this work, the Multi-Agent Multi-View Experimental and Digital Twin Rendezvous (MMEDR-Autonomous) is introduced as a unified framework comprising a learning-based optical navigation network, a reinforcement learning-based guidance approach under ongoing development, and a hardware-in-the-loop testbed. Navigation employs a lightweight monocular pose estimation network with multi-scale feature fusion, trained on realistic image augmentations to mitigate domain shift. The guidance component is examined with emphasis on learning stability, reward design, and systematic hyperparameter tuning under mission-relevant constraints. Prior Control Barrier Function results for Clohessy-Wiltshire dynamics are reviewed as a basis for enforcing safety and operational constraints and for guiding future nonlinear controller design within the MMEDR-Autonomous framework. The MMEDR-Autonomous framework is currently progressing toward integrated experimental validation in multi-agent rendezvous scenarios.
Figures & tables
Figure 1: Chaser and Target Spacecraft in LVLH Frame, Figure Adapted from Khoury (2020)
Figure 2: Overall CNN Architecture for Optical Navigation, Based on Combination of MobileNetV3Large, FPN, and Deep-6DPose ( Howard et al., 2019 ; Lin et al., 2017 ; Do et al., 2018 )
Augment Type
Probability - Lightbox
Probability - Sunlamp
Brightness and Contrast
0.8
0.8
Gaussian Noise
0.7
0.8
Motion Blur
0.7
0.8
ISO Noise
0.7
0.8
Gamma
0.6
0.7
Sun Flare
-
0.7
Table 1: List of Augmentations and Probability of Application
Figure 3: Current State of the DCV-Space Testing Facility
Figure 4: CR20A Link Dimensions
Link
θ
d (mm)
a (mm)
α (deg)
1
θ1
230
0
90
2
θ2
0
825.2
0
3
θ3
0
746
0
4
θ4
175.6
0
-90
5
θ5
128.8
0
90
6
θ6
136.5
0
0
Table 2: D-H Parameters for Dobot CR20A Robot
Figure 5: Overview of All MMEDR Subsystems
Figure 6: Docking Results from Manual Shaping and a 50m Initial Distance
Figure 7: Successful Iterations of Bayesian optimization
Figure 8: Bayesian optimization Trajectory with Velocity Constraints
Training
Lightbox
Sunlamp
Augments
Et (m)
Eq ( ∘ )
Ep∗ (-)
Et (m)
Eq ( ∘ )
Ep∗ (-)
Without
1.95
76.25
1.65
1.93
89.59
1.85
With
0.36
45.65
0.86
0.52
66.74
1.28
Table 3: Testing Results for Lightbox and Sunlamp Domains, With and Without Data Augmentation (Described in Section 4.2.1 )
Model
Lightbox
Sunlamp
Et (m)
Eq ( ∘ )
Ep∗ (-)
Et (m)
Eq ( ∘ )
Ep∗ (-)
SPN
0.45
65.12
1.21
0.65
92.95
1.73
KRN
2.25
44.53
1.12
14.64
80.95
3.73
Ours
0.36
45.65
0.86
0.52
66.74
1.28
Table 4: Comparison of Synthetic-Only Training, Tested on Lightbox and Sunlamp Domains
Figure 9: Synthetic Images of the Aura Spacecraft Generated in Blender
Spacecraft rendezvous and proximity operations cover the navigation, guidance, and control needed to approach, inspect, dock with, or capture spacecraft safely.
As the complexity of space missions increases, autonomous spacecraft guidance must accommodate transitions between mission phases with distinct dynamics, objectives, and constraints. Rendezvous and proximity operations (RPO) are particularly challenging because they span multiple operating regimes, from orbital-scale matching and far-range approach to close-range maneuvering and terminal docking. Existing reinforcement-learning approaches generally address only a subset of this sequence or rely on manually defined switching conditions between controllers. This study presents a hierarchical reinforcement-learning framework for autonomous, three-degree-of-freedom RPO that spans the complete trajectory from orbit matching to docking. Five specialized policies are trained for orbit matching, far-range approach, mid-range approach, close-range approach, and docking. A learned high-level manager policy then selects among these phase-specific controllers based on the evolving spacecraft state. The hierarchical approach is evaluated over the full end-to-end rendezvous sequence and compared with a fixed sequential-invocation heuristic to assess trajectory performance and transition behavior. Training and inference metrics are also analyzed for the individual phase policies and the complete hierarchical system.
Mariko Storey-Matsutani, Anatoly Zlotnik, Lee Holguin +2
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA · Los Alamos National Laboratory, Los Alamos, NM, USA
Autonomous free-flying robots in orbital environments require controllers that are both versatile and resource-efficient, yet maintaining a separate, task-specific policy for each mission profile is architecturally brittle and limits operational flexibility as requirements evolve. We introduce HYPER-GNC, a multi-task reinforcement learning framework in which a hypernetwork maps physics-informed task embeddings to the weights of a shared actor-critic policy, enabling a single compact controller to master four distinct GNC tasks: velocity tracking, docking, inspection, and navigation with obstacle avoidance. The continuous embedding space allows the controller to generalize to novel mission configurations at deployment time without any retraining. Extensive experiments demonstrate that HYPER-GNC achieves sample efficiency comparable to single-task specialists while maintaining stability under significant inertial perturbations and external body wrenches. We further validate the framework on a physical satellite emulator, successfully bridging the simulation-to-reality gap across all mission profiles. Code, trained models, and deployment scripts are made publicly available to support reproducibility.
Ricard Marsal I Castan, Aman Arora, Antoine Richard +3
University of Luxembourg · 2Georgia Institute of Technology
Autonomous rendezvous and proximity operations (RPO) in adversarial orbital environments require guidance architectures balancing target pursuit, safety preservation, and real-time adaptability under dynamically evolving interaction conditions. Although learning-based approaches show promise, their application to safety-critical orbital robotics remains limited by concerns regarding interpretability, robustness, and constraint awareness. This work presents an adaptive Model Predictive Control (MPC) framework for autonomous spacecraft RPO in multi-agent adversarial scenarios. The proposed architecture combines a constrained receding-horizon MPC formulation with a data-driven supervisory tuning layer that adjusts controller parameters from offline closed-loop evaluation and online interaction geometry. Relative motion follows Clohessy-Wiltshire (CW) dynamics, enabling computationally efficient finite-horizon prediction and real-time quadratic optimization. The MPC formulation incorporates actuator limits, predictive keep-out-zone constraints, slack-variable feasibility handling, and optional Control Barrier Function (CBF) safety filtering. Rather than generating thrust commands directly, the adaptive layer modifies interpretable MPC parameters, including tracking weights, safety penalties, minimum-separation objectives, and keep-out-zone objectives. The framework was evaluated in the official Kerbal Space Program Differential Game (KSPDG) Capture-the-Satellite environment through Monte Carlo simulations. Results demonstrate improved closed-loop robustness, adaptive maneuvering behavior, and rendezvous performance compared with fixed-parameter MPC while preserving safety-aware operation and real-time feasibility, providing a modular, interpretable foundation for adaptive spacecraft RPO.
Luca Sportelli, Tyler Barr, Cagri Kilic +1
Department of Aerospace Engineering, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114