Dynamics and Stability of Near-Future Artificial-Gravity Orbital Station Concepts

Artificial gravity (AG) is gaining renewed relevance as space agencies and private companies plan for longer-duration human spaceflight beyond Low Earth Orbit. While historical concepts such as toroidal stations or tethered bolas explored AG theoretically, few have addressed the practical challenges of implementing near-term, modular AG stations in orbital environments. This paper investigates the dynamics and environmental stability of two promising AG concepts achievable with existing or near-future launch capabilities: a spinning "Stick Station" based on Starship-class modules and a "Hub-and-Stick" station leveraging a counter-rotating architecture to achieve zero net angular momentum (ZNAM). These configurations are evaluated for their passive stability and susceptibility to environmental torques, such as gravity gradient and atmospheric drag, under the assumptions of rigid-body dynamics in a circular Earth orbit. Through detailed modeling and time-domain simulations, the paper assesses how each concept responds to orbital perturbations and identifies design trade-offs that impact their controllability and operational feasibility. Results show that while the Stick Station offers strong passive stability due to high angular momentum, its ability to reorient is severely constrained, posing challenges for continuous Earth- or Sun-facing operations. In contrast, the ZNAM architecture sacrifices passive stability but enables more flexible attitude control by canceling net angular momentum. These findings establish a foundational understanding of AG system dynamics in orbital conditions and provide critical insights for future development of control laws and hardware systems to enable safe and sustainable artificial gravity habitats in space.