StarCycler: A Simplified Approach to Artificial Gravity Space Station Design

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Building the first Artificial Gravity (AG) station demands carefully balanced trade-offs, particularly in determining its shape and size. Achieving a viable design requires reconciling the needs of multiple scientific disciplines. This post walks through the reasoning and decisions behind the StarCycler’s specifications, inviting you to explore the concept and draw your own conclusions. Follow along at https://www.starcycler.com for details.
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Optimizing Size and Rotation Speed
A significant reduction in station size is achieved by lowering the nominal artificial gravity to 0.7g, recognizing that 1g is not a strict physiological requirement. At 0.7g, most vascular and bone degradation will be mitigated, with reacclimation to Earth’s gravity comparable to carrying a heavy backpack.

Further size reduction is achieved by increasing the rotation rate. Using https://www.artificial-gravity.com/sw/SpinCalc/, an optimal configuration of 150 ft diameter, 5.2 RPM, and 0.7g was selected. This setup strikes a balance between comfort and constructability.

The torus shape is often favored for its gyroscopic stability, but its limited passenger capacity makes it financially unfeasible. Additionally, its stability comes at the cost of reduced controllability and maneuverability, as gyroscopic stability is inversely proportional to ease of orientation and motion control.
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Widening the Station
Widening a station introduces stability challenges but also unlocks opportunities to exploit additional physical phenomena.

StarCycler addresses these stability challenges through a Motion Management System. This system dynamically counterbalances internal movement (e.g., crew and equipment) to maintain rotational stability and localize structural stress loads.

As an isolated physical system, all spin or momentum control must remain internal. External influences would alter the station’s energy balance, making the need for internal control mechanisms essential.
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Determining the Width
In terms of gyroscopic stability, a station with equal width and diameter is the most unstable due to its ability to transfer force loads across the COM. Conversely, a torus shape offers high stability because it lacks the ability to transfer force loads effectively through the COM.

StarCycler’s ½ width x diameter configuration strikes an optimal balance between stability and maneuverability. When discussing the station’s "shape," this term more accurately refers to its mass/momentum profile.

The Motion Management System enables StarCycler to dynamically reconfigure its momentum profile, transitioning between a gyroscopic mode for enhanced stability and a maneuverable mode as required for operational control.
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G.E.M. – The Helm of StarCycler
The Center of Rotational Mass (COM) exhibits unique physical phenomena, including net zero acceleration and zero net torque from angular momentum. In the absence of acceleration, the station’s mass is measured solely in terms of its inertia (e.g., slugs or kilograms). This characteristic significantly reduces the energy required to orient the station when maneuvers are made from the COM.

Control Moment Gyroscopes (CMGs) must be positioned at the Center of Rotational Mass to function optimally. StarCycler employs a Gyro/Electro/Momentum (GEM) motor at the COM, designed as a large, high-performance CMG.

A GEM, weighing approximately 15,000 lbs and rotating at 20 RPM, generates significant momentum with its own independent axis of rotation. This configuration gives GEM ample energy to provide the necessary stabilization, rotational control, and reorientation capabilities critical to the station's operation.

GEM is capable of:
•   Spin-up and spin-down the station (on axis)
•   Gyro stabilization at high speeds (on axis)
•   Reorientation maneuvers (off axis)

Interestingly, when the StarCycler experiences the GEM's torque, it is felt internally at the COM, resulting in no gyro torque being generated from the station itself. However, GEM experiences the StarCycler’s torque as an external force, which in turn manifests as the GEM’s gyro torque.
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Constructability
Launching large objects into space presents significant challenges due to gravity and atmospheric resistance. Traditional methods rely on multiple launches of prefabricated components, as exemplified by the International Space Station (ISS), which required 40 assembly flights to achieve its 31,000 cu. ft. of pressurized volume.

StarCycler proposes a streamlined approach. A single booster can deliver the bare-bones test platform, consisting of:
•   Repurposed Booster (30 ft x 150 ft)
•   GEM Motor
•   Pop-up Spokes
•   Sectional Inflatable Structure

Once proven, the station can be upgraded with additional shielding, interior fabrication, and other enhancements. Employing a “build as you go” philosophy minimizes start-up cost and construction complexity.
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Invitation for Discussion
The StarCycler’s parameters are derived from existing research and thoughtful design considerations. Its innovative approach to artificial gravity, stability systems, and simplified construction methodology make it a compelling testbed for advancing space habitat technologies.

An AG research platform is long overdue, and StarCycler offers an affordable and practical solution. Its bare-bones platform comes at minimal cost, while its theories and design deserve serious study. Even if challenges arise, they will provide invaluable and empirical insights into AG station development.

A teaser website is available at StarCycler.com, StarCycler101.pdf is available for additional details. The full research paper, covering first principles, applied physics, and mechanical design breakthroughs, is available upon request.

We welcome your questions, insights, and feedback. Feel free to comment below or reach out directly.