CREW HaT: A Magnetic Shielding System for Space Habitats (2209.13624v1)

Abstract: At the dawn of a new space exploration age, aiming to send humans back to the Moon and for the first time to Mars, it is necessary to devise a solution to mitigate the impact that space radiation has on spacecraft and astronauts. Although technically challenging, active magnetic shielding is generally considered a promising solution. We propose a lightweight deployable system producing an open magnetic field around a space habitat. Our Cosmic Radiation Extended Warding (CREW) system consists of a cylindrical Halbach array coil arrangement, or Halbach Torus (HaT). This configuration generates an enhanced external magnetic field while suppressing it in the habitat volume. The CREW HaT takes advantage of recent innovations in high-temperature superconductors (e.g., ReBCO) that enables the needed high currents. We present a preliminary feasibility design of the magnetic shielding system and its collapsible mechanical structure to sustain the internal magnetic forces while protecting astronauts. We also lay down the next steps towards a more evolved and comprehensive device design.

• The paper introduces the CREW HaT system, which uses a deployable Halbach torus with eight racetrack coils to deflect up to 40% of 100 MeV GCR protons.
• It employs numerical simulations with GEANT4 to demonstrate a significant reduction in absorbed radiation dose compared to unshielded scenarios.
• The design leverages ReBCO superconductors and a Kevlar-reinforced aluminum support structure, paving the way for lightweight, robust shielding in long-duration space missions.

Analysis of the CREW HaT: A Magnetic Shielding System for Space Habitats

The paper "CREW HaT: A Magnetic Shielding System for Space Habitats" proposes an innovative approach to addressing the significant challenge of space radiation protection. In the context of human expeditions beyond Low Earth Orbit (LEO), radiation exposure is a critical risk factor, particularly the consequences of galactic cosmic rays (GCRs) and solar particle events (SPEs). The current paper advances the concept of the Cosmic Radiation Extended Warding (CREW) HaT system, a magnetic shielding approach using a cylindrical Halbach array, to mitigate this risk.

Technical Design and Feasibility

The CREW HaT system employs a deployable magnetic shield composed of eight racetrack coils arranged in a Halbach Torus configuration. This design aims to create an enhanced magnetic field in the surrounding space while minimizing its presence in the habitat itself. The coils utilize rare-earth barium copper oxide (ReBCO) high-temperature superconductors, facilitating the generation of requisite high currents with reduced mass compared to conventional superconductors. A notable design feature is the deployable structure which allows for compact transport and efficient operation in space.

The feasibility of the CREW HaT design was evaluated by optimizing its geometrical and operational parameters. A key objective was to maximize shielding efficiency, expressed as the ratio of deflected GCR particle trajectories to the incident ones. Preliminary results indicate the ability of the CREW HaT to deflect approximately 40% of 100 MeV GCR protons, implying potential for shielding higher energy particles given appropriate configuration adjustments.

Numerical Simulations and Preliminary Results

The paper describes a preliminary set of numerical simulations to estimate the full-body dose equivalent absorbed by astronauts. Utilizing the Monte Carlo code GEANT4, calculations show a reduction in dose equivalent with the CREW HaT in operation compared to a scenario devoid of magnetic shielding. This supports the potential of the magnetic shield to mitigate secondary radiation risks caused by primary GCR impacts on spacecraft materials.

Structural Implications

Mechanically, the system must withstand substantial magnetic and structural forces, particularly those generated between and within coils. The CREW HaT’s structural design incorporates a Kevlar-reinforced aluminum alloy support system to provide strength while maintaining a manageable weight. Key design components focus on the coil containment, radial support beams, and central support ring, each addressing specific mechanical demands from magnetic operations.

Future Directions

Moving forward, research will likely focus on refining the CREW HaT shielding capabilities against particles with GeV scale energies, leveraging absorbed radiation dose as a primary metric for optimization rather than shielding efficiency. The integration of passive shielding components at strategic locations offers a potential avenue for maximizing protection across a broader range of particle energies.

Additionally, harnessing the cold vacuum of space to assist with superconductive cooling could markedly improve operational efficiency. By investigating advanced materials and innovative mechanical designs, such studies aim to enhance the feasibility of foldable, lightweight magnetic shielding systems, ideally suited for long-haul missions to Mars and beyond.

Conclusion

The CREW HaT concept represents a significant step toward enabling the feasibility of extended human presence in space without the prohibitive risk of radiation exposure. The careful balance of innovative engineering and fundamental physical principles positions this research at the forefront of active radiation shielding for future manned space exploration missions. Further validation and development are paramount to realize the potential of this promising technology in practical applications.