PDH/CEU/FBPE Session #5: Spacecraft Radiation Shielding by a Dispersed Array of Superconducting Magnets
Location
Antigua Room
Start Date
26-5-2016 7:30 AM
End Date
26-5-2016 8:30 AM
Description
Radiation encountered in deep space poses a significant threat to the health of astronauts and the success of future NASA missions beyond low-Earth orbit (LEO). Isotropic galactic cosmic rays (GCRs) and intermittent solar particle events (SPEs) threaten to cause acute radiation sickness and exceed NASA's permissible exposure limits for cancer risk for the crew. One previously proposed safeguard against this risk, included in current ISS infrastructure, is the “armor” approach, by which thicker spacecraft walls absorb incoming radiation. However, this method quickly reaches a point of diminishing returns due to secondary particle showers produced within the walls. Another safeguard under consideration is the “artificial magnetosphere” approach, by which a dipole magnetic field, akin to Earth's magnetosphere, is produced in the immediate vicinity of the habitat by superconducting magnets attached to the outside of the spacecraft. While it may work as a deflecting shield, this method suffers from several concomitant, and so far unresolved, side effects. Here, as an alternative, we describe the ongoing study of a novel architecture of the magnetic shield capable of reducing the amount of radiation that reaches the astronaut habitat to a desired level, but without producing the above mentioned problems. Instead of one or a few very large solenoids in the vicinity of the habitat, we consider a reconfigurable array of smaller, self-propelled superconducting magnets (magnetic drones) forming a closed configuration of the magnetic field located at a certain distance from the spacecraft. This shielding architecture will be possible to deploy in parallel with the existing NASA Orion spacecraft infrastructure. The magnets can function in a persistent mode using state-of-the-art high temperature superconducting wires that require only passive cooling. We will present the results of computational models investigating the shielding properties of several configurations of multiple magnetic dipoles against charged particle radiation, including protons and heavy nuclei, with energies characteristic of GCRs and SPEs.
Our results show that as few as one small-scale (r = 20 cm; ~CubeSat size) superconducting loop, placed at a large distance from the spacecraft, can deflect a large fraction of incident SPE radiation from the habitat volume. Additionally, we will show that an evenly spherical “buckyball” array of as few as eight superconducting magnets can deflect GCR radiation from the central habitat, thus reducing the exposure risk to astronauts from such radiation by a significant amount during a long-duration mission beyond LEO.
Top Three Takeaways
This presentation is worth 1 PDH (FBPE-eligible) credential renewal.
Biographies
Dr. Chesny received his PhD from Florida Institute of Technology in 2013 with concentrations in solar physics and advanced plasma propulsion system development. He is currently a Postdoctoral First Award Fellow for the National Space Biomedical Research Institute researching a novel radiation shielding technique for future human long-duration missions deep space. He is also a co-founder of a small business doing basic R&D for the space program and fundamental space science research.
PDH/CEU/FBPE Session #5: Spacecraft Radiation Shielding by a Dispersed Array of Superconducting Magnets
Antigua Room
Radiation encountered in deep space poses a significant threat to the health of astronauts and the success of future NASA missions beyond low-Earth orbit (LEO). Isotropic galactic cosmic rays (GCRs) and intermittent solar particle events (SPEs) threaten to cause acute radiation sickness and exceed NASA's permissible exposure limits for cancer risk for the crew. One previously proposed safeguard against this risk, included in current ISS infrastructure, is the “armor” approach, by which thicker spacecraft walls absorb incoming radiation. However, this method quickly reaches a point of diminishing returns due to secondary particle showers produced within the walls. Another safeguard under consideration is the “artificial magnetosphere” approach, by which a dipole magnetic field, akin to Earth's magnetosphere, is produced in the immediate vicinity of the habitat by superconducting magnets attached to the outside of the spacecraft. While it may work as a deflecting shield, this method suffers from several concomitant, and so far unresolved, side effects. Here, as an alternative, we describe the ongoing study of a novel architecture of the magnetic shield capable of reducing the amount of radiation that reaches the astronaut habitat to a desired level, but without producing the above mentioned problems. Instead of one or a few very large solenoids in the vicinity of the habitat, we consider a reconfigurable array of smaller, self-propelled superconducting magnets (magnetic drones) forming a closed configuration of the magnetic field located at a certain distance from the spacecraft. This shielding architecture will be possible to deploy in parallel with the existing NASA Orion spacecraft infrastructure. The magnets can function in a persistent mode using state-of-the-art high temperature superconducting wires that require only passive cooling. We will present the results of computational models investigating the shielding properties of several configurations of multiple magnetic dipoles against charged particle radiation, including protons and heavy nuclei, with energies characteristic of GCRs and SPEs.
Our results show that as few as one small-scale (r = 20 cm; ~CubeSat size) superconducting loop, placed at a large distance from the spacecraft, can deflect a large fraction of incident SPE radiation from the habitat volume. Additionally, we will show that an evenly spherical “buckyball” array of as few as eight superconducting magnets can deflect GCR radiation from the central habitat, thus reducing the exposure risk to astronauts from such radiation by a significant amount during a long-duration mission beyond LEO.
