Deployed Electromagnetic Radiation Deflector Shield
Aerospace
Deployed Electromagnetic Radiation Deflector Shield (KSC-TOPS-97)
Creating a Zone of Minimum Radiation and Magnetic/Plasma Effects for Spacecraft
Overview
Spaceflight outside of the Earth's protective magnetic field is dangerous from a cosmic radiation perspective. Inside Earth's magnetic field, where the manned International Space Station (ISS) orbits, the radiation encountered is minimal and almost all is deflected by our planet's magnetic fields. However, outside that protective shield, the Sun's solar wind (high energy radiation, solar energetic particles or SEPs) consisting of protons, electrons, alpha particles and plasmas continuously bombards the spacecraft for the months or years of spaceflight. On occasion the Sun produces a CME (Coronal Mass Ejection) that vastly increases the energy and volume of this radiation. These particles damage human DNA as well as living tissue and can destroy sensitive electronics. The Deployed Electromagnetic Radiation Deflector Shield (DERDS) provides a magnetic field that will deflect SEPs and CMEs and other harmful solar and cosmic rays away from a manned spacecraft, robotic spacecraft, or manned extra-planetary base stations using an electromagnet that is deployed between the spacecraft/station and the source of radiation and creates a magnetosphere or zone of minimal radiation in which the spacecraft or base station would reside.
The Technology
The typical remedy for space radiation hazards has been to harden the space vehicle's electronics and software from these high-speed particles and placing heavy shielding in these manned or sensitive areas. This adds considerable weight and cost to the launch vehicle, reduces payload capacity, and is passive in nature. SEPs and CMEs can be deflected by a magnetic field to pass around the spacecraft and not be absorbed by it. This deflection of solar wind and radiation is due to the Lorentz force. However, a magnetic field that is attached to the spacecraft and enclosing it would cause other shielding issues with equipment and would require much more electrical power to operate due to the need to enclose the entire spacecraft within that attached magnetic field.
This would also perturb the data collection and transmissions of the spacecraft. Additionally, the generated magnetic field can capture some of the solar radiation as a plasma within the magnetic torus further impeding scientific data collection due to its close position to the spacecraft.
DERDS is deployed in space away from the protected spacecraft to remain between the radiation source and the spacecraft. It utilizes on board cosmic ray sensors to note the need for the strength of the magnetic field, and on-board sensors to position itself directly in line between the radiation source and the protected spacecraft or station. Onboard computers and thrusters maintain the required position, so that the magnetic field is positioned for the best deflection angle based on incoming radiation. The DERDS magnetic field can be varied in both direction, intensity, and time by use of both AC and DC electrical power inputs and varied as needed to optimize the deflection angle and power requirements. The magnetic field can also be perturbed in irregular or set patterns by onboard computers and sensors as needed to maintain the proper deflection of SEPs, CMEs, and other cosmic rays. DERDS creates a magnetic field that will not need to be so large (with a much larger power requirement) as to encompass the entire protected spacecraft, and the magnetic field will not interfere with the spacecraft.
Benefits
- Deflects harmful solar and cosmic rays
- Creates zone of minimal radiation
- Reduces need for additional shielding
- Reduces weight and cost of launch vehicle
Applications
- Manned Spacecraft
- Robotic Spacecraft
- Manned Extra-planetary Base Stations
Similar Results
Using the Power Grid for Geophysical Imaging
This technology utilizes the U.S. high-voltage power transmission grid system as an extremely large antenna to extract unprecedented spatiotemporal space physical and geological information from distributed GIC observations. GICs are measured using differential a magnetometer technique involving one fluxgate magnetometer under the transmission line and another reference magnetometer station nearby. The reference station allows subtraction of the natural field from the line measurement, leaving only the GIC-related Biot-Savart field. This allows inversion of the GIC amplitude. The magnetometer stations are designed to operate autonomously. They are low-cost, enabling large scale application with a large number of measurement locations.
Computer-implemented energy depletion radiation shielding
The difference between Layered Energy Depletion Radiation Shielding (LEDRS) and Stacked Energy Depletion Radiation Shielding (SEDRS) is how the piece of matter, or shield, is analyzed as radiation passes through the matter.
SEDRS involves using a defined and ordered stack of layers of shielding with different material properties such that the thickness and chemical properties of each material maximizes the absorption of energy from the radiation particles that are most damaging to the target. The SEDRS shielding method aims to provide the maximum level of energy absorption while still keeping shielding mass and volume low.
The process of LEDRS involves using layers of shielding material such that the thickness of each material is designed to absorb the maximum amount of energy from the radiation particles that are most damaging to the target after subsequent layers of shielding. The more energy is absorbed by the shielding material, the less energy will be deposited in the target minimizing the required mass to achieve a resulting lower dose for a given geometrical feature. The LEDRS shielding method aims to provide the maximum level of energy absorption. The process for designing LEDRS views potential radiation shields as a cascade of effects from each shielding layer to the next and is helpful for investigating the particular effects of each layer.
SEDRS and LEDRS can improve any technology that relies on the controlled manipulation of a radiation field by interaction with a material element.
Atomic Number (Z)-Grade Radiation Shields from Fiber Metal Laminates
This technology is a flexible, lighter weight radiation shield made from hybrid carbon/metal fabric and based on the Z-grading method of layering metal materials of differing atomic numbers to provide radiation protection for protons, electrons, and x-rays. To create this material, a high density metal is plasma spray-coated to carbon fiber. Another metal with less density is then plasma spray-coated, followed by another, and so on, until the material with the appropriate shielding properties is formed. Resins can be added to the material to provide structural adhesion, reducing the need for mechanical bonding. This material is amenable to molding and could be used to build custom radiation shielding to protect cabling and electronics in situations where traditional metal shielding is difficult to place.
System for Flight Control of Extremely Fast (Hypersonic) Aircraft
NASA’s MHD patch technology consists of two electrodes positioned a prescribed distance apart on the surface of the TPS of an aircraft or spacecraft and an electromagnetic coil placed directly below the electrodes with the magnetic field protruding out of the surface. During hypersonic flight, the conductive ionizing atmospheric flow over the surface enables current to flow between the two electrodes. This current is harnessed to power the electromagnet which in turn generates strong Lorentz forces that augment lift and drag forces for guidance, navigation, and control of the craft. Alternatively, the current can be used to charge a battery. Changing the size of the MHD patch (e.g., the length or distance between the electrodes), the strength of the electromagnet, or the direction of the magnetic field enables tuning of generated forces for a given craft design. Multiple MHD patches can be leveraged on a single craft.
In-silico evaluation of the MHD patch technology on select aeroshell designs for mock entry into planetary atmospheres has been performed. A 1m2 MHD patch exerts forces up to 200 kN under simulated Neptune atmosphere entry, significantly increasing the lift/drag (L/D) ratio for the aeroshell investigated. This value is the same order of magnitude as the “whole body” drag and lift forces computed for the aeroshell suggesting the generated forces can be used to control a craft.
Improved Hypersonic Aircraft Flight Control System
NASA’s MHD patch technology is composed of two electrodes positioned a prescribed distance apart recessed into angled channels on the surface of the TPS of an aircraft or spacecraft and an electromagnetic coil placed directly below the electrodes with the magnetic field protruding out of the surface. Note that the recessed/angled MHD patch described here is a special version of the original MHD patch described in LAR-TOPS-363. During hypersonic flight, the conductive ionizing atmospheric flow over the surface permits current to flow between the two electrodes. This current is harnessed to power the electromagnet which in turn generates strong Lorentz forces that augment lift and drag forces for guidance, navigation, and control of the craft. Alternatively, the current can be used to charge a battery. Changing the size of the MHD patch (e.g., the length or distance between the electrodes), the strength of the electromagnet, or the direction of the magnetic field enables tuning of generated forces for a given craft design. Multiple MHD patches can be leveraged on a single craft.
In-silico evaluation of the non-recessed, non-angled MHD patch technology on select aeroshell designs for mock entry into planetary atmospheres has been performed. A single 1m2 MHD patch exerts forces up to 200 kN under simulated Neptune atmosphere entry that can be used to control a craft.
