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LT RBR:. Long Term Radiation Belt Remediation. Joshua Davis ASTE 527 Space Concepts Studio. LT RBR:. RBR means removing the trapped electrons and ions from the near Earth environment for the benefit of manned and unmanned spacecraft. Radiation Environment’s Impact on Manned Spaceflight.

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Lt rbr

LT RBR:

Long Term Radiation Belt Remediation

Joshua Davis

ASTE 527

Space Concepts Studio


Lt rbr

LT RBR:

RBR means removing the trapped electrons and ions from the near Earth environment for the benefit of manned and unmanned spacecraft.


Lt rbr

Radiation Environment’s Impact on Manned Spaceflight

Temporary and permanent eye damage.

A majority of the radiation Astronauts receive on orbit is attributed to the trapped radiation particles in the inner Van Allen belt.

Increased risk of cancers as well as heart, digestive, and respiratory diseases.

Career exposure cannot exceed 3 percent risk of exposure-induced death (REID) at a 95% confidence level.

The daily dosage of radiation on the ISS is equal to 8 chest X-rays per day.

Time on orbit is limited by an Astronaut’s total radiation exposure, limiting the ability to study long term micro-gravity effects on Humans.

Average annual exposure on the Earth’s surface is .125 rem/year, on board ISS during solar maximum is .1 rem/day


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Energetic Particle & Plasma Hazards

before after

False stars in star tracker CCDs

Surface degradation from radiation

Solar array power decrease due to radiation damage

Electronics degrade due to total radiation dose

Solar array arc discharge

Single event effects in microelectronics: bit flips, fatal latch-ups

Spacecraft components become radioactive

Electromagnetic pulse from vehicle discharge

Induced Voltage

Cryogenic systems experience notable charged particle heating

Time


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Energetic Particle & Plasma Hazards

Arc Discharging


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Energetic Particle & Plasma Hazards

Solar Panel Power Decrease


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Energetic Particle & Plasma Hazards

Bit Flips/Single Event Upsets


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Particle Motion in Earth’s Magnetic Field


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Radiation Belts are Highly Dynamic


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Radiation Belts are Highly Dynamic

Video reconstructing belts with SAMPEX data from Oct 18, 2003 to Jan 1, 2004

http://www.youtube.com/watch?v=QwNNh4c9bR0

Oct 25

Oct 27

Oct 30

Nov 3


Natural remediation

Natural Remediation

Solar or Nuclear Events


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How RBR Works:

Change the particle’s pitch cone angle such that its velocity vector is pointed roughly parallel to the magnetic field lines.


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VLF:

Very Low Frequency Radio Waves

Space Based

Ground Based


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Experimental Data for Ground Based VLF RBR

Ambient flux conditions

Increase in loss-cone electron flux during VLF operation


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AFRL DSX to test Space Based VLF RBR

“The overall primary objective of DSX is to resolve critical feasibility issues of injecting VLF waves into the magnetosphere to determine how efficiently, how effectively, and to what degree of efficacy this can be accomplished. The goal is to assess the particle distribution, perturbations, and scattering effects on the particles as a result of the VLF waves produced by nature and by man-made systems on the ground and in space.”


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Starfish Prime – High Altitude Nuclear Explosion

“It has been suggested that even a “small” HANE (~10–20 kilotons) occurring at altitudes of 125–300 km would raise peak radiation fluxes in the inner radiation belt by 3–4 orders of magnitude, and lead to the loss of 90% of all low-Earth-orbit satellites within a month [Dupont, 2004].”

“the manned space program would need to be placed on hold for a year or more”

Crippled 1/3 of operational satellites and disabled 7 satellites in the months that followed due to the particles injected into the radiation belts, some of which persisted for 5 years.


Rapid response remediation

Rapid Response Remediation

Particles Remain

Rapid Remediation Occurs

Solar or Nuclear Event Occurs

Ionospheric Distortion Subsides

Ionospheric Distortion Begins

Event Ends


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Issues with RBR


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Radio Communication Fade vs. Solar Cycle – Thule


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Long Term Radiation Belt Remediation

Enhanced Remediation vs. Natural Remediation


Conclusion and future work for lt rbr

Conclusion and Future Work for LT RBR

VLF ground based architecture study for geographic locations of interest

Feasibility study of Long Term operation of VLF stations (power, cost, effectiveness)


References

References

  • Odenwald, Sten. "What Are Space Radiation Effects?" NASA. <http://radbelts.gsfc.nasa.gov/outreach/effects.html>.

  • Hess, Wilmot N. "Energetic Particles in the Inner Van Allen Belt." Space Science Reviews 1.2 (1962). <http://rd.springer.com/article/10.1007%2FBF00240580>

  • Hoyt, Robert P., and Forward, Robert L. "Radiation Remediation." Tethers Unlimited. <http://www.tethers.com/HiVOLT.html>.


References cont

References Cont.

  • Gamble, Rory. Et al. "Radiation Belt Electron Precipitation by Man-made VLF Transmissions." Journal of Geophysical Research 113 (2008): American Geophysical Union, 21 Oct. 2008. <http://www.agu.org/pubs/crossref/2008/2008JA013369.shtml>.

  • Rodger, Craig J. "The Atmospheric Implications of Radiation Belt Remediation." AnnalesGeophysicae 24 (2006). European Geosciences Union. <http://www.ann-geophys.net/24/2025/2006/angeo-24-2025-2006.pdf>.


References cont1

References Cont.

  • Basu, Santimay, and MacKenzie, E. “Ionospheric constraints on VHF/UHF communications links during solar maximum and minimum periods” Radio Science 23 (1988): American Geophysical Union, 17 Jan. 1988. <http://www.agu.org/journals/rs/v023/i003/RS023i003p00363/RS023i003p00363.pdf>.

  • Scherbath, Mark. Et al. "AFRL's Demonstration and Science Experiments (DSX) mission", Proc. SPIE 7438, Solar Physics and Space Weather Instrumentation III, 74380B (September 23, 2009); doi:10.1117/12.824898; <http://dx.doi.org/10.1117/12.824898>


Backup slides

Backup Slides


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Why does the Earth have a Radiation Belt?

A Radiation Belt is

more stylish than

Radiation Suspenders!


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Tethers Unlimited : HiVOLT


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Neutral Particle Injection

Ion-Cyclotron Turbulence Generation


Natural remediation analogy

Natural Remediation - Analogy

The radiation belts work in a similar fashion, the more particles coming into the system, the more particles come out of the system.

However, particles in the belts can become stuck for months or years, so equilibrium takes a very long time to reach after an event.

Just as with the bucket, if there are no particles in the radiation belt, the protective magnetosphere is unaffected

Water is poured into the top of the bucket and exits through a porous plug at the bottom of the bucket.

If the rate of water being poured into the system increases, the water level rises until the pressure causes an equilibrium condition

If there is no water, there is still a bucket.


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Increasing Density


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Radio Communication %Fade vs. Solar Cycle – Ascension Island


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