plasma effects

8/3/2019 Plasma Effects

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Ionospheric and Magnetospheric

Plasma (and Neutral Density)

Effects

David Cooke

Gregory GinetAir Force Research Laboratory

Space Vehicles Directorate

Hanscom AFB, MA

Solar and Space Physics and the Vision for Space Exploration

Wintergreen Resort, VA

16-20 October 2005


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We defineplasma effects as the result of interactions betweenthe naturalspace plasmaand aparticularsystem, e.g.communications, radar orsatellite.

Radio wave reflection and refraction

Radio link scintillation

Satellite drag (a neutral density effect)

Satellite surface charging and materials degradation

There can also be plasma effects due to active on-boardplasmasystems (but not addressed in thispresentation)

Electricpropulsion

Electron beams

Tethers

Plasma EffectsIntroduction


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Plasma EffectsIonosphere

Ionosphere formed by solar EUV/UVradiation

TURBULENTPLASMABUBBLES Subject to Raleigh-

Taylor instability

during day to night

transitionep nf

3109 }

o

p

f

fII

!

2

2

1

and is an inhomogeneous dielectric

POLAR IONOSPHERICDISTURBANCES

EQUATORIALIONOSPHERIC

DISTURBANCES

MAGNETICEQUATOR


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Plasma EffectsElectron Density

Effects HF communications, GPS single and dual frequency,radar & geolocation accuracy


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Plasma EffectsScintillation

Degrades UHF (SATCOM) and L-Band (GPS) systems


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Forecasting Algorithms& Modeling

DataExploitation

IonosphericSpace & Ground

Sensors

Real-time in-

situ and

remote

sensing data

Combination of physics-

based and empirical

forecasting techniques

Space, ground, and

modeled data usage for

forecasting

Plasma EffectsComm/Nav Outage Forecast System (C/NOFS)

Provide scintillation nowcasts

Develop capabilities to produce short (2-3 hrs before onset), medium (4-6 hrs before

onset) and long term (24-72 hrs before onset) scintillation forecasts

Improved understanding of equatorial ionosphere and scintillation triggers / inhibitors


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Plasma Efects

C/NOFS Payload Description

RAM Plasma Sensors

Planar Langmuir Probe (PLP)

Developed by AFRL/VS

(D. Hunton PI)

Measures: Ion Density, Ion

Density Variations, Electron

Temperature

Ion Velocity Meter(IVM)

Developed by Univ. of Texas

(R. Heelis PI)

Measures: Vector Ion Velocity,

Ion Density, Ion Temperature

Neutral Wind Meter(NWM) Developed by Univ. of Texas

(R. Heelis PI)

Measures: Vector Neutral

Wind VelocityRF Beacon

Coherent EM Radio Tomography (CERTO)

Developed by NRL (P. Bernhardt PI)

Measures: Remote sensing of RF scintillationsand LOS TEC

GPS ReceiverC/NOFS Occultation Receiver forIonospheric

Sensing and Specification (CORISS)

Developed by Aerospace (P. Straus PI)

Measures: Remote sensing of LOS TEC

Electric Field Instrument

Vector Electric Field

Instrument (VEFI)

Developed by NASA/GSFC

(R. Pfaff PI)

Measures: Vector AC andDC electric fields


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Plasma EffectsEquatorial Plasma Bubble Modeling

Problem: Equatorial plasma bubbles (EPBs) cause degradationof communication/navigation signals

Solution:

Derived global climatology (seasonal/longitudinal)

using DMSP data; validated with ROCSAT-1

equatorial satellite

Developed working 3D model of EPB development

Longitude

0 30 60 90 120 150 180 210 240 270 300 330 360

Jan

Feb

Mar

April

May

June

July

Aug

Sept

Oct

Nov

Dec

Jan

Longitude

EPB Occurrence Rates 1989 - 2003

45-50

40-4535-40

30-35

25-30

20-25

15-20

10-15

5-10

0-5

Africa India Pacific America AtlanticDMSP EPBs 1989 - 2003

2D

3D


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Plasma EffectsRe-entry

Reentryplasma effects oncommunication and navigationsystems

Air ionization and heat shieldablation generatesplasmasheatharound vehicle

Blackout of navigation andcommunication links

Reentryplasma isaffected byacomplex list ofvariables.

Vehicle geometry

Heat shield composition

Trajectory

GPS

Blackout

Comm

Blackout

Sensor

Blackout

Wake Signature

Incident RF

Antenna

Plasma

Understanding of the influence of

mission design variables is essential

for successful tradespace analysis.


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Drag errors degrade capability- Maintain catalog ofallspace objects

- Predict satellite positions

- Provide Collision Avoidance warnings

- Predict satellite reentries

- Optimize satellite design

PREDICTED

ACTUAL

0.8

0.85

0.9

0.95

1

1.05

1.1

1.15

1.2

Jan-70 Jan-74 Jan-78 Jan-82 Jan-86 Jan-90 Jan-94 Jan-98

Time

Data-to-ModelRatio

Normalized

Original

Thermospheric Cooling

0.7

0.8

0.9

1

1.1

1.2

50 100 150 200 250

Solar Flux

RatiotoModel

Neutral Density EffectsSatellite Drag


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Problem:Atmospheric densityvariations due to geomagneticstormsdegrade AFSPC satellite tracking capability

Solution:Develop data-driven first-principlesmodels to replace current

operational empiricalmodels forsatellite orbit prediction

Empirical model IOC at NORAD 2005

Improvement to 5% but still

Does not meet operational requirements Incapable of characterizing storms

No forecast capability

Frank Marcos, et al.

High-Accuracy Satellite Drag Model(HASDM)

Neutral Density EffectsModeling

Large storm-induced variations


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Plasmasheet & ring current

Outer zone electrons

Aurora

Inner belt protons

Plasma EffectsMagnetosphere


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Single event effects (SEE)

(ions > 40 MeV)

Dielectric charging

(electrons > 0.2 MeV)

Surface charging

(electrons 5-50 keV)

Total Dose

(> 5 MeV p+, > 1 Mev e-)

Ionospheric drivers

Optical backgrounds

Cosmic rays

Solar energetic particles

Space plasma

(and electromagnetic fields)

Trapped energetic particles

keV

GeV

Plasma EffectsSatellites

Population Hazard

Nuclear Detonation

Solar Eruption

Solar CellDegradation

Charging Damage


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Negotiations

Under Way

For Tempo 2

Settlement___________________________________Space News, August 4, 1997

SolarSolarArrayArray

Solarcell failures on TEMPO 2 GEO communicationssatellite

New failure mode discovered moving from 40 to 100 V arrays

Charging ofspacecraft leads to discharges between the arraysand the space

plasma

Subsequent Kapton pyrolosisleads to self-destruction of the 100 Volt arrays

Impact on finished,unlaunched satellitescurrentlyunder investigation

Plasma EffectsExample: Solar Array Breakdown


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Plasma effects on materials

M. Meshishnek


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HET main plume region

Sheath

HET

AFRL NASA-SEE partnership effort

Spacecraft charging and plasma interaction model

Supercedes previous NASA AF charging codes

Non-linear finite elements with continuous electricfields

Time dependent PIC and steady state plasmaalgorithms for self-consistent sheaths, wakes, and

plumes

Nested Cartesian grids plus local adaptive mesh

Object tool and import from 3rd party CAD tools

Version 3.0 for LEO & GEO released Jun 05 Object ToolKit and GEO charging

EP thruster plume effects C/NOFS potential scheme

Plasma EffectsNASCAP-2K

NASA-AF Spacecraft Charging Analyzer Program 2000

NASCAP2K Modelof STEREO


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Plasma EffectsCharge Control Technology

Ion Proportional Surface Emission Cathode

Goal: Passively emit electrons in proportion to

ion current

Surface emission cathode employs field

emission at metal-dielectric-vacuum interface

Plasma ions enhance the electron emission by

maintaining the positive space charge in the

substrate, eliminating need for gate

Status: In lab development

M.W. Geis and S. Deneault

CCS-II: Xenon plasma 8 yr@ 0.1 A; 13 Kg charged

CCS-I: Xenon plasma 1 yr @ 0.02 A; 20 Kg, 7 boxes.

Charge Control System - IIGoal: Developan easy to integrate plasma

emission source forcharge control.

Mitigate GEO charging

Controlactive spacecraft potential

Status: Prototype in lab testing.

.

35% reduction in weight

8X longerlifetime

1/3 complexity


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Surface

Density (kg m-3)

Plasma

Density (cm-3)

Ion Temp

(keV)

Electron

Temp (keV)

Surface B

Field (G)

Solar wind (1 AU) 2 - 20 0.001 - 0.3 0.01 - 0.2 2.0e-5 - 1.0e-6

Earth

Atmosphere 1.3

Ionosphere 3.0e+3 - 3.0e+6 3.0e-5 - 3.0e-4 3.0e-5 - 3.0e-4

Magnetoshere 1 - 3 (GEO) 5 - 30 (GEO) 1 - 10 (GEO) 0.3

Moon

Atmosphere tr ace Na, K

Ionosphere ~ 1.0e+4 0.02 - 0.3 photoelectrons

Magnetosphere X X X < 1.0e-4 (crust)

Mars

Atmosphere 1.80E-02

Ionosphere 1.0e+3 - 1.0e+5 2.0e-5 - 2.0e-4 2.0e-4 - 8.0e-4

Magnetosphere X X X < 1.6e-2 (crust)

Space Plasma EffectsDifferent Plasma Environments


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The Lunar Electrosphere

Thanks to John Freeman

The Moon is enveloped with a sheath of photoelectrons Observations from Apollo SIDE and CPLEE instruments

Day-side: surface potential about + 10 volts due primarily tophotoelectrons, N104/cc within 20cm of surface, few m total height(Freeman et.al., JGR, 1973)

Terminator: surface potential of order -50 volts or higher due to

energetic electrons from Solar Wind (Benson et.al., 1975)

Night-side: surface potential = -100 volts or higher in theplasmasheet. (Reasoner and Burke, 1972)

Possible hazard to equipment with exposed potentials

Water vapor events.

Observed on several occasions (Freeman et.al., 1973) H2O

+ clearly identified

Source of events remain unidentified

Dusty Plasma

Dust raised by impacts, activity, auto-levitation becomes photo-chargedand suspended against weak gravity. (Stubbs et.al, 2005)

Potential contamination source


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Plasma EffectsSummary

The space plasma environment can affect systems in many ways

Radio wave reflection and refraction

Radio link scintillation

Satellite drag (a neutral density effect)

Satellite surface charging and materials degradation

Regions ofmost concern for the Vision of Space Exploration:

Earth'smagnetosphere and ionosphere

The solar wind


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Backups


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Space Environment Hazards

Space Particle Hazards

Radiation degradation and

electronics upsets

Surface and internal charging /

discharging

Surface sputtering/contamination

Ionosphere/Neutral Hazards

Comm/Nav link degradation

and outage

Surveillance clutter

Satellite Drag

Direct Solar Hazards

Radio, optical and X-ray

interference Solar energetic particle

degradation and clutter

plasma effects

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