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Space Weather (SpW)
Near Earth Space Environment (NESE)
Implications for Spacecraft (S/C) Design
Yurdanur Tulunay, Ph.D., Space Research, UK, 1972
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keywords-statements
• Spaceweather (SpW)
• NESE interacts with S/C engineering subsystems and payloads
ancient dream
• Traveling among the stars, the planets, moon
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Isaac Newton
• 260 years ago had a complete understanding of what was required to
place an object in orbit around E+
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1957
• Technological ability to leave the E+’s surface
• First steps in exploration of our solar system
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challenge• Difficulty of getting a S/C into orbit
• S/C must be designed to operate in environments that are quite different from
those found on the E+’s surface.
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1971-1989
• Database of 2779 S/C anomalies related to interactions with NESE
(The Nat. Geophyl. Data Center, Boulder, Co., USA)
• NASA and AF S/C studies:
~20-25% of all S/C failures are related to NESE (Tribble, 1995)
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1993• NASA recognised the importance of the field of NESE by forming a national
program to coordinate a efforts in this area• International Standards Organisation (ISO) under charter from the UN formed a Space
System Technological Comm.one of the missions was to develope
internationaly recognised NESE standards.
(Song, et al., eds., 2001)
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1994 June
• 1st doc. by Anderson, B.J. (Ed.)
Natural Orbital Environment Guidelines for use in Aerospace Vehicle Development
NASA Technical Manual
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1999 - 2001• Space Weather and the ESA feasibility
studies2003 - 2005
• Space Weather Applications Pilot Project including Service Development Activities (SDA)
(Jansen, et al., 2004)
SWWT 1999 – today• Space Weather Working Team
• European Union (FP5, FP6 and FP7) and Space Weather
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• Seek to bridge the gap between space physics and astronautical engineering
►NESE◄
i.e.
Emphasis on the facets of the NESE that may degrade S/C subsystems
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objective
To obtain an understanding of the relationship between:
NESE and S/C
or
Space inst., operating principals
and design alternatives.
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content
• description of the NESE
• a discussion of the ways in which the NESE may interact with an orbiting S/C
• by relating the various NESE interactions to S/C design specifics
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justification Understanding these relationships is important to• S/C designers-must develop a spacecraft
capable of operating in specified orbital environment
• Payload providers-must provide instrumentation capable of delivering
high quality data under potentially
adverse conditions
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S/C design
• Regardless of the specific nature of
the payload, all the S/Cs must perform certain basic functions in order to enable the payload to function properly.
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Most S/Cs can be grouped into one of
the three orbital altitude range:
LEO
MEO (HEO)
GEO
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• LEO: perigee<1000 km altitude region
space shuttle operates mostly,
typically reserved for
i) largest operational payloads
(e.g. space station-Skylab, Mir, Salyut) or
ii) S/C need a close view of the E+
(e.g. LANDSAT, TIROS, DMSP)
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• MEO (or HEO): perigee:1000-2000 km altitude rangee.g. mostly reconnaissance sattelites placed on highly elliptical orbits.
• GEO: altitude 35800 km Popular with various surveillence
and communication S/Cs.
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• S/C’s orbital altitude
and
• orbital inclination (i). i=f(altitude)
(A given launch vehicle can launch the heaviest possible payload into an inclination=latitude of the launch site)
major impacts on the type and magnitude
of NESE effects experienced by a S/C.
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conclusion
• NESE may have a direct impact on a S/C subsystem’s ability to execute its design objective.
• Depending on the severity of the orbit, these interactions may be quite mild or may be mission threatening.
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SPACE ENVIRONMENTS
VACUUM NEUTRAL PLASMA RADIATION MM/OD
SPACE SYSTEMS
Solar UV
Outgassing & Contamination
Aerodynamic Drag
SputteringAtomic Oxygen Attack
Spacecraft Glow
Spacecraft ChargingVan Allen Belts
Galactic Cosmic Rays
Solar Proton Events
Impacts
Altitute Determination &
Control
Degradition of Sensors
Induced Torques
Change in sensor coating
Interference with sensors
Torques due to induced potentials
Avionics Upsets due to EMI from
arcingDegradition: SEU's, bit errors,...
EMI due to impacts
Electrical PowerChange in coverslide
tranmissions
Change in coverslide transmittance
Shift in floating
potential, reatraction of contaminants
Degradition of solar cell outputDestruction/ Obscuration of solar cells
Propulsion
Thruster plumes may be a contaminant
source
Drag makeup Fuel
Requirements
Shift in floating potential due to thruster firings
Rupture of pressurized
tanks
Structures EMI due to
impacts
Telemetry, Tracking &
Communications
Degradation of sensors
Change in sensor
coatingInterference with sensors
EMI due to arcing Degradition of electronicsEMI due to
impacts
Thermal ControlChange in surface
alpha / epsilon ratio
Change in surface alpha / epsilon ratio
Reatraction of contaminants
Cold surfaces may be experience heating
Degradition of alpha /
epsilon ratio
(Fortescue, Stark, eds, 1995)
30Impact
vaporization may stimulate
arcing
Impacts may
expose underlying surfaces to
erosion
Impacts may slightly
increase drag
Impacts may liberate
contaminantsImpactsMM/OD
SPEs suppress
GCRs
Solar Proton Events
Galactic Cosmic Rays
Radiation may increase charging
Radiation dose may increase
outgassing
Van Allen Belts
Rad.
Charged surfaces
may increase
sputtering
Spacecraft Charging
Plasma
Spacecraft Glow
AO attack may alter surface
conductivities
AO resistant materials
are susceptable
to glow
AO may clean contaminated
surfaces
Atomic Oxygen Attack
Sputtered material may contanimate sensitivesurfaces
Sputtering
Drag removes OD from
lower orbits
Flow may reflect contaminants to
S/C
Aerodynamic Drag
Neutral
Increases arcing rate
Outgassed material
may contribute to
glow
Outgassing & Contamination
Solar cycle alters OD density
Induces photoemission
of electronsSolar cycle alters atmospheric densities
Photochemical Deposition of contaminants
Solar UV
Vac.
ImpactsS P
EvenGCR
V A belts
Spacecraft Charging
Spacecraft Glow
Atomic Oxygen Attack
SputteringAerodynamic
DragOutgassing & Contamination
S UV
MM/ODRadiationPlasmaNeutralVacuum
Impact vaporization
may stimulate arcing
Impacts may
expose underlying surfaces to
erosion
Impacts may slightly
increase drag
Impacts may liberate
contaminantsImpactsMM/OD
SPEs suppress
GCRs
Solar Proton Events
Galactic Cosmic Rays
Radiation may increase charging
Radiation dose may increase
outgassing
Van Allen Belts
Rad.
Charged surfaces
may increase
sputtering
Spacecraft Charging
Plasma
Spacecraft Glow
AO attack may alter surface
conductivities
AO resistant materials
are susceptable
to glow
AO may clean contaminated
surfaces
Atomic Oxygen Attack
Sputtered material may contanimate sensitivesurfaces
Sputtering
Drag removes OD from
lower orbits
Flow may reflect contaminants to
S/C
Aerodynamic Drag
Neutral
Increases arcing rate
Outgassed material
may contribute to
glow
Outgassing & Contamination
Solar cycle alters OD density
Induces photoemission
of electronsSolar cycle alters atmospheric densities
Photochemical Deposition of contaminants
Solar UV
Vac.
ImpactsS P
EvenGCR
V A belts
Spacecraft Charging
Spacecraft Glow
Atomic Oxygen Attack
SputteringAerodynamic
DragOutgassing & Contamination
S UV
MM/ODRadiationPlasmaNeutralVacuum
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