THE SPACE ENVIRONMENT

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THE SPACE ENVIRONMENT
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Background

• Galileo
• Gravity
• Inertia
• Newton Laws of Motion
• A body remains at rest or in constant motion
  unless acted upon by external forces
• The time rate of change of an objects momentum
  is equal to the applied force
• For every action there is an equal and opposite
  reaction
• Newtons Law of Universal Gravitation
• The force of gravity between two bodies is
  proportional to the product of their masses and
  inversely proportional to the square of the
  distances between them

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Space

• What are its bounds
• Starting above the earth's hard surface
• Piloted Aircraft 15 NM
• Aerodynamics 62 NM
• Black Sky 100NM
• Ending
• Solar System
• Milky Way (our galaxy)
• 200 Billion Stars
• Other galaxies
• 100 Billion Galaxies
• Beyond ???

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WHAT IS SPACE?
SPACE BEGINS AT APPROXIMATELY 54 NAUTICAL MILES
(NM). HOWEVER, THE EFFECTS OF THE EARTHS
ATMOSPHERE ARE FELT BY ORBITING SATELLITES ALL
THE WAY UP TO 300 NM.
NOT TO SCALE
MOON MEAN DISTANCE 207,533 NM
EARTH EQUATORIAL DIA. 6,887 NM
VAN ALLEN RADIATION BELT TRAPPED RADIOACTIVE
PARTICLES IN EARTHS MAGNETIC FIELD STARTS AT 216
- 540 NM FADES OUT AT 21,600 NM PEAKS OCCUR AT
TWO RANGES 1080 - 2160 NM AND 7020 - 10,800 NM
SUN MEAN DISTANCE 80,717,100 NM
NEAREST STAR DISTANCE 2.04 X 1013 NM
ATMOSPHERE TROPOSPHERE UP TO 10.8 NM
STRATOSPHERE 10.8 - 21.6 NM (DENSITY gt 10-6
gm/cm3) IONOSPHERE APPROX. 37.8 - 162 NM
(DENSITY DOWN TO 10-14 gm/cm3)
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HAZARDS

• Particles
• Radiation
• Heat
• Cold
• Vacuum
• Space Debris

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The Sun

• Solar Cycle
• Corpuscular Radiation
• Solar Wind
• Sun Spots
• Solar Flares
• Solar Protons
• Geomagnetic Storms

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Vulnerable Components

• Electronics
• Sensors
• Power Supplies
• Thermal Coatings
• Moving Parts
• Tanks
• Lines Couplings

Communication
Weather
Surveillance Warning
Navigation
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CHIP HARDNESS CRITERIA
SPECIFICATION
UNITS COMMENTS

• CUMULATIVE DOSE RADS
  LONG TERM
  RADIATION
• 
  
  CHIP DEGRADES GRADUALLY
• DOSE RATE
  RADS/MICROSEC IMPULSE
  RADIATION
• 
  
  CHIP DEGRADES,
• 
  
  MAY RECOVER
• SINGLE EVENT UPSET
  PROBABILITY/DAY IMPACT OF SINGLE
• ENERGETIC NUCLEAR
• (HYDROGEN IRON)
• SOFT BIT ERROR IN DATA
• (NO CHIP DAMAGE)
• HARD CHIP TRANSISTOR
  FAILURE
• (PERMANENT DAMAGE)

1 RAD 10-5 J ABSORBED RADIATION PER GRAM OF
MATERIAL
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SPACE DOSE BASIC CONTENT
TRAPPED RADIATION SPACE NUCLEAR BURST
TRANSIENT

• IONS EMP
• HYDROGEN (PROTONS) X-RAYS
• HELIUM GAMMA RAYS
• LITHIUM NEUTRONS
• IRON (?)
• (NATURAL) ELECTRONS FISSION FRAGMENTS
• (MANDMADE) ELECTRONS (ELECTRONS)

EACH COMPONENT HAS CHARACTERISTIC ENERGY
DISTRIBUTION
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Van Allen Belts

• Two Belts
• From 250 to 750 miles out to 6200 miles
• 45 degrees north to 45 degrees south latitude
• From 6200 out to 37,000 to 52,000 miles
• High Altitude Burst 1962 (Starfish)
• July 9, 1962 nuclear detonation at 400 Km
• Eliminated low radiation slot between belts
• Increased radiation in belts

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Probability of Impact
- 1010- - - -
- 1- - - -
- 10-10- - - -
- 10-20- -
Apollo 10 M2 Surface and 10 Day Mission
Number of Impacts


1015
1
10-15
10-10
105
10-5
1010
Probability of Impact
Mass in Grams
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Space Environment Impacts

• Radio transmissions
• Satellite drag
• Spacecraft charging
• Magnetic anomalies
• Particle collisions