2. Lesson 2 Space Environment & Orbital Mechanics A537 SPACE ORIENTATION

3. The Space Environment Electromagnetic radiation and electrically-charged particles stream outward from the Sun and engulf the Earth. The radiation and particles interact with the Earth’s magnetic field and atmosphere. Electrically-charged particles Electromagnetic radiation Magnetosphere Earth

4. *Radio Wave VLF HF UHF SHF Infrared Ultraviolet X-ray Gamma Wavelength 10 -12 meters 10 -8 meters 10 -7 meters 10 -6 meters 0.01 meters 100 meters 0.5 meters 10 -3 meters 10 5 meters Electromagnetic Spectrum of Solar Energy * Not all types of radio waves are shown Causes ionization and heating of atoms and molecules AM Radio FM Radio Causes “traditional” weather Visible

5. TROPOSPHERE STRATOSPHERE MESOSPHERE THERMOSPHERE 25+ Satellites RADIATION BELTS 25+ Satellites MAGNETOSPHERE 30+ Satellites DMSP/NOAA GPS U-2 SHUTTLE SEAMLESSBATTLESPACESEAMLESSBATTLESPACE DSP MILSTAR DSCS FLTSAT GOES Comm SATCOM IONOSPHERE SPACE WEATHER Depiction of key environmental regions, examples of satellites currently in orbit, and approximate numbers of DoD satellites in orbit in various regions. (Not drawn to scale.) TERRESTRIAL WEATHER

6. Earth’s Magnetosphere Solar Wind

7. Magnetospheric Currents Interplanetary Magnetic Field Tail Current Magnetopause Cusp Magnetopause Current Corotating Ring Current Field Aligned Current Neutral Sheet Current

8. Aurora Visible light image - particle bombardment EUV image - auroral oval

9. The Solar Cycle Solar Minimum Solar Maximum 0 50 100 150 200 195419571960196319661969197219751978198119841987199019931996199920022005 Solar Cycles 19-23 Next Peak: 2000

10. Solar Flare An explosive release of energy previously stored in intense, complex magnetic fields

11. EHF (Extremely-High Frequency) Frequency 30 - 300 GHz 3 - 30 GHz Depiction of Radio Wave Signal Types and the General Effects Caused by the Ionosphere. VHF (Very-High Frequency) SHF (Super-High Frequency) UHF (Ultra-High Frequency) HF (High Frequency) MF (Medium Frequency) VLF (Very-Low Frequency) LF (Low Frequency) 300 MHz - 3 GHz 30 - 300 MHz 3 - 30 MHz 300 - 3000 KHz 30 - 300 KHz 3 - 30 KHz SATCOM GPS Ionosphere’s Effect Negligible Significant Refraction Phase and Amplitude Disruptions

12. UndisturbedIonosphere Shortwave Fades HF radiowave F D E

13. Ionosphere Scintillation SATCOM Disruption SATCOM thresholds Moderate (partially degraded): 4-12 dB Severe (SATCOM impossible): >12 dB

14. Impacts on GPS Navigation Signals Ionosphere Scintillation

15. Ionosphere True location Spacetrack Errors Apparent location

16. Radar and SATCOM Interference Radar interference Radio burst SATCOM interference

17. Ionosphere Radar Interference AURORA Signal reflected

18. Spacecraft Charging and Upsets Cause - electrically-charged particle bombardment, or solar illumination; combined with variations in vehicle shape and materials Effect - surface or deep charging (depends on particle energy) Result - electrostatic discharge (induces an electrical micro- current) Physical damage or logic upset Memory loss False command Solar wind

19. Satellite Disorientation False star? Particle stream (Protons)

20. Expected trajectory Launch Trajectory Errors and Payload Deployment Problems Charged particles Actual trajectory

21. Atmospheric Drag - Orbit Changes Expected position Actual position

22. August 1972 Solar Flare Radiation Hazard Astronauts on the moon could have received fatal radiation!

23. National Space Weather Services NASANASA FAAFAA Power companiesPower companies ResearchersResearchers Ham radio operatorsHam radio operators General publicGeneral public ArmyArmy NavyNavy Air ForceAir Force MarinesMarines Dept. of Commerce (NOAA) Space Weather Operations Boulder, CO Civilian Customers: Military Customers: Department of Defense (AF Space Command) 55th Space Weather Squadron (AF Space Forecast Center) Falcon AFB, CO

24. How to Get Support Request information or support through your local weather officer or unit Support assistance request (SAR) IAW AFI 15-118, requesting specialized weather support

25. Summary The near-Earth space environment is neither empty nor benign The near-Earth space environment is neither empty nor benign Many space weather hazards can impact military operations in space and on Earth Many space weather hazards can impact military operations in space and on Earth Space weather support helps designers, operators, and users optimize mission effectiveness Space weather support helps designers, operators, and users optimize mission effectiveness The near-Earth space environment is neither empty nor benign The near-Earth space environment is neither empty nor benign Many space weather hazards can impact military operations in space and on Earth Many space weather hazards can impact military operations in space and on Earth Space weather support helps designers, operators, and users optimize mission effectiveness Space weather support helps designers, operators, and users optimize mission effectiveness