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Space Environmental       Hazards   Effects of Space       Weather   Meidad Pariente
Space Environment Effects on     Satellites – Short Brief• The environment in space has  significant effect on satellites....
Satellite Charging• Satellite charging is a variation in  the electrostatic potential of a  satellite with respect to the ...
Deep Charging• Deep charging of a satellite occurs  when cosmic ray particles pass  through a satellite and ionize atoms  ...
Satellite Discharging• The satellites most vulnerable to  charging/discharging    are  those  located at geosynchronous al...
Hardware Damage• Sudden    electrostatic discharge  (high current or arc) can cause  hardware damage, such as:  • Blown fu...
Electric Problems• These discharges can result in  electrical or electronic problems,  such as:  •   False commands  •   O...
Particle Collision• High energy solar flare particles and  galactic cosmic rays can cause  direct damage to the surface of...
Space Environmental      Hazards  Anomalies Space      Weather
Sun Index• Two of the most used space weather  index are  • Smoothed Sunspot Number (SSN)      Geomagnetic Planetary Geoma...
Geomagnetic Disturbances• The disturbance of the geomagnetic  field may be measured by an a  magnetometer.• Several magnet...
Spacequake – A Magnetic Shock            wave
Kp and NOAA G-scale               Kp Index          NOAA Space                                Weather Scale               ...
NOAA Space Weather Scale for             Geomangetic Storm                                                          Physic...
NOAA Space Weather Scale for                  Solar Radiation Storm   AverageSc    Descr                                  ...
Geomagnetic Activity             vsNumber of Recorded Anomalies        (April 2010)
Space Environmental      Hazards    The Systems    Engineer POV
Designing a Robust satellite –   Good Engineering Practice• Environmental Testing is not  enough !• Glitches, Faulty hardw...
Designing a Robust satellite – Tips            and Tricks• Check, check and than double check  your system logic for dead ...
Hardware Protection• Exterior surface of satellite is  exposed      to    charging    and  overcharging, especially when u...
The Galaxy-15 Case Study• 5/4/2010 – Contact with Galaxy-15 Lost  •   Galaxy-15 team was unable to switch the      payload...
Conclusions• Anomaly trend proved to be correlated  with geomagnetic activity.• Most of current satellite designs proved  ...
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Space Weather Nov 2011 Open U Israel

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This presentation reviews the effects of space weather on satellites and gives tips and tricks of how to better design them

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Space Weather Nov 2011 Open U Israel

  1. 1. Space Environmental Hazards Effects of Space Weather Meidad Pariente
  2. 2. Space Environment Effects on Satellites – Short Brief• The environment in space has significant effect on satellites. The discussion below highlights the principal effects experienced by satellites. • Satellite Charging/ Deep Charging • Satellite Discharging • Hardware damage • Electric problems
  3. 3. Satellite Charging• Satellite charging is a variation in the electrostatic potential of a satellite with respect to the surrounding low density plasma around the satellite or to another part of the satellite.• The extent of the charging depends on both design and orbit.• The two primary mechanisms
  4. 4. Deep Charging• Deep charging of a satellite occurs when cosmic ray particles pass through a satellite and ionize atoms within, through collisions.• Some of these particles are solar in origin, but the majority are galactic and with no preference to time or light conditions.• They do show some dependence on
  5. 5. Satellite Discharging• The satellites most vulnerable to charging/discharging are those located at geosynchronous altitude. Discharges as high as 20,000 volts (V) have been experienced.• Satellites in geosynchronous orbits typically move both in and out of the upper regions of the Van Allen Radiation Belts and the Earths
  6. 6. Hardware Damage• Sudden electrostatic discharge (high current or arc) can cause hardware damage, such as: • Blown fuses or exploded transistors, capacitors and other electronic components • Vaporized metal parts • Structural damage • Breakdown of thermal coatings
  7. 7. Electric Problems• These discharges can result in electrical or electronic problems, such as: • False commands • On/Off circuit switching • Memory changes • Solar cell degradation • Degradation of optical sensors
  8. 8. Particle Collision• High energy solar flare particles and galactic cosmic rays can cause direct damage to the surface of a satellite. The damage can include vaporization of surface materials and structural damage. These particles can also enter star or horizon sensors and mimic reference points.
  9. 9. Space Environmental Hazards Anomalies Space Weather
  10. 10. Sun Index• Two of the most used space weather index are • Smoothed Sunspot Number (SSN) Geomagnetic Planetary Geomagnetic „Acrivity‟ • Solar „Acrivity‟ K Index (Kp) or SSNA Index (Ap)Level Kp Ap Level >250 Extreme 7-9 >100 Severe Storm 150-250 Very High 6 50-99 Major Storm 80-150 High 5 30-49 Minor Storm 40-80 Moderate 4 16-29 Active 20-40 Low 3 8-15 Unsettled 0-20 Very Low 0-2 0-7 Quiet
  11. 11. Geomagnetic Disturbances• The disturbance of the geomagnetic field may be measured by an a magnetometer.• Several magnetometer data from dozens of observatories in one minute intervals are potentially available.• The data is tracked in „real-time‟ and allows to monitor the current state of the geomagnetic conditions.
  12. 12. Spacequake – A Magnetic Shock wave
  13. 13. Kp and NOAA G-scale Kp Index NOAA Space Weather Scale Geomagnetic Storm Level Kp <= 4 G0 Kp = 5 G1 Kp = 6 G2 Kp = 7 G3 Kp = storm Weather Prediction CenterKp of 0 to 4 is below 8 NOAA Space G4
  14. 14. NOAA Space Weather Scale for Geomangetic Storm Physic AverageSc Descri al Frequency Effect to Spacecraft Operationsale ptor Measur (1 cycle = 11 e years) may experience extensive surface 4 per cycle ExtremG5 charging, problems with orientation, Kp=9 (4 days per e uplink/downlink and tracking satellites. cycle) may experience surface charging and 100 per cycleG4 Severe tracking problems, corrections may be Kp=8 (60 days per needed for orientation problems cycle) surface charging may occur on satellite components, drag may 200 per cycleG3 Strong increase on low-Earth-orbit satellites, Kp=7 (130 days per and corrections may be needed for cycle) orientation problems. corrective actions to orientation may
  15. 15. NOAA Space Weather Scale for Solar Radiation Storm AverageSc Descr Physical Frequency Effect to Spacecraft Operationsale iptor Measure (1 cycle = 11 years) Flux Number of Level of storm events >=10Me when Kp level Solar Radiation Storm V was met; particles (number of (ions) storm days) satellites may be rendered useless, memory impacts can cause loss of control, may cause Extre Fewer than 1S5 serious noise in image data, star-trackers may 105 me per cycle be unable to locate sources; permanent damage to solar panels possible. may experience memory device problems and noise on imaging systems; star-tracker 3 per cycleS4 Severe 104 problems may cause orientation problems, and solar panel efficiency can be degraded
  16. 16. Geomagnetic Activity vsNumber of Recorded Anomalies (April 2010)
  17. 17. Space Environmental Hazards The Systems Engineer POV
  18. 18. Designing a Robust satellite – Good Engineering Practice• Environmental Testing is not enough !• Glitches, Faulty hardware and computer mishaps due to environmental conditions must be considered and anticipated.• Satellites should be fully automatic for as long as possible (no less than 48 hours)
  19. 19. Designing a Robust satellite – Tips and Tricks• Check, check and than double check your system logic for dead ends.• If you have such a single point failure it will surly occur, hence protect the satellites with timeouts• Whenever possible perform sanity checks, especially regarding crucial data• Critical system parameters should
  20. 20. Hardware Protection• Exterior surface of satellite is exposed to charging and overcharging, especially when using ion thrusters, hence protection measured should be implemented on the outer surface as well• Listen to weather reports ! When a storm is approaching shut down all redundant units, and keep only
  21. 21. The Galaxy-15 Case Study• 5/4/2010 – Contact with Galaxy-15 Lost • Galaxy-15 team was unable to switch the payload off, hence causing interference to other satellites, enforcing evasive maneuvers and exposed to claims.• 23/10/2010 – Satellite reboot after battery drain • Satellite enters safe mode after six months of eastward drift• Currently – at 121ºW (originally 133ºW and drifted until 93ºW) used as a relay station for GPS signals
  22. 22. Conclusions• Anomaly trend proved to be correlated with geomagnetic activity.• Most of current satellite designs proved to be resilient to experienced geomagnetic activity.• Still catastophric events happen during peak events.• Galaxy 15 events to be investigated to carefully verify repeatabilty.

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