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SUMMARY:Proton belt radiation exposure to satellites - Alexander R. Lozins
 ki
DTSTART:20181113T130000Z
DTEND:20181113T140000Z
UID:TALK112093@talks.cam.ac.uk
CONTACT:Dr William Béthune
DESCRIPTION:Electric propulsion technology now enables satellite operators
  to achieve geostationary orbit efficiently without the use of chemical pr
 opellant via electric orbit raising. This includes the compromise of a lon
 ger raising period\, during which satellites traverse the hazardous radiat
 ion environment of the Van Allen belts. This is one of the numerous ways i
 n which utilisation of this region of space is increasing.\nThe higher rad
 iation exposure during electric orbit raising\, as well as for other types
  of missions\, must be accounted for by mission planners through the use o
 f environment models such as NASA’s AP8/AE8. However\, case studies such
  as the CRRES mission show our predictive capability is limited by dynamic
  changes to the proton belt and slot region that can occur in large solar 
 energetic particle trapping events\, raising the risk for spacecraft shiel
 ding to be under-designed.\nFollowing a discussion of the dynamic changes 
 that can affect the proton radiation environment\, we show the accumulatio
 n of solar cell damage due to non-ionising dose for a variety of electric 
 orbit raising scenarios based on real trajectories\, and discuss how varyi
 ng key engineering parameters affects the result.\nIn particular\, we show
  that the trajectory\, solar cell coverglass thickness and state of the pr
 oton belt can affect solar panel degradation accrued during electric orbit
  raising by up to ~10%. We conclude more real-time information is required
  on the transient nature of the outer proton belt to help assess radiation
  damage.
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
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