Summary

Description

<p>The ability to predict the occurrence and magnitude of solar particle events (coronal mass ejections and solar flares) has been elusive so exposure of astronauts and flight electronics to this radiation is a serious concern for NASA.  This work focuses on exposure of operational flight electronics to solar particle events, which can jeopardize human safety.  The NOAA Space Weather Scale uses the terminology “Solar Radiation Storms” to describe solar particle events and categorizes the level of event severity on a scale from S1 (Minor) to S5 (Extreme).  The size of these events spans orders of magnitude and therefore the resulting exposure to energetic particle radiation can cause a wide range of effects depending on the severity of the event.  For an S1 level event the effect on satellite operations according to the NOAA scale would be “none” while for an S5 level event “satellites may be rendered useless, memory impacts can cause loss of control, may cause serious noise in image data, star-trackers may be unable to locate sources; permanent damage to solar panels possible”.</p><p>The end result of this IRAD will be a <strong>quantitative</strong> “nowcasting” tool for solar storms with classification of the severity of the storm according to the NOAA Space Weather Scale for ease of interpretation by mission operations.   This would be used by mission operations as input for making decisions on whether systems and instrumentation should be shut down during an event.  These decisions would be driven by the particular features and susceptibilities of each spacecraft and its payload.</p><p>FY13 will be dedicated to development and verification of the quantitative aspects of the model techniques.  Short term predictions of solar storms will be verified based on space data taken by the GOES Space Environment Monitor (SEM) and the CRaTER instrument on the LRO spacecraft.  The latter is in an approximately 50 km circular lunar orbit.</p>