Description: Solar Particle Events (SPEs) represent a major hazard for extravehicular maneuvers by astronauts in Earth orbit, and for eventual manned interplanetary space travel. They can also harm aircraft avionics, communication and navigation. We propose to develop a system to aid forecasters in the prediction of such events, and in the identification/lengthening of "all clear" time periods when there is a low probability of such events occurring. The system leverages three recently developed technologies: physics-based models of the solar corona and inner heliosphere, robust CME modeling techniques, and empirical/physics-based assessments of energetic particle fluxes using the Earth-Moon-Mars Radiation Environment Module (EMMREM, University of New Hampshire). When completed, the proposed SPE Threat Assessment Tool, or STAT, will represent a significant step forward in our ability to assess the possible impact of SPE events.

Benefits: The CCMC, located at NASA GSFC, is presently testing different space weather models to assess their applicability for eventual operational settings. STAT would represent the coupling of two preeminent modeling capabilities at CCMC (CORHEL and EMMREM) to produce physics-based model predictions of SEP fluxes. STAT would also be of significant interest to NASA SRAG, which is charged with the difficult responsibility of ensuring that the radiation exposure received by astronauts remains below established safety limits. This requires identifying periods with a high probability of no SPEs, as well as recognizing the imminent threat of an SPE. STAT can aid SRAG in this endeavor by estimating particle fluxes and dose rates for possible eruptions when a threatening active region is identified.

SPEs are of concern not only to NASA, but to many government and commercial entities dependent on satellites and aircraft. For example, NOAA SWPC provides space weather information to a range of customers, for many of whom the forecasting of SPEs is a top priority. The Air Force is also interested in mitigation strategies for SPEs. The fledgling private manned launch services industry may wish to develop their own forecasting capabilities, as opposed to solely relying on government services. Once we have successfully developed STAT for NASA applications, we can address the needs of these customers as well.