Enhancement of the Geomagnetic Cutoff Models inside SIRE2 (SIRE2-Real)

The Space Ionizing Radiation Environment and Effects (SIRE2) toolkit was developed to provide the space radiation environment and effects community with state-of-the-art models that can be used not just for satellites but also for arbitrary trajectories. In this Phase II effort, the SIRE2-Real capabilities will be tested and integrated into the SIRE2 toolkit. SIRE2-Real will provide benchmarking of space environments to historical measurements and spacecraft anomalies. The SIRE2-Real capabilities will allow the user to select a historical time range for SIRE2-Real to determine the peak flux, flux-time series, and mission-integrated fluence for the solar energetic particle (SEP) environment. SIRE2-Real will also use the historical Dst value for the geomagnetic activity at Earth during the users historical time range and be able to perform geomagnetic cutoff calculations using the historical International Geomagnetic Reference Field (IGRF) epoch that is closest to the users mission. The Mission Specific Solar Radiation Environment Model (MSSREM) and the Smart-Shea 2022 geomagnetic cutoff model will need to be updated, tested, and integrated into SIRE2 to provide the SIRE-Real capability. The MSSREM model will provide the user with historical peak flux, flux time series, and mission-integrated fluence for a users mission. The Smart-Shea 2022 geomagnetic cutoff model will need to be extended to allow the user to select between multiple IGRF epochs in the calculation. The Fifth Gait team will also be looking to enhance the geomagnetic cutoff models inside of SIRE2. The first thing that will be examined is the use of the 20 km vs 450 km world cutoff grids in the Smart-Shea model to determine if there is any significant difference between using the two different grids. Penumbral transparencies and analysis of the October 20, 1989 shock interval are other areas of improvement in the geomagnetic cutoff models that will be examined during the Phase II effort. The space and radiation effects community rely on tools such as CREME96, SPENVIS, SPACERAD, and others for space environment and effects calculations. Fifth Gait Technologies has developed a state-of-the-art tool called Space Ionizing Radiation Environment and Effects (SIRE2) toolkit. SIRE2 provides updated models for solar, galactic, and trapped radiation, updated geomagnetic cutoff models, and an updated radiation transport model. In this Phase II effort, Fifth Gait will expand on the SIRE2 toolkit by developing the SIRE2-Real capabilities. SIRE2-Real will provide benchmarking of space environments to historical measurements and spacecraft anomalies. SIRE2-Real will provide historical solar energetic particle measurements and the ability to select different IGRF epochs in the cutoff calculations. The Fifth Gait team will also investigate improvements that can be made to enhance the geomagnetic cutoff models inside the SIRE2 toolkit. Any potential enhancements found can be used in future research to improve the SIRE2 toolkit and provide more accurate calculations to the community. In this Phase II effort, Fifth Gait Technologies will complete the following Technical Objectives: Invesitgate and quantify the signficance of the potential differences between the cutoff calculations using the 20km and 450km world cutoff grids. Extend the Smart-Shea 2022 model to other historical IGRF epochs. Extend the Smart-Shea 2022 model to higher geomagnetic activity levels. Quantify the impact of different model characteristics within the geomagnetic cutoff model Modify MSSREM to provide peak flux, flux time series, and mission-integrated fluence for historical SEP data. Develop the SIRE2-Real capabilities. Through the course of the Phase II effort, Fifth Gait will create the following deliverables: 20km vs 450km world grid report MSSREM Demonstration using historical SEP data. Smart-Shea 2022 model demonstration with the higher geomagnetic activity level Smart-Shea 2022 model demonstration using the different IGRF epochs in the cutoff calculations. SIRE2-Real Demonstration Report on geomagnetic cutoff model improvements investigated during the Phase II effort.
Benefits: When the Phase II effort is complete, NASA will have access to SIRE2-Real that can provide benchmarking of space environments to historical measurements. Spacecraft designers and operators will be able to use the benchmarking of space environments to assess spacecraft anomalies that would have occurred during the historical time range. With SIRE2-Real, NASA will be able to assess their spacecraft to historical measurements that have not been possible in the past, providing additional data on the survivability of their spacecraft. Major prime contractors have noted interest in using a SIRE-Real capability to assess spacecraft anomalies investigations. Companies like Boeing, Lockheed, Northrop, Raytheon, SpaceX and Blue Origin can use SIRE2-Real to assess their spacecraft with the benchmarking of space environments to historical measurements and assess the potential for spacecraft anomalies from the historical SEP event.