Evaluation of the dynamic cutoff rigidity model using dosimetry data from the STS-28 flight

Area of Science:

• Space physics and cosmic ray research.
• Magnetospheric modeling and space weather.
• Radiation dosimetry in space environments.

Background:

• Understanding space radiation is crucial for astronaut safety and mission planning.
• Previous models did not fully capture the dynamic nature of Earth's magnetosphere and its impact on particle cutoff rigidities.
• The Kp magnetic index is a standard measure of geomagnetic activity.

Purpose of the Study:

• To develop and validate a dynamic cutoff rigidity model for predicting solar particle penetration through the magnetosphere.
• To assess the model's accuracy by comparing computed doses with actual measurements from the space shuttle.
• To cover the full spectrum of geomagnetic activity levels.

Main Methods:

• Utilized the Tsyganenko magnetospheric model to compute global grids of vertical cutoff rigidities.
• Developed a dynamic model with a range encompassing all Kp magnetic index levels.
• Compared model predictions with measured radiation doses on the space shuttle during the August 1989 solar proton event.

Main Results:

• The dynamic cutoff rigidity model successfully predicted the regions of the space shuttle orbit exposed to solar protons.
• A strong one-to-one correspondence was found between predicted and measured solar particle dose events.
• The model's accuracy was validated against real-world spaceflight data.

Conclusions:

• The developed dynamic cutoff rigidity model provides a reliable tool for predicting solar particle radiation exposure.
• This model enhances our understanding of magnetospheric shielding against cosmic rays.
• Accurate prediction of radiation environments is essential for future space exploration and astronaut safety.