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Low altitude dose measurements from APEX, CRRES and DMSP
E G Mullen1, M S Gussenhoven, J T Bell
1Geophysics Directorate, Phillips Laboratory, Hanscom AFB, MA 01731, USA.
Advances in Space Research : the Official Journal of the Committee on Space Research (COSPAR)
|September 7, 2001
Summary
This study models radiation dose at low altitudes using satellite data, revealing that shielding is ineffective beyond 1/4 inch of aluminum for orbits near the inner radiation belt.
Area of Science:
- Space physics
- Radiation dosimetry
- Satellite engineering
Background:
- The low-altitude radiation environment, particularly near the inner radiation belt, presents significant challenges.
- Understanding radiation exposure is critical for satellite longevity and mission success.
Purpose of the Study:
- To model radiation dose at low altitudes (down to 350 km) using satellite data.
- To develop a practical tool for calculating radiation dose for user-selected orbits.
- To analyze the effectiveness of shielding for low-altitude orbits.
Main Methods:
- Utilized dosimeter data from APEX, CRRES, and DMSP satellites (1984-1996).
- Developed dose models for the inner edge of the radiation belt.
- Created the APEXRAD personal computer utility for dose calculations.
- Analyzed dose variations based on altitude, inclination, and particle type.
Main Results:
- Dose models were constructed for the inner edge of the radiation belt.
- The APEXRAD utility allows for user-specific orbital dose calculations.
- Shielding greater than approximately 1/4 inch of aluminum proved largely ineffectual for low-altitude orbits.
- Outer zone electron contributions to low-altitude dose are significant only for thin shielding and vary with magnetic activity and solar cycle.
Conclusions:
- Radiation dose at low altitudes is highly dependent on orbital parameters and shielding.
- The APEXRAD tool provides valuable insights for mission planning and satellite design.
- Further research into radiation effects is crucial for space exploration.
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