Galactic cosmic ray radiation levels in spacecraft on interplanetary missions

Area of Science:

• Space radiation physics
• Astrobiology
• Spacecraft engineering

Background:

• Interplanetary missions expose crews to high levels of galactic cosmic rays (GCRs).
• Accurate estimation of radiation dose is critical for astronaut safety and mission planning.
• Existing models require validation and refinement for diverse mission scenarios.

Purpose of the Study:

• To estimate crew radiation levels inside spacecraft during interplanetary missions.
• To assess the impact of various shielding materials on GCR protection.
• To provide detailed radiation metrics including particle fluxes and dose equivalents.

Main Methods:

• Utilized the Langley Research Center's HZETRN (galactic cosmic ray transport) computer code.
• Employed the Computerized Anatomical Man (CAM) model for organ-specific dose assessment.
• Simulated radiation transport and interaction with different shielding materials.

Main Results:

• Quantified particle fluxes, linear energy transfer (LET) spectra, absorbed dose, and dose equivalent.
• Identified significant variations in radiation levels based on shielding type and thickness.
• Provided organ-specific radiation dose estimations for GCR protection studies.

Conclusions:

• HZETRN and CAM models provide robust tools for assessing spacecraft radiation environments.
• Shielding material selection significantly influences astronaut radiation exposure.
• Further research is needed to optimize shielding strategies for long-duration missions.