Space radiation measurements on-board ISS--the DOSMAP experiment

Area of Science:

• Space science
• Radiation physics
• Human physiology

Background:

• Space radiation poses a significant risk to astronauts.
• Accurate dosimetry is crucial for human spaceflight safety.
• Previous missions provide limited data for long-duration spaceflights.

Purpose of the Study:

• To measure integrated absorbed doses, heavy ion fluxes, and dose rates within the US Lab.
• To characterize the space radiation environment during the Dosimetric Mapping experiment.
• To compare active and passive dosimetry measurements.

Main Methods:

• Utilized a dosimetry package including thermoluminescence dosemeter (TLD) chips, nuclear track detectors (NTDPs), and a silicon dosimetry telescope (DOSTEL).
• Employed the PILLE readout system for TLD measurements.
• Collected data on charged particle count rates and dose rates at various locations.

Main Results:

• Ionizing radiation dose rates ranged from 153 to 231 microGy/day.
• Active device dose rates closely matched TLD measurements within +/- 10%.
• Mean dose equivalent rate measured by DOSTEL was 535 microSv/day, lower than previous Shuttle missions.

Conclusions:

• The dosimetry package provided reliable measurements of the space radiation environment.
• Active and passive dosimetry methods showed good agreement.
• Measured dose rates were lower than those experienced during Shuttle-Mir missions, indicating improved shielding or orbital differences.