FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-17/8

Title and Subtitle: Approximating Shielding Effects on Galactic Cosmic Radiation Effective Dose Rate Calculations During Extreme Altitude and Sub-Orbital Flights Using CARI-7/7A

Report Date: February 2017

Authors: Copeland, K

Abstract: The dominant source of ionizing radiation in the aerospace environment is galactic cosmic radiation (GCR). Traditionally, calculations of exposure rates for vehicle occupants in aircraft have not included vehicle structure; while in spacecraft, vehicle structure is considered without atmosphere.

This report describes modifications applicable to CARI-7 and CARI-7A to allow inclusion of the effects of vehicle structure on calculations of effective dose rate from GCR throughout a suborbital mission in a lightly shielded vehicle (20 g/cm2). Required coefficients and an example of the technique are provided for aluminum shielding.

While results are considerably different than if shielding were entirely neglected, they vary by less than 8% from the simple approximation of 1:1 substitution of additional atmospheric depth for aluminum.

Key Words: CARI-7, in-flight radiation exposure, extreme-altitude flight, sub-orbital flight, crewmember dosimetry

No. of Pages: 8