Trapped belt variations and their effects on human space flightsVariations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. This paper reports the existence of a second proton belt and its subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an 18-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt was ten months. Proton populations in the second belt returned to values of quiescent times within 18 months. The increase in absorbed dose attributed to protons in the second belt was approximately 20 percent. Passive dosimeter measurements were in good agreement with this value.
Document ID
19940034487
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Robbins, Donald E. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Badhwar, Gautam D. (NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 16, 2013
Publication Date
October 1, 1993
Subject Category
Aerospace Medicine
Report/Patent Number
IAF PAPER 93-137
Meeting Information
Meeting: IAF, International Astronautical Congress