title: Gamma-ray measurements from the space shuttle during a solar flare.
abstract: An X2/2B level solar flare occurred on 12 August, 1989, during the last day of the flight of the Space Shuttle Columbia (STS-28).  Detectors on the GOES 7 satellite observed increased X-ray fluxes at approximately 1400 GMT and a solar particle event (SPE) at approximately 1600 GMT.  Measurements with the bismuth germanate (BGO) detector of the Shuttle Activation Monitor (SAM) experiment on STS-28 showed factors of two to three increases in count rates at high latitudes comparable to those seen during South Atlantic Anomaly (SAA) passages beginning at about 1100 GMT.  That increased activity was observed at both north and south high latitudes in the 57 degrees, 300 kilometer orbit and continued until the detector was turned off at 1800 GMT.  Measurements made earlier in the flight over the same geographic coordinates did not produce the same levels of activity.  This increase in activity may not be entirely accounted for by observed geomagnetic phenomena which were not related to the solar flare.
authors.affiliation: Space Astronomy Laboratory, University of Florida, Gainesville 32609, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Haskins
authors.forename: J E
authors.initials: JE
authors.lastname: McKisson
authors.forename: A G
authors.initials: AG
authors.lastname: Weisenberger
authors.forename: D W
authors.initials: DW
authors.lastname: Ely
authors.forename: T A
authors.initials: TA
authors.lastname: Ballard
authors.forename: C S
authors.initials: CS
authors.lastname: Dyer
authors.forename: P R
authors.initials: PR
authors.lastname: Truscott
authors.forename: R B
authors.initials: RB
authors.lastname: Piercey
authors.forename: A V
authors.initials: AV
authors.lastname: Ramayya
mesh_terms: D001729:Bismuth; D005720:Gamma Rays; D005857:Germanium; D008280:Magnetics; D011522:Protons; D011834:Radiation Monitoring / Q000295:instrumentation*; D011835:Radiation Protection; D011874:Radiometry; D012974:Sodium Iodide; D016082:Solar System; D013026:Space Flight / Q000295:instrumentation*; D018531:Spacecraft / Q000295:instrumentation*
chemical_list: D011522:Protons; D005857:Germanium; C042364:bismuth germanium oxide; D012974:Sodium Iodide; D001729:Bismuth