Radiation measurements aboard Spacelab 1

The radiation environment inside Spacelab 1 was measured by a set of passive radiation detectors distributed throughout the volume inside the module, in the access tunnel, and outside on the pallet. Measurements of the low linear energy transfer (LET) component obtained from the thermoluminescence detectors ranged from 102 to 190 millirads, yielding an average low LET dose rate of 11.2 millirads/day inside the module, about twice the low LET dose rate measured on previous flights of the Space Shuttle. Because of the higher inclination of the orbit (57 versus 28.5 deg for previous Shuttle flights), substantial fluxes of highly ionizing high charge and energy galactic cosmic ray particles were observed, yielding an overall average mission dose-equivalent of about 150 millirems, more than three times higher than that measured on previous Shuttle missions.