Measurement of Solar and Cosmic Radiation during Spaceflight

The external platform of the International Space Station (ISS) will provide aunique opportunity for exobiological studies under space conditions, e.g., spacevacuum, solar UV radiation, cosmic radiation, and temperature extremes. In orderto facilitate this research, ESA is developing the EXPOSE facility to be attachedto the External Pallet of the truss structure of the ISS. The experiment is plannedfor a duration of 18 months during the ISS early utilization period. Experimentson the ``Responses of Organisms to the Space Environment (ROSE)ʹʹ will studythe survival of spores from bacteria, fungi, ferns, etc., under space conditions andthus investigate whether life could potentially survive extended travel through space.In parallel to the exposure of the biological material, the charged particle and solarextraterrestrial radiation will be measured with a multichannel dosimeter. Thisinstrument is based on two separate developments. The dosimeter which determinessolar radiation in four channels is based on the ground-based ELDONET (Europeanlight dosimeter network) instrument which has been developed to measure solar UVand visible radiation in three channels. The other part of the instrument is based on a256 channel dosimeter of cosmic radiation which was developed and used on theRussian space station Mir. A final miniature prototype has been developed to fit thespace available. The instrument incorporates the latest technologies such as SurfaceMounted Devices (SMDs), switchable amplifiers, as well as on-board microprocessorcontrol. Several software packages have been developed to record the solar visible andUV, and charged particle, radiations, to display them in graphical form and to store them for future analysis. All recorded data will be made available to the public via the Internet.