Besides the effects of the microgravity environment, and the psychological and psychosocial
problems encountered in confined spaces, radiation is the main health detriment for long duration
human space missions. The radiation environment encountered in space differs in nature
from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in
radiation levels far exceeding the ones encountered on earth for occupational radiation workers.
Accurate knowledge of the physical characteristics of the space radiation field in dependence
on the solar activity, the orbital parameters and the different shielding configurations of the
International Space Station ISS is therefore needed. For the investigation of the spatial and
temporal distribution of the radiation field inside the European COLUMBUS module the experiment
DOSIS (Dose Distribution Inside the ISS) under the lead of DLR has been launched
on July 15th 2009 with STS-127 to the ISS. The experimental package was transferred from the
Space Shuttle into COLUMBUS on July 18th. It consists of a combination of passive detector
packages (PDP) distributed at 11 locations inside the European Columbus Laboratory and two
active radiation detectors (Dosimetry Telescopes = DOSTELs) with a DDPU (DOSTEL Data
and Power Unit) in a Nomex pouch (DOSIS MAIN BOX) mounted at a fixed location beneath
the European Physiology Module rack (EPM) inside COLUMBUS. The active components of
the DOSIS experiment were operational from July 18th 2009 to June 16th 2011. After refurbishment
the hardware has been reactivated on May 15th 2012 as active part of the DOSIS
3D experiment and provides continuous data since this activation. The presentation will focus
on the latest results from the two DOSTEL instruments as absorbed dose, dose equivalent and
the related LET spectra gathered within the DOSIS (2009 - 2011) and DOSIS 3D (since 2012)
experiment. The CAU contributions to DOSIS and DOSIS 3D are financially supported by
BMWi under Grants 50WB0826, 50WB1026, 50WB1232 and 50WB1533
