R3DE: Radiation Risk Radiometer-Dosimeter on the International Space Station—Optical Radiation Data Recorded During 18 Months of EXPOSE-E Exposure to Open Space

Abstract

Radiation Risk Radiometer-Dosimeter E (R3DE) served as a device for measuring ionizing and non-ionizing radiation as well as cosmic radiation reaching biological samples located on the EXPOSE platform EXPOSE-E. The duration of the mission was almost 1.5 years (2008)(2009). With four channels, R3DE detected the wavelength ranges of photosynthetically active radiation (PAR, 400-700 nm), UVA (315-400 nm), UVB (280-315 nm), and UVC (< 280 nm). In addition, the temperature was recorded. Cosmic ionizing radiation was assessed with a 256-channel spectrometer dosimeter (see separate report in this issue). The light and UV sensors of the device were calibrated with spectral measurement data obtained by the Solar Radiation and Climate Experiment (SORCE) satellite as standard. The data were corrected with respect to the cosine error of the diodes. Measurement frequency was 0.1 Hz. Due to errors in data transmission or temporary termination of EXPOSE power, not all data could be acquired. Radiation was not constant during the mission. At regular intervals of about 2 months, low or almost no radiation was encountered. The radiation dose during the mission was 1823.98 MJ m -2 for PAR, 269.03 MJ m -2 for UVA, 45.73 MJ m -2 for UVB, or 18.28 MJ m -2 for UVC. Registered sunshine duration during the mission was about 152 days (about 27% of mission time).The surface of EXPOSE was most likely turned away from the Sun for considerably longer. R3DE played a crucial role on EXPOSE-EuTEF (EuTEF, European Technology Exposure Facility), because evaluation of the astrobiology experiments depended on reliability of the data collected by the device. Observed effects in the samples were weighted by radiation doses measured by R3DE.

Time Profile of Cosmic Radiation Exposure During the EXPOSE-E Mission: The R3DE Instrument

“…The analysis of the UV and temperature data obtained during the R3DE mission on EXPOSE-E are the subject of another paper (Schuster et al, 2012).…”

“…The main results of the present study include the following: (1) three different radiation sources were detected and quantified-galactic cosmic rays (GCR), energetic protons from the South Atlantic Anomaly (SAA) region of the inner radiation belt, and energetic electrons from the outer radiation belt (ORB); (2) . The analysis of the UV and temperature data is a subject of another article (Schuster et al, 2012). …”

Overview of the ISS Radiation Environment Observed during the ESA EXPOSE‐R2 Mission in 2014–2016

“…As noted in Dachev et al (2016) during the past 16 years numerous ionizing radiation instruments have successfully flown on the ISS and European Space Agency's (ESA) Biopan-5/6 facilities on Foton M2/M3 satellites (Damasso et al, 2009;Häder et al, 2009). Recently, ESA's EXPOSE multi-use platform has performed three experiments, designated as E, R, and R2, all of which hosted the deposited energy spectrometer (DES) radiation risk radiometer-dosimeter (R3D) instruments (Dachev, Horneck, et al, 2012;Dachev, Tomov, et al, 2012;Dachev, Semkova, et al, 2015;Schuster et al, 2012). These detectors were collaboratively developed by Bulgarian and German teams (Häder et al, 2009;Häder & Dachev, 2003) and have been part of a suite of astrobiology instruments (de Vera et al, 2012;Rabbow et al, 2012Rabbow et al, , 2015.…”

Overview of the Liulin type instruments for space radiation measurement and their scientific results

“…9) with a 256 channel ionizing radiation monitoring spectrometer, a 3 channel UV and a 1 channel photosynthetically active radiation (PAR) spectrometer functioned on the ESA European Technology Exposure Facility (EuTEF) platform inside the EXPOSE-E facility outside of the European Columbus module of the ISS between 20 February 2008 and 1 September 2009 with 10-s resolution behind 0.45 g cm 2 of shielding (Horneck et al, 1998;Dachev et al, 2012a;Schuster et al, 2012).…”

“…2) used the same measurement procedure as the LIULIN instrument. It was developed and qualified for space together with French and Russian colleagues for the unsuccessful Mars-96 mission (Semkova et al, 1994). The LIULIN and RADIUS-MD instruments were designed to provide data only for the dose rate and particle flux in a single detector, but not the deposited energy spectrum.…”