Sun Monitoring on the External Payload Facility of Columbus - SOLar Auto-Calibrating EUV/UV Spectrophotometers (Solar-SOLACES) - 08.20.14

Overview | Description | Applications | Operations | Results | Publications | Imagery
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Sun Monitoring on the External Payload Facility of Columbus - SOLar Auto-Calibrating EUV/UV Spectrophotometers (Solar-SOLACES) measures the extreme-ultraviolet/ultraviolet (EUV/UV) solar spectrum (17 nm to 220 nm) with moderate spectral resolution from the sun.

Science Results for Everyone

This investigation records the extreme ultraviolet (EUV) radiation intensity on the surface during the extended solar activity minimum, which reached lowest intensity in mid-September 2009, and its subsequent increase. Solar activity levels comparison shows that EUV radiation is lowest at the lowest solar activity level. Differences between EUV intensity at solar minimum and local solar maximum are much higher for wavelengths shorter than 40 nm. The largest EUV intensity differences were noted in the iron spectral lines. Data from this investigation are being used to examine the impact of solar radiation on the Earth’s climate and to improve our understanding of the interaction between different layers of the atmosphere.



The following content was provided by Gerhard Schmidtke, and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Erasmus Experiment Archive.

Experiment Details

OpNom TBD

Principal Investigator(s)

  • Gerhard Schmidtke, Fraunhofer-Institut for Physikalische Messtechnik, Freiburg, Germany

  • Co-Investigator(s)/Collaborator(s)
  • R Brunner, Fraunhofer-Institut fur Physikalische Messtechnik, Freiburg, Germany

  • Developer(s)
    Information Pending
    Sponsoring Space Agency
    European Space Agency (ESA)

    Sponsoring Organization
    Information Pending

    Research Benefits
    Information Pending

    ISS Expedition Duration
    October 2007 - October 2015

    Expeditions Assigned
    16,17,18,19/20,21/22,23/24,25/26,27/28,29/30,31/32,33/34,35/36,37/38,39/40,41/42,43/44

    Previous ISS Missions
    Solar-SOLACES was first operated on ISS Expedition 16.

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    Experiment Description

    Research Overview

    • Solar-SOLACES (Sun Monitoring on the External Payload Facility of Columbus - SOLar Auto-Calibrating EUV/UV Spectrophotometers) will measure the solar spectral irradiance from 17 to 220 nm at 0.5 to 2 nm spectral resolution. By an auto-calibration capability, it is expected to gain long-term spectral data with a high absolute resolution. In its center, it contains 4 EUV-spectrometers.


    • To perform the required absolute calibration, ionization chambers are used as second type of instruments. The absolute solar irradiance within a short spectral range is determined by a double ionization chamber, which is continuously filled with a certain type of gas. The spectral range within the calibration is performed, and determined by a band pass filter at the light entrance of the ionization chamber.

    Description

    Solar-SOLACES (Sun Monitoring on the External Payload Facility of Columbus - SOLar Auto-Calibrating EUV/UV Spectrophotometers) measures spectral irradiance in the extreme-UV and UV (16-220 nm) regions at moderate spectral resolution.

    The instruments are mounted on a multipurpose Coarse Pointing Device (CPD), which tracks the Sun as it compensates for the Station's orbital motion. The CPD consists of a Control Unit (CU), CPD Mechanical Assembly (CMA) and Sun Sensor. It tracks the Sun in two axes with an accuracy of 1 degree and a stability of 0.3 degrees (over 10 seconds). It provides pointing ranges of +/- 40 degrees along the primary rotational axis, and +/- 25 degrees along the secondary axis.

    The CU integrates the data handling, control and communication functions into a single box. It uses ESA's Standard Payload Computer board, and its design is partly based on the Remote Power Distribution Assembly.

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    Applications

    Space Applications

    The awareness of the environment of the Earth and of the sun radiation level and spectrum is of importance to both Earth-based and space-borne systems as well as to advanced studies on climate. Monitoring the sun radiation outside of the Earth atmosphere over a large electromagnetic spectrum and correlating with parallel observations with other space missions and on ground helps provide the accurate data required to support predictive models and anticipate on the influence of sun radiation on our environment.

    Earth Applications

    The awareness of the environment of the Earth and of the sun radiation level and spectrum is of importance to both Earth-based and space-borne systems as well as to advanced studies on climate. Monitoring the sun radiation outside of the Earth atmosphere over a large electromagnetic spectrum and correlating with parallel observations with other space missions and on ground helps provide the accurate data required to support predictive models and anticipate on the influence of sun radiation on our environment.

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    Operations

    Operational Requirements
    Information Pending

    Operational Protocols
    Information Pending

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    Results/More Information

    Beginning in April 2008, SOLACES recorded the extreme ultraviolet (EUV) irradiance during the extended solar activity minimum, which reached the point of lowest EUV intensity in mid September 2009, from the Columbus External Platform Facility of the ISS. SOLACES has since been observing the EUV irradiance during the increasing solar activity. The comparison of spectra at different solar activity levels shows that, at lowest activity, the EUV irradiance is always the lowest, too. In general, the differences between the EUV intensity observed at the solar minimum and local solar maximum are much higher for wavelengths shorter than 40 nm than for wavelengths longer than 40 nm, with the largest EUV intensity differences noted in the iron (Fe) spectral lines.

    The data from SOLACES will be used to investigate the impact of the solar irradiance variability on the Earth’s climate as well as improve understanding of the interaction between the thermosphere and ionosphere (Nikutowski et al. 2011).

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    Results Publications

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

      Schmidtke G, Brunner R, Eberhard D, Halford B, Klocke U, Knothe M, Konz W, Riedel W, Wolf H.  SOL–ACES: Auto-calibrating EUV/UV spectrometers for measurements onboard the International Space Station. Advances in Space Research. 2006 January; 37(2): 273-282. DOI: 10.1016/j.asr.2005.01.112.

      Schmidtke G, Froelich C, Thuillier MG.  ISS-SOLAR: Total (TSI) and spectral (SI) irradiance measurements. Advances in Space Research. 2006 January; 37(2): 255-264. DOI: 10.1016/j.asr.2005.01.009.

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    Related Websites
    The information on this page is provided courtesy of the ESA Erasmus Experiment Archive.
    Columbus Mission - European Experiment Programme

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    Imagery