EXPOSE R2- Photochemistry on the Space Station (EXPOSE-R2-P.S.S.) - 06.14.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Solar ultraviolet photons are a major source of energy to initiate chemical reactions in the solar system, and many experimental programs on Earth are devoted to studies of the evolution of organic molecules through such chemical reactions. A wide variety of organic compounds are tested during the Photochemistry on the Space Station (P.S.S.) experiment to improve the understanding of chemical evolution in organic-rich astrophysical environments (comets, meteorites, Titan, interstellar medium), and where organic matter is being looked for (Martian surface and subsurface).
Science Results for Everyone
Information Pending

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

OpNom:

Principal Investigator(s)
Hervé Cottin, Université Paris Est Créteil et Université Paris Diderot, Créteil, France

Co-Investigator(s)/Collaborator(s)
Information Pending

Developer(s)
European Space Agency (ESA), Noordwijk, Netherlands
Université Paris-Est Créteil & Université Paris Diderot CNRS , Créteil , France
OHB System AG, Bremen, Germany

Sponsoring Space Agency
European Space Agency (ESA)

Sponsoring Organization
European Space Agency

Research Benefits
Scientific Discovery, Space Exploration

ISS Expedition Duration
March 2014 - March 2016

Expeditions Assigned
39/40,41/42,43/44,45/46

Previous Missions
Information Pending

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Experiment Description

Research Overview

Life as we know it is, without exception, based on complex organic (carbon-based) compounds, such as proteins and nucleic acids (DNA and RNA), with some organic molecules consisting of hundreds or thousands of atoms ordered in a specific way. The chance of life starting is staggering in its unlikelihood, and was undoubtedly the end product of a long process of chemical evolution. This may have started with carbon-based molecules being formed in the core of giant red stars that were ejected into space. The processes that brought life from these simple compounds, to proteins and nucleic acids, is still a mystery though it is known that ultraviolet radiation has a significant effect on breaking down and reassembling chemical compounds in space, and in the atmospheres of planets.
 
Solar ultraviolet photons are a major source of energy to initiate chemical reactions in the solar system, and many experimental programs on Earth are devoted to studies of the evolution of organic (containing carbon) molecules through such chemical reactions. However, the complete solar UV spectrum is hard to reproduce in the lab; therefore, experiments in this area need to be conducted in a space environment. A wide variety of organic compounds which simulate compounds that can be found in interstellar space, or in the atmospheres of planetary bodies, is to be tested during the Photochemistry on the Space Station (P.S.S.) experiment to improve the understanding of chemical evolution in organic-rich astrophysical environments (comets, meteorites, Saturn’s moon Titan, interstellar medium), and where organic matter is being looked for (Martian surface and subsurface).
 
 

Description
Information Pending

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Applications

Space Applications
The processes that brought life from simple compounds to proteins and nucleic acids is still a mystery, though it is known that ultraviolet radiation has a significant effect on breaking down and reassembling chemical compounds in space, and the atmospheres of planets. Unravelling this mystery is a fundamental goal of organic chemistry, which is a key element of ESA research in astrobiology. This research may one day help to discover the key to where, and how, along a complex chain of chemical events stretching back in time, chemistry turned into biology, and help to look for the signatures of current and previous life on other planets.

Earth Applications
Life as we know it is based on complex organic (carbon-based) compounds, such as proteins and nucleic acids (DNA and RNA), with some organic molecules consisting of hundreds or thousands of atoms ordered in a specific way. Cells, plants and animals are all constructed from that same molecular jigsaw puzzle, and have apparently evolved over time from some simple, common ancestor. Life is the end product of a long process of chemical evolution which may have started with carbon-based molecules ejected from the core of giant red stars. This research may one day help to discover the key to where, and how, along this complex chain of events stretching back in time, chemistry turned into biology and help to piece together how life started on Earth.

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Operations

Operational Requirements and Protocols

  • Transport of 3 Expose-R2 sample carrier trays to ISS.
  • Storage on ISS before exposure is a maximum of 6 months.
  • Installation of sample carrier trays into, and Sun shield over, Expose-R2 payload.
  • Installation of Expose-R2 payload outside Russian ISS segment on the URM-D platform during Russian EVA.
  • Checkout and commissioning including evacuation of selected sample carriers by telecommand.
  • Removal of Sun shield during second Russian EVA.
  • Continuous exposure outside ISS for optimum 12, maximum of 18, minimum of 10 months.
  • Closing of vacuum valves by telecommand and de-installation of Expose-R2 payload during third Russian EVA.
  • De-installation of sample trays from Expose-R2 payload.
  • Download of trays.
  • Photos before, during and after exposure.
During the exposure period the experiment remains passive. Environmental parameters (temperature, UV irradiation, ionizing radiation) are being measured by sensors not part of the P.S.S. experiment.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites
Further details about PSS from ESA's Erasmus Experiment Archive

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Imagery