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A Comprehensive Characterization of Microorganisms and Allergens in Spacecraft Environment (99-E049)
Principal Investigator
Research Area:
Species Studied
Scientific Name: Homo sapiens Species: Human

Classical Microbial Risk Assessment focuses on key components such as hazard identification and characterization, dose-response, and exposure. Thus, the determination of risk from infectious disease during long-duration missions is composed of several factors including the concentration and the characteristics of the infectious agent. Therefore, a thorough knowledge of the microorganisms on board a spacecraft is essential in mitigating infectious disease risk to the crew. While preventive measures are taken to minimize the transfer of potential pathogens to spacecraft, several medically significant organisms have been isolated from both the Mir and International Space Station (ISS). Historically, the method for isolation and identification of microorganisms from spacecraft environmental samples depended upon their growth on culture media. While extensive, culture media may still only isolate a small percentage of the viable bacteria from a consortium. Current operational monitoring care of ISS surface, air, and potable water using culture-based techniques to date has shown 1) relatively low microbial concentrations, 2) common environmental isolates, 3) several opportunistic pathogens, 4) occasional spike in microbial concentration level, often associated with unexpected moisture on surfaces, and 5) occasional fluctuation in potable water that could be associated with biofilm buildup.

The Surface, Water, and Air Biocharacterization (SWAB) Flight Experiment was designed with the general aim of developing advanced collection and analysis techniques to better understand the microbial ecology and potential health risks in spacecraft, specifically focusing on the application of molecular identification techniques. The specific aims of this experiment were:

  • Collection of preflight and in-flight surface, air and water samples using methods that would allow for long-term storage of samples
  • Extraction of DNA from environmental samples that may be used to perform molecular analyses
  • Analysis of samples using Denaturing Gradient Gel Electrophoresis (DGGE)
  • Development of real-time PCR assays to detect specific molecular targets for specific medically significant organisms

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  • Publications
    Castro VA, Thrasher AN, Healy M. Ott CM, Pierson DL. Microbial characterization during the early habitation of the International Space Station. Microbial Ecology. February 2004; 47(2):119-126.[]

    Cruz P, Stetzenbach LD, Klima-Comba AK, Stevens VL, Castro VA, Ott CM, Pierson DL. "Enhanced Detection of Fungi in the Spacecraft Environment." 105th General Meeting of the American Society for Microbiology, Atlanta, GA, June 5-9, 2005.

    Mehta et al. Stress-induced subclinical reactivation of Varicella Zoster Virus in astronauts. Journal of Medical Virology. 2004; 72:174-179.[]

    Ott CM, Bruce RJ, Pierson DL. Microbial characterization of free floating condensate aboard the Mir Space Station. Microbial Ecology. February 2004; 47(2):133-136.[]

    Ott CM, Castro VA, Bassinger VJ, Fontenot SL, Bruce RJ, Cruz P, Stetzenbach LD, Pierson DL. "A Comprehensive Characterization of Microorganisms and Allergens in Spacecraft Environment." NASA Bioastronautics Investigators' Workshop, Galveston, TX, January 2005.

    Ott CM, John J, Castro VA, Cruz P, Buttner MP, Pierson DL. "A Comprehensive haracterization of Microorganisms and Allergens in Spacecraft Environment." NASA Human Research Program Investigators' Workshop, League City, TX, January 2007.

    Ott CM, John J, Castro VA, Cruz P, Buttner MP, Pierson DL. "Characterization of Microorganisms in Spacecraft Environments." 26th International Space Development Conference, Addison, Texas, May 25-28, 2007.

    Pierson, DL. Microbial contamination of spacecraft. Gravitational and Space Bulletin. June 2001; 14(2):1-6.[]

    Colony count, microbial
    Air microbiology
    Water microbiology

    Photo Gallery
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    Data Information
    Data Availability
    Archive is complete. Data sets are not publicly available but can be requested.
    Data Sets+ Request data

    Colony forming unit (CFU)
    Epstein-Barr Virus
    Microbial count: air
    Microbial count: surface
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    Mission/Study Information
    Mission Launch/Start Date Landing/End Date Duration
    Expedition 13 03/22/2006 09/24/2006 186 days
    Expedition 14 09/18/2006 04/21/2007 215 days
    Expedition 15 04/07/2007 10/21/2007 197 days
    Expedition 16 10/10/2007 04/19/2008 192 days
    Expedition 20 05/27/2009 10/11/2009 137 days
    Expedition 21 10/11/2009 12/01/2009 51 days
    Expedition 22 11/30/2009 03/18/2010 109 days
    Expedition 23 03/18/2010 06/01/2010 75 days
    Expedition 24 06/01/2010 09/25/2010 117 days

    Human Research Program (HRP) Human Research Roadmap (HRR) Information
    Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

    The Human Research Roadmap is located at:

    + Click here for information of how this experiment is contributing to the HRP's path for risk reduction.

    Additional Information
    Other Key People
    Managing NASA Center
    Johnson Space Center (JSC)
    Responsible NASA Representative
    Johnson Space Center LSDA Office
    Project Manager: Pamela A. Bieri
    Institutional Support
    National Aeronautics and Space Administration (NASA)
    Alternate Experiment Name
    Proposal Source
    Hardware Items