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CAST participates in PPOSS
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Qian Xuesen Laboratory of Space Technology
China Aerospace Components Engineering Center
Institute of Spacecraft System Engineering
Beijing Institute of Spacecraft Environment Engineering
Institute of Telecommunication and Navigation Satellites
CAST-Xi'an Institute of Space Radio Technology
Beijing Institute of Control Engineering
Beijing Institute of Space Mechanics and Electricity
Lanzhou Institute of Physics
Beijing Institute of Space Science and Technology Information
Shandong Aerospace Electro-technology Institute
Beijing Orient Institute of Measurement and Test
Tianjin Institute of Aerospace Mechanical and Electrical Equipment
Beijing Spacecrafts Manufacturing Factory
DFH Satellite Co., Ltd.
Space Star Technology Co., Ltd.
Aerospace Dongfanghong development Ltd. Shenzhen
Shenzhou Investment Management Co., Ltd.
China Spacesat Co., Ltd.
Space Biotechnology Group
Institute of Spacecraft Application System Engineering

International Agreement on Planetary Protection


International Agreement on Planetary Protection


COSPAR Planetary Protection Activities

COSPAR has formed a Planetary Protection Panel to:

  • Develop, maintain, and promulgate planetary protection knowledge, policy, and plans to prevent the harmful effects of such contamination.

  • Through symposia, workshops, and topical meetings at COSPAR Assemblies to provide an international forum for exchange of information in this area.

  • Inform the international community, e.g., the Committee on the Peaceful Uses of Outer Space (COPUOS) of the United Nations, as well as various other bilateral and multilateral organizations, of COSPAR decisions in this area.


The details of how the policies might be carried out is important and the Space Studies Board (SSB), a branch of National Research Council (NRC), has produced a series of recommendations for specific missions.

 Recent Mars Planetary Protection Studies by the Space Studies Board

The following two studies laid the ground rules:

1992  Biological Contamination of Mars: Issues and Recommendations, which reported advice to NASA on measures to protect Mars from contamination by Earth organisms, as well as overall policy guidance.

1997  Mars Sample Return: Issues and Recommendations, which reported advice to NASA on Mars sample return missions.

 SSB Recommendations for Mars Sample Return

  • Samples returned from Mars should be contained and treated as though potentially hazardous until proven otherwise.

  • If sample containment cannot be verified en route to Earth, the sample and spacecraft should either be sterilized in space or not returned to Earth.

  • Integrity of sample containment should be maintained through reentry and transfer to a receiving facility

  •  Controlled distribution of unsterilized materials should only occur if analyses determine the sample not to contain a biological hazard.

  •  Planetary protection measures adopted for the first sample return should not be relaxed for subsequent missions without thorough scientific review and concurrence by an appropriate independent body.

  • Avoiding contamination of returned samples with organisms or organic material of terrestrial origin:  “It will be important to stringently avoid the possibility that terrestrial organisms, their remains, or organic matter in general could inadvertently be incorporated into sample material returned from Mars.   Contamination with terrestrial material would compromise the integrity of the sample by adding confusing background to potential discoveries related to extinct or extant life on Mars….  Because the detection of life or evidence of pre biotic chemistry is a key objective of Mars exploration, considerable effort to avoid such contamination is justified.”

  • In-flight sterilization.

Sample handling and preservation

Two issues were considered important:

  • Ensuring sample containment

  • Avoiding return of uncontained martian material


Planetary Protection Requirements for Sample Return (1)

Sterilization of outbound spacecraft (Category IV-B)

  • Concern is that terrestrial contamination of the returned sample may precipitate “false positive” in the search for evidence of extraterrestrial life, or in the hazard determination protocol.

  • Departures from sterilization requirement must be justified by thorough modeling and/or experimentation.


Clean/sterilize spacecraft surfaces that will come into contact with sample, and keep them clean

  • Prevention of recontamination/cross-contamination is the hard part.

  • If contamination cannot be avoided, it needs to be extensively characterized.

  • An inability to unequivocally identify a viable entity in the sample as Earth-life may mean that an unsterilized sample can never be released from containment.


Planetary Protection Requirements for Sample Return (2)

Sealed Extraterrestrial sample container

  • Prevent accidental release into Earth’s environment (the technical challenge may be to confirm that the sample is sealed).

Design multiple means for sealing the container (multiple layers)

  • Provide for fail-safe maintenance of seal in various Earth-landing modes.

  • Provide for initial verification that design performed sealing action, and verify only anomalous indications and non-nominal situations.

  • If verification of seal and completion of nominal operations cannot be demonstrated, then Earth return must be abandoned.


Planetary Protection Requirements for Sample Return (3)

  •  Break the chain of contact with the planetary body:

    • Preclude any   “hitchhiker” entities traveling with the returned vehicle (and not   contained within the sealed sample container).

  • Design for Mars isolation in sample canister loading, launch, and transfer operations:

    • Avoid   recontamination during sample-transfer operations subsequent to Mars   Return Vehicle launch.

    • Provide additional   containment of sample canister within Earth Return Vehicle.


Planetary Protection Requirements for Sample Return (4)

Quarantine and testing

  • Contain unsterilized samples until required “biohazard” testing is completed.

  • Conduct initial characterization of returned samples and allocate portion for biohazard determination.

  • Allocate sterilized samples for special testing prior to distribution of unsterilized sample portion (may be necessary for completion of biohazard testing, as well).

  • Avoid Earth contamination of the sample throughout sample receiving, initial characterization, biohazard testing, and subsequent curation and distribution.


 Current Mars Planetary Protection Study by the Space Studies Board

  • Certification and Curation of Martian Samples.

  • Committee on Planetary and Lunar Exploration.

Requirements for a quarantine and biosafety certification facility for extraterrestrial samples, with the central question:

  • What are the criteria that must be satisfied before samples can be released from the quarantine facility?

Closely related issues include:

  • What are the optimal techniques for isolating and handling planetary materials, determining their content of biota (if any), and carrying out basic geochemical characterization studies in the certification facility?

  • How much capability for scientific analysis beyond that required for biosafety certification should be incorporated into the facility, and what principles should govern the utilization of this scientif



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