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.”
Sample handling and preservation
Two issues were considered important:
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
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:
Design for Mars isolation in sample canister loading, launch, and transfer operations:
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
Requirements for a quarantine and biosafety certification facility for extraterrestrial samples, with the central question:
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 scientific capability?
To what extent can valuable lessons be learned from the Apollo quarantine experience?
In addition to Mars, a mission to the Jupiter moon, Europa, is planned and attention is now being paid as to its protection from contamination.
NRC Study: Preventing the Forward Contamination of Europa
The NRC Space Studies Board task group is evaluating the planetary protection requirements and methods used to prevent forward contamination of Europa in future orbiter and lander missions and will recommend any necessary changes. Specifically, they will:
assess the levels of cleanliness and sterilization required to prevent forward contamination of Europa given Europa's unique environment and our current understanding of terrestrial microorganisms;
review methods used to achieve the appropriate level of cleanliness and sterilization of spacecraft and recommend alternatives in light of recent advances in science and technology; and,
identify scientific investigations that should be accomplished to reduce the uncertainty in the above assessment.
Europa Orbiter Science Objectives
Group 1 Objectives:
Determine the presence or absence of a subsurface ocean;
Characterize the three-dimensional distribution of any subsurface liquid water and its overlying ice layers; and,
Understand the formation of surface features, including sites of recent or current activity, and identify candidate landing sites for future lander missions.
Group 2 Objectives:
Characterize the surface composition, especially compounds of interest to pre biotic chemistry;
Map the distribution of important constituents on the surface; and
Characterize the radiation environment in order to reduce the uncertainty for future missions, especially landers.
Recommendations: NRC Report on Small Body Sample-Return
All samples returned from planetary satellites and small solar system bodies that must be contained should be treated as potentially hazardous until proven otherwise.
No sample containment and handling is warranted beyond what is needed for scientific purposes for:
Moon, Io, new comets, Interstellar Dust Particles (IDP)* with a High Degree of Confidence
Phobos, Deimos, Callisto, C-type asteroids, undifferentiated metamorphosed asteroids, differentiated asteroids, all other comets, IDP’s* with a Lesser Degree of Confidence
Strict containment and handling are warranted for:
Europa, Ganymede, P-type asteroids, D-type asteroids, IDP’s*
Sample return provisions for contained samples are the same as for Mars
*Depending on parent body and time of exposure to space environment
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. For samples returned from bodies where a Lesser Degree of Confidence is indicated for containment and handling, a conservative, case-by-case approach should be used to assess the containment and handling requirements
NASA should consult with or establish an advisory committee with expertise in the planetary and biological sciences relevant to such an assessment
NASA should consult with or establish an advisory committee of experts from the scientific community when developing protocols and methods to examine returned samples for indicators of past or present extraterrestrial life forms