The problems of spreading Earth-origin biological materials to other planets and space in general, was recognized early in the space exploration programs of most countries, around the world.  In 1967 the UN Treaty on Outer Space included a paragraph which dealt with the subject.

In the USA, NASA developed its own planetary protection policy, and this is a model which should be followed by anyone exploring space.   It is simple, straightforward and summed up in two short statements.

From these two statements NASA has developed a series of documents which sets out the ground rules and specifies what needs to be done to fulfill the policy.

In order to carry out the policy, responsibility for its implementation must be set.

• Maintaining the required activities in support of policy at NASA Headquarters
• Assuring that the research and technology activities required to implement policy are conducted
• Monitoring space flight missions as necessary to meet requirements for certification

In addition individual responsibility will be placed on individual Program Directors, who have to:

• Meet requirements of planetary protection policy
• Provide conduct of reviews, inspections and evaluations

Certain constraints may have to be placed on a mission if it is thought that any form of contamination may result.

• Reduction of spacecraft biological contamination
• Constraints on spacecraft operating procedures
• Spacecraft organic inventory and restrictions
• Restrictions on the handling of returned samples
• Documentation of spacecraft trajectories and spacecraft material archiving

Planetary Protection Mission Categories (NPG 8020.12B)

International collaboration that everyone is following the same policy and adopting the same standards in the exploration of outer space is vital.   There would be little point in NASA following these policies if other countries and commercial users of space do not adhere to the same rules.  Agreement is being sought through The Committee on Space Research (COSPAR).

• COSPAR established by the International Council of Scientific Unions, is the interdisciplinary scientific organization concerned with international progress in space exploration.
• COSPAR maintains a Planetary Protection Policy approved by the Council and archived with the Secretariat in Paris.
• COSPAR’s policy development and promulgation capabilities need to be clarified and intensified to meet the requirements of currently planned international solar system exploration missions.

• 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.

• 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

• Ensuring sample containment
• Avoiding return of uncontained martian material

• 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.

• 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.

• 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.

•  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.

• 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.

• 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 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.

• 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.

• 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.

• 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.

• 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

Our thanks go to Dr John Rummel,  NASA's Planetary Protection Officer, for the content of this page.

 

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