Planetary Protection Requirements for Human and Robotic Missions to Mars
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Concepts and Approaches for Mars Exploration (2012) 4331.pdf PLANETARY PROTECTION REQUIREMENTS FOR HUMAN AND ROBOTIC MISSIONS TO MARS. R. Mogul1, P. D. Stabekis2, M. S. Race3, and C. A. Conley4, 1California State Polytechnic University, Pomona, 3801 W. Temple Ave, Pomona, CA 91768 ([email protected]), 2Genex Systems, 525 School St. SW, Suite 201, Washington D.C. 20224 ([email protected]), 3SETI Institute, Mountain View, CA 94043, 4NASA Head- quarters, Washington D.C. 20546 ([email protected]) Introduction: Ensuring the scientific integrity of mission. Hardware involved in the acquisition and Mars exploration, and protecting the Earth and the storage of samples from Mars must be designed to human population from potential biohazards, requires protect Mars material from Earth contamination, and the incorporation of planetary protection into human ensure appropriate cleanliness from before launch spaceflight missions as well as robotic precursors. All through return to Earth. Technologies needed to ensure missions returning samples from Mars are required to sample cleanliness at levels similar to those maintained comply with stringent planetary protection require- by the Viking project, in the context of modern space- ments for this purpose, recent refinements to which are craft materials, are yet to be developed. reported here. The objectives of planetary protection policy are As indicated in NASA Policy Directive NPD the same for both human and robotic missions; howev- 8020.7G (section 5c), to ensure compliance with the er, the specific implementation requirements will nec- Outer Space Treaty planetary protection is a mandatory essarily be different. Human missions will require component for all solar system exploration, including additional planetary protection approaches that mini- human missions. International planetary protection mize contamination released due to human exploration, policy and guidelines for compliance with Treaty obli- including protocols on how to access locations on gations are maintained by the Committee on Space Mars (both characterized and uncharacterized) and Research (COSPAR) of the International Council for performance standards for human support systems. Science, which advises the United Nations on matters Robotic elements of human missions must still follow of space exploration. relevant planetary protection requirements: access to The reformulation of the Mars Exploration Pro- Mars “special regions” (see NPR 8020.12D for defini- gram must include timely and methodical approaches tion) involves stringent cleanliness requirements, to develop appropriate technologies that comply with which will necessitate targeted technology develop- planetary protection requirements, to ensure that pro- ment for both hardware cleaning and clean transfer gram architectures involving combined human and capabilities. A conceptual approach is presented in robotic missions benefit from crosscutting technologies NASA's Draft Reference Architecture 5, but imple- and leveraged cost [1-3]. As indicated in several re- mentation requirements for human-based exploration cent reports [4-7], the primary concerns for planetary must be refined in the context of specific planned mis- protection and Mars exploration include preventing the sions. forward contamination of Mars, documentation of as- Protecting Astronauts: Article IX of the Outer tronaut health, and preventing backward contamination Space Treaty require States Parties to take 'appropriate of the Earth. Significant investments will be needed (as measures' to avoid 'adverse changes in the environment supported by the NRC Decadal Survey) in technolo- of the Earth resulting from the introduction of extrater- gies for health monitoring, minimization of astronaut restrial matter.' Minimizing exposure of astronauts to contact with Mars dust/soil, bioburden measurements potentially hazardous Mars materials, as well as moni- and life detection, and the containment and handling of toring astronaut health and microbial populations car- samples returned from Mars. ried by human missions, are key factors in facilitating Protecting Mars: Preventing the forward contam- the safe return of astronauts to Earth. Comprehensive ination of Mars by biological organisms from Earth is monitoring is essential, to ensure adequate documenta- necessary to facilitate the study of life in our solar sys- tion in order to provide confidence that in-flight ill- tem. Experience with past robotic missions has in- nesses or other potential biohazards are of Earth origin. formed the development of requirements and imple- This will be required for planetary protection purposes mentation options that are explicitly detailed in at a level significantly greater than that needed to doc- COSPAR policy and NASA Procedural Requirements ument astronaut health alone. document NPR 8020.12 (currently, version D). For Additionally, planetary protection technology landed hardware, compliance with these requirements needs include the development of human habitat involves rigorous bioburden reduction and accounting egress/ingress procedures that minimize contact with pre-launch, and operational constraints through end of Martian material; medical monitoring procedures be- Concepts and Approaches for Mars Exploration (2012) 4331.pdf fore, during and, after EVA; monitoring of the micro- ments refinement and technology development. Com- bial inventory of human habitats; and quarantine pro- pliance with planetary protection requirements on ro- cedures for affected astronauts. Guidelines for the botic and human Mars missions is required by both human exploration of Mars, as presented in COSPAR national policy and international treaty; however, spe- policy, provide the framework to support requirements cific approaches for minimizing human-associated in these areas, however, specific implementation ap- contamination and human exposure are still to be es- proaches will most usefully be developed in the con- tablished. text of anticipated technology developments in human Considerable effort by both NASA and ESA has health monitoring and molecular environmental micro- gone into identifying technologies needed for robotic biology. Mars Sample Return, although actual development of Protecting Earth: Preventing adverse effects on the necessary technologies to comply with planetary the Earth's environment as a result of returning astro- protection requirements is only starting, and within nauts and/or samples from Mars is the highest plane- NASA is on hold. Technologies developed for human tary protection priority in COSPAR guidelines, in ac- Mars missions must also incorporate planetary protec- cordance with Article IX of the Outer Space Treaty. tion constraints from their earliest development, to Requirements for Mars Sample Return involve strin- ensure that costs are appropriately allocated and mini- gent restrictions on release of unsterilized Mars mate- mize difficulty for demonstrating compliance down- rial into the Earth environment. The European Science stream. Although minimal exposure is the goal, not all Foundation (ESF) has recently completed a study on human-associated processes and mission operations assuring the safety of robotic Mars sample return mis- can be conducted within closed systems, and astro- sions [8] and has endorsed previous guidance that the nauts will inevitably be exposed to Martian materials. constraints be formulated as an assurance level for the Thus, studies assessing the biotoxicity of Martian dust release of a particle of martian material of a size that and other materials, as well as monitoring, quarantine, could potentially carry biological hazards. Specific and treatment technologies for affected astronauts are numerical requirements recommended by the ESF in- necessities for ensuring their return, and the safety of volve ensuring that a particle of unsterilized Mars ma- Earth. terial is contained with a probability of 1x10-6. In con- Planetary protection is critical to protecting the bio- sideration of new information about viruses and genet- sphere of the Earth as well as the success of scientific ic transfer agents, the particle size limit recommended investigations focusing on Mars life and habitability, by the ESF study for containment is 10nm. Contain- and therefore is an essential element in the architecture ment at this level is required until samples are charac- of the Mars Exploration Program—for which the nec- terized and demonstrated to be safe for release, which essary preparatory activities will require significant includes satisfactory completion of a life detection investment. protocol, although re-allocation of the full 'probability of release' is anticipated upon successful introduction of the return capsule into an Earth-based containment References: facility. Technologies for life detection, and the proto- [1] Conley, C. A. and Rummel, J. D. (2010). Acta col itself, are also areas in need of additional develop- Astronaut., 66, 792-797. [2] McKay, C. P. and Davis, W. L. ment and technical refinement. (1989). Ad. Space Res., 9, 197-202. [3] Race, M. S., et al. (2011) 41st International Conference on Environmental The Apollo Program provides a cautionary exam- Systems, AIAA-2011-5093. [4] Joint NASA/ESA Workshop ple of how NASA has implemented planetary protec- on Mars Planetary Protection and Human Systems Research tion on human missions in the past, for both astronaut and Technology (2005) Report. [5] Criswell, M., et al. (2005) and samples—and illustrates