Biological assessment of Ariane 5 fairing

United Nations Space Treaties [10 and 11] require the preservation of planets and of Earth from contamination. All nations part to these Treaties shall take measures to prevent forward and backward contamination during missions exploring our solar system. As observer for the United Nations Committee on Peaceful Uses of Outer Space, the COSPAR (Committee of Space Research) defines and handles the applicable policy and proposes recommendations to Space Agencies [COSPAR Planetary Protection Panel, Planetary Protection Policy accepted by the COSPAR Council and Bureau, 20 October 2002, amended 24 March 2005. http://www.cosparhq.org/scistr/PPPolicy.htm.]. The goal is to protect celestial bodies from terrestrial biological contamination as well as to protect the Earth environment from an eventual biohazard which may be carried by extraterrestrial samples or by space systems returning to Earth. According to the applicable specifications, including in our case the French requirements [CNES, System Safety. Planetary Protection Requirements. Normative referential CNES RNC-CNES-R-14, CNES Toulouse, ed. 4, 04 October 2002.], the prevention of forward contamination is accomplished by reducing the bioburden on space hardware to acceptable, prescribed levels, including in some instances system sterilization, assembling and integrating the appropriate spacecraft systems in cleanrooms of appropriate biological cleanliness, avoiding or controlling any recontamination risk, and limiting the probability impact of space systems. In order to prepare for future exploration missions [Debus, A., Planetary protection: organization requirements and needs for future planetary exploration missions, ESA conference publication SP-543, pp 103–114, 2003.], and in particular for missions to Mars requiring to control the spacecraft bioburden, a test program has been developed to evaluate the biological contamination under the fairing of the Ariane 5 launcher.     

Estimation and assessment of Mars contamination.

Since the beginning of the exploration of Mars, more than fourty years ago, thirty-six missions have been launched, including fifty-nine different space systems such as fly-by spacecraft, orbiters, cruise modules, landing or penetrating systems. Taking into account failures at launch, about three missions out of four have been successfully sent toward the Red Planet. The fact today is that Mars orbital environment includes orbiters and perhaps debris, and that its atmosphere and its surface include terrestrial compounds and dormant microorganisms. Coming from the UN Outer Space Treaty [United Nations Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (the "Outer Space Treaty") referenced 610 UNTS 205 - resolution 2222(XXI) of December 1966] and according to the COSPAR planetary protection policy recommendations [COSPAR Planetary Protection Policy (20 October 2002), accepted by the Council and Bureau, as moved for adoption by SC F and PPP, prepared by the COSPAR/IAU Workshop on Planetary Protection, 4/02 with updates 10/0, 2002], Mars environment has to be preserved so as not to jeopardize the scientific investigations, and the level of terrestrial material brought on and around Mars theoretically has to comply with this policy. It is useful to evaluate what and how many materials, compounds and microorganisms are on Mars, to list what is in orbit and to identify where all these items are. Considering assumptions about materials, spores and gas location and dispersion on Mars, average contamination levels can be estimated. It is clear now that as long as missions are sent to other extraterrestrial bodies, it is not possible to keep them perfectly clean. Mars is one of the most concerned body, and the large number of missions achieved, on-going and planned now raise the question about its possible contamination, not necessarily from a biological point of view, but with respect to all types of contamination. Answering this question, will help to assess the potential effects of such contamination on scientific results and will address concerns relative to any ethical considerations about the contamination of other planets.     

Overview of current capabilities and research and technology developments for planetary protection

The pace of scientific exploration of our solar system provides ever-increasing insights into potentially habitable environments, and associated concerns for their contamination by Earth organisms. Biological and organic-chemical contamination has been extensively considered by the COSPAR Panel on Planetary Protection (PPP) and has resulted in the internationally recognized regulations to which spacefaring nations adhere, and which have been in place for 40 years. The only successful Mars lander missions with system-level “sterilization” were the Viking landers in the 1970s. Since then different cleanliness requirements have been applied to spacecraft based on their destination, mission type, and scientific objectives. The Planetary Protection Subcommittee of the NASA Advisory Council has noted that a strategic Research & Technology Development (R&TD) roadmap would be very beneficial to encourage the timely availability of effective tools and methodologies to implement planetary protection requirements. New research avenues in planetary protection for ambitious future exploration missions can best be served by developing an over-arching program that integrates capability-driven developments with mission-driven implementation efforts. This paper analyzes the current status concerning microbial reduction and cleaning methods, recontamination control and bio-barriers, operational analysis methods, and addresses concepts for human exploration. Crosscutting research and support activities are discussed and a rationale for a Strategic Planetary Protection R&TD Roadmap is outlined. Such a roadmap for planetary protection provides a forum for strategic planning and will help to enable the next phases of solar system exploration.     

Implementing planetary protection requirements for sample return missions.

NASA is committed to exploring space while avoiding the biological contamination of other solar system bodies and protecting the Earth against potential harm from materials returned from space. NASA's planetary protection program evaluates missions (with external advice from the US National Research Council and others) and imposes particular constraints on individual missions to achieve these objectives. In 1997 the National Research Council's Space Studies Board published the report, Mars Sample Return: Issues and Recommendations, which reported advice to NASA on Mars sample return missions, complementing their 1992 report, The Biological Contamination of Mars Issues and Recommendations. Meanwhile, NASA has requested a new Space Studies Board study to address sample returns from bodies other than Mars. This study recognizes the variety of worlds that have been opened up to NASA and its partners by small, relatively inexpensive, missions of the Discovery class, as well as the reshaping of our ideas about life in the solar system that have been occasioned by the Galileo spacecraft's discovery that an ocean under the ice on Jupiter's moon Europa might, indeed, exist. This paper will report on NASA's planned implementation of planetary protection provisions based on these recent National Research Council recommendations, and will suggest measures for incorporation in the planetary protection policy of COSPAR.     

载人火星探测的行星保护

行星保护是影响载人火星探索任务的重要问题之一。载人探测的行星保护包括3个方面,即防止来源于地球的微生物污染目标星球的正向污染防护、防止外来生物对地球的潜在危害的逆向污染防护,以及确保航天员的健康和安全。国际宇航界已经开始针对载人火星探测的行星保护制定政策法规和开展技术研讨。本文介绍了行星保护的定义和法理依据,简要回顾了美国国家航空航天局在“阿波罗登月”中的行星保护措施,并对未来载人火星探测中的主要污染物、污染途径以及污染防护策略进行了初步探讨。     

Planetary Protection Policy (U.S.A.).

Through existing treaty obligations of the United States, NASA is committed to exploring space while avoiding biological contamination of the planets, and to the protection of the Earth against harm from materials returned from space. Because of the similarities between Mars and Earth, plans for the exploration of Mars evoke discussions of these Planetary Protection issues. US Planetary Protection Policy will be focused on the preservation of these goals in an arena that will change with the growth of scientific knowledge about the martian environment. Early opportunities to gain the appropriate data will be used to guide later policy implementation. Because human presence on Mars will result in the end of Earth's separation from the martian environment, it is expected that precursor robotic missions will address critical planetary protection concerns before humans arrive.     

Planetary protection issues for sample return missions.

Sample return missions from a comet nucleus and the Mars surface are currently under study in the US, USSR, and by ESA. Guidance on Planetary Protection (PP) issues is needed by mission scientists and engineers for incorporation into various elements of mission design studies. Although COSPAR has promulgated international policy on PP for various classes of solar system exploration missions, the applicability of this policy to sample return missions, in particular, remains vague. In this paper, we propose a set of implementing procedures to maintain the scientific integrity of these samples. We also propose that these same procedures will automatically assure that COSPAR-derived PP guidelines are achieved. The recommendations discussed here are the first step toward development of official COSPAR implementation requirements for sample return missions.     

A consensus approach to planetary protection requirements: recommendations for Mars lander missions.

Over the last several years, the nature of the surface conditions on the planet Mars, our knowledge of the growth capabilities of Earth organisms under extreme conditions, and future opportunities for Mars exploration have been under extensive review in the United States and elsewhere. As part of these examinations, in 1992 the US Space Studies Board made a series of recommendations to NASA on the requirements that should be implemented on future missions that will explore Mars. In particular, significant changes were recommended in the requirements for Mars landers, changes that significantly alleviated the burden of planetary protection implementation for these missions. In this paper we propose a resolution implementing this new set of recommendations, for adoption by COSPAR at its 30th meeting in Hamburg. We also discuss future directions and study areas for planetary protection, in light of changing plans for Mars exploration.     

Planetary protection issues and the future exploration of Mars.

A primary scientific theme for the Space Exploration Initiative (SEI) is the search for life, extant or extinct, on Mars. Because of this, concerns about Planetary Protection (PP), the prevention of biological cross-contamination between Earth and other planets during solar system exploration missions, have arisen. A recent workshop assessed the necessity for, and impact of, PP requirements on the unmanned and human missions to Mars comprising the SEI. The following ground-rules were adopted: 1) information needed for assessing PP issues must be obtained during the unmanned precursor mission phase prior to human landings; 2) returned Mars samples will be considered biologically hazardous until proven otherwise; 3) deposition of microbes on Mars and exposure of the crew to Martian materials are inevitable when humans land; and, 4) human landings are unlikely until it is demonstrated that there is no harmful effect of Martian materials on terrestrial life forms. These ground-rules dictated the development of a conservative PP strategy for precursor missions. Key features of the proposed strategy include: 1) for prevention of forward contamination, all orbiters will follow Mars Observer PP procedures for assembly, trajectory, and lifetime. All landers will follow Viking PP procedures for assembly, microbial load reduction, and bioshield; and, 2) for prevention of back contamination, all sample return missions will have PP requirements which include fail-safe sample sealing, breaking contact chain with the Martian surface, and containment and quarantine analysis in an Earth-based lab. In addition to deliberating on scientific and technical issues, the workshop made several recommendations for dealing with forward and back contamination concerns from non-scientific perspectives.     

Planetary environment protection ID no: F3.3-M.1.05 implications for the development of a network of surface stations on Mars.

The European Space Agency's studies of a Comet Nucleus Sample Return mission (ROSETTA) as its Planetary Cornerstone in its long-term programme 'Horizon 2000' and the Marsnet mission, a potential contribution of the Agency to an international network of surface stations on Mars, has revived the interest in the present state of Planetary Protection requirements. MARSNET was one of the four candidate missions selected in April 1991 for further Design Feasibility (Phase A) Studies. Furthermore, of all space agencies participating in planetary exploration activities only the United States National Aeronautics and Space Administration had a well established Planetary Protection Policy on Viking and other relevant planetary missions, whereas ESA is considering the feasibility and potential impact of a planetary protection policy on its Marsnet mission, within the framework of a tight budgetary envelope applicable to ESA's medium (M) class missions. This paper will discuss in general terms the impact of Planetary Protection measures, its implications for Marsnet and the issues arising from this for the implementation of the mission in ESA's scientific programme.     

Planetary protection issues for Mars sample acquisition flight projects.

The planned NASA sample acquisition flight missions to Mars pose several interesting planetary protection issues. In addition to the usual forward contamination procedures for the adequate protection of Mars for the sake of future missions, there are reasons to ensure that the sample is not contaminated by terrestrial microbes from the acquisition mission. Recent recommendations by the Space Studies Board (SSB) of the National Research Council (United States), would indicate that the scientific integrity of the sample is a planetary protection concern (SSB, 1997). Also, as a practical matter, a contaminated sample would interfere with the process for its release from quarantine after return for distribution to the interested scientists. These matters are discussed in terms of the first planned acquisition mission.     

Planetary protection issues in advance of human exploration of Mars.

Current planetary quarantine considerations focus on robotic missions and attempt a policy of no biological contamination. The presence of humans on Mars, however, will inevitably result in biological contamination and physical alteration of the local environment. The focus of planetary quarantine must therefore shift toward defining and minimizing the inevitable contamination associated with humans. This will involve first determining those areas that will be affected by the presence of a human base, then verifying that these environments do not harbor indigenous life nor provide sites for Earth bacteria to grow. Precursor missions can provide salient information that can make more efficient the planning and design of human exploration missions. In particular, a robotic sample return mission can help to eliminate the concern about returning samples with humans or the return of humans themselves from a planetary quarantine perspective. Without a robotic return the cost of quarantine that would have to be added to a human mission may well exceed the cost of a robotic return mission. Even if the preponderance of scientific evidence argues against the presence of indigenous life, it must be considered as part of any serious planetary quarantine analysis for missions to Mars. If there is life on Mars, the question of human exploration assumes an ethical dimension.     

Planetary protection policy overview and application to future missions.

The 1967 treaty on the peaceful uses of outer space reflected both concerns associated with the unknown nature of the space environment and the desire of the world scientific community to preserve the pristine nature of celestial objects until such times as they could be studied in an effective manner. Since 1967, NASA has issued policy directives that have adopted the guidelines of COSPAR for protecting the planets from contamination by Earth organisms and for protecting the Earth from the unknown. This paper presents the current status of planetary protection (quarantine) policy within NASA, and a prospectus on how planetary protection and back contamination issues might be addressed in relation to future missions envisioned for development by NASA either independently, or in cooperation with the space agencies of other nations.     

Measuring the economic benefits of a national planetary protection policy to regulate future private space activities between Earth and Mars: Results of a contingent valuation survey in Greece

The emergence of private space actors may soon enable the growth of the novel market segments of space research and exploration, space resources utilization, and human access to space. The interdisciplinary field of Planetary Protection has to keep up with these advances. Planetary Protection is defined as a set of guidelines that aim to prevent the forward contamination of celestial bodies with biological material from Earth and the backward contamination of the terrestrial biosphere with extraterrestrial biological material. As space entrepreneurs acquire and develop the resources and competencies for commercial access to space, significant questions are expected to be raised in the future with respect to potential forward and backward contamination issues, particularly with respect to activities between Earth and Mars. Although such private activities do not seem to pose a serious Planetary Protection threat at the moment, certain preparatory steps need to be taken in order to prudently inform the relevant policy-making procedures. This work describes the application of the Contingent Valuation Method, a useful tool of the environmental economics discipline, with the aim of demonstrating a novel approach to estimate the economic valuation of the external benefits of preventing forward and backward contamination between Earth and Mars. Particularly, via a survey specifically developed for this purpose, a set of questions are used to elicit the perceived economic value that respondents place on the prevention of forward and backward contamination; the survey is administered to a national probability sample in Greece, and the generated data is processed through statistical analysis. The Contingent Valuation Method is a popular and well-established stated preference valuation technique; these techniques are often the more suitable choice for ex-ante valuations of future changes, and are currently the only known approach to capture all the aspects of the economic value of non-market goods. Through an initial proof-of-concept in Greece, the goal of this work is to provide useful insights on the expected external benefits of a national Planetary Protection policy to regulate future private space activities between Earth and Mars, and to encourage a larger-scale application of this tool in other countries around the world.     

Planetary protection program for Mars 94/96 mission.

Mars surface in-situ exploration started in 1975 with the American VIKING mission. Two probes landed on the northern hemisphere and provided, for the first time, detailed information on the martian terrain, atmosphere and meteorology. The current goal is to undertake larger surface investigations and many projects are being planned by the major Space Agencies with this objective. Among these projects, the Mars 94/96 mission will make a major contributor toward generating significant information about the martian surface on a large scale. Since the beginning of the Solar System exploration, planets where life could exist have been subject to planetary protection requirements. Those requirements accord with the COSPAR Policy and have two main goals: the protection of the planetary environment from influence or contamination by terrestrial microorganisms, the protection of life science, and particularly of life detection experiments searching extra-terrestrial life, and not life carried by probes and spacecrafts. As the conditions for life and survival for terrestrial microorganisms in the Mars environment became known, COSPAR recommendations were updated. This paper will describe the decontamination requirements which will be applied for the MARS 94/96 mission, the techniques and the procedures which are and will be used to realize and control the decontamination of probes and spacecrafts.     

Societal issues as Mars mission impediments: planetary protection and contamination concerns.

Societal and non-scientific factors represent potentially significant impediments for future Mars missions, especially in areas involving planetary protection. This paper analyzes public concerns about forward contamination to Mars and back contamination to Earth, evaluates major areas where lack of information may lead to uncontrollable impacts on future missions, and concludes that NASA should adopt a strategy that actively plans both the generation and subsequent management of planetary protection information to ensure that key audiences obtain needed information in a timely manner. Delay or avoidance in dealing with societal issues early in mission planning will increase the likelihood of public opposition, cost increases and missed launch windows. While this analysis of social and non-scientific considerations focuses on future Mars missions, the findings are also relevant for RTG launches, nuclear propulsion and other NASA activities perceived to have health, safety or environmental implications.     

火星无人探测与行星保护

行星保护是每一个开展深空探测的国家都要面对的问题,火星是太阳系里最可能存在地外生命的星球之一,也是行星保护的重点关注对象,在我国火星探测即将正式启动之际,对标国际上行星保护的政策、标准、技术和管理措施,对我国未来在火星探测中满足国际上行星保护的要求至关重要。主要回顾了行星保护的历史,国外在火星探测历史上行星保护正向防护所采取的措施,以及现代科学技术发展对行星保护正向防护相关技术的影响,并对我国未来火星及深空探测活动中应该采取的行星保护正向污染防护技术提出了建议。     

Planetary protection and the search for life beneath the surface of Mars.

The search for traces of extinct and extant life on Mars will be extended to beneath the surface of the planet. Current data from Mars missions suggesting the presence of liquid water early in Mars' history and mathematical modeling of the fate of water on Mars imply that liquid water may exist deep beneath the surface of Mars. This leads to the hypothesis that life may exist deep beneath the Martian surface. One possible scenario to look for life on Mars involves a series of unmanned missions culminating with a manned mission drilling deep into the Martian subsurface (approximately 3Km), collecting samples, and conducting preliminary analyses to select samples for return to earth. This mission must address both forward and back contamination issues, and falls under planetary protection category V. Planetary protection issues to be addressed include provisions stating that the inevitable deposition of earth microbes by humans should be minimized and localized, and that earth microbes and organic material must not contaminate the Martian subsurface. This requires that the drilling equipment be sterilized prior to use. Further, the collection, containment and retrieval of the sample must be conducted such that the crew is protected and that any materials returning to earth are contained (i.e., physically and biologically isolated) and the chain of connection with Mars is broken.     

Critical issues in connection with human missions to Mars: protection of and from the Martian environment.

Human missions to Mars are planned to happen within this century. Activities associated therewith will interact with the environment of Mars in two reciprocal ways: (i) the mission needs to be protected from the natural environmental elements that can be harmful to human health, the equipment or to their operations; (ii) the specific natural environment of Mars should be protected so that it retains its value for scientific and other purposes. The following environmental elements need to be considered in order to protect humans and the equipment on the planetary surface: (i) cosmic ionizing radiation, (ii) solar particle events; (iii) solar ultraviolet radiation; (iv) reduced gravity; (v) thin atmosphere; (vi) extremes in temperatures and their fluctuations; and (vii) surface dust. In order to protect the planetary environment, the requirements for planetary protection as adopted by COSPAR for lander missions need to be revised in view of human presence on the planet. Landers carrying equipment for exobiological investigations require special consideration to reduce contamination by terrestrial microorganisms and organic matter to the greatest feasible extent. Records of human activities on the planet's surface should be maintained in sufficient detail that future scientific experimenters can determine whether environmental modifications have resulted from explorations.     

Selection of sterilization methods for planetary return missions.

Two tasks must be accomplished to provide planetary protection for Mars return missions: (1) sterilization of the scientific module to be landed on Mars and (2) reliable sterilization of all material returned to Earth, while ensuring the scientific integrity of martian samples. This paper examines similarity and differences between these two tasks, and includes a discussion of technological implementation conditions and the nature of terrestrial and hypothesized martian microflora. The feasibility of a number of chemical and physical (ultraviolet and ionizing radiation and heating) methods of sterilization for use on the ground and onboard are discussed and compared. A combination of different methods will probably be selected as the most appropriate for ensuring planetary protection on the return mission.