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.     

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 related to human missions to Mars

In accordance with the United Nations Outer Space Treaties [United Nations, Agreement Governing the Activities of States on the Moon and Other Celestial Bodies, UN doc A/RES/34/68, resolution 38/68 of December 1979], currently maintained and promulgated by the Committee on Space Research [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], missions exploring the Solar system must meet planetary protection requirements. Planetary protection aims to protect celestial bodies from terrestrial contamination and to protect the Earth environment from potential biological contamination carried by returned samples or space systems that have been in contact with an extraterrestrial environment. From an exobiology perspective, Mars is one of the major targets, and several missions are currently in operation, in transit, or scheduled for its exploration. Some of them include payloads dedicated to the detection of life or traces of life. The next step, over the coming years, will be to return samples from Mars to Earth, with a view to increasing our knowledge in preparation for the first manned mission that is likely to take place within the next few decades. Robotic missions to Mars shall meet planetary protection specifications, currently well documented, and planetary protection programs are implemented in a very reliable manner given that experience in the field spans some 40 years. With regards to sample return missions, a set of stringent requirements has been approved by COSPAR [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], and technical challenges must now be overcome in order to preserve the Earth’s biosphere from any eventual contamination risk. In addition to the human dimension of the mission, sending astronauts to Mars will entail meeting all these constraints. Astronauts present huge sources of contamination for Mars and are also potential carriers of biohazardous material on their return to Earth. If they were to have the misfortune of being contaminated, they themselves would become a biohazard, and, as a consequence, in addition to the technical constraints, human and ethical considerations must also be taken into account.     

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。     

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。     

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.     

Planetary Protection and the astrobiological exploration of Mars: Proactive steps in moving forward

Future efforts towards Mars exploration should include a discussion about the effects that the strict application of Planetary Protection policies is having on the astrobiological exploration of Mars, which is resulting in a continued delay in the search for Martian life. As proactive steps in the path forward, here we propose advances in three areas. First, we suggest that a redefinition of Planetary Protection and Special Regions is required for the case of Mars. Particularly, we propose a definition for special places on Mars that we can get to in the next 10–20?years with rovers and landers, where try to address questions regarding whether there is present-day near-surface life on Mars or not, and crucially doing so before the arrival of manned missions. We propose to call those special places “Astrobiology Priority Exploration” regions (APEX regions). Second, we stress the need for the development of robotic tools for the characterization of complex organic compounds as unequivocal signs of life, and particularly new generations of complex organic chemistry and biosignature detection instruments, including advances in DNA sequencing. And third, we advocate for a change from the present generation of SUV-sized landers and rovers to new robotic assets that are much easier to decontaminate such as microlanders: they would be very small with limited sensing capabilities, but there would be many of them available for launch and coordination from an orbiting platform. Implementing these changes will help to move forward with an exploration approach that is much less risky to the potential Mars biosphere, while also being much more scientifically rigorous about the exploration of the “life on Mars” question – a question that needs to be answered both for astrobiological discovery and for learning more definitive lessons on Planetary Protection.     

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.     

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.     

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.     

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.     

Planetary protection considerations for MarsNet and Mars sample return missions.

The ESA MarsNet mission proposal consists most probably of a trio of Mars landers. These landers each contain a variety of scientific equipment. The network of stations demands for a definition of its planetary protection requirements. With respect to the MarsNet mission only forward contamination problems will be considered. Future involvement of European efforts in planetary exploration including sample returns will also raise the problem of back contamination. A tradeoff study for the overall scientific benefit with respect to the approximative cost is necessary. Planetary protection guide-lines will be proposed by an interdisciplinary and international board of experts working in the fields of both biology and planetary science. These guide-lines will have to be flexible in order to be modified with respect to new research results, e.g. on adaptation of microorganisms to extreme (space) conditions. Experiments on the survival of microorganisms at conditions of simulated Mars surface and subsurface will have to be conducted in order to obtain a baseline data collection as a reference standard for future guide-lines.     

Planetary protection issues of private endeavours in research,exploration, and human access to space: An environmental economics approach to forward contamination

In light of the rapidly growing New Space Economy, the landscape of space exploration and development activities will certainly become much more complicated year by year. Relevant commercial space actors have already emerged, pushing the boundaries of entrepreneurial space ventures beyond the Earth-oriented upstream and downstream market segments and opening up the path towards the novel segments of space exploration, space resources utilization, and space research. Planetary protection is usually defined as a set of guidelines concerning the avoidance of bidirectional biological material exchange between the Earth and other celestial bodies. Recent success stories of established and new-entrant NewSpace actors, although posing no realistic planetary protection threat at present, clearly indicate that serious work needs to be done in order for the relevant guidelines to keep up with the rapid advances of the technology development cycles that occur within NewSpace companies. This need may become even more urgent, as space entrepreneurs acquire and develop the resources and competencies to target the currently underserved market segments of space research, exploration, and utilization. As of now, these capabilities were maintained solely by public space agencies; thus, all planetary protection priorities, strategies, and responsibilities were discussed, agreed-upon, and delegated for implementation among national and international working groups of public stakeholders. Although top-down regulations can be effective in controlling the quality and conformity of the deliverables of private subcontractors to public contractors, international planetary protection frameworks might need to evolve even beyond such unmet public-private interaction and partnership models. For this reason, this study did not focus on the legal and political issues of mandating NewSpace actors to adhere to planetary protection guidelines; rather, drawing from the field of sustainable development on Earth, an environmental economics approach was followed, with the goal of viewing the relationship between planetary protection and private space exploration and development as another “tragedy of the commons” problem that must be settled accordingly. After the problem’s framing, i.e. the conceptual presentation and synthesis of four extraterrestrial non-excludable goods, the initial approach of their total economic value, and the negative externalities of their exploitation, a discussion of the forward contamination mitigation costs was conducted. Drawing from the literature and using examples from both the terrestrial and aerospace sectors, a pre-emptive move was suggested: the establishment of a global industry consortium for the pre-competitive collaboration in forward contamination mitigation technologies, centered on an international planetary protection analogue program and its respective testbed facility.     

Fundamental studies concerning planetary quarantine in space.

If there is a possibility that the organisms carried from Earth to space can live for a significant period on planets, the contamination of planets should be prevented for the purpose of future life-detection experiments. In connection with quarantine for interplanetary missions, we have examined the survivabilities of terrestrial microorganisms under simulated space conditions. In this study, examined the survivabilities of terrestrial organisms under simulated Mars conditions. The Mars conditions were simulated by ultraviolet (UV) and proton irradiation under low temperature, high vacuum, and simulated gaseous conditions. After exposure to the simulated Mars condition, the survivabilities of the organisms were examined. The spores of Bacillus subtilis and Aspergillus niger, some anaerobic bacterias and algaes, showed considerably high survivabilities even after UV and proton irradiation corresponding to 200 years on Mars. This subject is not restricted to academic curiosity but concerns problems involving the contamination of Mars with terrestrial organisms carried by space-probes.     

A lunar L2-Farside exploration and science mission concept with the Orion Multi-Purpose Crew Vehicle and a teleoperated lander/rover

A novel concept is presented in this paper for a human mission to the lunar L2 (Lagrange) point that would be a proving ground for future exploration missions to deep space while also overseeing scientifically important investigations. In an L2 halo orbit above the lunar farside, the astronauts aboard the Orion Crew Vehicle would travel 15% farther from Earth than did the Apollo astronauts and spend almost three times longer in deep space. Such a mission would serve as a first step beyond low Earth orbit and prove out operational spaceflight capabilities such as life support, communication, high speed re-entry, and radiation protection prior to more difficult human exploration missions. On this proposed mission, the crew would teleoperate landers/rovers on the unexplored lunar farside, which would obtain samples from the geologically interesting farside and deploy a low radio frequency telescope. Sampling the South Pole-Aitken basin, one of the oldest impact basins in the solar system, is a key science objective of the 2011 Planetary Science Decadal Survey. Observations at low radio frequencies to track the effects of the Universe’s first stars/galaxies on the intergalactic medium are a priority of the 2010 Astronomy and Astrophysics Decadal Survey. Such telerobotic oversight would also demonstrate capability for human and robotic cooperation on future, more complex deep space missions such as exploring Mars.     

载人火星探测飞行方案

对世界各国载人火星探测的研究情况进行了简要综述,研究了国内外有关载人火星探测飞行方案,提出了载人火星探测方案确定的原则和方案基本思想.给出了一种载人火星探测飞行方案的总体设计,包括飞行轨道方案和载人火星飞船方案等.尤其对轨道设计的重要的两个参数——速度增量和飞行时间进行了详细计算.最后给出了飞行轨道选择、火星飞船从地球到火星和从火星返回地球等的轨道方案和火星飞船各组成部分方案的详细设计结果.     

火星探测器轨道运动建模的时空基准转换研究

火星探测的理论研究和工程实践需要一套便于描述火星探测器轨道运动的时空基准转换体系,环火星轨道的探测任务期间需要给出探测器以火星为基准的运动信息,而地面测控只能获得探测器以地球为基准的运动信息。为此,文章定义了一套新的以火星为基准的坐标系以及过渡到以地球为基准的坐标系,并给出了各坐标系转换的求解方法。最后,对以文中所提出的时空转换基准为基础建立的火星探测器轨道运动模型进行数值仿真,并将计算结果同STK进行了比较,验证了该时空转换体系的正确性。     

Designing planetary protection into the Mars Observer mission.

Planetary protection has been an important consideration during the process of designing the Mars Observer mission. It affected trajectory design of both the interplanetary transfer and the orbits at Mars; these in turn affected the observation strategies developed for the mission. The Project relied mainly on the strategy of collision avoidance to prevent contamination of Mars. Conservative estimates of spacecraft reliability and Martian atmosphere density were used to evaluate decisions concerning the interplanetary trajectory, the orbit insertion phase at Mars, and operations in orbit at Mars and afterwards. Changes in the trajectory design, especially in the orbit insertion phase, required a refinement of those estimates.     

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.