Issues of exploration: human health and wellbeing during a mission to Mars.

Today, the tools are in our hands to enable us to travel away from our home planet and become citizens of the solar system. Even now, we are seriously beginning to develop the robust infrastructure that will make the 21st century the Century of Space Travel. But this bold step must be taken with due concern for the health, safety and wellbeing of future space explorers. Our long experience with space biomedical research convinces us that, if we are to deal effectively with the medical and biomedical issues of exploration, then dramatic and bold steps are also necessary in this field. We can no longer treat the human body as if it were composed of muscles, bones, heart and brain acting independently. Instead, we must lead the effort to develop a fully integrated view of the body, with all parts connected and fully interacting in a realistic way. This paper will present the status of current (2000) plans by the National Space Biomedical Research Institute to initiate research in this area of integrative physiology and medicine. Specifically, three example projects are discussed as potential stepping stones towards the ultimate goal of producing a digital human. These projects relate to developing a functional model of the human musculoskeletal system and the heart.     

Science strategy for human exploration of Mars.

The scientific objectives of Mars exploration can be framed within the overarching theme of exploring Mars as another home for life, both for evidence of past or present life on Mars, and as a potential future home for human life. The two major areas of research within this theme are: 1) determining the relationship between planetary evolution, climate change, and life, and 2) determining the habitability of Mars. Within this framework, this paper discusses the exploration objectives for exobiology, climatology and atmospheric science, geology, and martian resource assessment. Human exploration will proceed in four major phases: 1) Precursor missions which will obtain environmental knowledge necessary for human exploration, 2) Emplacement phase which includes the first few human landings where crews will explore the local area of the landing site; 3) Consolidation phase missions where a permanent base will be constructed and crews will be capable of detailed exploration over regional scales; 4) Utilization phase, in which a continuously occupied permanent Mars base exists and humans will be capable of detailed global exploration of the martian surface. The phases of exploration differ primarily in the range and capabilities of human mobility. In the emplacement phase, an unpressurized rover, similar to the Apollo lunar rover, will be used and will have a range of a few tens of kilometers. In the Consolidation phase, mobility will be via a pressurized all-terrain vehicle capable of expeditions from the base site of several weeks duration. In the Utilization phase, humans will be capable of several months long expeditions to any point on the surface of Mars using a suborbital rocket equipped with habitat, lab, and return vehicle. Because of human mobility limitations, it is important to extend the range and duration of exploration in all phases by using teleoperated rover vehicles. Site selection for human missions to Mars must consider the multi-decade time frame of these four phases. We suggest that operations in the first two phases be focused in the regional area containing the Coprates Quadrangle and adjacent areas.     

Exobiological exploration of Mars.

Of all the other planets in the solar system, Mars remains the most promising for further elucidating concepts about chemical evolution and the origin of life. Strategies were developed to pursue three exobiological objectives for Mars exploration: determining the abundance and distribution of the biogenic elements and organic compounds, detecting evidence of an ancient biota on Mars, and determining whether indigenous organisms exist anywhere on the planet. The three strategies are quite similar and, in fact, share the same sequence of phases. In the first phase, each requires global reconnaissance and remote sensing by orbiters to select sites of interest for detailed in situ analyses. In the second phase, lander missions are conducted to characterize the chemical and physical properties of the selected sites. The third phase involves conducting "critical" experiments at sites whose properties make them particularly attractive for exobiology. These critical experiments would include, for example, identification of organics, detection of fossils, and detection of extant life. The fourth phase is the detailed analysis of samples returned from these sites in Earth-based laboratories to confirm and extend previous discoveries. Finally, in the fifth phase, human exploration is needed to establish the geological settings for the earlier findings or to discover and explore sites that are not accessible to robotic spacecraft.     

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.     

Radiation environment due to galactic and solar cosmic rays during manned mission to Mars in the periods between maximum and minimum solar activity cycles.

A possibility of a manned mission to Mars without exceeding the current radiation standards is very doubtful during the periods of minimum solar activity since the dose equivalent due to galactic cosmic rays exceeds currently recommended standards even inside a radiation shelter with an equivalent of 30 g cm-2 aluminum. The radiation situation at the time of maximum solar activity is determined by the occurrence of major solar proton events which are exceedingly difficult to forecast. This paper discusses the radiation environment during a manned mission to Mars in the years between minimum and maximum solar activity when the galactic cosmic ray intensity is considerably reduced, but the solar flare activity has not yet maximized.     

ASTEX: An in situ exploration mission to two near-Earth asteroids

ASTEX (ASTeroid EXplorer) is a concept study of an in situ exploration mission to two Near-Earth-Asteroids (NEAs), which consists of an orbiting element and two individual lander units. The target candidates have different mineralogical compositions, i.e. one asteroid is chosen to be of “primitive’’ nature, the other to be a fragment of a differentiated asteroid. The main scientific goals of the ASTEX mission are the exploration of the physical, geological, and mineralogical nature of the NEAs. The higher level goal is the provision of information and constraints on the formation and evolution of our planetary system. The study identified realistic mission scenarios, defined the strawman payload as well as the requirements and options for the spacecraft bus including the propulsion system, the landers, the launcher, and assessed and defined the requirements for the mission’s operational ground segment.     

载人月球极地探测定点返回轨道设计

针对载人月球极地探测任务,对定点返回轨道优化设计问题进行了研究。根据月球极地轨道的特性,介绍了三种返回轨道机动方案。结合三脉冲变轨方案,采用了从初步计算到精确计算的串行求解策略,对定点返回轨道进行优化设计。初步计算阶段,建立了基于近月点伪参数的三段二体拼接模型,将三脉冲机动段与月球逃逸段解耦,求解轨道初值;精确计算阶段,提出了两段拼接方法,分别进行逆向和正向高精度数值积分。经过仿真测试,验证了该策略求解的有效性和准确性。最后,通过大量的仿真计算,分析了定点返回轨道的特性。研究结论对未来载人月球极地探测定点返回轨道方案的设计具有重要的参考价值。     

Applying fuzzy bi-dimensional scenario-based model to the assessment of Mars mission architecture scenarios

Sending man to Mars has been a long-held dream of humankind. NASA plans human planetary explorations using approaches that are technically feasible, have reasonable risks and have relatively low costs. This study presents a novel Multi-Attribute Decision Making (MADM) model for evaluating a range of potential mission scenarios for the human exploration of Mars. The three alternatives identified by the Mission Operations Directorate (MOD) at the Johnson Space Center (JSC) include split mission, combo lander and dual scenarios. The proposed framework subsumes the following key methods: first, the conjunction method is used to minimize the number of alternative mission scenarios; second, the Fuzzy Risk Failure Mode and Effects Analysis (RFMEA) is used to analyze the potential failure of the alternative scenarios; third, the fuzzy group Real Option Analysis (ROA) is used to estimate the expected costs and benefits of the alternative scenarios; and fourth, the fuzzy group permutation approach is used to select the optimal mission scenario. We present the results of a case study at NASA’s Johnson Space center to demonstrate: (1) the complexity of mission scenario selection involving subjective and objective judgments provided by multiple space exploration experts; and (2) a systematic and structured method for aggregating quantitative and qualitative data concerning a large number of competing and conflicting mission events.     

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.     

Characteristics of solar particle events at Mars relative to Earth

While not specifically designed to detect solar energetic particle radiation, the Electron Reflectometer onboard Mars Global Surveyor (MGS/ER) collected such data from January 1999 through October 2006. Energetic protons (?25 MeV) and other ions penetrated the MGS/ER shielding and registered counts within the instrument’s electronics. During solar particle events (SPE’s), prolonged enhancements in the particle background were observed at Mars with time intensity profiles similar to Earth based SPE observations. Throughout the lifespan of MGS/ER, 85 distinct SPE’s were observed. Basic characteristics of Mars based SPE observations and the frequency of SPE occurrences at Mars are compared to corresponding Earth based observations. Approximately 22% of SPE’s that occurred during MGS/ER operation were observed at Earth but not Mars. Similarly, 19% of SPE’s were observed at Mars but not Earth. Time intensity profiles at Earth and Mars match predictions provided in the literature, based on the physical location of the detector with respect to the motion of the interplanetary shock wave. Note: The work described herein was largely conducted as part of a doctoral dissertation produced by the author.     

Problems and conception of ensuring radiation safety during Mars missions.

The Mars mission differs from near-Earth manned space flights by radiation environment and duration. The importance of effective using the weight of the spacecraft increases greatly because all the necessary things for the mission must be included in its starting weight. For this reason the development of optimal systems of radiation safety ensuring (RSES) acquires especial importance. It is the result of sharp change of radiation environment in the interplanetary space as compared to the one in the near-Earth orbits and significant increase of the interplanetary flight duration. The demand of a harder limitation of unfavorable factors effects should lead to radiation safety (RS) standards hardening. The main principles of ensuring the RS of the Mars mission (optimizing, radiation risk, ALARA) and the conception of RSES, developed on the basis of the described approach and the experience obtained during orbital flights are presented in the report. The problems that can impede the ensuring of the crew members' RS are also given here.     

The VESTA project: Combined studies of Mars and small bodies of the solar system

A mission to Mars and small solar system bodies is presently studied as a possible collaboration between INTERCOSMOS, CNES, ESA and eventually other participants. The VESTA concept, based on the same strategy as the successful VEGA mission, is more ambitious, as two spacecrafts separate soon after launch: a soviet spacecraft, dedicated to the study of Mars, and a spacecraft dedicated to the study of small bodies, under the responsibility of CNES and ESA. This spacecraft would use Mars gravity assists to visit up to 4 small bodies in less than 5 years. The mission is duplicated, which means that up to 8 small bodies could be studied (e.g. 6 main belt asteroids, 1 apollo-amor asteroid and 1 short period comet). Low relative velocities (< 3.5 km/s) should allow to drop a penetrator on two large main belt asteroids, such as 4 Vesta and 1 Ceres (1994 launch).     

Applied superconductivity and superfluidity for the exploration of the Moon and Mars.

We discuss how superconductivity and superfluidity can be applied to solve the challenges in the exploration of the Moon and Mars. High sensitivity instruments using phenomena of superconductivity and superfluidity can potentially make significant contributions to the fields of navigation, automation, habitation, and resource location. Using the quantum nature of superconductivity, lightweight and very sensitive diagnostic tools can be made to monitor the health of astronauts. Moreover, the Moon and Mars offer a unique environment for scientific exploration. We also discuss how powerful superconducting instruments may enable scientists to seek answers to several profound questions about nature. These answers will not only deepen our appreciation of the universe, they may also open the door to paradigm-shifting technologies.     

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 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.     

On the negligible role of manned missions for the geological exploration of Mars: a commentary.

At the 28th Plenary Meeting of the Committee on Space Research (COSPAR) in The Hague, The Netherlands, there was on June 28, 1990, a session of commission MF.1 on Impact of Human Expeditions to Mars, in which, among others, the benefits of manned Mars missions for the geological survey of Mars were discussed. The present commentary does not intend to discuss the pros and cons of manned space flight or of Mars exploration at large, but will reiterate some of the points made in that discussion concerning the justification of manned versus automated Mars exploration in the context of geologic sciences.     

Chemical evolution of primitive solar system bodies.

In this paper we summarize some of the most salient observations made recently on the organic molecules and other compounds of the biogenic elements present in the interstellar medium and in the primitive bodies of the solar system. They include the discovery of the first phosphorus molecular species in dense interstellar clouds, the presence of complex organic ions in the dust and gas phase of Halley's coma, the finding of unusual, probably presolar, deuterium-hydrogen ratios in the amino acids of carbonaceous chondrites, and new developments on the chemical evolution of Titan, the primitive Earth, and early Mars. Some of the outstanding problems concerning the synthesis of organic molecules on different cosmic bodies are also discussed from an exobiological perspective.     

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.     

Systematic approach to life support system analyses and integration.

This paper is devoted to the consideration of possible viewpoint on CELSS development and design. If the aim to create practically applicable CELSS is accepted then the task to optimize the process of CELSS research and development in terms of minimum cost, hours, maximum applicability, scientific contribution, etc. becomes actual. Requirements of applicability and scientific significance are synergetic since understanding of general properties of CELSS gives an ability to create CELSS for different applications. To accomplish the task three main groups of parameters have to be optimized: i) configuration and operating parameters of developing CELSS itself; ii) organizational management of research and development of CELSS; iii) features of an area where CELSS is planned to be used (space missions, terrestrial applications, or biosphere investigation) and where requirements to CELSS characteristic come from. Given paper is a brief review presented some attempts to arrange mentioned above into some set of formalized and interacting criteria, and some progression of research stages derived from these criteria.