Integration of In-Situ Resource Utilization into lunar/Mars exploration through field analogs

The ability to extract and process resources at the site of exploration into useful products such as propellants, life support and power system consumables, and radiation and rocket exhaust plume debris shielding, known as In-Situ Resource Utilization or ISRU, has the potential to significantly reduce the launch mass, risk, and cost of robotic and human exploration of space. The incorporation of ISRU into missions can also significantly influence technology selection and system development in other areas such as power, life support, and propulsion. For example, the ability to extract or produce large amounts of oxygen and/or water in-situ could minimize the need to completely close life support air and water processing system cycles, change thermal and radiation protection of habitats, and influence propellant selection for ascent vehicles and surface propulsive hoppers. While concepts and even laboratory work on evaluating and developing ISRU techniques such as oxygen extraction from lunar regolith have been going on since before the Apollo 11 Moon landing, no ISRU system has ever flown in space, and only recently have ISRU technologies been developed at a scale and at a system level that is relevant to actual robotic and human mission applications. Because ISRU hardware and systems have never been demonstrated or utilized before on robotic or human missions, architecture and mission planners and surface system hardware developers are hesitant to rely on ISRU products and services that are critical to mission and system implementation success. To build confidence in ISRU systems for future missions and assess how ISRU systems can best influence and integrate with other surface system elements, NASA, with international partners, are performing analog field tests to understand how to take advantage of ISRU capabilities and benefits with the minimum of risk associated with introducing this game-changing approach to exploration. This paper will describe and review the results of four analog field tests (Moses Lake in 6/08, Mauna Kea in 11/08, Flagstaff in 9/09, and Mauna Kea in 1/10) that have begun the process of integrating ISRU into robotic and human exploration systems and missions, and propose future ISRU-related analog field test activities that can be performed in collaboration with non-US space agencies.     

地外人工光合成装置研制与试验

原位资源利用技术是地外生命保障体系构建、实现人类地外生存的有效途径，是载人深空探索的核心技术。基于微通道技术的人工光合成反应器，采用流动反应器设计，用于低微重力等特殊环境条件下模拟人工光合作用，实现CO２向O２和含碳燃料的转化。微通道芯片通过气液剪切作用力使气体反应产物快速脱离电极表面并随反应介质排出反应器，理论上可以克服微重力条件对反应过程的影响，尚需进行微重力试验进行验证。同时，微通道结构可以通过精确控制反应气液的压力、流速、流量比等反应条件，获得优化的反应条件。通过地面试验，验证了该反应器将CO２还原为O２和含碳化合物的功能可行性。以Au和Ir/C作为阴极和阳极材料，3V电压条件下，O２产率可达11.74mL/h。此外，基于人工光合成反应器搭建了集反应模块、控制模块、流路驱动模块以及检测模块等于一体的地外人工光合成装置，形成原位反应、介质供给、精确控制、在线收集和检测等功能一体化的系统，并实现CO２有效转换和O２供给。为后续技术成熟度更高的反应装置研制、高产物选择性的含碳化合物转化以及人工光合成反应装置在轨试验奠定了理论和实践基础。     

Use of sunlight for plant lighting in a bioregenerative life support system – Equivalent system mass calculations

Plant lighting is a critical issue for cost effectiveness of bioregenerative systems. A plant lighting system using sunlight has been investigated and compared to systems using electrical lighting. Co-generation of electricity and use of in situ resource utilization (ISRU) were also considered. The fixed part of equivalent system mass was found to be reduced by factors of from 3.1 to 3.9, according to the mission assumptions. The time-dependent part of equivalent system mass was reduced by a smaller value, of about 1.05. Cost effectiveness of bioregeneration has been compared to the cost of shipping food. Break-even times for different Lunar and Mars missions were generally in the order of 2–10 years, and were quite sensitive to the assumptions. There is significant scope for future refinement of these values, and work is ongoing.     

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.     

Development and research program for a soil-based bioregenerative agriculture system to feed a four person crew at a Mars base.

For humans to survive during long-term missions on the Martian surface, bioregenerative life support systems including food production will decrease requirements for launch of Earth supplies, and increase mission safety. It is proposed that the development of "modular biospheres"--closed system units that can be air-locked together and which contain soil-based bioregenerative agriculture, horticulture, with a wetland wastewater treatment system is an approach for Mars habitation scenarios. Based on previous work done in long-term life support at Biosphere 2 and other closed ecological systems, this consortium proposes a research and development program called Mars On Earth(TM) which will simulate a life support system designed for a four person crew. The structure will consist of 6 x 110 square meter modular agricultural units designed to produce a nutritionally adequate diet for 4 people, recycling all air, water and waste, while utilizing a soil created by the organic enrichment and modification of Mars simulant soils. Further research needs are discussed, such as determining optimal light levels for growth of the necessary range of crops, energy trade-offs for agriculture (e.g. light intensity vs. required area), capabilities of Martian soils and their need for enrichment and elimination of oxides, strategies for use of human waste products, and maintaining atmospheric balance between people, plants and soils.     

地外二氧化碳转化利用技术研究现状与展望

为有效解决未来长期载人地外生存面临的物资供给等关键问题,获得更高的氧回收率、能量转化效率和更低的应用成本,亟须发展更高效的地外二氧化碳转化利用技术。文章总结了地外二氧化碳利用的发展现状并分析了近期的研究进展,发现不同技术之间差异大,在航天应用过程中,需充分考虑地外环境限制因素,以选用更合适的技术。空间站上已搭载的Sabatier装置和火星车上的MOXIE装置初步实现了地外二氧化碳还原。以“地外人工光合成”为代表的常温二氧化碳转化技术可为地外环控生保提供新路线。其不仅能够实现地外氧气供给,还可获得甲酸、乙烯和甲烷等有机分子作为燃料或生物转化原料。随着相关基础研究的不断发展,有望实现二氧化碳的高效转化和高附加值有机物、甚至碳糖食物的生产。地外二氧化碳转化利用技术的发展,将实现地外密闭环境下的废弃资源利用与物质循环,降低载人空间站、载人深空飞船的物资供应需求,也将为原位资源利用火星大气中的二氧化碳提供创新思路,以支撑未来可承受、可持续的地外生存任务。     

An attempt to determine the ideal psychological profiles for crews of long term space missions.

This paper reviews possible psychological criteria for selection at individual level (personality, psychological stability, competence, social skills) as well as at crew level (crew size, gender, compatability, group homeostasis). Once astronauts have been selected an important effort will have to be made pre-flight to prepare the crew to the autonomy necessary for a Mars trip. During the mission psychological support will be important, but probably limited by the mission constraints. At this stage, mission success will probably rely mainly on the capacity of the crew to prevent and manage crises internally. Post-flight psychological support is necessary to help astronauts to readapt to a normal way of life on Earth.     

火星软着陆能量最优制导律转移能力分析

着陆器在动力下降段的转移能力是影响定点软着陆的重要因素。文章从转移能力的角度出发,研究火星软着陆动力下降段能量最优制导律,分析燃料质量系数、时间权重以及不同初始高度和速度对转移能力的影响。由于能量最优制导律不能保证满足路径约束,因此对于确定的着陆器初始状态,着陆器转移能力不仅与燃料质量系数有关,还受到制导律本身的制约。当转移距离超过一定的界限时,尽管燃料充足,着陆轨迹会进入地表以下,造成任务失败。时间权重是能量最优制导律的关键参数,既影响燃耗,也影响着陆轨迹的形状。实际工程任务中,为实现燃料的充分利用,需根据着陆器状态调整制导律中的时间权重。本文给出了最优时间权重的确定方法,实现了一定燃料质量系数下的最大转移能力。     

γ-ray spectroscopy in Mars orbit during solar proton events

Understanding the evolution of Mars requires determining the composition of the surface and atmosphere of the planet. The European Space Agency’s ExoMars rover mission, which is expected to launch in 2016, is part of the Aurora programme. The instruments on the rover will search for evidence of life on Mars and will map a sub-section of the Martian surface, extracting compositional information. Currently our understanding of the bulk composition (and mineralogy) of Mars relies on orbital data from instruments on-board satellites such as 2001 Mars Odyssey, Mars Reconnaissance Orbiter and Mars Express, in addition to in-situ instrumentation on rovers such as Spirit and Opportunity. γ-ray spectroscopy can be used to determine the composition of Mars, but it has yet to be successfully carried out in-situ on Mars. This study describes some of the results obtained from the γ-ray spectrometer on 2001 Mars Odyssey during solar proton events and discusses whether the increased emissions are useful in γ-ray spectroscopy. The study shows that although increased γ-ray emissions were expected from the Martian surface during a solar proton event, they were not detected from orbit probably due to insufficient signal-to-background. However, this does not preclude the possibility of measuring changes in γ-ray flux corresponding to changes in solar activity on the surface of the planet.     

A neutral gas mass spectrometer to measure the chemical composition of the stratosphere

The Polar Balloon Atmospheric Composition Experiment (P-BACE) is a new generation of neutral gas mass spectrometer based on the time-of-flight principle. P-BACE is the scientific experiment on the Mars Environment Analog Platform (MEAP) flown successfully on a balloon mission in summer 2008. The MEAP mission was flown with a 334,000 m³ helium balloon in the stratosphere on a semicircular trajectory from northern Sweden around the North Pole to Canada using the summer northern hemispheric wind current. The atmospheric conditions at an atmospheric altitude of 35–40 km are remarkably similar to those on the surface of Mars and thus the balloon mission was an ideal testbed for our mass spectrometer P-BACE. Originally this instrument was designed for in situ measurements of the chemical composition of the Martian atmosphere.P-BACE has a unique mass range from 0 to 1000 amu/q with a mass resolution m/Δm (FWHM) > 1000, and the dynamic range is at least six orders of magnitude. During this experiment, the acquisition of one mass spectrum is a sum of 65,535 single spectra, recorded in a time frame of 66 s.The balloon mission lasted 5 days and had successfully demonstrated the functionality of the P-BACE instrument during flight conditions. We had recorded more than 4500 mass spectra. With little modifications, P-BACE can be used on a planetary mission for Mars, but for example also for Venus or Mercury, if placed on a satellite.     

Development Progress of China's First Mars Exploration Mission: Its Scientific Objectives and Payloads

China's first Mars exploration mission is scheduled to be launched in 2020. It aims not only to conduct global and comprehensive exploration of Mars by use of an orbiter but also to carry out in situ observation of key sites on Mars with a rover. This mission focuses on the following studies:topography, geomorphology, geological structure, soil characteristics, water-ice distribution, material composition, atmosphere and ionosphere, surface climate, environmental characteristics, Mars internal structure, and Martian magnetic field. It is comprised of an orbiter, a lander, and a rover equipped with 13 scientific payloads. This article will give an introduction to the mission including mission plan, scientific objectives, scientific payloads, and its recent development progress.      

Network science landers for Mars

The NetLander Mission will deploy four landers to the Martian surface. Each lander includes a network science payload with instrumentation for studying the interior of Mars, the atmosphere and the subsurface, as well as the ionospheric structure and geodesy. The NetLander Mission is the first planetary mission focusing on investigations of the interior of the planet and the large-scale circulation of the atmosphere. A broad consortium of national space agencies and research laboratories will implement the mission. It is managed by CNES (the French Space Agency), with other major players being FMI (the Finnish Meteorological Institute), DLR (the German Space Agency), and other research institutes. According to current plans, the NetLander Mission will be launched in 2005 by means of an Ariane V launch, together with the Mars Sample Return mission. The landers will be separated from the spacecraft and targeted to their locations on the Martian surface several days prior to the spacecraft's arrival at Mars. The landing system employs parachutes and airbags. During the baseline mission of one Martian year, the network payloads will conduct simultaneous seismological, atmospheric, magnetic, ionospheric, geodetic measurements and ground penetrating radar mapping supported by panoramic images. The payloads also include entry phase measurements of the atmospheric vertical structure. The scientific data could be combined with simultaneous observations of the atmosphere and surface of Mars by the Mars Express Orbiter that is expected to be functional during the NetLander Mission's operational phase. Communication between the landers and the Earth would take place via a data relay onboard the Mars Express Orbiter.     

Consistency of gas exchange of man and plants in a closed ecological system: lines of attack on the problem.

Gas exchange between man and plants in a closed ecological system based on atmosphere regeneration by plant photosynthesis is made consistent by attaining the equilibrium of human CO2 discharge and the productivity of the gas consuming bioregenerator. In this case the gas exchange might be, however, qualitatively disturbed from the equilibrium in terms of oxygen making it accumulate or decrease continuously in the air of the system. Gas exchange equilibrium in terms of O2 was attained in long-term experiments by equality of the human respiration coefficient and the plant assimilation coefficient. Varying the ratio of these parameters it is possible to control the oxygen concentration in the atmosphere to be reclaimed.     

火星大气进入下降着陆段测控通信关键技术研究

着眼于我国首次火星探测任务着陆器EDL(Entry Descent and Landing)飞行段高风险特性,结合火星大气和地表环境分析了这一飞行阶段的主要特点和难点,系统地回顾了国外历次火星着陆任务的基本概况和任务失败的经验教训,并以美国"好奇号"着陆任务为例介绍了EDL期间可采用的主要通信手段,详细梳理了火星大气黑障段通信策略、调制体制选择以及高动态弱信号检测处理方案等测控通信需要解决的关键技术。最后对我国首次火星探测任务的关键技术攻关,任务准备和实施提出了建议。     

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.     

Rapid impactor sample return (RISR) mission scenario

Due to the long lead time and great expense of traditional sample return mission plans to Mars or other astronomical bodies, there is a need for a new and innovative way to return materials, potentially at a lower cost. The Rapid Impactor Sample Return (RISR) mission is one such proposal. The general mission scenario involves a single pass of Mars, a Martian moon or an asteroid at high speeds (7 km/s), with the sample return vehicle skimming just 1 or 2 m above a high point (such as a top ridge on Olympus Mons on Mars) and releasing an impactor. The impactor strikes the ground, throwing up debris. The debris with roughly the same forward velocity will be captured by the sample return vehicle and returned to Earth. There is no delay or orbit in the vicinity of Mars or the asteroid: RISR is a one-pass mission. This paper discusses some of the details of the proposal. Calculations are presented that address the question of how much material can be recovered with this technique. There are concerns about the effect of Mars tenuous atmosphere. However, it will be noted that such issues do not occur for RISR style missions to Phobos, Deimos, or asteroids and Near Earth Objects (NEOs). Recent test results in the missile defense community (IFTs 6–8 in 2001, 2002) have scored direct hits at better than 1 m accuracy with closing velocities of 7.6 km/s, giving the belief that accuracy and sensing issues are developed to a point that the RISR mission scenario is feasible.     

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.     

深空探测器在轨推力器参数辨识方法

针对中国首次自主火星探测任务需要，结合环绕器质量特性和推进系统布局构型，分析了喷气卸载对整器角动量的影响。在分析的基础上，通过飞轮卸载前后三轴转速变化规律，计算整器角动量变化情况，并解算出每次喷气时产生的冲量及推力方向偏差；通过同组推力器作用时对各轴的扰动，解算整器质心坐标。利用在轨数据分析了天问一号探测器巡航段6次使用不同推力器的喷气卸载情况，解算的推力器方向偏差、质心坐标和地面设计值进行比对，实测推力方向偏差不超过0.6°，质心绝对偏差小于18mm，验证了计算方法的有效性和正确性，可作为后续轨控任务的点火方向制定、燃料预算的输入依据。     

Regenerative life support systems--why do we need them?

Human exploration of the solar system will include missions lasting years at a time. Such missions mandate extensive regeneration of life support consumables with efficient utilization of local planetary resources. As mission durations extend beyond one or two years, regenerable human life support systems which supply food and recycle air, water, and wastes become feasible; resupply of large volumes and masses of food, water, and atmospheric gases become unrealistic. Additionally, reduced dependency on resupply or self sufficiency can be an added benefit to human crews in hostile environments far from the security of Earth. Comparisons of resupply and regeneration will be discussed along with possible scenarios for developing and implementing human life support systems on the Moon and Mars.