The ESA approach to low-cost planetary missions

While ESA has never adopted the mantra of “cheaper, faster, better” there has been considerable pressure to reduce mission costs in recent years. To this end, ESA has implemented a number of changes to its procurement procedures which are now being implemented in missions such as SMART-1, Mars Express and which will be applied to future missions such as the Mercury Cornerstone. This paper outlines the approach taken to each and describes the missions.     

A low-cost femtosatellite to enable distributed space missions

A new class of distributed space missions is emerging which requires hundreds to thousands of satellites for real-time, distributed, multi-point sensing to accomplish long-awaited remote sensing and science objectives. These missions, stymied by the lack of a low-cost mass-producible solution, can become reality by merging the concepts of distributed satellite systems and terrestrial wireless sensor networks. However, unlike terrestrial sensor nodes, space-based nodes must survive unique environmental hazards while undergoing complex orbital dynamics. A novel sub-kilogram very small satellite design is needed to meet these requirements. Sub-kilogram satellite concepts are developing elsewhere, such as traditional picosatellites and microengineered aerospace systems. Although viable technical solutions, these technologies currently come at a high cost due to their reliance on high-density technology or custom manufacturing processes. While evaluating these technologies, two untapped technology areas became evident that uniquely encompass low cost and mass producibility by leveraging existing commercial production techniques: satellite-on-a-chip (SpaceChip) and satellite-on-a-printed circuit board (PCBSat). This paper focuses on the design, build, and test results of a prototype PCBSat with a prototype unit cost less than $300. The paper concludes with mission applications and future direction.     

火星载人探测中辐射防护综述

火星探测是人类太空探索的重要组成部分,火星载人探测中航天员的辐射安全问题是人们最为关心的问题。文章扼要介绍了美国/俄罗斯火星载人探测技术的发展过程,重点阐述了探测中的辐射环境、辐射效应以及国外探测结果;在此基础上,对火星探测中的辐射剂量进行了预示,提出了辐射防护建议。     

Distributed telemetry & telecommand for future sunsat missions

This paper will describe the conceptional design of a telemetry and telecommand system to be employed on the next generation SUNSAT microsatellite. The performance of the centralized, time division multiplexed telemetry system used on SUNSAT I can be optimized in terms of size, flexibility and bandwidth utilization. Therefore a method will be presented to implement a reliable, decentralized telemetry and telecommand (T&T) system based on experience gained from SUNSAT 1 and conforming to the Consultative Committee for Space Data Systems recommendations. Controller Area Network technology will be evaluated as a possible solution to realize a robust, multi-master and fault-tolerant T&T system. The expected performance and system improvements of the new T&T system will be compared to the current system used on SUNSAT 1.     

大型机载 SIGINT系统的任务、设计原则及技术体制探析

简要叙述了大型机载SIGIN T 飞机在现代战争中的主要任务,归纳给出了机载SIGIN T 系统的设计原则,并在分析外军现役机载SIGIN T系统技术特点的基础上,提出了大型机载SIGIN T系统的功能结构和技术体制,为深入研究提供参考。     

Manned missions to Mars: Minimizing risks of failure

Some major risks-of-failure issues for the future manned missions to Mars are discussed, with an objective to address criteria for making such missions possible, successful, safe and cost-effective. The following astronautical and instrumentation-and-equipment-reliability related aspects of the missions are considered: redundancies and backup strategies; costs; assessed probability of failure as a suitable reliability criterion for the instrumentation (equipment); probabilistic assessment of the likelihood of the mission success and safety. It is concluded that parametric risk modeling is a must for a risk-driven decision-making process.     

Flexbus — an attractive technical solution for small missions

Responding to the demand for a ‘faster, cheaper, better’ implementation of space related services, Domier Satellitensysteme GmbH has established and exercised an approach for the development and production of satellites and the corresponding ground equipment for small missions, referred to as Flexbus. It allows to support space service customers starting from mission engineering via design, development and manufacturing of the necessary hardware, the launch service and ending with the hand-over of the operational system. Flexbus harmonises a modular component concept with a sound design and development approach, as a whole providing the means to offer high quality products in a fairly short time and for competitive pricing. This paper will outline the major features of the Flexbus approach and describe application examples.     

Revolutionary systems and technologies for missions to the outer planets

The Advanced Deep Space System Development Program is managed by the Jet Propulsion Laboratory for NASA and is also called X2000. X2000 is organized to create advanced flight and ground systems for the exploration of the outer planets and beyond; it has been created to develop the engineering elements of flight and ground systems. Payloads will be developed by another team. Each X2000 delivery gets its requirements from a set of planned missions, or “mission customers”.The X2000 First Delivery Project supports missions to the Sun (to 4 solar radii), Europa (looking for a liquid ocean), Mars (in support of several Mars missions including a sample return), a comet (including a sample return), and Pluto followed by a trip into the Kuiper belt. This set of missions leads to some outstanding requirements:

• 1.1. Long-life (10–12 years)
• 2.2. Total Ionizing Dose of 4 Mrad (for a Europa Orbiter)
• 3.3. Average power consumption less than or equal to 150 Watts
• 4.4. Autonomous operations that result in an extreme reduction in operations costs

This paper describes the X2000 first delivery and its technologies following a brief overview of the program.     

RPS strategies to enable NASA''s next decade robotic Mars missions

NASA's proposed roadmap for robotic Mars exploration over the next decade is influenced by science goals, technology needs and budgetary considerations. These requirements could introduce potential changes to the succession of missions, resulting in both technology feed forward and heritage. For long duration robotic surface missions at locations, where solar power generation is not feasible or limited, Radioisotope Power Systems (RPS) could be considered. Thus, RPSs could provide enabling power technologies for some of these missions, covering a power range from 10s of milliwatts to potentially a kilowatt or even higher. Currently, NASA and DoE with their industry partners are developing two RPSs, both generating about 110 W(e) at BOL. These systems will be made available as early as 2009. The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)—with static power conversion—was down-selected as a potential power source for the MSL mission. Development of small-RPSs is in a planning stage by NASA and DoE; potentially targeting both the 10s of milliwatts and 10s of watts power ranges. If developed, Radioisotope Heat Unit (RHU) based systems—generating 10s to 100s of milliwatts—could power small adjunct elements on larger missions, while the GPHS module-based systems—each generating 10s of watts—could be stacked to provide the required power levels on MER class surface assets. MMRTGs and Stirling Radioisotope Generators (SRGs) could power MSL class or larger missions. Advanced Radioisotope Power Systems (ARPS) with higher specific powers and increased power conversion efficiencies could enhance or even enable missions towards the second half of the next decade. This study examines the available power system options and power selection strategies in line with the proposed mission lineup, and identifies the benefits and utility of the various options for each of the next decade launch opportunities.     

The overredundant spacecraft—A competitive approach to future telecommunication satellites

Present operational space telecommunication systems are based on simultaneous availability of more than one satellite on orbit, mainly a spare satellite in addition to the operational one.Considering the costs associated to the delivery of extra flight models and to extra launchers, the question is asked whether it would not be advantageous to launch a very limited number of “overredundant” spacecraft instead of several standard satellites.The paper gives main conditions of reliability, size and redundancy concept under which an “overredundant” spacecraft could be a competitive approach to future operational systems.     

Human missions to Mars: new psychological challenges and research issues

Human exploratory missions to Mars represent the most exciting future vision of human space flight. With respect to the distance to travel and mission duration, these missions will provide unique psychological challenges that do not compare to any other endeavor humans ever have attempted. The present paper presents outcomes of two recent projects sponsored by the European Space Agency--Humex and Reglisse--where these challenges and risks have been analyzed in some detail, and where concepts for future research have been developed. This presentation involves three steps. At first, it will be shown that our current psychological knowledge derived from orbital spaceflight and analogue environments is not sufficient to assess the specific risks of mission into outer space. Secondly, new psychological challenges of missions to Mars will be identified with respect to three different areas: (1) individual adaptation and performance, (2) crew interactions, and (3) concept and methods of psychological countermeasures. Finally, different options and issues of preparatory psychological research will be discussed.     

A non-earthcentric approach to life detection

The ultimate goal of a comprehensive life detection strategy is never to miss life when we encounter it. To accomplish this goal, we must define life in universal, that is, non-Earthcentric, measurable terms. Next, we must understand the nature of biosignatures observed from the measured parameters of life. And finally, we must have a clear idea of the end-member states for the search--what does life, past life, or no life look like (in terms of the measured parameters) at multiple spatial and temporal scales? If we can approach these problems both in the laboratory and in the field on Earth, then we have a chance of being able to detect life elsewhere in our solar system. What are the required limits of detection at each of those scales? What spatial, spectral, and temporal resolutions are necessary to detect life? These questions are actively being investigated in our group, and in this report, we present our strategy and approach to non-Earthcentric life detection.     

Products from NASA's in-space propulsion technology program applicable to low-cost planetary missions

Since September 2001, NASA's In-Space Propulsion Technology (ISPT) program has been developing technologies for lowering the cost of planetary science missions. Recently completed is the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. Two other cost saving technologies nearing completion are the NEXT ion thruster and the Aerocapture technology project. Under development are several technologies for low-cost sample return missions. These include a low-cost Hall-effect thruster (HIVHAC) which will be completed in 2011, light-weight propellant tanks, and a Multi-Mission Earth Entry Vehicle (MMEEV). This paper will discuss the status of the technology development, the cost savings or performance benefits, and applicability of these in-space propulsion technologies to NASA's future Discovery, and New Frontiers missions, as well as their relevance for sample return missions.     

Approaches to the development of biomedical support systems for piloted exploration missions

Many aspects of the biomedical systems developed and realized aboard orbital stations, the International space station in the first place, deserve to be regarded as predecessors of the systems for health monitoring and maintenance of future exploration crews. At the same time, there are issues and tasks which have not been yet fully resolved. Specifically, these are prevention of the adverse changes in body systems and organs due to microgravity, reliable protection from the spectrum of space radiation, and elucidation of possible effects of hypomagnetic environment. We should not walk away from search and development of key biomedical technologies such as a system of automated fitness evaluation and a psychodiagnostic complex for testing and optimization of operator′s efficiency, and others. We have to address a large number of issues related to designing the composite life support systems of the utmost autonomy, closure and ecological safety of the human environment that will provide transformation of all kinds of waste. Another crucial task is to define a concept of the onboard medical center and dataware including the telemedicine technology. All the above developments should assimilate the most recent achievements in physiology, molecular biology, genetics, and advanced medical technologies. Biomedical researches on biosatellites also do not lose topicality.     

US export controls and Canadian autonomy to collaborate on international space missions

Canada is a space power with unique technical niches that support opportunities for collaboration on space technologies. When U.S.-origin space technologies are involved Canada's ability to collaborate internationally may be conditional on US law and policy. As a result, US export control law can be directly linked to the success or failure of Canadian collaboration. This article examines the strategic impact of U.S. export controls on Canadian autonomy to collaborate on international missions, including multi-use missions. Canadian space export control policy is also examined more broadly with the goal of providing specific policy recommendations that will enhance Canada's future as an international space actor.     

Planetary protection—A microbial ethics approach

Planetary protection policies designed to reduce the cross-transfer of life on spacecraft from one planet to another can either be formulated from the pragmatic instrumental needs of scientific exploration, or from ethical principles. I address planetary protection concerns by starting from a normative ethical framework for the treatment of microorganisms. This argues that they have intrinsic value at the level of the individual through to the level of the community, but at the individual level this ethic can only be theoretical. This approach yields a solution to the problem of the inevitable contamination of Mars by human explorers and suggests that in some instances the local contamination of other planets may be acceptable. An exception would be where this contamination would cause destruction of microbial ecosystems. Within the framework of such an ethic, the term ‘planetary protection’ may be normatively too narrow and ‘planetary preservation’ may better describe the activity of controlling cross-inoculation of planets. I discuss an example of a contamination event that might be ethically acceptable within the framework of ‘preservation’, but would be regarded as unacceptable under current planetary ‘protection’ guidelines.     

Project Icarus: A review of local interstellar medium properties of relevance for space missions to the nearest stars

I review those properties of the interstellar medium within 15 light-years of the Sun, which will be relevant for the planning of future rapid (v≥0.1c) interstellar space missions to the nearest stars. As the detailed properties of the local interstellar medium (LISM) may only become apparent after interstellar probes have been able to make in situ measurements, the first such probes will have to be designed conservatively with respect to what can be learned about the LISM from the immediate environment of the Solar System. It follows that studies of interstellar vehicles should assume the lowest plausible density when considering braking devices, which rely on transferring momentum from the vehicle to the surrounding medium, but the highest plausible densities when considering possible damage caused by the impact of the vehicle with interstellar material. Some suggestions for working values of these parameters are provided. This paper is a submission of the Project Icarus Study Group.     

High performance nuclear thermal propulsion system for near term exploration missions to 100 A.U. and beyond

A new compact ultra light nuclear reactor engine design termed MITEE (MIniature Reac Tor EnginE) is described. MITEE heats hydrogen propellant to 3000 K, achieving a specific impulse of 1000 seconds and a thrust-to-weight of 10. Total engine mass is 200 kg, including reactor, pump, auxiliaries and a 30% contingency. MITEE enables many types of new and unique missions to the outer solar system not possible with chemical engines. Examples include missions to 100 A.U. in less than 10 years, flybys of Pluto in 5 years, sample return from Pluto and the moons of the outer planets, unlimited ramjet flight in planetary atmospheres, etc. Much of the necessary technology for MITEE already exists as a result of previous nuclear rocket development programs. With some additional development, initial MITEE missions could begin in only 6 years.     

Deuterium-free water (1H2O) in complex life-support systems of long-term space missions

Heavy water containing deuterium displays toxic property. It is stated that any quantity of a heavy isotope of hydrogen--deuterium--is undesirable to animals and plants. It was earlier shown by us that physical-chemical life support systems on board the "MIR" station fractionate (change) isotopes of hydrogen, oxygen and carbon. Therefore, the problem of regenerative systems in habitable space objects should include removal, from water, of a heavy stable isotope of hydrogen--deuterium. In this article we consider one method of obtaining deuterium-free water--decomposition of distillate water in an electrolyser to hydrogen and oxygen with subsequent synthesis in a catalytic or high-temperature reactor. The influence of deuterium-free water on the growth and development of Arabidopsis thaliana and Japanese quail is investigated. It is shown that with the help of the electrolysis method it is possible to fabricate water containing 80% less deuterium in comparison with SMOW. Experimentally, it is proved on a culture of Arabidopsis thaliana and Japanese quail that water with reduced contents of deuterium (80%) displays positive biological activity.