Mars Express spacecraft: design and development solutions for affordable planetary missions

The spacecraft designed to support the ESA Mars Express mission and its science payloads is customized around an existing avionics well suited to environmental and operational constraints of deep-space interplanetary missions. The reuse of the avionics initially developed for the Rosetta cometary program thanks to an adequate ESA cornerstone program budget paves the way for affordable planetary missions.The costs and schedule benefits inherited from reuse of up-to-date avionics solutions validated in the frame of other programs allows to focus design and development efforts of a new mission over the specific areas which requires customization, such as spacecraft configuration and payload resources. This design approach, combined with the implementation of innovative development and management solutions have enabled to provide the Mars Express mission with an highly capable spacecraft for a remarkably low cost. The different spacecraft subsystems are all based on adequate design solutions. The development plan ensures an exhaustive spacecraft verification in order to perform the mission at minimum risk. New management schemes contribute to maintain the mission within its limited funding.Experience and heritage gained on this program will allow industry to propose to Scientists and Agencies high performance, low-cost solutions for the ambitious Mars Exploration Program of the forthcoming decade.     

Phoenix--the first Mars Scout mission

NASA has initiated the first of a new series of missions to augment the current Mars Program. In addition to the systematic series of planned, directed missions currently comprising the Mars Program plan, NASA has started a series of Mars Scout missions that are low cost, price fixed, Principal [correction of Principle] Investigator-led projects. These missions are intended to provide an avenue for rapid response to discoveries made as a result of the primary Mars missions, as well as allow more risky technologies and approaches to be applied in the investigation of Mars. The first in this new series is the Phoenix mission which was selected as part of a highly competitive process. Phoenix will use the Mars 2001 Lander that was discontinued in 2000 and apply a new set of science objectives and mission objectives and will validate this soft lander architecture for future applications. This paper will provide an overview of both the Program and the Project.     

Transforming solar system exploration: The origins of the Discovery Program, 1989–1993

The Discovery Program is a rarity in the history of NASA solar system exploration: a reform program that has survived and continued to be influential. This article examines its emergence between 1989 and 1993, largely as the result of the intervention of two people: Stamatios “Tom” Krimigis of the Johns Hopkins University Applied Physics Laboratory (APL), and Wesley Huntress of NASA, who was Division Director of Solar System Exploration 1990–92 and the Associate Administrator for Space Science 1992–98. Krimigis drew on his leadership experience in the space physics community and his knowledge of its Explorer program to propose that it was possible to create new missions to the inner solar system for a fraction of the existing costs. He continued to push that idea for the next two years, but it took the influence of Huntress at NASA Headquarters to push it on to the agenda. Huntress explicitly decided to use APL to force change on the Jet Propulsion Laboratory and the planetary science community. He succeeded in moving the JPL Mars Pathfinder and APL Near Earth Asteroid Rendezvous (NEAR) mission proposals forward as the opening missions for Discovery. But it took Krimigis's political skill and access to Sen. Barbara Mikulski in 1993 to get the NEAR into the NASA budget, thereby likely ensuring that Discovery would not become another one-mission program.     

美国火星表面探测使命述评（下）

从1975年8月发射（1976年7月着陆火星）的海盗-1探测器以来,美国已成功执行了6次火星表面探测使命,即海盗-1与海盗-2轨道器/着陆器,＂火星探路者＂（MPF）着陆器/巡游车,＂勇气＂与＂机遇＂火星探测巡游车（MER）,以及＂凤凰＂着陆器;而推迟到2011年发射的火星科学实验室（MSL）将火星着陆技术与表面巡游车技术推向一个新的高度。从＂海盗＂着陆器到MSL＂好奇心＂巡游车、美国历经三种火星着陆系统与三代火星表面巡游车技术的发展。三种着陆系统为着陆腿着陆系统（＂海盗＂与＂凤凰＂）,气囊着陆系统（MPF与MER）,以及空中吊机着陆系统（MSL）。三代巡游车为MPF＂旅居者＂巡游车、MER＂勇气＂与＂机遇＂巡游车,以及MSL＂好奇心＂巡游车。现在,美国在火星进入、降落与着陆（EDL）运作与表面避障移动方面,已达到技术成熟与先进的水平,满足安全着陆与表面移动探测的要求。文章阐述美国上述七项火星表面探测使命的立项背景、科学目标与有效载荷、飞行系统组成,以及飞行运作程序;分析美国火星着陆技术与表面巡游车技术的发展。     

美国火星表面探测使命述评（上）

从1975年发射（1976年着陆火星）的海盗-1探测器以来,美国已成功执行了6次火星表面探测使命,即海盗-1与海盗-2轨道器/着陆器,＂火星探路者＂（MPF）着陆器/巡游车,＂勇气＂与＂机遇＂火星探测巡游车（MER）,以及＂凤凰＂着陆器;而推迟到2011年发射的＂好奇心＂火星科学实验室（MSL）将火星着陆技术与表面巡游车技术推向一个新的高度。从＂海盗＂着陆器到＂好奇心＂巡游车、美国历经三种火星着陆系统与三代火星表面巡游车技术的发展。三种着陆系统为着陆腿着陆系统（＂海盗＂与＂凤凰＂）,气囊着陆系统（MPF与MER）,以及空中吊机着陆系统（MSL）。三代巡游车为MPF＂旅居者＂巡游车、MER＂勇气＂与＂机遇＂巡游车,以及MSL＂好奇心＂巡游车。现在,美国在火星进入、降落与着陆（EDL）运作与表面避障移动方面,已达到技术成熟与先进的水平,满足安全着陆与表面移动探测的要求。文章阐述美国上述七项火星表面探测使命的立项背景、科学目标与有效载荷、飞行系统组成,以及飞行运作程序;分析美国火星着陆技术与表面巡游车技术的发展。     

Following the water,the new program for Mars exploration

In the wake of the loss of Mars Climate Orbiter and Mars Polar Lander in late 1999, NASA embarked on a major review of the failures and subsequently restructured all aspects of what was then called the Mars Surveyor Program--now renamed the Mars Exploration Program. This paper presents the process and results of this reexamination and defines a new approach which we have called "Program System Engineering". Emphasis is given to the scientific, technological, and programmatic strategies that were used to shape the new Program. A scientific approach known as "follow the water" is described, as is an exploration strategy we have called "seek--in situ--sample". An overview of the mission queue from continuing Mars Global Surveyor through a possible Mars Sample Return Mission launch in 2011 is provided. In addition, key proposed international collaborations, especially those between NASA, CNES and ASI are outlined, as is an approach for a robust telecommunications infrastructure.     

The Mars Sample Return Project.

The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles.     

Mitigation of the impact of terrestrial contamination on organic measurements from the Mars Science Laboratory

The objective of the 2009 Mars Science Laboratory (MSL), which is planned to follow the Mars Exploration Rovers and the Phoenix lander to the surface of Mars, is to explore and assess quantitatively a site on Mars as a potential habitat for present or past life. Specific goals include an assessment of the past or present biological potential of the target environment and a characterization of its geology and geochemistry. Included in the 10 investigations of the MSL rover is the Sample Analysis at Mars (SAM) instrument suite, which is designed to obtain trace organic measurements, measure water and other volatiles, and measure several light isotopes with experiment sequences designed for both atmospheric and solid-phase samples. SAM integrates a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer supported by sample manipulation tools both within and external to the suite. The sub-part-per-billion sensitivity of the suite for trace species, particularly organic molecules, along with a mobile platform that will contain many kilograms of organic materials, presents a considerable challenge due to the potential for terrestrial contamination to mask the signal of martian organics. We describe the effort presently underway to understand and mitigate, wherever possible within the resource constraints of the mission, terrestrial contamination in MSL and SAM measurements.     

Piloted operations at a near-Earth object (NEO)

In late 2006, NASA's Constellation Program sponsored a study to examine the feasibility of sending a piloted Orion spacecraft to a near-Earth object. NEOs are asteroids or comets that have perihelion distances less than or equal to 1.3 astronomical units, and can have orbits that cross that of the Earth. Therefore, the most suitable targets for the Orion Crew Exploration Vehicle (CEV) are those NEOs in heliocentric orbits similar to Earth's (i.e. low inclination and low eccentricity). One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure of the United States Space Exploration Policy and is highly complementary to NASA's planned lunar sortie and outpost missions circa 2020. A human expedition to a NEO would not only underline the broad utility of the Orion CEV and Ares launch systems, but would also be the first human expedition to an interplanetary body beyond the Earth–Moon system. These deep space operations will present unique challenges not present in lunar missions for the onboard crew, spacecraft systems, and mission control team. Executing several piloted NEO missions will enable NASA to gain crucial deep space operational experience, which will be necessary prerequisites for the eventual human missions to Mars.Our NEO team will present and discuss the following:

• new mission trajectories and concepts;

• operational command and control considerations;

• expected science, operational, resource utilization, and impact mitigation returns; and

• continued exploration momentum and future Mars exploration benefits.

Meditations on the new space vision: the Moon as a stepping stone to Mars

The Vision for Space Exploration invokes activities on the Moon in preparation for exploration of Mars and also directs International Space Station (ISS) research toward the same goal. Lunar missions will emphasize development of capability and concomitant reduction of risk for future exploration of Mars. Earlier papers identified three critical issues related to the so-called NASA Mars Design Reference Mission (MDRM) to be addressed in the lunar context: (a) safety, health, and performance of the human crew; (b) various modalities of mission operations ranging surface activities to logistics, planning, and navigation; and (c) reliability and maintainability of systems in the planetary environment. In simple terms, lunar expeditions build a résumé that demonstrates the ability to design, construct, and operate an enterprise such as the MDRM with an expectation of mission success. We can evolve from Apollo-like missions to ones that resemble the complexity and duration of the MDRM. Investment in lunar resource utilization technologies falls naturally into the Vision. NASA must construct an exit strategy from the Moon in the third decade. With a mandate for continuing exploration, it cannot assume responsibility for long-term operation of lunar assets. Therefore, NASA must enter into a partnership with some other entity--governmental, international, or commercial--that can responsibly carry on lunar development past the exploration phase.     

Piloted operations at a near-Earth object (NEO)

In late 2006, NASA's Constellation Program sponsored a study to examine the feasibility of sending a piloted Orion spacecraft to a near-Earth object. NEOs are asteroids or comets that have perihelion distances less than or equal to 1.3 astronomical units, and can have orbits that cross that of the Earth. Therefore, the most suitable targets for the Orion Crew Exploration Vehicle (CEV) are those NEOs in heliocentric orbits similar to Earth's (i.e. low inclination and low eccentricity). One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure of the United States Space Exploration Policy and is highly complementary to NASA's planned lunar sortie and outpost missions circa 2020. A human expedition to a NEO would not only underline the broad utility of the Orion CEV and Ares launch systems, but would also be the first human expedition to an interplanetary body beyond the Earth–Moon system. These deep space operations will present unique challenges not present in lunar missions for the onboard crew, spacecraft systems, and mission control team. Executing several piloted NEO missions will enable NASA to gain crucial deep space operational experience, which will be necessary prerequisites for the eventual human missions to Mars.Our NEO team will present and discuss the following:

• •new mission trajectories and concepts;
• •operational command and control considerations;
• •expected science, operational, resource utilization, and impact mitigation returns; and
• •continued exploration momentum and future Mars exploration benefits.

     

火星精确着陆制导问题分析与展望

美国火星科学实验室(MSL)任务成功将“好奇”号火星车着陆到火星表面,开创了火星精确着陆探测的新局面。以MSL着陆任务为典型代表,分析了目前火星着陆探测进入、下降和着陆（Entry, Descent and Landing, EDL）过程的制导方案及制导系统的发展趋势。以在火星高海拔、复杂地形区域定点着陆为潜在工程目标,归纳了火星EDL过程面临的制导主要问题。根据未来制导系统自主性和自适应性的技术需求及潜在工程任务制导面临的问题,提出了火星EDL制导方面需要解决的关键技术,并对其在未来工程中的应用潜力进行了展望。     

好奇心号巡视器及其特点分析

"火星科学实验室"(Mars Science Laboratory,MSL)是NASA于2011年11月26日发射的火星探测器,其上的好奇心号(Curiosity)巡视器已经于2012年8月6日着陆火星;其主要科学目标包括研究火星存在生命的可能性、火星气候特征、火星地质过程,并为将来的载人着陆作准备;经过多次论证,其着陆区为盖尔撞击坑(Gale Crater)。与过去的火星巡视器相比,它携带了更加先进的科学仪器,能够精确分析采集样品的化学成分、光谱特征等;在科学工作小组的指导下,其运行模式包括行走、勘查、接近目标、接触目标与样品分析;通过上述工作,"火星科学实验室"将对火星生命及可居住性进行全面探测。     

Russian program of planetary missions

In the area of Solar System Exploration most of recently proposed mission oriented to the studies of Mars. Except MARS-96 and possibly MARS SAMPLE RETURN missions other Mars missions use Molnija class launchers. All Russian missions heavily involve international partners.     

A gateway for human exploration of space? The weak stability boundary

NASA's plans for future human exploration of the Solar System describe only missions to Mars. Before such missions can be initiated, much study remains to be done in technology development, mission operations and human performance. While, for example, technology validation and operational experience could be gained in the context of lunar exploration missions, a NASA lunar program is seen as a competitor to a Mars mission rather than a step towards it. The recently characterized weak stability boundary in the Earth–Moon gravitational field may provide an operational approach to all types of planetary exploration, and infrastructure developed for a gateway to the Solar System may be a programmatic solution for exploration that avoids the fractious bickering between Mars and Moon advocates. This viewpoint proposes utilizing the concept of Greater Earth to educate policy makers, opinion makers and the public about these subtle attributes of our space neighborhood.     

Mars scientific investigations as a precursor for human exploration.

In the past two years, NASA has begun to develop and implement plans for investigations on robotic Mars missions which are focused toward returning data critical for planning human missions to Mars. The Mars Surveyor Program 2001 Orbiter and Lander missions will mark the first time that experiments dedicated to preparation for human exploration will be carried out. Investigations on these missions and future missions range from characterization of the physical and chemical environment of Mars, to predicting the response of biology to the Mars environment. Planning for such missions must take into account existing data from previous Mars missions which were not necessarily focused on human exploration preparation. At the same time, plans for near term missions by the international community must be considered to avoid duplication of effort. This paper reviews data requirements for human exploration and applicability of existing data. It will also describe current plans for investigations and place them within the context of related international activities.     

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.     

火星进入、下降与着陆技术的新进展——以“火星科学实验室”为例

文章以"火星科学实验室"为例,对火星进入、下降和着陆(EDL)技术的新进展进行了分析和总结。首先,简要介绍了"火星科学实验室"任务需求和遇到的技术挑战;然后,详细说明了相应的对策以及具体技术方案,并针对当前所遇到的问题,列举了一些可能的解决方法;最后,对"火星科学实验室"发展的新技术、新方法进行了总结。     

Roadmap to a human Mars mission

We propose a new roadmap for the preparation of the first human mission to Mars. This proposal is based on the work of ISECG and several recent recommendations on human Mars mission architectures. A table is proposed to compare the possible benefits of different preparatory missions. Particular attention is paid to the possibility of qualifying important systems thanks to a heavy Mars sample return mission. It is shown that this mission is mandatory for the qualification of Mars aerocapture at scale-1, EDL systems at scale 1 and Mars ascent. Moreover, it is a good opportunity to test many other systems, such as the heavy launcher and the transportation systems for the trips beyond LEO. These tests were not mentioned in the last ISECG report. This strategy is facilitated in the case of the simplified Mars mission scenarios that have recently been presented because it is suggested that relatively small vehicles with small crew sizes are used in order to optimize the payload mass fraction of the landing vehicles and to avoid the LEO assembly. An important finding of the study is that a human mission to the surface of the Moon is not required for the qualification of the systems of a human mission to Mars. Since affordability is a key criterion, two important missions are proposed in the roadmap. The first is a heavy Mars sample return mission and the second is a manned mission to a high Earth orbit or eventually to the vicinity of the Moon. It is shown that both missions are complementary and sufficient to qualify all the critical systems of the Mars mission.     

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.