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.     

核热推进载人火星探测方案设计

针对载人火星探测任务,结合我国现有技术基础,提出我国载人火星探测方案,重点研究载人火星探测任务推进系统的设计。首先,综合考虑载人深空探测任务的约束,采用Pork-Chop图设计了适用于不同任务场景的转移轨迹;然后,参考我国空间站技术,基于核热推进系统设计了我国载人火星探测任务的飞船;最后,对核热推进系统的发动机台数和推力进行了优化,得到了适用于不同任务场景的最优推进系统组合方案。本文所研究内容为我国未来载人火星探测任务提供了有益参考。     

Biomedical problems of EVA support during manned space flight to Mars

Current projects of manned missions to Mars are aimed to their realization in the second-third decades of this century. The purpose of this paper is to determine and review the main biomedical problems, that require a first and foremost decision for safety support of extravehicular activity (EVA) carried out by crewmembers of the Mars expedition. To a number of such problems the authors of the paper attribute a creation of adequate EVA equipment intended, first, for assembly of interplanetary spacecraft on the Earth orbit, performance of maintenance operations and scientific researches on the external surface of spacecraft during interplanetary flight and, secondly, for work on the Mars surface. New generation of space suits with low weight, high mobility and acceptable risk of decompression sickness must be as a central component of EVA equipment. The program for preparation to a Mars expedition also has to include special investigations in order to design the means and methods for a reliable protection of crew against space radiation, to elaborate the approach to medical monitoring and primary medical care during autonomous space mission, to maintain good health condition of crewmembers during EVA under the Mars gravity (0.38 g) after super long-term flight in weightlessness.     

[Interior] Configuration options,habitability and architectural aspects of the transfer habitat module (THM) and the surface habitat on Mars (SHM)/ESA's AURORA human mission to Mars (HMM) study

This paper discusses the findings for [Interior] configuration options, habitability and architectural aspects of a first human spacecraft to Mars.In 2003 the space architecture office LIQUIFER was invited by the European Space Agency's (ESA) AURORA Program committee to consult the scientists and engineers from the European Space and Technology Center (ESTEC) and other European industrial communities with developing the first human mission to Mars, which will take place in 2030, regarding the architectural issues of crewed habitats.The task was to develop an interior configuration for a transfer vehicle (TV) to Mars, especially a transfer habitation module (THM) and a surface habitat module (SHM) on Mars. The total travel time Earth—Mars and back for a crew of six amounts to approximately 900 days. After a 200-day-flight three crewmembers will land on Mars in the Mars excursion vehicle (MEV) and will live and work in the SHM for 30 days. For 500 days before the 200-day journey back the spacecraft continues to circle the Martian orbit for further exploration. The entire mission program is based on our present knowledge of technology. The project was compiled during a constant feedback-design process and trans-disciplinary collaboration sessions in the ESA-ESTEC concurrent design facility.Long-term human space flight sets new spatial conditions and requirements to the design concept. The guidelines were developed from relevant numbers and facts of recognized standards, interviews with astronauts/cosmonauts and from analyses about habitability, sociology, psychology and configuration concepts of earlier space stations in combination with the topics of the individual's perception and relation of space.Result of this study is the development of a prototype concept for the THM and SHM with detailed information and complete plans of the interior configuration, including mass calculations. In addition the study contains a detailed explanation of the development of the Design process including all suggested design and configuration options.     

Venus Express: Scientific goals, instrumentation, and scenario of the mission

The first European mission to Venus (Venus Express) is described. It is based on a repeated use of the Mars Express design with minor modifications dictated in the main by more severe thermal environment at Venus. The main scientific task of the mission is global exploration of the Venusian atmosphere, circumplanetary plasma, and the planet surface from an orbiting spacecraft. The Venus Express payload includes seven instruments, five of which are inherited from the missions Mars Express and Rosetta. Two instruments were specially designed for Venus Express. The advantages of Venus Express in comparison with previous missions are in using advanced instrumentation and methods of remote sounding, as well as a spacecraft with a broad spectrum of capabilities of orbital observations.     

Venus Express—Science observations experience at Venus

The Venus Express mission is the European Space Agency's (ESA) first spacecraft at Venus. It was launched in November 2005 by a Soyuz–Fregat launcher and arrived at Venus in April 2006. The mission covers a broad range of scientific goals including physics, chemistry, dynamics and structure of the atmosphere as well as atmospheric interaction with the surface and several aspects of the surface itself. Furthermore, it investigates the plasma environment and interaction of the solar wind with the atmosphere and escape processes.One month after the arrival at Venus the Venus Express spacecraft started routine science operations. Since then Venus Express has been observing Venus every day for more than one year continuously making new discoveries.In order to ensure that all the science objectives are fulfilled the Venus Express Science Operations Centre (VSOC) has the task of coordinating and implementing the science operations for the mission. During the first year of Venus observations the VSOC and the experiment teams gained a lot of experience in how to make best use of the observation conditions and payload capabilities. While operating the spacecraft in orbit we also acquired more knowledge on the technical constraints and more insight in the science observations and their results.As the nominal mission is coming to an end, the extended mission will start from October 2007. The Extended Science Mission Plan was developed taking into account the lessons learned. At the same time new observations were added along with specific fine-tuned observations in order to complete the science objectives of the mission.This paper will describe how the previous observations influence the current requirements for the observations around Venus today and how they influence the observations in the mission extension. Also it will give an overview of the Extended Science Mission Plan and its challenges for the future observations.     

The European space exploration programme: current status of ESA's plans for Moon and Mars exploration

After a large consultation with the scientific and industrial communities in Europe, the Aurora Space Exploration Programme was unanimously approved at the European Space Agency (ESA) Council at ministerial level in Edinburgh in 2001. This marked the start of the programme's preparation phase that was due to finish by the end of 2004. Aurora features technology development robotic and crewed rehearsal missions aimed at preparing a human mission to Mars by 2033. Due to the evolving context, both international and European, ESA has undertaken a review of the goals and approach of its exploration programme. While maintaining the main robotic missions that had been conceived during Aurora, the European Space Exploration Programme that is currently being proposed to the Aurora participating states and other ESA Member States has a reviewed approach and will feature a greater synergy with other ESA programmes. The paper will present the process that led to the revision of ESA's plans in the field of exploration and will give the current status of the programme.     

The future of human spaceflight.

After the Apollo Moon program, the international space station represents a further milestone of humankind in space, International follow-on programs like a manned return to the Moon and a first manned Mars Mission can be considered as the next logical step. More and more attention is also paid to the topic of future space tourism in Earth orbit, which is currently under investigation in the USA, Japan and Europe due to its multibillion dollar market potential and high acceptance in society. The wide variety of experience, gained within the space station program, should be used in order to achieve time and cost savings for future manned programs. Different strategies and roadmaps are investigated for space tourism and human missions to the Moon and Mars, based on a comprehensive systems analysis approach. By using DLR's software tool FAST (Fast Assessment of Space Technologies), different scenarios will be defined, optimised and finally evaluated with respect to mission architecture, required technologies, total costs and program duration. This includes trajectory analysis, spacecraft design on subsystem level, operations and life cycle cost analysis. For space tourism, an expected evolutionary roadmap will be described which is initiated by short suborbital tourism and ends with visionary designs like the Space Hotel Berlin and the Space Hotel Europe concept. Furthermore the potential space tourism market, its economic meaning as well as the expected range of the costs of a space ticket (e.g. $50,000 for a suborbital flight) will be analysed and quantified. For human missions to the Moon and Mars, an international 20 year program for the first decades of the next millennium is proposed, which requires about $2.5 Billion per year for a manned return to the Moon program and about $2.6 Billion per year for the first 3 manned Mars missions. This is about the annual budget, which is currently spend by the USA only for the operations of its Space Shuttle fleet which generally proofs the affordability of such ambitious programs after the build-up of the International Space Station, when corresponding budget might become again available.     

A complexity-based risk assessment of low-cost planetary missions: when is a mission too fast and too cheap?

Under constrained budgets and rigid schedules, NASA and industry have greatly increased their utilization of small satellites to conduct low-cost planetary investigations. Recent failed small planetary science spacecraft such as Mars Polar Lander (MPL) and Mars Climate Orbiter (MCO), and impaired missions such as Mars Global Surveyor (MGS) have fueled the ongoing debate on whether NASA's “Faster, Better, Cheaper” (FBC) approach is working. Several noteworthy failures of earth-orbiting missions have occurred as well including Lewis and the Wide-field Infrared Experiment (WIRE). While recent studies have observed that FBC has resulted in lower costs and shorter development times, these benefits may have been achieved at the expense of lowering probability of success. One question remaining to be answered is when is a mission “too fast and too cheap” that it is prone to failure? This paper assesses NASA FBC missions in terms of a complexity index measured against development time and spacecraft cost. A comparison of relative failure rates of recent planetary and earth-orbiting missions are presented, and conclusions regarding dependence on system complexity are drawn.     

European small geostationary communications satellites

Hispasat Advanced Generation 1 (HAG1) is the first satellite using the SGEO platform, which is under the development in the ESA Artes-11 program. Since the last presentation in the IAC 2007, a European industrial consortium led by OHB has completed the mission and spacecraft design. The platform Preliminary Design Review has been carried out in May 2008. The customer for the first mission is a commercial operator—Hispasat. The contract was signed in December 2008 and the satellite will be launched in 2012. To give confidence to the customer, SGEO platform will use up to date flight proven technologies. HAG1 carries 20/24 Ku-band and 3/5 Ka-band transponders to provide commercial services. Some innovative payload technologies will also be flown on board of HAG1 to gain in-orbit heritage. SGEO has also been selected as the baseline platform for the ESA Data Relay Satellite (EDRS). Phase-A study has just kicked off in January 2009. The targeted launch date is 2013. Heinrich Hertz will also use the SGEO platform. Heinrich Hertz is funded by the German Space Agency (DLR) and provides flight opportunities for technologies and components developed by the German Space Industry. With the HAG1 contract in hand, and EDRS and Heinrich Hertz in the line, OHB with its partners has the confidence that it will be able to speed up the product development of the SGEO platform for potential customers in the commercial market. This paper will first present the updated platform design and the status of the product development will be followed with the introduction of innovative payload technologies on board the first mission—HAG1 and ended with the mission concepts of EDRS and Heinrich Hertz missions.     

Life science experiments during the German-Russian MIR '97 mission

Manned spaceflight has been an important element of the German space program over the last decades. This is demonstrated by the nationally managed space missions Spacelab D-l (1985), D-2 (1993), and MIR '92 as well as by the participation in the 1st Spacelab mission FSLP (1983), the NASA missions IML-1 (1992) and IML-2 (1994), as well as in the ESA missions EUROMIR '94 and '95. On February 12th, this year, the German cosmonaut Reinhold Ewald was launched together with his Russian colleagues Wasilij Zibliew and Alexander Lasudkin onboard of a Soyuz spacecraft for another stay of a German cosmonaut onboard of the Russian Space Station MIR. This mission--the so-called German/Russian MIR '97--was, of course, another cornerstone with regard to the cooperation between Russian and German space organizations. The cooperation in the area of manned missions began 1978 with the flight of the German cosmonaut Sigmund Jahn onboard of Salyut 6, at that time a cooperation between the Soviet Union and the German Democratic Republic in the frame of the Interkosmos Program. In March 1992, it was followed by the flight of Klaus Dietrich Flade with his stay onboard of MIR. After two further successful ESA missions, EUROMIR '94 and '95 with the two German cosmonauts Ulf Merbold and Thomas Reiter and with a marked contribution of German scientists, the decision was taken to perform another German/Russian MIR mission, the so-called MIR '97. In Germany, MIR'97 was managed and performed in a joint effort between several partners. DARA, the German Space Agency, was responsible for the overall program and project management, while DLR, the German Aerospace Research Establishment, was responsible for the cosmonaut training, for medical operations, for the mission control at GSOC in Oberpfaffenhofen as well as for user support.     

The deep space 1 extended mission

The primary mission of Deep Space 1 (DS1), the first flight of the New Millennium program, completed successfully in September 1999, having exceeded its objectives of testing new, high-risk technologies important for future space and Earth science missions. DS1 is now in its extended mission, with plans to take advantage of the advanced technologies, including solar electric propulsion, to conduct an encounter with comet 19P/Borrelly in September 2001. During the extended mission, the spacecraft's commercial star tracker failed; this critical loss prevented the spacecraft from achieving three-axis attitude control or knowledge. A two-phase approach to recovering the mission was undertaken. The first involved devising a new method of pointing the high-gain antenna to Earth using the radio signal received at the Deep Space Network as an indicator of spacecraft attitude. The second was the development of new flight software that allowed the spacecraft to return to three-axis operation without substantial ground assistance. The principal new feature of this software is the use of the science camera as an attitude sensor. The differences between the science camera and the star tracker have important implications not only for the design of the new software but also for the methods of operating the spacecraft and conducting the mission. The ambitious rescue was fully successful, and the extended mission is back on track.     

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.     

Rosetta: The ESA comet rendezvous mission

Rosetta was selected in November 1993 for the ESA Cornerstone 3 mission, to be launched in 2003, dedicated to the exploration of the small bodies of the solar system (asteroids and comets). Following this selection, the Rosetta mission and its spacecraft have been completely reviewed: this paper presents the studies performed the proposed mission and the resulting spacecraft design.

Three mission opportunities have been identified in 2003–2004, allowing rendezvous with a comet. From a single Ariane 5 launch, the transfer to the comet orbit will be supported by planetary gravity assists (two from Earth, one from Venus or Mars); during the transfer sequence, two asteroid fly-bys will occur, allowing first mission science phases. The comet rendezvous will occur 8–9 years after launch; Rosetta will orbit around the comet and the main science mission phase will take place up to the comet perihelion (1–2 years duration).

The spacecraft design is driven (i) by the communication scenario with the Earth and its equipment, (ii) by the autonomy requirements for the long cruise phases which are not supported by the ground stations, (iii) by the solar cells solar array for the electrical power supply and (iv) by the navigation scenario and sensors for cruise, target approach and rendezvous phases. These requirements will be developed and the satellite design will be presented.     

载人航天器地面试验验证体系研究

在载人航天器的研制过程中,地面试验验证是保证产品在实际应用环境中正常运行、满足任务要求的主要手段之一。文章在对载人航天器试验技术与方法调研的基础上,系统总结了载人航天器试验覆盖性分析和验证的成功经验,提出了载人航天器系统级试验规划设计方法,找出了系统试验验证技术的薄弱环节。结合载人航天后续任务的特点,从试验管理、试验覆盖性分析、仿真与试验的协调、新型试验技术、试验基础设施等5个方面提出了载人航天器试验技术发展方向和需重点解决的问题,可为后续载人航天器的研制和试验技术发展提供支持。     

欧空局今后十年空间探测战略

欧空局目前正在研究今后十年的空间探测任务,这些任务可以分为两大类,一类是具有研究性的地球探测任务,另一类是可供使用的地球观察任务。这些研究要求的卫星质量不同,小的不足1000kg,大的可达3000kg;功率不同,小的不到500W,大的超过1500W;轨道高度也不同,从500km到800km。除降雨量观测任务由于飞行器结构和系统的限制是在低倾角轨道上执行外,其他大部分任务将在太阳同步轨道上执行。     

载人小行星探测的任务特点与实施途径探讨

介绍了载人小行星探测的发展现状,对目前美国基于"猎户座"飞船的载人小行星探测的概要方案进行了描述,包括探测器系统组成、运载火箭和飞行方案等内容。从速度增量、目标星引力等方面,分析了载人小行星探测的任务特点,并与载人火星探测、载人月球探测以及无人小行星探测的任务特点进行了比较。给出了载人小行星探测的实施途径建议,包括目标星选择、载人飞船系统设计等。讨论了其所涉及的推进、星际飞行安全保障、小行星表面行走等关键技术。研究结果可为我国开展载人深空探测提供参考。     

Concept study on Deep Space Orbit Transfer Vehicle

In this paper, the concept of Orbit Transfer Vehicle for Deep Space Exploration (Deep Space OTV) is proposed, and its effectiveness and feasibility are discussed. Basic concept is the separation of two functions required for the deep space exploration, the transportation to the destination, and the exploration at the destination. Deep Space OTV is a spacecraft specialized for the transportation to the deep space destination. It is an expendable spacecraft propelled by solar electric propulsion. The payload of Deep Space OTV is Explorer, which is a spacecraft specialized for the exploration at the deep space destination. The effectiveness of the concept is discussed qualitatively, focused on the merits of the separations of two functions. The feasibility of Deep Space OTV is discussed based on the conceptual design of the spacecraft and its applicability to deep space missions. Several deep space missions are modeled and the payload capacity of Deep Space OTV is estimated. The missions include Asteroid rendezvous, Mars orbiter, Lunar lander, and so on.     

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.