Human and robotic repair of a solar array wing during ISS assembly mission 10A

With the installation of a new module and the relocation of three other modules, including multiple hand-offs from the station arm (SSRMS) to the shuttle arm (SRMS), International Space Station (ISS) assembly mission 10A/STS-120 was anticipated to be one of the most complicated ISS assembly missions ever attempted. The assembly operations became even more complex when a solar array wing (SAW) on the relocated Port-6 (P6) truss segment ripped while being extended. Repairing the torn SAW became the single most important objective for the remainder of STS-120, with future ISS assembly missions threatened by reduced power generation capacity if the SAW could not be repaired. Precise coordination between the space shuttle and ISS robotics teams led to an operational concept that combined the capabilities of the SRMS and SSRMS robotic systems in ways far beyond their original design capacities. Benefits of consistent standards for ISS robotic interfaces have been previously identified, but the advantages of having two such versatile and compatible robotic systems have never been quite so spectacular. This paper describes the role of robotics in the emergency SAW repair and highlights how versatility within space robotics systems can allow operations far beyond the intended design scenarios.     

Human and robotic repair of a solar array wing during ISS assembly mission 10A

With the installation of a new module and the relocation of three other modules, including multiple hand-offs from the station arm (SSRMS) to the shuttle arm (SRMS), International Space Station (ISS) assembly mission 10A/STS-120 was anticipated to be one of the most complicated ISS assembly missions ever attempted. The assembly operations became even more complex when a solar array wing (SAW) on the relocated Port-6 (P6) truss segment ripped while being extended. Repairing the torn SAW became the single most important objective for the remainder of STS-120, with future ISS assembly missions threatened by reduced power generation capacity if the SAW could not be repaired. Precise coordination between the space shuttle and ISS robotics teams led to an operational concept that combined the capabilities of the SRMS and SSRMS robotic systems in ways far beyond their original design capacities. Benefits of consistent standards for ISS robotic interfaces have been previously identified, but the advantages of having two such versatile and compatible robotic systems have never been quite so spectacular. This paper describes the role of robotics in the emergency SAW repair and highlights how versatility within space robotics systems can allow operations far beyond the intended design scenarios.     

The future of space medicine.

In November 2000, the National Aeronautics and Space Administration (NASA) and its partners in the International Space Station (ISS) ushered in a new era of space flight: permanent human presence in low-Earth orbit. As the culmination of the last four decades of human space flight activities. the ISS focuses our attention on what we have learned to date. and what still must be learned before we can embark on future exploration endeavors. Space medicine has been a primary part of our past success in human space flight, and will continue to play a critical role in future ventures. To prepare for the day when crews may leave low-Earth orbit for long-duration exploratory missions, space medicine practitioners must develop a thorough understanding of the effects of microgravity on the human body, as well as ways to limit or prevent them. In order to gain a complete understanding and create the tools and technologies needed to enable successful exploration. space medicine will become even more of a highly collaborative discipline. Future missions will require the partnership of physicians, biomedical scientists, engineers, and mission planners. This paper will examine the future of space medicine as it relates to human space exploration: what is necessary to keep a crew alive in space, how we do it today, how we will accomplish this in the future, and how the National Aeronautics and Space Administration (NASA) plans to achieve future goals.     

Technical and economical comparison between a modular geostationary space platform and a cluster of satellites

In recent years, the identification of a large number of telecommunication missions reflects a growing demand for the provision of a large variety of communications and data transmission services performed by a space segment.

At present, communication space segment use a single operational satellite per orbit position. However, the expected increase of communication channels per space segment will lead to a corresponding increase of satellite mass and size which could exceed the capabilities of existing launch vehicles in terms of mass and volume requirements. Those considerations, coupled with the threatening saturation of the geostationary orbit, lead to the conclusion that an optimal space segment concept must be defined on a technical as well as economical point of view.

Two main concepts may be envisaged: one is a large platform, which can be assembled either in geostationary orbit (resulting in several launches, rendez-vous and docking), or in low earth orbit by using the STS; the other concept is a cluster of satellites.

These candidate concepts are designed to meet the requirements of a reference mission. They are characterized by the required number of modules to be launched, the type of launcher, the new subsystems or equipments to be developed. The concepts are evaluated following technical criteria such as adaptability to other missions, flexibility, growth potential. A cost/benefit evaluation of each solution is presented. A comparison between the different concepts is then made on the basis of the technical/economical attractiveness of each solution.     

Study on JAXA elements for international lunar vicinity mission

JAXA has commenced technical research for contributing as a part of international partnership for the space exploration in Lunar vicinity. One of the candidates is the cargo transport mission with the combination of Cryogenic Propulsion Stage(s) (CPS) and a transfer vehicle derived from Japanese un-manned vehicle used for ISS. The CPS needs advanced technologies to keep the propellant for long mission duration and they will be useful in further missions beyond moon. This paper reports the profile of the mission, vehicle configurations, and the transport capabilities.     

Stepping stones toward global space exploration

Several nations are currently engaging in or planning for robotic and human space exploration programs that target the Moon, Mars and near-Earth asteroids. These ambitious plans to build new space infrastructures, transport systems and space probes will require international cooperation if they are to be sustainable and affordable. Partnerships must involve not only established space powers, but also emerging space nations and developing countries; the participation of these new space actors will provide a bottom-up support structure that will aid program continuity, generate more active members in the space community, and increase public awareness of space activities in both developed and developing countries. The integration of many stakeholders into a global space exploration program represents a crucial element securing political and programmatic stability. How can the evolving space community learn to cooperate on a truly international level while engaging emerging space nations and developing countries in a meaningful way? We propose a stepping stone approach toward a global space exploration program, featuring three major elements: (1) an international Earth-based field research program preparing for planetary exploration, (2) enhanced exploitation of the International Space Station (ISS) enabling exploration and (3) a worldwide CubeSat program supporting exploration. An international Earth-based field research program can serve as a truly global exploration testbed that allows both established and new space actors to gain valuable experience by working together to prepare for future planetary exploration missions. Securing greater exploitation of the ISS is a logical step during its prolonged lifetime; ISS experiments, partnerships and legal frameworks are valuable foundations for exploration beyond low Earth orbit. Cooperation involving small, low-cost missions could be a major stride toward exciting and meaningful participation from emerging space nations and developing countries. For each of these three proposed stepping stones, recommendations for coordination mechanisms are presented.     

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.     

发展X-37B空间飞机的背后动因分析

文章通过对X-37B飞行器的飞行试验任务分析,指出了X-37B飞行器不是空天飞机,也不是全球快速打击平台,而是一种低成本太空进入能力的飞行验证器,它的作用定位在空间而不是在空中。通过飞行试验和验证试验,旨在打造一个可重复使用的轨道转移运载器。将美国2010年航天战略的重大调整、国际空间站的运行延期和航天飞机退役等事件结合起来,对X-37B发展的背后动因进行分析,有助于了解美国航天发展的未来趋势。经过动因的详尽分析,指出要特别关注美国航天战略调整的两个重心转向,尤其是两个转向背后的动机。如何正确地认识国际空间站的作用定位,对于审视载人航天的未来发展有重要意义。美国航天战略的调整使载人航天的重心回到近地轨道上。基于中国目前的能力现实,建议中国的载人航天重心放在地球轨道上,做好各种能力的建设,并利用这些能力把地球轨道上的事做得更好。     

Rationale and systems architecture for a near-term human lunar return

Early human missions to the Moon have landed on six different sites on the lunar surface. These have all been in the low-latitude regions of the near side of the Moon. Early missions were designed primarily to assure crew safety rather than for scientific value. While the later missions added increasingly more challenging science, they remained restricted to near-side, low-latitude sites. Since the 1970s, we have learned considerably more about lunar planetology and resources. A return within the next five to ten years can greatly stimulate future human space exploration activities. We can learn much more about the distribution of lunar resources, especially about hydrogen, hydrated minerals, and water ice because they appear to be abundant near the lunar poles. The presence of hydrogen opens the possibility of industrial use of lunar resources to provide fuel for space transportation throughout the solar system.This paper discusses the rationale for near-term return of human crews to the Moon, and the advantages to be gained by selecting the Moon as the next target for human missions beyond low-Earth orbit. It describes a systems architecture for early missions, including transportation and habitation aspects. Specifically, we describe a primary transportation architecture that emphasizes existing Earth-to-orbit transportation systems, using expendable launch vehicles for cargo delivery and the Space Shuttle and its derivatives for human transportation. Transfer nodes should be located at the International Space Station (ISS) and at the Earth-Moon L1 (libration point).Each of the major systems is described, and the requisite technology readiness is assessed. These systems include Earth-to-orbit transportation, lunar transfer, lunar descent and landing, surface habitation and mobility, and return to Earth. With optimum reliance on currently existing space systems and a technology readiness assessment, we estimate the minimum development time required and perform order-of-magnitude cost estimates of a near-term human lunar mission.     

Outlook of possible European contributions to future exploration scenarios and architectures

Building upon the important experience acquired with the development of the International Space Station, the major spacefaring countries are working within the International Space Exploration Coordination Group (ISECG) at the definition of a coordinated framework for expanding the human presence beyond the Low Earth Orbit, the Global Exploration Roadmap (GER). The GER defines a long-range strategy for global exploration and include three major elements.

• •Common goals of ISECG participating agencies for space exploration.
• •Notional mission scenarios which are technically feasible and programmatically implementable. Two mission scenarios were defined in the 1st iteration of the GER: the “Asteroid Next” and the “Moon Next” mission scenarios.
• •Identification of near-term opportunities for coordination and cooperation related to e.g. the development of technologies, the implementation of robotic missions to destination of interest for closing strategic knowledge gaps which need to be addressed prior to human missions as well as the utilization of ISS for demonstration of exploration enabling capabilities.

In 2009 two studies have been awarded by ESA to Industrial Teams led by Thales Alenia Space—Italy and by Astrium—Germany to define, analyze and assess optional European scenarios for future human spaceflight and exploration activities, and to derive the required capabilities for the investigated timeframe until the year 2033. Work on the European scenarios has been aligned with and informed by the international work on the GER.A conceptual design of different Building Block Elements, representing critical contributions to international Design Reference Missions (DRM's) included in the ISECG GER, has been performed and analyzed with respect to programmatic risks, budgets and required technologies. Key driving requirements for the analyzed Building Block elements have been derived from the international DRM's included in the GER.The interim outcomes of the human exploration scenario study will be presented, identifying opportunities for European Contributions to an international exploration undertaking.     

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.

     

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.

Aeroshell design techniques for aerocapture entry vehicles

A major goal of NASA's In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe's aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.     

Innovations in mission architectures for exploration beyond low Earth orbit

Through the application of advanced technologies and mission concepts, architectures for missions beyond Earth orbit have been dramatically simplified. These concepts enable a stepping stone approach to science driven; technology enabled human and robotic exploration. Numbers and masses of vehicles required are greatly reduced, yet the pursuit of a broader range of science objectives is enabled. The scope of human missions considered range from the assembly and maintenance of large aperture telescopes for emplacement at the Sun-Earth libration point L2, to human missions to asteroids, the moon and Mars. The vehicle designs are developed for proof of concept, to validate mission approaches and understand the value of new technologies. The stepping stone approach employs an incremental buildup of capabilities, which allows for future decision points on exploration objectives. It enables testing of technologies to achieve greater reliability and understanding of costs for the next steps in exploration.     

Crew autonomy for deep space exploration: Lessons from the Antarctic Search for Meteorites

Future piloted missions to explore asteroids, Mars, and other targets beyond the Moon will experience strict limitations on communication between vehicles in space and control centers on Earth. These limitations will require crews to operate with greater autonomy than any past space mission has demonstrated. The Antarctic Search for Meteorites (ANSMET) project, which regularly sends small teams of researchers to remote parts of the southern continent, resembles a space mission in many ways but does not rely upon a control center. It provides a useful crew autonomy model for planners of future deep space exploration missions. In contrast to current space missions, ANSMET gives the crew the authority to adjust competing work priorities, task assignments, and daily schedules; allows the crew to be the primary monitor of mission progress; demands greater crew accountability for operational errors; requires the crew to make the most of limited communication bandwidth; adopts systems designed for simple operation and failure recovery; and grants the crew a leading role in the selection and stowage of their equipment.     

Aeroshell design techniques for aerocapture entry vehicles

A major goal of NASA's In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe's aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.     

High energy-density propulsion—reducing the risk to humans in planetary exploration

The potential benefits to humankind of space exploration are tremendous. Space is not only the final frontier but is also the next marketplace. The orbital space above Earth offers tremendous opportunities for both strategic assets and commercial development. The critical obstacle retarding the use of the space around the Earth is the lack of low cost access to orbit. Further out, the next giant leap for mankind will be the human exploration of Mars. Almost certainly within the next 30 years, a human crew will brave the isolation, the radiation, and the lack of gravity to walk on and explore the Red planet. Both of these missions will change the outlook and perspective of every human being on the planet. However, these missions are expensive and extremely difficult. Chemical propulsion has demonstrated an inability to achieve orbit cheaply and is a very high-risk option to accomplish the Mars mission. An alternative solution is to develop a high performance propulsion system. Nuclear propulsion has the potential to be such a system. The question will be whether humanity is willing to take on the challenge.     

Human exploration of near earth asteroids: Mission analysis for chemical and electric propulsion

This paper presents a mission analysis comparison of human missions to asteroids using two distinct architectures. The objective is to determine if either architecture can reduce launch mass with respect to the other, while not sacrificing other performance metrics such as mission duration. One architecture relies on chemical propulsion, the traditional workhorse of space exploration. The second combines chemical and electric propulsion into a hybrid architecture that attempts to utilize the strengths of each, namely the short flight times of chemical propulsion and the propellant efficiency of electric propulsion. The architectures are thoroughly detailed, and accessibility of the known asteroid population is determined for both. The most accessible asteroids are discussed in detail. Aspects such as mission abort scenarios and vehicle reusability are also discussed. Ultimately, it is determined that launch mass can be greatly reduced with the hybrid architecture, without a notable increase in mission duration. This demonstrates that significant performance improvements can be introduced to the next step of human space exploration with realistic electric propulsion system capabilities. This leads to immediate cost savings for human exploration and simultaneously opens a path of technology development that leads to technologies enabling access to even further destinations in the future.     

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.     

Preparing EMU for Space Station

In today's fiscally constrained environment, it can be expected that systems designed for one space program will increasingly be used to support other programs. The example of the U.S. extravehicular mobility unit (EMU), designed for use with the Space Shuttle, and now part of the baseline for the International Space Station (ISS) program, illustrates the adaption process. Certifying the Shuttle's EMU for use aboard ISS requires addressing three fundamental issues: Identifying new ISS requirements to be imposed on the EMU. Extending Shuttle's EMU on-orbit service interval to meet ISS's longer missions. Certifying Shuttle's EMU to meet new environments unique to ISS. Upon completion of the certification process, Shuttle's EMU will meet all requirements for supporting both the Shuttle and ISS program. This paper discusses the processes for addressing these issues and progress to date in achieving resolution.