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Abstract: Orbital debris poses a significant threat to spacecraft health and safety. Recent events such as China''s anti-satellite test and the Breeze-M rocket explosion have led to an even greater awareness and concern in the satellite community. Therefore, the National Aeronautics and Space Administration (NASA) has established requirements that routine conjunction assessment screening shall be performed for all maneuverable spacecraft having perigees <2000km or within 200km of geosynchronous altitude. NASA''s Goddard Space Flight Center (GSFC) has developed an operational collision risk assessment process to protect NASA''s high-value unmanned (robotic) assets that has been in use since January 2005. This paper provides an overview of the NASA robotic conjunction assessment process, including descriptions of the new tools developed to analyze close approach data and of the risk mitigation strategies employed. In addition, statistical data describing the number of conjunctions experienced are presented. A debris avoidance maneuver performed by Aura in June of 2008 is described in detail to illustrate the process. [Copyright &y& Elsevier]

Abstract: Introduction: NASA has played an influential role in bringing the enthusiasm of space science to schools across the United States since the 1980s. The evolution of this public outreach has led to a variety of NASA funded education programs designed to promote student interest in science, technology, engineering, math, and geography (STEM-G) careers. Purpose: This paper investigates the educational outreach initiatives, structure, and impact of two of NASA''s largest educational programs: the NASA Explorer School (NES) and NASA Spaceward Bound programs. Results: Since its induction in 2003 the NES program has networked and provided resources to over 300 schools across the United States. Future directions include further development of mentor schools for each new NES school selected, while also developing a longitudinal student tracking system for NES students to monitor their future involvement in STEM-G careers. The Spaceward Bound program, now in its third year of teacher outreach, is looking to further expand its teacher network and scientific collaboration efforts, while building on its teacher mentorship framework. [Copyright &y& Elsevier]

Abstract: To stimulate the commercial space transportation industry, the National Aeronautics and Space Administration (NASA) is facilitating the demonstration of Commercial Orbital Transportation Services (COTS) to Low Earth Orbit (LEO) by private-sector companies. In 2006, NASA entered into funded agreements with two such companies to share NASA''s $500 million investment, Space Exploration Technologies (SpaceX) and Rocketplane Kistler (RpK), each of which proposed to obtain the additional private financing needed to complete its flight demonstrations. In 2007, NASA terminated the agreement with RpK because it failed to meet a series of technical and financial milestones which were necessary to receive the incremental NASA payments. In 2008, NASA conducted another competition for the remaining $170 million of NASA funding and entered into a funded agreement with Orbital Sciences Corporation (OSC). This paper provides an overview of the COTS approach of SpaceX and OSC and the status of their efforts to develop reliable and cost-effective commercial transportation to serve the LEO marketplace. [Copyright &y& Elsevier]

Abstract: Active debris removal (ADR) was suggested as a potential means to remediate the low Earth orbit (LEO) debris environment as early as the 1980s. The reasons ADR has not become practical are due to its technical difficulties and the high cost associated with the approach. However, as the LEO debris populations continue to increase, ADR may be the only option to preserve the near-Earth environment for future generations. An initial study was completed in 2007 to demonstrate that a simple ADR target selection criterion could be developed to reduce the future debris population growth. The present paper summarizes a comprehensive study based on more realistic simulation scenarios, including fragments generated from the 2007 Fengyun-1C event, mitigation measures, and other target selection options. The simulations were based on the NASA long-term orbital debris projection model, LEGEND. A scenario where, at the end of mission lifetimes, spacecraft and upper stages were moved to 25-year decay orbits, was adopted as the baseline environment for comparison. Different annual removal rates and different ADR target selection criteria were tested, and the resulting 200-year future environment projections were compared with the baseline scenario. Results of this parametric study indicate that (1) an effective removal strategy can be developed using a selection criterion based on the mass and collision probability of each object, and (2) the LEO environment can be stabilized in the next 200 years with an ADR removal rate of five objects per year. [Copyright &y& Elsevier]

Abstract: The Ares V Cargo launch vehicle that is being designed by NASA for the Constellation Program, with its 10m diameter fairing and ability to place 130,000kg in low earth orbit, will enable telescopes with apertures much larger than the 6.5m of the James Webb Space Telescope to be placed in orbit. In this paper we revisit our designs for large aperture telescopes that could be launched with today''s expendable launch vehicles and show what aperture sizes would be enabled by the Ares V. Our assessment includes both monolithic and autonomously deployed telescopes, as well as those which could be assembled on orbit. We also address the requirements these payloads might impose on the Ares V design. [Copyright &y& Elsevier]

Abstract: The International Space Station (ISS) is rapidly approaching the long-awaited completion of assembly. All United States (US) core elements have been integrated and tested on-orbit and the principle elements of the European and Japanese laboratories were successfully deployed in 2008. The fully envisioned configuration is on schedule to be completed as planned by the end of US government fiscal year 2010. Section 507 of the NASA Authorization Act of 2005 designated the US segment of the ISS as a “national laboratory”, thereby opening up its use to other US government agencies, US private firms and US non-profit institutions. This paper reports on progress toward identifying and entering into agreements with entities outside of NASA that plan to use the ISS in the post-assembly timeframe. The original 1984 vision of a robust, multi-mission space station serving as a platform for the advancement of US science, technology and industry will soon be achieved. [Copyright &y& Elsevier]

Abstract: In the sector of information and communication technologies (ICT), whether in the USA, Japan, or Europe, innovative services are already in use, based on large-scale space-based infrastructure investments. Such systems are e.g. earth observation, telecommunication, and navigation, timing and positioning satellites. In combination with the advent of powerful handheld terminals and the demand for ubiquitous services, it is expected that info-mobility applications will reveal new sources of business in the years ahead, using in particular the Earth observation and future GALILEO systems to position any feature or user anywhere in the world within a few meter accuracy. Hence, satellite-based capabilities provide new and unique opportunities for economic stimulation and development. Many incubators and innovation centers in Europe have already grasped this growth potential. Yet, for many European players business growth appears below expectations compared to developments in the USA following the launch of GPS (Global Positioning System). Europe still has to overcome intrinsic barriers to seize these new business opportunities faster and with more visible economic impact by leveraging on SMEs and regional innovation centers to expand the commercial utilization of satellite capabilities and mobilization of appropriate financial resources. The paper elaborates on the INVESat project (funded by the EuropeInnova—European Commission), which aims at bridging the gap between Innovative enterprises and financial InVEstors in the emerging markets of SaTellite applications. The critical success factors required to stimulate and support more efficiently investments in this bread of innovative services will also be highlighted. [Copyright &y& Elsevier]

Abstract: As the NASA Vision for Space Exploration takes shape, one of the key issues that will affect the lunar exploration is the ability to provide electric power to various surface locations. This power should be available through daylight times as well as night times. While nuclear reactors and radioisotope power sources are a choice for continuous power, it is the purpose of this paper to explore the advantages of an electric propulsion spacecraft plus laser power beaming to provide power to any location on the lunar surface. The starting point for the electric propulsion mission is a 500km altitude. Thrusting only occurs when the satellite is in sunlight. Radiation damage that occurs during transit of the Earth''s radiation belts is taken into account. The satellite is placed in a 30,000 by 500km orbit around the moon where it beams power to locations within 45° north or south of the equator. Laser power beaming only occurs when the satellite views the sun and the surface location is in the dark. Power delivered to the surface over a two year mission is presented along with the results of adding a second satellite. With two satellites, the maximum time when the site won’t receive power at night is about three days. This significantly reduces the need for a lunar storage system. [Copyright &y& Elsevier]

Abstract: First in NASA''s New Frontiers series of missions, the New Horizons spacecraft was successfully launched on January 19, 2006. New Horizons is scheduled to perform a gravity assist at Jupiter on February 28, 2007, arrive at Pluto on July 14, 2015; completing an extended mission to at least one Kuiper Belt Object in subsequent years. The concept of operations requires a star tracker that operates autonomously both in a standard three-axis “staring” mode during operations involving instrument observations and in a spin stabilized mode during cruise operations with nominal rotational rates up to 5rpm. With the support of the Johns Hopkins University Applied Physics Laboratory, Galileo Avionica redesigned their Autonomous Star Trackers (ASTR) to use time-delayed integration techniques to provide autonomous spacecraft attitude estimates at 10Hz at spin rates up to 10rpm. This paper will present the performance of the upgraded ASTR in both inertial stare and spin stabilized modes for the first six months of the mission. In addition, effects of the vehicle motion on performance, effects of stray light and direct Sun blinding on tracking and performance, and unanticipated “features” or characteristics of the ASTRs will be discussed. [Copyright &y& Elsevier]

Abstract: As personal mobility increases, people spend more time in their vehicles. Furthermore, a large segment of today''s workforce is part of a growing mobile service industry. This mobile society creates opportunities to increase productivity which do not yet exist. Today''s commuting time could be better utilized and mobile business transactions could be more efficiently conducted, by integrating mobile IP wireless services in vehicles. By means of a direct to mobile user Internet access, and total IP services, integrated into automobiles, S@tMax services can empower the mobile business movement therefore improving productivity. This paper presents a commercial system architecture that will deliver an optimized solution for direct to mobile user Internet access, through an integration of a ground based network infrastructure, use of existing communications satellites and the development of a proprietary satellite system. As a result of a detailed systems engineering process, the architectures of the space, ground and infrastructures segments will be presented. Furthermore, the benefits of on-orbit servicing were examined in the S@tMax context. The approach proposed is considered as an important step towards enforcing main roadway IP coverage in the US, for near-continuous communications and services. [Copyright &y& Elsevier]

Abstract: By using electrodynamic drag to greatly increase the orbital decay rate, an electrodynamic space tether can remove spent or dysfunctional spacecraft from low Earth orbit (LEO) rapidly and safely. Moreover, the low mass requirements of such tether devices make them highly advantageous compared to conventional rocket-based de-orbit systems. However, a tether system is much more vulnerable to space debris impacts than a typical spacecraft and its design must be proved to be safe up to a certain confidence level before being adopted for potential applications. To assess space debris related concerns, in March 2001 a new task (Action Item 19.1) on the “Potential Benefits and Risks of Using Electrodynamic Tethers for End-of-life De-orbit of LEO Spacecraft” was defined by the Inter-Agency Space Debris Coordination Committee (IADC). Two tests were proposed to compute the fatal impact rate of meteoroids and orbital debris on space tethers in circular orbits, at different altitudes and inclinations, as a function of the tether diameter to assess the survival probability of an electrodynamic tether system during typical de-orbiting missions. IADC members from three agencies, the Italian Space Agency (ASI), the Japan Aerospace Exploration Agency (JAXA) and the US National Aeronautics and Space Administration (NASA), participated in the study and different computational approaches were specifically developed within the framework of the IADC task. This paper summarizes the content of the IADC AI 19.1 Final Report. In particular, it introduces the potential benefits and risks of using tethers in space, it describes the assumptions made in the study plan, it compares and discusses the results obtained by ASI, JAXA and NASA for the two tests proposed. Some general conclusions and recommendations are finally extrapolated from this massive and intensive piece of research. [Copyright &y& Elsevier]

Abstract: Solar TErrestrial RElations Observatory (STEREO), the third mission in NASA''s Solar Terrestrial Probes program, launched aboard a single Delta II 7925 launch vehicle on October 25, 2006 from Cape Canaveral. This two-year mission employs two nearly-identical, space-based observatories, one ahead of the Earth in its orbit, and the other trailing behind, to provide the first stereoscopic measurements of the sun and its coronal mass ejections, or CMEs. The STEREO observatories utilize four sets of solar arrays, each of which experienced a two-stage deployment on-orbit. This paper illustrates material considerations in the solar array subsystem design. It first focuses on the solar array substrate, considering material coefficient of thermal expansion (CTE) concerns when choosing a substrate laminate to which the solar cells will adhere. It then explores a similar issue when choosing a substrate insert material. Next, the focus shifts to material considerations in the solar array hinge design. This design was driven not just by function, but by a host of different material considerations, ranging from mass savings to fabrication time and cost. [Copyright &y& Elsevier]

Abstract: Upcoming National Aeronautics and Space Administration (NASA) mission concepts include satellite arrays to facilitate imaging and identification of distant planets. These mission scenarios are diverse, including designs such as the terrestrial planet finder-occulter (TPF-O), where a monolithic telescope is aided by a single occulter spacecraft, and the micro-arcsecond X-ray imaging mission (MAXIM), where as many as 16 spacecraft move together to form a space interferometer. Each design, however, requires precise reconfiguration and star tracking in potentially complex dynamic regimes. This paper explores control methods for satellite imaging array reconfiguration in multi-body systems. Specifically, optimal nonlinear control and geometric control methods are derived and compared to the more traditional linear quadratic regulators, as well as input state feedback linearization. These control strategies are implemented and evaluated for the TPF-O mission concept. [Copyright &y& Elsevier]

Abstract: NASA''s 2006 Solar System Exploration Roadmap recommended a set of robotic exploration missions for the next 30 years, in small, medium and large mission classes. These proposed missions are expected to target planets, moons and small bodies in the Solar System, while encountering diverse extreme environmental conditions through their mission phases. These extreme environments (EE) include high and low temperatures and pressures, and high radiation environments at various planetary destinations. EE conditions are often coupled, including high temperatures and pressures near the surface of Venus; or low temperatures and radiation at the Jovian System, for instance near Europa. Extreme environments due to mission operations are also a consideration, for example aeroshell thermal heating during planetary entry. While some of the technologies for EE mitigation are currently available, development of numerous new technologies are also required to enable missions and thus NASA''s exploration plans. In response, a comprehensive assessment was performed to identify the state of practice for EE technologies. Furthermore, recommendations were given for future technology developments. In this paper we outline the findings of the EE Technologies Study Team, including discussions on the state of practice of EE technologies; mission impacts; and emerging technology capabilities to enable mission architectures. Under emerging technologies we describe protection systems; component hardening for electronics, mechanisms and energy storage under high and low temperature conditions; and mobility operations. It is expected that the recommendations from the EE report would assist NASA with technology program planning and would help identifying priorities for near term technology investments. [Copyright &y& Elsevier]

Abstract: To stimulate the commercial space industry and potentially serve the logistics needs of the International Space Station (ISS) in the post-Space Shuttle era, the National Aeronautics and Space Administration (NASA) in 2006 began the Commercial Orbital Transportation Services (COTS) initiative. NASA entered into agreements with two U.S. firms, Rocketplane Kistler and Space Exploration Technologies to share up to 485,000,000 USD to demonstrate cargo transportation services to and from Low Earth orbit (LEO), with an option for additional funds to demonstrate human transportation services. Subsequently, NASA also entered into unfunded agreements with five companies to develop innovative space transportation capabilities. This paper reviews this unique initiative, describes the concepts of these seven companies, and discusses the potential of this emerging industry to make LEO more accessible. [Copyright &y& Elsevier]

Abstract: The intentional break-up of the Fengyun-1C spacecraft on 11 January 2007 via a hypervelocity collision with a ballistic object created the most severe artificial debris cloud in Earth orbit since the beginning of space exploration. More than 2000 debris of the order of 10cm or greater in size have been identified by the US Space Surveillance Network. The majority of these debris reside in long-lived orbits. The NASA Orbital Debris Program Office has conducted a thorough examination of the nature of the Fengyun-1C debris cloud, using Space Surveillance Network (SSN) data for larger debris and special Haystack radar observations for smaller debris. These data have been compared with the NASA standard satellite break-up model for collisions, and the results are presented in this paper. The orbital longevity of the debris have also been evaluated for both small and large debris. The consequent long-term spatial density effects on the low Earth orbit regime and the potential effect of the debris cloud on the growth of the near-Earth satellite population have been addressed. [Copyright &y& Elsevier]

Abstract: Modeling the future orbital debris environment is a difficult task. In addition to making reasonable assumptions on key parameters such as future launch traffic and solar activity projections, one needs to rely on a Monte Carlo approach to evaluate potential future on-orbit explosions and collisions. Even with the same input parameters, the outcome of the projected debris populations could vary significantly from one Monte Carlo run to the next. A common approach to assess the growth of future debris populations is to evaluate the average of multiple Monte Carlo runs. The number of runs is typically between 10 and 30, depending on the speed of the simulation program and the available computer resources. However, the characteristics of the future debris populations may not be fully unveiled by a limited number of Monte Carlo simulations. The main objective of this paper is to analyze results from 200 Monte Carlo simulations of the future debris environment, using the NASA long-term orbital debris evolutionary model LEGEND. The projected debris populations in terms of the mean, median, standard deviation, standard error of the mean, and the distribution of the debris populations at the end of the 100-year projection are analyzed. [Copyright &y& Elsevier]

Abstract: Supporting NASA''s Science Mission Directorate, the In-Space Propulsion Technology (ISPT) Program is developing solar sail propulsion (SSP) for use in robotic science and exploration of the solar system. SSP will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-m solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn''s Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L’Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. These sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails—perhaps as much as 150m on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (150m) required for first generation solar sail missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing. [Copyright &y& Elsevier]

Abstract: Announced in January 2004, NASA''s “Vision for Space Exploration” describes an ambitious series of missions, including a plan to return humans to the moon before the end of the next decade as well as eventual crewed missions to Mars. To accomplish these missions, NASA is developing “Constellation Systems”, a system of systems that will create the required vehicles, systems, and infrastructure. The first vehicle produced for Constellation Systems will be the Crew Exploration Vehicle (CEV). The CEV is a spacecraft designed to affordably, reliably, and safely transfer crew from the Earth''s surface to destinations beyond. Since Constellation Systems relies on a flexible, modular architecture to accomplish different missions, the CEV will be a very versatile vehicle. Initially, it will be used to transfer crew and cargo to and from the International Space Station. By the end of the next decade, it will transfer four astronauts from the Earth''s surface, dock with the Earth Departure Stage for the trip to a Lunar Orbit, then maintain itself autonomously there while the crew explores the surface below. The CEV design utilizes experience and technology from previous programs like Apollo and the Space Shuttle, but combines that with modern materials, manufacturing techniques, and avionics. This paper explores the requirements and design factors which drove the definition of the vehicle configuration. [Copyright &y& Elsevier]

Abstract: The Cassini Mission to Saturn, a joint undertaking by NASA, the European Space Agency, and the Italian Space Agency, is now at about the mid-point of its planned four-year tour of the Saturnian system. Close encounters with Titan and the smaller icy satellites are occurring on schedule, and observations of these bodies along with Saturn''s atmosphere, its rings, and magnetosphere are being made and scientific data returned on a daily basis. The icy satellites are turning out to be more distinct and unique than had been anticipated, the dynamics of the ring particles have been shown to be even more extensive than expected, and Titan''s atmosphere had surprises for both the scientists as well as the engineers. A denser than expected upper atmosphere of Titan has led to the requirement to modify the planned orbital tour about Saturn to increase the flyby altitudes for about 20 of the Titan flybys to values above the originally planned 950km level in order to avoid the risk of atmospherically induced torques causing the spacecraft to be unable to maintain its commanded attitude. Navigation of the spacecraft on the tour continues to go exceptionally well, with optical navigation enabling delivery accuracies to some of the satellites down to the 1 or 2km level, and propellant consumption is running slightly below budget. Science observation sequence development and execution have been highly successful in acquiring virtually all of the originally designed observations. This paper summarizes the supporting engineering activities over the past year in support of operating the mission, as well as provides a high-level summary of the scientific results of the Cassini mission to date. [Copyright &y& Elsevier]

Abstract: Both the United Nations (UN) and the US Federal Communications Commission (FCC) have published a ruling that calls for geostationary earth orbit (GEO) satellites to be placed in a disposal orbit at the end of their operational lives. Current procedures utilize spacecraft residual propellant and represent a major life-limiting factor for GEO satellites. An alternative approach would be to allow a space tug to capture and move the satellites after all of their fuel has been exhausted. This extended lifetime can provide significant additional revenue to some satellite operators. Before committing to such a capability, however, the lifecycle costs of a space tug infrastructure must be carefully weighed against the opportunity costs of the current retirement practice. This paper investigates the questions of tug costs, perceived benefits, and service fee. It builds a framework that can be used in evaluating various on-orbit servicing opportunities and proposes that the service fee should be charged as a percentage of the additional revenue received by the satellite operators and analyzes how cost estimation uncertainties affect the value of on-orbit tugging. The presented analysis concludes that until advanced propulsion systems gain greater use, retirement via a space tug will be of value for the 10–20 most expensive GEO assets. [Copyright &y& Elsevier]

Abstract: Nearly six years after the launch of the first International Space Station element, and four years after its initial occupation, the United States and our 6 international partners have made great strides in operating this impressive Earth orbiting research facility. This past year we have done so in the face of the adversity of operating without the benefit of the Space Shuttle. In his January 14, 2004, speech announcing a new vision for America''s space program, President Bush affirmed the United States’ commitment to completing construction of the International Space Station by 2010. The President also stated that we would focus our future research aboard the Station on the long-term effects of space travel on human biology. This research will help enable human crews to venture through the vast voids of space for months at a time. In addition, ISS affords a unique opportunity to serve as an engineering test bed for hardware and operations critical to the exploration tasks. NASA looks forward to working with our partners on International Space Station research that will help open up new pathways for future exploration and discovery beyond low Earth orbit. This paper provides an overview of the International Space Station Program focusing on a review of the events of the past year, as well as plans for next year and the future. [Copyright &y& Elsevier]

Abstract: Small satellite systems appear to be antithetical to human spaceflight systems and flagship robotic satellite systems: Small satellite missions have more focused scientific objectives, lower cost, far less complexity, and shorter development and deployment schedules. The shorter schedules offer an opportunity for injecting new technology into their design as a means for keeping costs and schedule under control, for enabling cost-effective operations, and for taking advantage of innovative ideas. It is often the case that small satellite missions benefit from technologies specifically targeted for their application, but benefits may also be realized by adopting or injecting technologies originally developed for human spaceflight systems, especially if these technologies were conceived using multi-use and multi-disciplinary development principles. In this paper, the authors discuss the precedent of injecting new technology developed for human spaceflight systems into small satellite missions. More importantly, the authors will present five new technologies recently proposed for making the NASA Space Shuttle safer to fly, all of which are directly applicable to small satellite mission design and operations. The technologies, when matured, will provide a means to create new generations of ultra-reliable flight hardware and software. The technologies are all currently at the developmental phase and require modest investment to achieve operational status. [Copyright &y& Elsevier]

Abstract: The United States space exploration goals expressed in January 2004 call for the retirement of the Space Transportation System (STS or Shuttle) following completion of International Space Station (ISS) construction. Since the Shuttle is instrumental in transporting large quantities of cargo to and from the ISS, this functional capability must be preserved to ensure ongoing station operations in a post-Shuttle era. Fulfilling ongoing cargo transport requirements to the ISS is a prime opportunity for NASA to reduce costs and preserve and repurpose the unique and limited Shuttle resource by acquiring cargo transportation services commercially. Further, implementing such a service prior to retirement of the Shuttle reduces risk to the vehicle and her crews by eliminating their use for routine cargo transport missions while accelerating the readiness for alternative ISS-support transportation. This paper examines ISS cargo traffic requirements, provides an assessment of current and proposed cargo vehicles envisioned for ISS cargo transport, and examines major cost drivers associated with development of cargo transport systems. Consideration of these factors, coupled with SPACEHAB''s extensive involvement in cargo transport to the Mir and ISS, has led to the development of a Commercial Payload Service (CPS). The CPS mission models, system description and performance, and structure of the commercial service model are presented. [Copyright &y& Elsevier]

Abstract: In order to verify that the International Space Station (ISS) payload facility racks do not disturb the microgravity environment of neighboring facility racks and that the facility science operations are not compromised, a testing and analytical verification process must be followed. Currently no facility racks have taken this process from start to finish. The authors are participants in implementing this process for the NASA Glenn Research Center (GRC) Fluids and Combustion Facility (FCF). To address the testing part of the verification process, the Microgravity Emissions Laboratory (MEL) was developed at GRC. The MEL is a 6 degree of freedom inertial measurement system capable of characterizing inertial response forces (emissions) of components, sub-rack payloads, or rack-level payloads down to ''s. The inertial force output data, generated from the steady state or transient operations of the test articles, are utilized in analytical simulations to predict the on-orbit vibratory environment at specific science or rack interface locations. Once the facility payload rack and disturbers are properly modeled an assessment can be made as to whether required microgravity levels are achieved. The modeling is utilized to develop microgravity predictions which lead to the development of microgravity sensitive ISS experiment operations once on-orbit. The on-orbit measurements will be verified by use of the NASA GRC Space Acceleration Measurement System (SAMS). The major topics to be addressed in this paper are: (1) Microgravity Requirements, (2) Microgravity Disturbers, (3) MEL Testing, (4) Disturbance Control, (5) Microgravity Control Process, and (6) On-Orbit Predictions and Verification. [Copyright &y& Elsevier]

Abstract: The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration''s (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly. [Copyright &y& Elsevier]

Abstract: Students from the University of Michigan have developed a small satellite—dubbed Icarus—to serve as an active endmass for NASA''s ProSEDS (Propulsive Small Expendable Deployer System) electrodynamic-tether propulsion mission. The ProSEDS experiment will be launched in early 2004 as a secondary payload attached to the second stage of a Delta-II rocket. Following the completion of the Delta-II primary mission, the Icarus endmass satellite will be cast off from the Delta-II second stage, deploying a 12 km space tether. Throughout tether deployment, and for the duration of the ProSEDS mission, Icarus will collect and transmit data on tether deployment and dynamics. The endmass is responsible for providing tether–endbody location information (using a GPS receiver) and endbody attitude dynamics (using an aspect magnetometer). The data from these instruments will be stored and transmitted to ground telemetry stations. This paper details the Icarus satellite system and lessons learned from the project. [Copyright &y& Elsevier]

Data from weather satellites have become integral to the weather forecast process in the United States and abroad. Satellite data are used to derive improved forecasts for short-term routine weather, long-term climate change, and for predicting natural disasters. The resulting forecasts have saved lives, reduced weather-related economic losses, and improved the quality of life. Weather information routinely assists in managing resources more efficiently and reducing industrial operating costs. The electric energy industry in particular makes extensive use of weather information supplied by both government and commercial suppliers. Through direct purchases of weather data and information, and through participating in the increasing market for weather derivatives, this sector provides measurable indicators of the economic importance of weather information.Space weather in the form of magnetic disturbances caused by coronal mass ejections from the sun creates geomagnetically induced currents that disturb the electric power grid, sometimes causing significant economic impacts on electric power distribution. This paper examines the use of space-derived weather information on the U.S. electric power industry. It also explores issues that may impair the most optimum use of the information and reviews the longer-term opportunities for employing weather data acquired from satellites in future commercial and government activity. [Copyright &y& Elsevier]

NASA''s Next Generation Launch Technology (NGLT) program is developing and maturing advanced propulsion and vehicle systems technologies and flight vehicle concepts to enable future development of safer and more economical launch systems. Within NGLT, NASA is developing advanced air breathing propulsion systems and demonstrating these systems in hypersonic flight vehicles. The flight demonstrations are necessary to fully validate these technologies for application to future space launch vehicles and other flight systems.NASA''s Hyper-X Program (X-43A) began the effort to flight demonstrate hypersonic air breathing propulsion systems to provide technologies that will enable development of safer and more economic space access vehicles in the future. Following X-43A, NASA, in collaboration with the United States (US) Department of Defense (DoD), is developing additional, progressively more complex hypersonic X-vehicles that will demonstrate new air breathing propulsion systems, propulsion-airframe integration, and other vehicle systems technologies required for high speed flight up to Mach 15. These technologies will contribute to safer, more reliable and more economic future launch systems and hypersonic aircraft/missiles.This paper describes NASA''s current hypersonic flight demonstration projects, status of the efforts, and plans for future vehicles. [Copyright &y& Elsevier]

There is a belief that exists in the United States about public support for NASA''s activities. The belief is almost universally held that NASA and the cause of space exploration enjoyed outstanding public support and confidence in the 1960s during the era of Apollo and that public support waned in the post-Apollo era, only to sink to quite low depths in the decade of the 1990s. These beliefs are predicated on anecdotal evidence that should not be discounted, but empirical evidence gleaned from public opinion polling data suggest that some of these conceptions are totally incorrect and others are either incomplete or more nuanced than previously believed. This paper explores evolution of public support for space exploration since the 1960s. Using polling data from a variety of sources it presents trends over time and offers comments on the meaning of public perceptions for the evolution of space policy and the development of space exploration in the United States. [Copyright &y& Elsevier]

Delta IV is one of two competing Evolved Expendable Launch Vehicle (EELV) systems being developed in an industry/United States Government partnership to meet the needs of the new era of space launch for the early decades of the 21st Century. The Rocketdyne Division of The Boeing Company and the United States Air Force have developed a 650 Klbf sea-level (2.9 MN) class liquid hydrogen/liquid oxygen main engine for the Delta IV family of EELV. The purpose of this paper is to present the innovative approach to the design, development, testing and certification of the RS-68 engine. [Copyright &y& Elsevier]

The Skybridge system is a worldwide ATM broadband communication system based on a 80 low Earth orbit satellite constellation. The minimization of space debris generation has been taken into account very early in the frame of this program.The objectives are, first to identify the contribution of Skybridge to the space debris generation and secondly to assess the risk due to space debris for the whole system. This paper summarizes the approach of the Skybridge program for debris assessment and mitigation.As no international regulation dealing with this subject exists, the analysis is based on the existing NASA 1740 Safety Standard. The methodology and the software presented in this document were applied to demonstrate the compliance of Skybridge with the requirements. In addition the new CNES standard was used to derive additional requirements.The first point deals with the production of space debris in the various mission phases: this concerns debris released during launch, constellation deployment and mission operations. Besides these normal operations, space debris can also be generated through material ageing or in case of accidents such as explosion due to on-board stored energy or collision with other orbiting objects.In the second part the collision risk is analyzed: the probability of collision with the large cataloged objects is determined. Concerning the smaller debris, the flux models give the probability of impact per surface unit: the analysis identifies components most vulnerable to debris impact together with their shielding and gives the associated probability of failure taking into account the architecture of the satellite.The problem of the post-mission disposal procedure is then discussed in the third part. [Copyright &y& Elsevier]

This paper proposes to discuss space research cooperation between France and the United States as it existed at the beginning of the 1960s.Among NASA's missions, when created in 1958, was to conduct a policy of international cooperation. Great Britain and Canada responded rapidly to the NASA's proposals.With France, however, the situation was quite different. At that time, Paris wanted to develop large scale space research activities of its own.For this purpose, in January 1959, the French government created the “Comite´ des Recherches Spatiales”, which had two missions: to organize the space research in France and to participate in international space affairs. Although French research at that time was sufficiently advanced in sounding rockets and military missiles to develop a program whose objective was to create a national launcher, France's scientists did not really have enough experience in satellite design, unlike most other countries involved in space research during this period.At this time, several cooperative programs were initiated between France and the United States, in fields such as rocket experiments, visual observation satellites and satellites tracking. However, the first major cooperative program between the two countries concerned the development of a scientific satellite—later known as FR-1— which was launched in December 1965. [Copyright &y& Elsevier]

NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user application communities by addressing scientific questions that pertain to human radiation exposure, climate change, and technological systems. This will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on these systems.The formulation of the LWS Program architecture and implementation plan is currently in progress with inputs from the science and engineering communities. There are plans for two groups of science spacecraft: (a) solar dynamics elements that observe the Sun and track disturbances originating there and (b) geospace elements located between the Sun and the Earth and around the Earth to measure downstream effects the geospace response to changes in solar activity. Plans also include a data analysis component to improve scientific understanding, and a series of Space Environment Testbeds to provide infusion of the improved understanding to the design and operations of future missions.The LWS Program is developing partnerships with other US and International agencies and industry to augment existing capabilities. The full paper will give an overview of the program architecture and the implementation and partnering plan for LWS. [Copyright &y& Elsevier]

In the 36 years between June 1965 and February 2001, the US human space flight program has conducted 100 spacewalks, or extravehicular activities (EVAs), as NASA officially calls them. EVA occurs when astronauts wearing spacesuits travel outside their protective spacecraft to perform tasks in the space vacuum environment. US EVA started with pioneering feasibility tests during the Gemini Program. The Apollo Program required sending astronauts to the moon and performing EVA to explore the lunar surface. EVA supported scientific mission objectives of the Skylab program, but may be best remembered for repairing launch damage to the vehicle and thus saving the program. EVA capability on Shuttle was initially planned to be a kit that could be flown at will, and was primarily intended for coping with vehicle return emergencies. The Skylab emergency and the pivotal role of EVA in salvaging that program quickly promoted Shuttle EVA to an essential element for achieving mission objectives, including retrieving satellites and developing techniques to assemble and maintain the International Space Station (ISS). Now, EVA is supporting assembly of ISS.This paper highlights development of US EVA capability within the context of the overarching mission objectives of the US human space flight program. [Copyright &y& Elsevier]