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This work presents a novel cooperative path planning for formation keeping robots traversing along a road with obstacles and possible narrow passages. A unique challenge in this problem is a requirement for spatial and temporal coordination between vehicles while ensuring collision and obstacle avoidance.
A keynote speech outlining the importance of collaboration and diversity in the workplace. The 20-minute speech describes NASA's challenges and accomplishments over the years and what lies ahead. Topics include: diversity and inclusion principles, international cooperation, Kennedy Space Center planning and development, opportunities for cooperation, and NASA's vision for exploration.
Established in May 6, 1995, the purpose of this International Strategic Planning Group for Microgravity Science and Applications Research is to develop and update, at least on a biennial basis, an International Strategic Plan for Microgravity Science and Applications Research. The member space agencies have agreed to contribute to the development of a Strategic Plan, and seek the implementation of the cooperative programs defined in this Plan. The emphasis of this plan is the coordination of hardware construction and utilization within the various areas of research including biotechnology, combustion science, fluid physics, materials science and other special topics in physical sciences. The Microgravity Science and Applications International Strategic Plan is a joint effort by the present members - ASI, CNES, CSA, DLR, ESA, NASA, and NASDA. It represents the consensus from a series of discussions held within the International Microgravity Strategic Planning Group (IMSPG). In 1996 several space agencies initiated multilateral discussions on how to improve the effectiveness of international microgravity research during the upcoming Space Station era. These discussions led to a recognition of the need for a comprehensive strategic plan for international microgravity research that would provide a framework for cooperation between international agencies. The Strategic Plan is intended to provide a basis for inter-agency coordination and cooperation in microgravity research in the environment of the International Space Station (ISS) era. This will be accomplished through analysis of the interests and goals of each participating agency and identification of mutual interests and program compatibilities. The Plan provides a framework for maximizing the productivity of space-based research for the benefit of our societies.
The ISS Research Project draws Life (non-human) and Physical Sciences investigations on the ISS, free flyer and ground-based into one coordinated project. The project has two categories: I. Exploration Research Program: a) Utilizes the ISS as a low Technology Readiness Level (TRL) test bed for technology development, demonstration and problem resolution in the areas of life support, fire safety, power, propulsion, thermal management, materials technology, habitat design, etc.; b) Will include endorsement letters from other ETDP projects to show relevancy. II. Non-Exploration Research Program; a) Not directly related to supporting the human exploration program. Research conducted in the life (non-human) and physical sciences; b) The program will sustain, to the maximum extent practicable, the United States scientific expertise and research capability in fundamental microgravity research. Physical Sciences has about 44 grants, and Life Sciences has approximately 32 grants, mostly with universities, to conduct low TRL research; this includes grants to be awarded from the 2008 Fluid Physics and Life Science NRA's.
The goals of this research were to develop design concepts to support the task of enroute flight planning. And within this context, to explore and evaluate general design concepts and principles to guide the development of cooperative problem solving systems. A detailed model is to be developed of the cognitive processes involved in flight planning. Included in this model will be the identification of individual differences of subjects. Of particular interest will be differences between pilots and dispatchers. The effect will be studied of the effect on performance of tools that support planning at different levels of abstraction. In order to conduct this research, the Flight Planning Testbed (FPT) was developed, a fully functional testbed environment for studying advanced design concepts for tools to aid in flight planning.
Planetary rovers exploring the surface of Mars face a challenging operational environment that requires close cooperation between deliberative planning and behavioral execution in order to most efficiently leverage the robot’s capabilities into science value returned to earth. The Self-Reliant Rovers project envisions future rover missions that require only occasional high-level direction from human controllers to successfully conduct detailed in-situ studies of its Martian environs. To achieve this high degree of autonomy, this work leverages a spectrum of planning and execution techniques that allow the rover to respond appropriately to both opportunity and adversity it encounters. Small perturbations are accommodated at first by behavioral adaptation, with more and more extensive disruptions handled in turn by executive administration of plan flexibility, heuristic-guided plan repair strategies, and finally comprehensive replanning from science campaign goals. The integrated system has been deployed and tested on a terrestrial rover in an environment and under scenarios that anticipate those faced by future Mars rovers. This paper recounts complexities of planning and execution coordination faced in the rover domain and the practical solutions employed to address them. Particular emphasis is given to lessons from the field and foibles ripe for remedy by future advances in planning and execution research.
Mission profiles for a Mars Surface Sample Return (MSSR) mission are considered. A profile using separate launches for a lander/ascent module and an orbiter/return system could use present technology and is appropriate for international cooperation. The achievement of clean interfaces between major building blocks and ease of controlling back contamination are advantages offered by the concept. A spatially distributed surface sample could be obtained by using multiple landers delivering samples to a common orbiter. The Pioneer Venus program, originally planned as a cooperative NASA-ESRO project, resulted in development of a standardized spacecraft bus yielding benefits at minimized cost. The first joint US-European planetary mission now planned is the launch of a Pioneer class orbiter to Jupiter in 1980. Feasibility studies are being conducted.
A spectrum of plans has been prepared to illustrate the range of practical sharing possibilities available so as to assist Ames Research Center (ARC) and European Space Research Organization (ESRO) in selection of a program meeting mutual goals. Five plans are described showing increased participation by ESRO WITH ascending plan number. Each of these has sharing properties fulfilling particular requirements such as available ESRO budget level, extent of ESRO program responsibility, matching particular ESRO capability, and cost saving to ARC through sharing. All plans apply to orbiter sharing only. A sharing plan based on the model Plan 4 may offer the most attractive division of Pioneer Venus between ARC and ESRO. This plan allows ESRO to bear primary responsibility for the orbiter and to avoid an extensive financial burden. Savings to ARC are commensurate with ARC loss of program control. Duplication of effort is avoided by using orbiter subsystems that are common to the probe bus and orbiter.
Launch plans for the International Infrared Astronomical Satellite (IRAS) are provided.
The spectacularly cryovolcanic moon Enceladus is a major source of plasma for the Saturn magnetosphere via ionization of the ejected molecular species and ice grains. Field-aligned plasma flows from the Enceladus environment visibly impact the moon's magnetic footpoint in Saturn's polar auroral region, while water group and other ions from the moon emissions diffuse radially throughout the magnetosphere and may be the dominant source of oxygen for Titan's oxygen-poor upper atmosphere. But the moon-magnetosphere interaction is bidirectional in the sense that the moon surface is globally exposed to constant irradiation by the returning magnetospheric ions and by energetic electrons from the field-aligned and radially diffusing populations. The returning ion source operates both on global scales of the magnetosphere and locally for highly reactive species produced in the ejecta plume. All of these sources likely combine to produce a highly oxidized global surface layer. Since plasma electrons and ions are cooled by interaction with neutral gas and E-ring ice grains from Enceladus, the moon emissions have a governing effect on the seed populations of energetic particles that irradiate the surface. The proposed subsurface polar sea and transient crustal overturn in the south polar region could bring the polar surface oxidants into contact with hydrocarbons and ammonia to make oxidation product gases contributing to the cryovolcanic jets, a process first proposed by Cooper et al. (Plan. Sp. Sci., 2009). As has been previously suggested for Europa, the 'oxidants could contribute to enhanced astrobiological potential of Enceladus, perhaps even higher than for Europa where organic hydrocarbons have not yet been directly detected. Unlike Europa, Enceladus shows no sign of an oxygen-dominated exosphere that could otherwise be indicative of extreme surface and interior oxidation inhibiting the detectable survival and evolution of complex organics.
There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal has been two-fold. First, we have been developing specific system designs to help with this important practical problem. Second, we have been using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These design concepts are described below, along with illustrations of their application.
LunaNet is planned to be the network of networks operated by a set of cooperating organizations to provide interoperable Communications, networking, Position, Navigation, and Timing (CPNT) services to users on and around the Moon based on a framework of mutually agreed-upon standards, protocols, frequency bands and interface requirements. LunaNet follows a service-oriented architecture that is agnostic about the types of organizations that provide services, e.g., government, industry, or academia. LunaNet is open, scalable, resilient, secure, and extensible. To achieve these goals, LunaNet Service Providers (LNSP) must coordinate with each other to define and develop the architecture, to plan initial and evolved capabilities, and to operate their networks. One of the central LunaNet tenets is the use of shared spectrum. For example, the Lunar Augmented Navigation Service (LANS) acts like a Global Navigation Satellite System (GNSS) such as the US Global Positioning System (GPS) or European Galileo but the LNSPs’ contributions to LunaNet must use the same frequency band (2483.5 MHz-2500.0 MHz) and transmit the same waveform synchronized by highly accurate clocks so that Users ‘see’ one virtual network and use the same multilateration algorithm to determine their positions. This necessitates a high degree of spectrum coordination. NASA’s Lunar and Human Spaceflight Spectrum Management Team has been actively supporting development of the LunaNet Interoperability Specification (LNIS), soliciting inputs from spectrum policy and planning experts across NASA, ESA and JAXA. Cislunar spectrum use considerations have been studied and adjudicated within the Space Frequency Coordination Group (SFCG) and inform the ongoing discussion of a lunar communication and navigation architecture within the existing radio regulatory framework of the International Telecommunication Union, leading to the 2027 World Radiocommunication Conference (WRC-27). The frequency plan contained in the publicly released draft of the LunaNet Interoperability Specification reflects the initial phase of exploration (roughly to 2030) defining an optimal set of radio frequencies in appropriately allocated services consistent with WRC-23 decisions for use by known or planned CPNT applications, while striving to maximize coexistence and compatibility amongst cislunar systems and other systems within the near-Earth regime (< 2 million km from Earth). Important considerations include: protection of extremely sensitive receive-only radio astronomy systems on the lunar far side, known as the Shielded Zone of the Moon (SZM); compatibility between Direct with Earth (DWE) communications links and links needed to support relay satellites in lunar orbit with their customer systems on orbit or on the lunar surface; compatibility between multiple lunar surface communications systems and capabilities over varied and challenging terrain and distances; as well as ensuring compatibility and interoperability between navigation systems which either leverage Earth-based or in-situ lunar systems. In addition, the lunar CPNT architecture is envisioned to be the basis – with adjustments – of the future Mars CPNT architecture as we expand into the solar system using Interplanetary Networking (IPN). The second phase of lunar spectrum definition will address planned international capabilities for the next decade that will require action at WRC-27 and beyond. This paper will discuss each of these considerations in more depth and how the current LunaNet frequency plan addresses them.
A brief review of the research accomplishments by NASA in meeting the needs of the space program for precise time in satellite tracking is presented. As a major user of precise time signals for clock synchronization of NASA's worldwide satellite tracking networks, the agency provided much of the necessary impetus for the development of stable frequency sources and time synchronization technology. The precision in time required for both satellite tracking and space science experiments has increased at a rate of about 1 order of magnitude per decade from 1 ms in the 1950's to 100 microsec during the Apollo era in the 1960's to 10 microsec in the 1970's. In the 1980's, when the Tracking and Data Relay Satellite System (TDRSS) comes into operation, satellite timing requirements will be extended to 1 microsec and below. These requirements are needed for spacecraft autonomy and data packeting which are now in active planning stages.
Currently based on ground and aerial surveys, the land cover data base of the Pennsylvania Power and Light Company is routinely used for modelling the effects of alternative generating plant and transmission line sites on the local and regional environment. The development of a satellite-based geographic information system would facilitate both the preparation of environmental impact statements by power companies and assessment of the data by the Nuclear Regulatory Commission. A cooperative project is planned to demonstrate the methodology for integrating satellite data into an existing geographic information system, d to further evaluate the ability of satellite data in modeling environmental conditions that would be applied in the preparation and assessment of environmental impact statements.
The design of a permanently manned space station is discussed. The role of the space shuttle, planning guidelines, international cooperation, and commercial possibilities are among the topics discussed.
The design of a permanently manned Space Station is discussed. The role of the Space Shuttle, planning guidelines, international cooperation, and commercial possibilities are among the topics discussed.
The Colloquium and Workshop on Multiscale Coupled Modeling was held for the purpose of addressing modeling issues of importance to planning for the Cooperative Multiscale Experiment (CME). The colloquium presentations attempted to assess the current ability of numerical models to accurately simulate the development and evolution of mesoscale cloud and precipitation systems and their cycling of water substance, energy, and trace species. The primary purpose of the workshop was to make specific recommendations for the improvement of mesoscale models prior to the CME, their coupling with cloud, cumulus ensemble, hydrology, air chemistry models, and the observational requirements to initialize and verify these models.
NASA/Marshall Space Flight Center (MSFC) has an ongoing effort to transfer to industry the technologies developed at MSFC for rocket propulsion systems. The Technology Utilization (TU) Office at MSFC promotes these efforts and accepts requests for assistance from industry. One such solicitation involves a request from North American Marine Jet, Inc. (NAMJ) for assistance in the design of a water-jet-drive system to fill a gap in NAMJ's product line. NAMJ provided MSFC with a baseline axial flow impeller design as well as the relevant working parameters (rpm, flow rate, etc.). This baseline design was analyzed using CFD, and significant deficiencies identified. Four additional analyses were performed involving MSFC changes to the geometric and operational parameters of the baseline case. Subsequently, the impeller was redesigned by NAMJ and analyzed by MSFC. This new configuration performs significantly better than the baseline design. Similar cooperative activities are planned for the design of the jet-drive inlet.