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Embedded CLIPS for SDI BM/C3 simulation and analysis

Nichols Research Corporation is developing the BM/C3 Requirements Analysis Tool (BRAT) for the U.S. Army Strategic Defense Command. BRAT uses embedded CLIPS/Ada to model the decision making processes used by the human commander of a defense system. Embedding CLlPS/Ada in BRAT allows the user to explore the role of the human in Command and Control (C2) and the use of expert systems for automated C2. BRAT models assert facts about the current state of the system, the simulated scenario, and threat information into CLIPS/Ada. A user-defined rule set describes the decision criteria for the commander. We have extended CLIPS/Ada with user-defined functions that allow the firing of a rule to invoke a system action such as weapons release or a change in strategy. The use of embedded CLIPS/Ada will provide a powerful modeling tool for our customer at minimal cost.

Gossage, Brett↗

NASA's Plans for Developing Life Support and Environmental Monitoring and Control Systems

Life Support and Monitoring have recently been reworked in response to the Vision for Space Exploration. The Exploration Life Support (ELS) Project has replaced the former Advanced Life Support Element of the Human Systems Research and Technology Office. Major differences between the two efforts include: the separation of thermal systems into a new stand alone thermal project, deferral of all work in the plant biological systems, relocation of food systems to another organization, an addition of a new project called habitation systems, and overall reduction in the number of technology options due to lower funding. The Advanced Environmental Monitoring and Control (AEMC) Element is retaining its name but changing its focus. The work planned in the ELS and AEMC projects is organized around the three major phases of the Exploration Program. The first phase is the Crew Exploration Vehicle (CEV). The ELS and AEMC projects will develop hardware for this short duration orbital and trans-lunar vehicle. The second phase is sortie landings on the moon. Life support hardware for lunar surface access vehicles including upgrades of the CEV equipment and technologies which could not be pursued in the first phase due to limited time and budget will be developed. Monitoring needs will address lunar dust issues, not applicable to orbital needs. The ELS and AEMC equipment is of short duration, but has different environmental considerations. The third phase will be a longer duration lunar outpost. This will consist of a new set of hardware developments better suited for long duration life support and associated monitoring needs on the lunar surface. The presentation will show the planned activities and technologies that are expected to be developed by the ELS and AEMC projects for these program phases.

Lawson, B. Michael↗

OpenNEX: An open collaboration platform for the earth science community

Satellite data from the past several decades provide the most consistent record of land-surface processes that form the basis for scientific assessments of the impacts of climate variations and changes on the environment and human social-economical activities. During this time, scientific research on the characterization and assessment of environmental changes had tended to focus on large-scale land-surface changes with significant social-economic impacts. Increasingly, attention is shifting toward changes that occur more locally and that most directly relate to the everyday life of the majority of the population. In addition, there has been needs to develop management and policy decision support systems that are based on local environmental information. Almost at the same time, the advancement in sensor technology has allowed us to collect an unprecedented volume of environmental data. These data must be curated and analyzed to extract useful information for research and decision support purposes. Established in 2013 and funded by NASA, the Open NASA Earth eXchange (OpenNEX; https://opennex.org/ , Jia et al., 2019 ) project partnered with Amazon Web Services (AWS) to make available a large amount of Earth observing data, modeling results, and analysis tools on the AWS. OpenNEX provides researchers, developers, educators, and ordinary users with easy access to an integrated Earth science computational and data platform, enabling citizen scientists and application developers to realize the full value of NASA data assets and software tools. To encourage the public's engagement in this project, NASA ran virtual workshops and prize competitions. The virtual workshops provided online lectures and tutorials about how prominent scientists used the data in their research and the tutorials gave examples how to use the tools to interrogate the data in the Amazon cloud. Finally, the prize competitions allowed much wider participation in the OpenNEX project and enable testing the non-traditional projects and out-of-box ideas. OpenNEX has continued to evolve and mature. Here, we highlight new features and functionalities available to the community.

Jian Zhang↗

Pilot Study of Medications Exposed to Vacuum

Background Few studies have been conducted regarding the effects of vacuum on medications and their packaging. While relevant on the International Space Station, understanding these effects becomes even more critical as future NASA missions venture farther away from Earth. Vehicles supporting the Artemis missions will have dedicated, vehicle-specific medical kits as well as crew medical accessory kits. Although most of the kits will be stored in a pressurized, climate-controlled volume, there are specific scenarios in which they may become exposed to vacuum. These include the vehicle being brought to vacuum to enable clearance of atmospheric contaminants, and on Human Landing System (HLS), in the airlock (in which kits may be stored) during extravehicular activities. Overview The Exploration Medical Integrated Product Team (XMIPT) in collaboration with the Department of Defense is conducting a pilot study to assess the effects of vacuum on the medications and their packaging to be used in exploration missions. Phase A of this study will focus on manufacturer’s package integrity and Phase B on identifying chemical changes through active pharmaceutical ingredient (API) testing of the medications at 0, 4.5 and 9 months post exposure. Two exposure durations, 1 hour and 8 hours were selected to represent the expected time at vacuum for an Orion contaminated atmosphere vent/repress and the time at vacuum for a lunar surface EVA. The medications for this study were identified based on those currently being considered for future Artemis missions and represent the types of pharmaceuticals and formulations that are likely to comprise an exploration formulary. Discussion The results from this pilot study will aid in decision making related to the development of medical kits, medication packaging and stowage for long duration lunar and Mars missions, and inform the direction of future medication in vacuum studies.

Vacuum↗

Integrating Large Scale Data Sets to Develop Predictive Hypotheses of Low-Dose Radiation-Induced Health Effects

Over one hundred years of radiation biology research has revealed much about the DNA damages induced by the deposition of energy from exposure to ionizing radiation and the subsequent cellular responses. However, there are still significant gaps in our understanding of how these might lead to detrimental health effects, particularly at low doses (100 mGy (milligray)). Recent advances in high throughput omics technologies enable interrogation of induced radiation effects at the genomic, proteomic and metabolomic levels. These include changes in gene expression, protein modifications, e.g., phosphorylation, acetylation, and methylation, and metabolic changes. We will discuss the integration of data obtained from multiple omics platforms to understand radiation dose, and dose rate effects in a complex human tissue model as a function of time. We will use as an example our results on the low dose responses in a 3D human skin model.

ionizing radiation↗

An Open Computing Infrastructure that Facilitates Integrated Product and Process Development from a Decision-Based Perspective

Computer applications for design have evolved rapidly over the past several decades, and significant payoffs are being achieved by organizations through reductions in design cycle times. These applications are overwhelmed by the requirements imposed during complex, open engineering systems design. Organizations are faced with a number of different methodologies, numerous legacy disciplinary tools, and a very large amount of data. Yet they are also faced with few interdisciplinary tools for design collaboration or methods for achieving the revolutionary product designs required to maintain a competitive advantage in the future. These organizations are looking for a software infrastructure that integrates current corporate design practices with newer simulation and solution techniques. Such an infrastructure must be robust to changes in both corporate needs and enabling technologies. In addition, this infrastructure must be user-friendly, modular and scalable. This need is the motivation for the research described in this dissertation. The research is focused on the development of an open computing infrastructure that facilitates product and process design. In addition, this research explicitly deals with human interactions during design through a model that focuses on the role of a designer as that of decision-maker. The research perspective here is taken from that of design as a discipline with a focus on Decision-Based Design, Theory of Languages, Information Science, and Integration Technology. Given this background, a Model of IPPD is developed and implemented along the lines of a traditional experimental procedure: with the steps of establishing context, formalizing a theory, building an apparatus, conducting an experiment, reviewing results, and providing recommendations. Based on this Model, Design Processes and Specification can be explored in a structured and implementable architecture. An architecture for exploring design called DREAMS (Developing Robust Engineering Analysis Models and Specifications) has been developed which supports the activities of both meta-design and actual design execution. This is accomplished through a systematic process which is comprised of the stages of Formulation, Translation, and Evaluation. During this process, elements from a Design Specification are integrated into Design Processes. In addition, a software infrastructure was developed and is called IMAGE (Intelligent Multidisciplinary Aircraft Generation Environment). This represents a virtual apparatus in the Design Experiment conducted in this research. IMAGE is an innovative architecture because it explicitly supports design-related activities. This is accomplished through a GUI driven and Agent-based implementation of DREAMS. A HSCT design has been adopted from the Framework for Interdisciplinary Design Optimization (FIDO) and is implemented in IMAGE. This problem shows how Design Processes and Specification interact in a design system. In addition, the problem utilizes two different solution models concurrently: optimal and satisfying. The satisfying model allows for more design flexibility and allows a designer to maintain design freedom. As a result of following this experimental procedure, this infrastructure is an open system that it is robust to changes in both corporate needs and computer technologies. The development of this infrastructure leads to a number of significant intellectual contributions: 1) A new approach to implementing IPPD with the aid of a computer; 2) A formal Design Experiment; 3) A combined Process and Specification architecture that is language-based; 4) An infrastructure for exploring design; 5) An integration strategy for implementing computer resources; and 6) A seamless modeling language. The need for these contributions is emphasized by the demand by industry and government agencies for the development of these technologies.

Hale, Mark A.↗

Understanding the International Space Station Crew Perspective following Long-Duration Missions through Data Analytics & Visualization of Crew Feedback

The International Space Station (ISS) first became a home and research laboratory for NASA and International Partner crewmembers over 16 years ago. Each ISS mission lasts approximately 6 months and consists of three to six crewmembers. After returning to Earth, most crewmembers participate in an extensive series of 30+ debriefs intended to further understand life onboard ISS and allow crews to reflect on their experiences. Examples of debrief data collected include ISS crew feedback about sleep, dining, payload science, scheduling and time planning, health & safety, and maintenance. The Flight Crew Integration (FCI) Operational Habitability (OpsHab) team, based at Johnson Space Center (JSC), is a small group of Human Factors engineers and one stenographer that has worked collaboratively with the NASA Astronaut office and ISS Program to collect, maintain, disseminate and analyze this data. The database provides an exceptional and unique resource for understanding the "crew perspective" on long duration space missions. Data is formatted and categorized to allow for ease of search, reporting, and ultimately trending, in order to understand lessons learned, recurring issues and efficiencies gained over time. Recently, the FCI OpsHab team began collaborating with the NASA JSC Knowledge Management team to provide analytical analysis and visualization of these over 75,000 crew comments in order to better ascertain the crew's perspective on long duration spaceflight and gain insight on changes over time. In this initial phase of study, a text mining framework was used to cluster similar comments and develop measures of similarity useful for identifying relevant topics affecting crew health or performance, locating similar comments when a particular issue or item of operational interest is identified, and providing search capabilities to identify information pertinent to future spaceflight systems and processes for things like procedure development and training. In addition, the comments were scored for sentiment using a polarity scoring algorithm to identify both positive and negative comments for particular groups and clusters, allowing the team to make analytically informed decisions regarding future hardware and operating procedures. The use of polarity scoring with time series analysis was used to provide insight into how crew health and habitability is changing throughout various spaceflight increments or the station lifecycle as a whole. Finally, a visualization framework was developed to address the needs of the end users to search for and analyze comments by user, category or mission. This paper will discuss how the use of an analytical framework in conjunction with the current human interface, improved the understanding of crew perspective and shortened the time for analysis allowing for more informed decisions and rapid development of improvements. These methods are significantly optimizing the way that this valuable data can be assessed and applied to current and future spaceflight design and development. This collaboration allows the FCI OpsHab team to effectively analyze and share data in a more automated and timely fashion. Trends are no longer derived manually and can be illustrated effectively and accurately with these evolving techniques to an ever growing group of human spaceflight end users.

Bryant, Cody↗

Calibration and Validation of a Finite ELement Model of THor-K Anthropomorphic Test Device for Aerospace Safety Applications

The THOR anthropomorphic test device (ATD) has been developed and continuously improved by the National Highway Traffic Safety Administration to provide automotive manufacturers an advanced tool that can be used to assess the injury risk of vehicle occupants in crash tests. Recently, a series of modifications were completed to improve the biofidelity of THOR ATD [1]. The updated THOR Modification Kit (THOR-K) ATD was employed at Wright-Patterson Air Base in 22 impact tests in three configurations: vertical, lateral, and spinal [2]. Although a computational finite element (FE) model of the THOR had been previously developed [3], updates to the model were needed to incorporate the recent changes in the modification kit. The main goal of this study was to develop and validate a FE model of the THOR-K ATD. The CAD drawings of the THOR-K ATD were reviewed and FE models were developed for the updated parts. For example, the head-skin geometry was found to change significantly, so its model was re-meshed (Fig. 1a). A protocol was developed to calibrate each component identified as key to the kinematic and kinetic response of the THOR-K head/neck ATD FE model (Fig. 1b). The available ATD tests were divided in two groups: a) calibration tests where the unknown material parameters of deformable parts (e.g., head skin, pelvis foam) were optimized to match the data and b) validation tests where the model response was only compared with test data by calculating their score using CORrelation and Analysis (CORA) rating system. Finally, the whole ATD model was validated under horizontal-, vertical-, and lateral-loading conditions against data recorded in the Wright Patterson tests [2]. Overall, the final THOR-K ATD model developed in this study is shown to respond similarly to the ATD in all validation tests. This good performance indicates that the optimization performed during calibration by using the CORA score as objective function is not test specific. Therefore confidence is provided in the ATD model for uses in predicting response in test conditions not performed in this study such those observed in the spacecraft landing. Comparison studies with ATD and human models may also be performed to contribute to future changes in THOR ATD design in an effort to improve its biofidelity, which has been traditionally based on post-mortem human subject testing and designer experience.

Putnam, J. B.↗

Design and Testing of an Automated System using Thermochromatic Liquid Crystals to Determine Local Heat Transfer Coefficients for an Impinging Jet

Using thermochromatic liquid crystal to measure surface temperature, an automated transient method with time-varying free-stream temperature is developed to determine local heat transfer coefficients. By allowing the free-stream temperature to vary with time, the need for complicated mechanical components to achieve a step temperature change is eliminated, and by using the thermochromatic liquid crystals as temperature indicators, the labor intensive task of installing many thermocouples is omitted. Bias associated with human perception of the transition of the thermochromatic liquid crystal is eliminated by using a high speed digital camera and a computer. The method is validated by comparisons with results obtained by the steady-state method for a circular Jet impinging on a flat plate. Several factors affecting the accuracy of the method are evaluated.

Tan, Benjamin↗

Effect of Microgravity on Mammalian Lymphocytes

The effect of microgravity on mammalian system is an important and interesting topic for scientific investigation, since NASA s objective is to send manned flights to planets like Mars and eventual human colonization. The Astronauts will be exposed to microgravity environment for a long duration of time during these flights. Our objective of research is to conduct in vitro studies for the effect of microgravity on mammalian immune system and nervous system. We did our preliminary investigations by exposing mammalian lymphocytes and astrocyte cells to a microgravity simulator cell bioreactor designed by NASA and manufactured at Synthecon, Inc. (USA).Our initial results showed no significant change in cytokine expression in these cells up to a time period of 120 hours exposure. Our future experiments will involve exposure for a longer period of time.

Banerjee, H.↗

Microbiological Characterization and Concerns of the International Space Station Internal Active Thermal Control System

Since January 1999, the chemical the International Space Station Thermal Control System (IATCS) and microbial state of (ISS) Internal Active fluid has been monitored by analysis of samples returned to Earth. Key chemical parameters have changed over time, including a drop in pH from the specified 9.5 +/- 0.5 ta = 58.4, an increase in the level of total inorganic carbon (TIC), total organic carbon (TOC) and dissolved nickel (Ni) in the fluid, and a decrease in the phosphate (PO,) level. In addition, silver (AS) ion levels in the fluid decreased rapidly as Ag deposited on internal metallic surfaces of the system. The lack of available Ag ions coupled with changes in the fluid chemistry has resulted in a favorable environment for microbial growth. Counts of heterotrophic bacteria have increased from less than 10 colony-forming units (CFUs)/l00 mL to l0(exp 6) to l0(exp 7) CFUs/100 mL. The increase of the microbial population is of concern because uncontrolled microbiological growth in the IATCS can contribute to deterioration in the performance of critical components within the system and potentially impact human health if opportunistic pathogens become established and escape into the cabin atmosphere. Micro-organisms can potentially degrade the coolant chemistry; attach to surfaces and form biofilms; lead to biofouling of filters, tubing, and pumps; decrease flow rates; reduce heat transfer; initiate and accelerate corrosion; and enhance mineral scale formation. The micro- biological data from the ISS IATCS fluid, and approaches to addressing the concerns, are summarized in this paper.

Roman, Monsi C.↗

BioSentinel: Optimizing Growth Conditions for Improved Yeast Cell Viability After Long-Term Desiccation

NASA's BioSentinel mission is one of thirteen secondary payloads to be deployed on the Space Launch System Exploration Mission-1 (SLS EM-1). The BioSentinel nanosatellite will be sent into a heliocentric orbit beyond Low Earth Orbit (LEO), to study the effects of deep space radiation on the budding yeast, Saccharomyces cerevisiae. Ionizing radiation encountered in deep space can create damaging lesions in DNA, including double strand breaks (DSBs). Budding yeast is suitable as a biological model to study these effects, as it is eukaryotic, and can be desiccated for prolonged periods while retaining viability, thus serving as a robust analog for human cells. On the ground, yeast cells are grown in liquid medium, then loaded into the wells of microfluidic cards and air dried prior to integration into the payload. Once the spacecraft reaches its target heliocentric orbit, a mixture of growth medium and metabolic indicator dye will be pumped into the microwells at specific time points to rehydrate the cells and allow them to grow. A 3-color LED detection system will measure changes in growth and metabolism resulting from ionizing radiation exposure. BioSentinel contains a wild type control strain and a rad51 mutant that is defective for DNA damage repair. In this study, we will determine the optimal amount of time to grow diploid yeast cells in liquid culture before they are desiccated for space flight. After an extended time in stationary phase, they become more tolerant to desiccation due to stress caused by nitrogen starvation. However, excessive exposure can lead to loss of viability and to a heterogeneous cell population due to sporulation. Since viability loss during desiccation poses a risk to mission success, a stress preconditioning process during initial growth may increase long-term cell viability. To determine the growth period that improves desiccation tolerance but allows for retention of uniform radiation sensitivity, we will grow both strains in liquid medium for a varying number of days (4 to 7), desiccate the cells, and then observe changes to cell viability and ionizing radiation sensitivity over time. Supported by the Space Life Sciences Training Program at NASA Ames Research Center.

Cui, Kaixin↗

Developing High-Throughput Organ-On-A-Chip Models to Investigate the Effects of Ionizing Radiation on the Central Nervous System

One of the main health risks in human space exploration is central nervous system (CNS) damage by ionizing radiation. Irradiation with simulated GCRs or their components, or high doses of low-LET radiation such as gamma rays, in animal models has been shown to cause neuronal damage together with glial cell activation and neuroinflammation and has been associated with prolonged cognitive and behavioral dysfunction. The extent of CNS damage in response to any insult, including ionizing radiation, is partially regulated by the blood-brain barrier (BBB), which enables immune cells to enter the CNS. The main cellular regulators of BBB permeability are astrocytes, which also modulate neuronal death, immune responses and oxidative stress, and thus could serve as a robust CNS-specific target for countermeasure development. However, studies on BBB permeability and astrocyte functions in regulating CNS responses to ionizing radiation have been limited, especially in human tissue/organ analogs. Therefore, we have established a high throughput 3D organ-on-a-chip system to study human CNS functions in response to ionizing radiation, with the eventual goal of adapting it to spaceflight missions. We utilized commercially available OrganoPlate system (Mimetas, Inc.) seeded with primary or induced pluripotent stem cell-derived human cells for developing 3D neuronal-astrocytic and BBB models. We investigated both immediate and delayed CNS dose responses to 0.5-1 Gy X-rays by measuring BBB permeability and morphology, and astrocyte activation. We have also quantified secreted markers of oxidative stress and cell viability. In the future, we are planning to monitor dendritic, axonal and synaptic changes in neurons, evaluate the combined exposures to simulated microgravity and ionizing radiation, and compare the responses to low and high-LET ionizing radiation. We anticipate these studies could indicate novel cellular and mechanistic targets for countermeasure developments to improve CNS functions in astronauts.

Malkani, Sherina↗

Human Response to Simulated Low-Intensity Sonic Booms

NASA's High Speed Research (HSR ) program in the 1990s was intended to develop a technology base for a future High-Speed Civil Transport (HSCT). As part of this program, the NASA Langley Research Center sonic boom simulator (SBS) was built and used for a series of tests on subjective response to sonic booms. At the end of the HSR program, an HSCT was deemed impractical, but since then interest in supersonic flight has reawakened, this time focusing on a smaller aircraft suitable for a business jet. To respond to this interest, the Langley sonic boom simulator has been refurbished. The upgraded computer-controlled playback system is based on an SGI O2 computer, in place of the previous DEC MicroVAX. As the frequency response of the booth is not flat, an equalization filter is required. Because of the changes made during the renovation (new loudspeakers), the previous equalization filter no longer performed as well as before, so a new equalization filter has been designed. Booms to be presented in the booth are preprocessed using the filter. When the preprocessed signals are presented into the booth and measured with a microphone, the results are very similar to the intended shapes. Signals with short rise times and sharp "corners" are observed to have a small amount of "ringing" in the response. During the HSR program a considerable number of subjective tests were completed in the SBS. A summary of that research is given in Leatherwood et al. (Individual reports are available at http://techreports.larc.nasa.gov/ltrs/ltrs.html.) Topics of study included shaped sonic booms, asymmetrical booms, realistic (recorded) boom waveforms, indoor and outdoor booms shapes, among other factors. One conclusion of that research was that a loudness metric, like the Stevens Perceived Level (PL), predicted human reaction much more accurately than overpressure or unweighted sound pressure level. Structural vibration and rattle were not included in these studies.

Sullivan, Brenda M.↗

Space Resources and Mining: Current Objectives, Plans, and Missions

Why are Space Resources and Their Use Important? There are many reasons why people and nations want to explore space, and there are many different ways in which space can be explored. A critical interface linking both the ‘why’ and the ‘how’ of space exploration is the identification, extraction, and use of resources in space. In both NASA’s Journey to Mars: Pioneering Next Steps in Space Exploration released in October of 2015 and the Global Exploration Roadmap released in August 2013, the ability to find, quantify, extract, process, and use space resources was identified as a critical objective by NASA and over 14 other space agencies for achieving affordable and sustainable human exploration beyond Earth’s orbit, encouraging and creating new commercial entities and markets based on space activities, and increasing the terrestrial economy and quality-of-life benefits for all humankind. Robotic and especially human space exploration up to this point in time can be considered to be ‘Earth reliant’ in that everything needed to support and enable the mission is launched from Earth. The past Apollo missions to the Moon and the International Space Station currently in orbit above the Earth all rely on hardware, habitats, power, transportation, and life support consumables sent from Earth to keep the crew alive and working. As the distance from Earth increases, the cost of transportation and the risks due to failures and logistics disruptions also increases. By using resources found at the site of exploration to make mission critical consumables (such as propellants, fuel cell reactants and life support commodities), spare parts, and infrastructure needed to support surface activities (such as landing pads, roads, habitats/shelters, and power/thermal systems) commonly referred to as In Situ Resource Utilization, a significant amount of launch mass and cost can be saved and risk reduced. The ability to do these things also changes how exploration is performed from Earth Reliant to NASA’s goal of ‘Earth Independent’ exploration. After the US Apollo program was over, people began to recognize that it had been an inspiration for a generation of young students to go into Science, Technology, Engineering and Math (STEM) fields, and that the US industry and economy had significantly grown and lived off these students and the technological advances made to achieve these missions for decades. Space exploration should no longer be focused solely on scientific advancement or national pride, but for economic growth and population standard of living advancement. Considering the economic value of human exploration and how it could expand the economy of the US was brought to full light in a speech by John Marburger, the director of US Office of Science and Technology Policy under George W Bush at the Goddard Symposium in 2006. In his speech he highlighted that the ultimate goal was not to just Explore space but to Use space for the benefit of mankind. He further stated that the use of off-planet resources, in this case from the Moon, should be a critical architectural consideration for human space exploration to make it more affordable and sustainable. This could be achieved in two ways. The first is to start by encouraging and commercializing the extraction and production of transportation and life support related products from space resources, which could than lead to other resource uses once an affordable transportation architecture is established. The second is to encourage the spin-in of terrestrial technologies into space applications and spin-off of space technologies into terrestrial applications to increase the efficiency and profitability of terrestrial industries.

Sanders, Gerald B.↗

On-orbit spacecraft servicing: An element in the evolution of space robotics applications

This paper addresses the renewed interest in on-orbit spacecraft servicing (OSS), and how it fits into the evolution of space applications for intelligent robots. Investment in the development of space robotics and associated technologies is growing as nations recognize that it is a critical component of the exploration and commercial development of space. At the same time, changes in world conditions have generated a renewal of the interest in OSS. This is reflected in the level of activity in the U.S., Japan and Europe in the form of studies and technology demonstration programs. OSS is becoming widely accepted as an opportunity in the evolution of space robotics applications. Importantly, it is a feasible proposition with current technologies and the direction of ongoing research and development activities. Interest in OSS dates back more than two decades, and several programs have been initiated, but no operational system has come on line, arguably with the Shuttle as the exception. With new opportunities arising, however, a fresh look at the feasibility of OSS is warranted. This involves the resolution of complex market, technical and political issues, through market studies, economic analyses, mission requirement definitions, trade studies, concept designs and technology demonstrations. System architectures for OSS are strongly dependent on target spacecraft design and launch delivery systems. Performance and cost factors are currently forcing significant changes in these areas. This presents both challenges and opportunities in the provision of OSS services. In conclusion, there is no question OSS will become a reality, but only when the technical feasibility is combined with either economic viability or political will. In the evolution of space robotics satellite servicing can become the next step towards its eventual role in support of planetary exploration and human beings' journey out into the universe.

Anders, Carl J.↗

Intent Specifications

We have been investigating the implications of using abstractions based on intent rather than the aggregation and information-hiding abstractions commonly used in software en- gineering: Cognitive psychologists have shown that intent abstraction is consistent with human problem-solving processes. We believe that new types of specifications and designs based on this concept can assist in understanding and specifying requirements, capturing the most important design rationale information in an efficient and economical way, and supporting the process of identifying and analyzing required changes to minimize the introduction of errors. The goal of hierarchical abstraction is to allow both top-down and bottom-up reasoning about a complex system. In computer science, we have made much use of (1) part-whole abstractions where each level of a hierarchy represents an aggregation of the components at a lower level and of (2) information-hiding abstractions where each level contains the same conceptual information but hides some details about the concepts, that is, each level is a refinement of the information at a higher level.

Leveson, Nancy G.↗

Earth: Earth Science and Health

A major new NASA initiative on environmental change and health has been established to promote the application of Earth science remote sensing data, information, observations, and technologies to issues of human health. NASA's Earth Sciences suite of Earth observing instruments are now providing improved observations science, data, and advanced technologies about the Earth's land, atmosphere, and oceans. These new space-based resources are being combined with other agency and university resources, data integration and fusion technologies, geographic information systems (GIS), and the spectrum of tools available from the public health community, making it possible to better understand how the environment and climate are linked to specific diseases, to improve outbreak prediction, and to minimize disease risk. This presentation is an overview of NASA's tools, capabilities, and research advances in this initiative.

Maynard, Nancy G.↗