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At least 127 records · Page 7

The SCRAM tool-kit

This paper proposes a new series of on-orbit capabilities to support the near-term Hubble Space Telescope, Extended Duration Orbiter, Long Duration Orbiter, Space Station Freedom, other orbital platforms, and even the future manned Lunar/Mars missions. These proposed capabilities form a toolkit termed Space Construction, Repair, and Maintenance (SCRAM). SCRAM addresses both intra-Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) needs. SCRAM provides a variety of tools which enable welding, brazing, cutting, coating, heating, and cleaning, as well as corresponding nondestructive examination. Near-term IVA-SCRAM applications include repair and modification to fluid lines, structure, and laboratory equipment inside a shirt-sleeve environment (i.e. inside Spacelab or Space Station). Near-term EVA-SCRAM applications include construction of fluid lines and structural members, repair of punctures by orbital debris, refurbishment of surfaces eroded by contaminants. The SCRAM tool-kit also promises future EVA applications involving mass production tasks automated by robotics and artificial intelligence, for construction of large truss, aerobrake, and nuclear reactor shadow shields structures. The leading candidate tool processes for SCRAM, currently undergoing research and development, include Electron Beam, Gas Tungsten Arc, Plasma Arc, and Laser Beam. A series of strategic space flight experiments would make SCRAM available to help conquer the space frontier.

Tamir, David↗

BATSE imaging survey of the Galactic plane

The burst and transient source experiment (BATSE) onboard the Compton Gamma Ray Observatory (CGRO) provides all sky monitoring capability, occultation analysis and occultation imaging which enables new and fainter sources to be searched for in relatively crowded fields. The occultation imaging technique is used in combination with an automated BATSE image scanner, allowing an analysis of large data sets of occultation images for detections of candidate sources and for the construction of source catalogs and data bases. This automated image scanner system is being tested on archival data in order to optimize the search and detection thresholds. The image search system, its calibration results and preliminary survey results on archival data are reported on. The aim of the survey is to identify a complete sample of black hole candidates in the galaxy and constrain the number of black hole systems and neutron star systems.

Grindlay, J. E.↗

Carbon rod furnace infrared source

A carbon rod furnace infrared source has been built and has proven to be a reliable and trouble-free source despite the high rod temperature of 2500 K. The furnace offers several advantages over previous furnaces. These include an increase in usable rod length to 6.35 cm, extended rod life, and a fully automated power supply for the furnace. Construction and operational details are discussed.

Boyd, W. J.↗

Marking parts to aid robot vision

The premarking of parts for subsequent identification by a robot vision system appears to be beneficial as an aid in the automation of certain tasks such as construction in space. A simple, color coded marking system is presented which allows a computer vision system to locate an object, calculate its orientation, and determine its identity. Such a system has the potential to operate accurately, and because the computer shape analysis problem has been simplified, it has the ability to operate in real time.

Bales, J. W.↗

Overcoming limitations of model-based diagnostic reasoning systems

The development of a model-based diagnostic system to overcome the limitations of model-based reasoning systems is discussed. It is noted that model-based reasoning techniques can be used to analyze the failure behavior and diagnosability of system and circuit designs as part of the system process itself. One goal of current research is the development of a diagnostic algorithm which can reason efficiently about large numbers of diagnostic suspects and can handle both combinational and sequential circuits. A second goal is to address the model-creation problem by developing an approach for using design models to construct the GMODS model in an automated fashion.

Holtzblatt, Lester J.↗

Vision-guided gripping of a cylinder

The motivation for vision-guided servoing is taken from tasks in automated or telerobotic space assembly and construction. Vision-guided servoing requires the ability to perform rapid pose estimates and provide predictive feature tracking. Monocular information from a gripper-mounted camera is used to servo the gripper to grasp a cylinder. The procedure is divided into recognition and servo phases. The recognition stage verifies the presence of a cylinder in the camera field of view. Then an initial pose estimate is computed and uncluttered scan regions are selected. The servo phase processes only the selected scan regions of the image. Given the knowledge, from the recognition phase, that there is a cylinder in the image and knowing the radius of the cylinder, 4 of the 6 pose parameters can be estimated with minimal computation. The relative motion of the cylinder is obtained by using the current pose and prior pose estimates. The motion information is then used to generate a predictive feature-based trajectory for the path of the gripper.

Nicewarner, Keith E.↗

Assessment and Management of the Risks of Debris Hits During Space Station EVAs

The risk of EVAs is critical to the decision of whether or not to automate a large part of the construction of the International Space Station (ISS). Furthermore, the choice of the technologies of the space suit and the life support system will determine (1) the immediate safety of these operations, and (2) the long-run costs and risks of human presence in space, not only in lower orbit (as is the case of the ISS) but also perhaps, outside these orbits, or on the surface of other planets. The problem is therefore both an immediate one and a long-term one. The fundamental question is how and when to shift from the existing EMU system (suit, helmet, gloves and life support system) to another type (e.g. a hard suit), given the potential trade-offs among life-cycle costs, risks to the astronauts, performance of tasks, and uncertainties about new systems' safety inherent to such a shift in technology. A more immediate issue is how to manage the risks of EVAs during the construction and operation of the ISS in order to make the astronauts (in the words of the NASA Administrator) "as safe outside as inside". For the moment (June 1997), the plan is to construct the Space Station using the low-pressure space suits that have been developed for the space shuttle. In the following, we will refer to this suit assembly as EMU (External Maneuvering Unit). It is the product of a long evolution, starting from the U.S. Air Force pilot suits through the various versions and changes that occurred for the purpose of NASA space exploration, in particular during the Gemini and the Apollo programs. The Shuttle EMU is composed of both soft fabrics and hard plates. As an alternative to the shuttle suit, at least two hard suits were developed by NASA: the AX5 and the MRKIII. The problem of producing hard suits for space exploration is very similar to that of producing deep-sea diving suits. There was thus an opportunity to develop a suit that could be manufactured for both purposes with the economies of scale that could be gained from a two-branch manufacturing line (space and deep sea). Of course, the space suit would need to be space qualified. Some of the problems in adopting one of the hard suits were first that the testing had to be completed, and second that it required additional storage space. The decision was made not to develop a hard suit in time for the construction and operation of the ISS. Instead, to improve the safety of the current suit, it was decided to reinforce the soft parts of the shuttle EMU with KEVLAR linings to strengthen it against debris impacts. Test results, however, show that this advanced suit design has little effect on the penetration characteristics.

Pate-Cornell, Elisabeth↗

Mars Data Visualization and E/PO with Marsoweb

Marsoweb is a collaborative web environment that has been developed for the Mars research community to better visualize and analyze Mars orbiter data. Its goal is to enable online data discovery by providing an intuitive, interactive interface to data from the Mars Global Surveyor and other orbiters. Recently Marsoweb has served a prominent role as a resource center for the site selection process for the Mars Explorer Rover 2003 missions. In addition to hosting a repository of landing site memoranda and workshop talks, it includes a Java-based interface to a variety of datamaps and images. This interface enables the display and numerical querying of data, and allows data profiles to be rendered from user-drawn cross-sections. High-resolution Mars Orbiter Camera (MOC) images (currently, over 100,000) can be graphically perused; browser-based image processing tools can be used on MOC images of potential landing sites. An automated VRML atlas allows users to construct 'flyovers' of their own regions-of-interest in 3D. These capabilities enable Marsoweb to be used for general global data studies, in addition to those specific to landing site selection. As of September 2002, over 70,000 distinct users from NASA, USGS, academia, and the general public have accessed Marsoweb.

Gulick, V. C.↗

Using Automated Scheduling for Mission Design: A Case Study for EMIT

The Earth Surface Mineral Dust Source InvesTigation (EMIT) is an Earth Ventures-Instrument (EVI-4) mission to map the surface mineralogy of arid dust source regions. EMIT used automated scheduling technology to analyze aspects of the mission design. The automated scheduling technology was used to construct schedules which were then automatically analyzed with respect to science acquired. These analyses can be performed for a range of spacecraft hardware configurations, observation strategies, and science requirements. By studying the effects of changes on the above inputs, better hardware configurations, observation strategies, and science requirements can be formulated. The use of a pointing mirror on EMIT was under consideration, and this analysis aided in determining whether or not to keep it as part of the design of the instrument. Clouds will also have a large impact on the coverage of science targets achievable by the mission. Analysis was done on how clouds could impact the coverage achievable as well as the data volume. This analysis with clouds also aided in determining the coverage criteria for the mission. It was necessary to find a criteria that was achievable with some margin as well as satisfies the science goals of the mission.

Thompson, David R.↗

Automated Verification of Specifications with Typestates and Access Permissions

We propose an approach to formally verify Plural specifications based on access permissions and typestates, by model-checking automatically generated abstract state-machines. Our exhaustive approach captures all the possible behaviors of abstract concurrent programs implementing the specification. We describe the formal methodology employed by our technique and provide an example as proof of concept for the state-machine construction rules. The implementation of a fully automated algorithm to generate and verify models, currently underway, provides model checking support for the Plural tool, which currently supports only program verification via data flow analysis (DFA).

Siminiceanu, Radu I.↗

An Automated Optical Fiber Puller for Use in Low-Earth Orbit

With the slowdown in space station construction, limiting astronaut time for scientific experiments, an effort is being made to automate certain experiments. One such experiment is production of heavy metal fluoride fibers in the microgravity environment. Previous work by this author and others have shown that microgravity inhibits crystallization of ZBLAN glass. Thus an automated experiment has been designed. This experiment will consist of several elements, one which includes the use of an autonomous robot to initiate fiber pulling. The first element will be to melt the preform to eliminate crystals. The preform tip will then be heated to the viscosity necessary for fiber drawing. The robot will initiate the draw and attach the fiber end to the take-up reel. Once fiber pulling has commenced, sensors will be used to detect a fiber break, whereupon the robot can re-initiate the pulling process. The fiber will be coated with a polymer and the polymer cured with ultraviolet light. A laser micrometer will be used to monitor fiber diameter. The experiment is designed so that up to 10 preforms can be pulled into fiber during one flight. The apparatus will be mounted on a free-flying carrier which will be placed into low-earth orbit from the cargo bay of the space shuttle by the shuttle robot arm. The experiment can be started by a signal from the shuttle or from the ground via telescience. The experiment will proceed automatically using specially designed algorithms and will be monitored from the ground. The carrier will be picked up by the shuttle before return to earth.

Tucker, Dennis S.↗

Automatic Command Sequence Generation

Automatic Sequence Generator (Autogen) Version 3.0 software automatically generates command sequences for the Mars Reconnaissance Orbiter (MRO) and several other JPL spacecraft operated by the multi-mission support team. Autogen uses standard JPL sequencing tools like APGEN, ASP, SEQGEN, and the DOM database to automate the generation of uplink command products, Spacecraft Command Message Format (SCMF) files, and the corresponding ground command products, DSN Keywords Files (DKF). Autogen supports all the major multi-mission mission phases including the cruise, aerobraking, mapping/science, and relay mission phases. Autogen is a Perl script, which functions within the mission operations UNIX environment. It consists of two parts: a set of model files and the autogen Perl script. Autogen encodes the behaviors of the system into a model and encodes algorithms for context sensitive customizations of the modeled behaviors. The model includes knowledge of different mission phases and how the resultant command products must differ for these phases. The executable software portion of Autogen, automates the setup and use of APGEN for constructing a spacecraft activity sequence file (SASF). The setup includes file retrieval through the DOM (Distributed Object Manager), an object database used to store project files. This step retrieves all the needed input files for generating the command products. Depending on the mission phase, Autogen also uses the ASP (Automated Sequence Processor) and SEQGEN to generate the command product sent to the spacecraft. Autogen also provides the means for customizing sequences through the use of configuration files. By automating the majority of the sequencing generation process, Autogen eliminates many sequence generation errors commonly introduced by manually constructing spacecraft command sequences. Through the layering of commands into the sequence by a series of scheduling algorithms, users are able to rapidly and reliably construct the desired uplink command products. With the aid of Autogen, sequences may be produced in a matter of hours instead of weeks, with a significant reduction in the number of people on the sequence team. As a result, the uplink product generation process is significantly streamlined and mission risk is significantly reduced. Autogen is used for operations of MRO, Mars Global Surveyor (MGS), Mars Exploration Rover (MER), Mars Odyssey, and will be used for operations of Phoenix. Autogen Version 3.0 is the operational version of Autogen including the MRO adaptation for the cruise mission phase, and was also used for development of the aerobraking and mapping mission phases for MRO.

Fisher, Forest↗

An operational system for subject switching between controlled vocabularies: A computational linguistics approach

The NASA Lexical Dictionary (NLD), a system that automatically translates input subject terms to those of NASA, was developed in four phases. Phase One provided Phrase Matching, a context sensitive word-matching process that matches input phrase words with any NASA Thesaurus posting (i.e., index) term or Use reference. Other Use references have been added to enable the matching of synonyms, variant spellings, and some words with the same root. Phase Two provided the capability of translating any individual DTIC term to one or more NASA terms having the same meaning. Phase Three provided NASA terms having equivalent concepts for two or more DTIC terms, i.e., coordinations of DTIC terms. Phase Four was concerned with indexer feedback and maintenance. Although the original NLD construction involved much manual data entry, ways were found to automate nearly all but the intellectual decision-making processes. In addition to finding improved ways to construct a lexical dictionary, applications for the NLD have been found and are being developed.

Silvester, J. P.↗

Designing a Flight Test of a Flight Path Management System for Advanced Air Mobility Research

The National Aeronautics and Space Administration (NASA) has completed a flight test to evaluate the performance of an onboard prototype automation system operating in future high density urban airspace. The test was part of a research investigation of the Urban Air Mobility (UAM) concept, with a focus on a future environment having hundreds of simultaneous operations over a metropolitan area. The complexity of this future UAM airspace may require automation capable of replanning an aircraft’s path in the presence of traffic and other changing constraints. A live-virtual-constructive (LVC) approach was used to conduct the test. Prototype automation technology was integrated into one of the two live aircraft, which were combined with virtual traffic to create a mixed reality environment at the target airspace density. In-flight evaluation enabled verification of the automation’s functions and discovery of any unexpected behaviors resulting from its operation in an actual flight environment. The in-flight evaluation also provided data for validation of air traffic simulations. This paper discusses the design, methodology, and challenges overcome to conduct a successful flight test. Remaining challenges, future work, and recommendations to improve the flight test capability are also discussed.

Advanced Air Mobility↗

Geometry Modeling for Unstructured Mesh Adaptation

The quantification and control of discretization error is critical to obtaining reliable simulation results. Adaptive mesh techniques have the potential to automate discretization error control, but have made limited impact on production analysis workflow. Recent progress has matured a number of independent implementations of flow solvers, error estimation methods, and anisotropic mesh adaptation mechanics. However, the poor integration of initial mesh generation and adaptive mesh mechanics to typical sources of geometry has hindered adoption of adaptive mesh techniques, where these geometries are often created in Mechanical Computer- Aided Design (MCAD) systems. The difficulty of this coupling is compounded by two factors: the inherent complexity of the model (e.g., large range of scales, bodies in proximity, details not required for analysis) and unintended geometry construction artifacts (e.g., translation, uneven parameterization, degeneracy, self-intersection, sliver faces, gaps, large tolerances be- tween topological elements, local high curvature to enforce continuity). Manual preparation of geometry is commonly employed to enable fixed-grid and adaptive-grid workflows by reducing the severity and negative impacts of these construction artifacts, but manual process interaction inhibits workflow automation. Techniques to permit the use of complex geometry models and reduce the impact of geometry construction artifacts on unstructured grid workflows are models from the AIAA Sonic Boom and High Lift Prediction are shown to demonstrate the utility of the current approach.

Park, Michael A.↗

A learning apprentice for software parts composition

An overview of the knowledge acquisition component of the Bauhaus, a prototype computer aided software engineering (CASE) workstation for the development of domain-specific automatic programming systems (D-SAPS) is given. D-SAPS use domain knowledge in the refinement of a description of an application program into a compilable implementation. The approach to the construction of D-SAPS was to automate the process of refining a description of a program, expressed in an object-oriented domain language, into a configuration of software parts that implement the behavior of the domain objects.

Allen, Bradley P.↗

Knowledge-based vision for space station object motion detection, recognition, and tracking

Computer vision, especially color image analysis and understanding, has much to offer in the area of the automation of Space Station tasks such as construction, satellite servicing, rendezvous and proximity operations, inspection, experiment monitoring, data management and training. Knowledge-based techniques improve the performance of vision algorithms for unstructured environments because of their ability to deal with imprecise a priori information or inaccurately estimated feature data and still produce useful results. Conventional techniques using statistical and purely model-based approaches lack flexibility in dealing with the variabilities anticipated in the unstructured viewing environment of space. Algorithms developed under NASA sponsorship for Space Station applications to demonstrate the value of a hypothesized architecture for a Video Image Processor (VIP) are presented. Approaches to the enhancement of the performance of these algorithms with knowledge-based techniques and the potential for deployment of highly-parallel multi-processor systems for these algorithms are discussed.

Symosek, P.↗