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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

The PASCAL-HDM Verification System

The PASCAL-HDM verification system is described. This system supports the mechanical generation of verification conditions from PASCAL programs and HDM-SPECIAL specifications using the Floyd-Hoare axiomatic method. Tools are provided to parse programs and specifications, check their static semantics, generate verification conditions from Hoare rules, and translate the verification conditions appropriately for proof using the Shostak Theorem Prover, are explained. The differences between standard PASCAL and the language handled by this system are explained. This consists mostly of restrictions to the standard language definition, the only extensions or modifications being the addition of specifications to the code and the change requiring the references to a function of no arguments to have empty parentheses.

Source record↗
NASA NTRS1983

HDM/PASCAL Verification System User's Manual

The HDM/Pascal verification system is a tool for proving the correctness of programs written in PASCAL and specified in the Hierarchical Development Methodology (HDM). This document assumes an understanding of PASCAL, HDM, program verification, and the STP system. The steps toward verification which this tool provides are parsing programs and specifications, checking the static semantics, and generating verification conditions. Some support functions are provided such as maintaining a data base, status management, and editing. The system runs under the TOPS-20 and TENEX operating systems and is written in INTERLISP. However, no knowledge is assumed of these operating systems or of INTERLISP. The system requires three executable files, HDMVCG, PARSE, and STP. Optionally, the editor EMACS should be on the system in order for the editor to work. The file HDMVCG is invoked to run the system. The files PARSE and STP are used as lower forks to perform the functions of parsing and proving.

Hare, D.↗
NASA NTRS1993

Reactive system verification case study: Fault-tolerant transputer communication

A reactive program is one which engages in an ongoing interaction with its environment. A system which is controlled by an embedded reactive program is called a reactive system. Examples of reactive systems are aircraft flight management systems, bank automatic teller machine (ATM) networks, airline reservation systems, and computer operating systems. Reactive systems are often naturally modeled (for logical design purposes) as a composition of autonomous processes which progress concurrently and which communicate to share information and/or to coordinate activities. Formal (i.e., mathematical) frameworks for system verification are tools used to increase the users' confidence that a system design satisfies its specification. A framework for reactive system verification includes formal languages for system modeling and for behavior specification and decision procedures and/or proof-systems for verifying that the system model satisfies the system specifications. Using the Ostroff framework for reactive system verification, an approach to achieving fault-tolerant communication between transputers was shown to be effective. The key components of the design, the decoupler processes, may be viewed as discrete-event-controllers introduced to constrain system behavior such that system specifications are satisfied. The Ostroff framework was also effective. The expressiveness of the modeling language permitted construction of a faithful model of the transputer network. The relevant specifications were readily expressed in the specification language. The set of decision procedures provided was adequate to verify the specifications of interest. The need for improved support for system behavior visualization is emphasized.

Crane, D. Francis↗
NASA NTRS1986

Ada(R) Test and Verification System (ATVS)

The Ada Test and Verification System (ATVS) functional description and high level design are completed and summarized. The ATVS will provide a comprehensive set of test and verification capabilities specifically addressing the features of the Ada language, support for embedded system development, distributed environments, and advanced user interface capabilities. Its design emphasis was on effective software development environment integration and flexibility to ensure its long-term use in the Ada software development community.

Strelich, Tom↗
NASA NTRS2018

Simulation and Verification System and Method

A simulation and verification system and method. An interoperability server provides a communications hub for communications between communicating nodes. Nodes connected to a first protocol data bus communicate in a first protocol, e.g., a half-duplex bus protocol. Nodes connected to a second protocol data bus communicate in a second protocol, e.g., a full-duplex bus protocol. A time synchronization bus provides time-frames for synchronizing operation of connected nodes. Interceptors optionally intercept communications between nodes.

Seeger, Steven↗
NASA NTRS1977

Documentation requirements for Applications Systems Verification and Transfer projects (ASVTs)

NASA's Application Systems Verification and Transfer Projects (ASVTs) are deliberate efforts to facilitate the transfer of applications of NASA-developed space technology to users such as federal agencies, state and local governments, regional planning groups, public service institutions, and private industry. This study focused on the role of documentation in facilitating technology transfer both to primary users identified during project planning and to others with similar information needs. It was understood that documentation can be used effectively when it is combined with informal (primarily verbal) communication within each user community and with other formal techniques such as organized demonstrations and training programs. Documentation examples from eight ASVT projects and one potential project were examined to give scope to the investigation.

Suchy, J. T.↗
NASA NTRS1973

Design of the software development and verification system (SWDVS) for shuttle NASA study task 35

An overview of the Software Development and Verification System (SWDVS) for the space shuttle is presented. The design considerations, goals, assumptions, and major features of the design are examined. A scenario that shows three persons involved in flight software development using the SWDVS in response to a program change request is developed. The SWDVS is described from the standpoint of different groups of people with different responsibilities in the shuttle program to show the functional requirements that influenced the SWDVS design. The software elements of the SWDVS that satisfy the requirements of the different groups are identified.

Drane, L. W.↗
NASA NTRS1976

A plan for application system verification tests: The value of improved meteorological information, volume 1

The framework within which the Applications Systems Verification Tests (ASVTs) are performed and the economic consequences of improved meteorological information demonstrated is described. This framework considers the impact of improved information on decision processes, the data needs to demonstrate the economic impact of the improved information, the data availability, the methodology for determining and analyzing the collected data and demonstrating the economic impact of the improved information, and the possible methods of data collection. Three ASVTs are considered and program outlines and plans are developed for performing experiments to demonstrate the economic consequences of improved meteorological information. The ASVTs are concerned with the citrus crop in Florida, the cotton crop in Mississippi and a group of diverse crops in Oregon. The program outlines and plans include schedules, manpower estimates and funding requirements.

Source record↗
NASA NTRS2011

Development of Sample Verification System for Sample Return Missions

This paper describes the development of a proof of-concept sample verification system (SVS) for in-situ mass measurement of planetary rock and soil sample in future robotic sample return missions. Our proof-of-concept SVS device contains a 10 cm diameter pressure sensitive elastic membrane placed at the bottom of a sample canister. The membrane deforms under the weight of accumulating planetary sample. The membrane is positioned in proximity to an opposing substrate with a narrow gap. The deformation of the membrane makes the gap to be narrower, resulting in increased capacitance between the two nearly parallel plates. Capacitance readout circuitry on a nearby printed circuit board (PCB) transmits data via a low-voltage differential signaling (LVDS) interface. The fabricated SVS proof-of-concept device has successfully demonstrated approximately 1pF/gram capacitance change

Electrodes↗
NASA NTRSDate not supplied

An Integrated Development Environment for the Prototype Verification System

The steep learning curve of formal technologies is a well-known barrier to the adoption of formal verification tools in industry. This paper presents VSCode-PVS, a modern integrated development environment for the Prototype Verification System (PVS). This new environment integrates the editing and proof management functionalities of PVS in Visual Studio Code, a popular code editor widely used by software developers. VSCode-PVS provides functionalities that developers expect to find in modern verification tools but are not available in the standard Emacs front-end of PVS, such as auto-completion, point-and-click navigation of definitions, live diagnostics for errors, and literate programming. The main features and architecture of the environment are presented, along with a comparison with other similar tools.

Paolo Masci↗
NASA NTRS2015

Damage Detection and Verification System (DDVS) for In-Situ Health Monitoring

Project presentation for Game Changing Program Smart Book Release. Detection and Verification System (DDVS) expands the Flat Surface Damage Detection System (FSDDS) sensory panels damage detection capabilities and includes an autonomous inspection capability utilizing cameras and dynamic computer vision algorithms to verify system health. Objectives of this formulation task are to establish the concept of operations, formulate the system requirements for a potential ISS flight experiment, and develop a preliminary design of an autonomous inspection capability system that will be demonstrated as a proof-of-concept ground based damage detection and inspection system.

Damage detection↗
NASA NTRS1982

WTS-4 system verification unit for wind/hydroelectric integration study

The Bureau of Reclamation (Reclamation) initiated a study to investigate the concept of integrating 100 MW of wind energy from megawatt-size wind turbines with the Federal hydroelectric system. As a part of the study, one large wind turbine was purchased through the competitive bid process and is now being installed to serve as a system verification unit (SVU). Reclamation negotiated an agreement with NASA to provide technical management of the project for the design, fabrication, installation, testing, and initial operation. Hamilton Standard was awarded a contract to furnish and install its WTS-4 wind turbine rated at 4 MW at a site near Medicine Bow, Wyoming. The purposes for installing the SVU are to fully evaluate the wind/hydro integration concept, make technical evaluation of the hardware design, train personnel in the technology, evaluate operation and maintenance aspects, and evaluate associated environmental impacts. The SVU will be operational in June 1982. Data from the WTS-4 and from a second SVU, Boeing's MOD-2, will be used to prepare a final design for a 100-MW farm if Congress authorizes the project.

Watts, A. W.↗
NASA NTRS2010

Crew Exploration Vehicle Potable Water System Verification Description

A stored water system on the crew exploration vehicle (CEV) will supply the crew with potable water for: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain the quality of the water, transferred from the orbiter to the International Space Station, stored in contingency water containers. In the CEV water system, a depletion of the ionic silver biocide is expected due to ionic silver-plating onto the surfaces of materials within the CEV water system, thus negating its effectiveness as a biocide. Because this may be the first time NASA is considering a stored water system for long-term missions that do not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point-of-use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform the testing that will help alleviate concerns related to the CEV water system.

Tuan, George↗
NASA NTRS2009

Crew Exploration Vehicle (CEV) Potable Water System Verification Description

The Crew Exploration Vehicle (CEV), also known as Orion, will ferry a crew of up to six astronauts to the International Space Station (ISS), or a crew of up to four astronauts to the moon. The first launch of CEV is scheduled for approximately 2014. A stored water system on the CEV will supply the crew with potable water for various purposes: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain quality of the water transferred from the Orbiter to the ISS and stored in Contingency Water Containers (CWCs). In the CEV water system, the ionic silver biocide is expected to be depleted from solution due to ionic silver plating onto the surfaces of the materials within the CEV water system, thus negating its effectiveness as a biocide. Since the biocide depletion is expected to occur within a short amount of time after loading the water into the CEV water tanks at the Kennedy Space Center (KSC), an additional microbial control is a 0.1 micron point of use filter that will be used at the outlet of the Potable Water Dispenser (PWD). Because this may be the first time NASA is considering a stored water system for longterm missions that does not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point of use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform testing to help alleviate those concerns related to the CEV water system. Results from the test plans laid out in the paper presented to SAE last year (Crew Exploration Vehicle (CEV) Potable Water System Verification Coordination, 2008012083) will be detailed in this paper. Additionally, recommendations for the CEV verification will be described for risk mitigation in meeting the physicochemical and microbiological requirements on the CEV PWS.

Peterson, Laurie↗
NASA NTRS1975

An overview of the applications systems verification test on snowcover mapping

The capability of the LANDSAT and NOAA satellites to accurately measure snowcovered area on various size watersheds was demonstrated. Recent research has shown a highly significant statistical relationship between satellite-derived snowcovered area at the beginning of the snowmelt period and seasonal runoff. The decision was made to test the results of several satellite snowcovered area studies in an Applications Systems Verification Test (ASVT) Program where quasi-operational evaluations of total technical capability are performed. The objective of these ASVT's is to provide all the information necessary for a potential user to make effective decisions concerning the implementation of the new remote sensing technology in an operational applications system.

Rango, A.↗
NASA NTRS2005

Thermal System Verification and Model Validation for NASA's Cryogenic Passively Cooled James Webb Space Telescope (JWST)

A thorough and unique thermal verification and model validation plan has been developed for NASA s James Webb Space Telescope. The JWST observatory consists of a large deployed aperture optical telescope passively cooled to below 50 Kelvin along with a suite of several instruments passively and actively cooled to below 37 Kelvin and 7 Kelvin, respectively. Passive cooling to these extremely low temperatures is made feasible by the use of a large deployed high efficiency sunshield and an orbit location a! !he L2 Lagrange p~in!. Another enabling feature is the scale or size of the observatory that allows for large radiator sizes that are compatible with the expected power dissipation of the instruments and large format Mercury Cadmium Telluride (HgCdTe) detector arrays. This passive cooling concept is simple, reliable, and mission enabling when compared to the alternatives of mechanical coolers and stored cryogens. However, these same large scale observatory features, which make passive cooling viable, also prevent the typical flight configuration fully-deployed thermal balance test that is the keystone to most space missions thermal verification plan. JWST is simply too large in its deployed configuration to be properly thermal balance tested in the facilities that currently exist. This reality, when combined with a mission thermal concept with little to no flight heritage, has necessitated the need for a unique and alternative approach to thermal system verification and model validation. This paper describes the thermal verification and model validation plan that has been developed for JWST.

Parrish, Keith↗
NASA NTRS2005

Thermal System Verification and Model Validation for NASA's Cryogenic Passively Cooled James Webb Space Telescope

A thorough and unique thermal verification and model validation plan has been developed for NASA s James Webb Space Telescope. The JWST observatory consists of a large deployed aperture optical telescope passively cooled to below 50 Kelvin along with a suite of several instruments passively and actively cooled to below 37 Kelvin and 7 Kelvin, respectively. Passive cooling to these extremely low temperatures is made feasible by the use of a large deployed high efficiency sunshield and an orbit location at the L2 Lagrange point. Another enabling feature is the scale or size of the observatory that allows for large radiator sizes that are compatible with the expected power dissipation of the instruments and large format Mercury Cadmium Telluride (HgCdTe) detector arrays. This passive cooling concept is simple, reliable, and mission enabling when compared to the alternatives of mechanical coolers and stored cryogens. However, these same large scale observatory features, which make passive cooling viable, also prevent the typical flight configuration fully-deployed thermal balance test that is the keystone to most space missions thermal verification plan. JWST is simply too large in its deployed configuration to be properly thermal balance tested in the facilities that currently exist. This reality, when combined with a mission thermal concept with little to no flight heritage, has necessitated the need for a unique and alternative approach to thermal system verification and model validation. This paper describes the thermal verification and model validation plan that has been developed for JWST. The plan relies on judicious use of cryogenic and thermal design margin, a completely independent thermal modeling cross check utilizing different analysis teams and software packages, and finally, a comprehensive set of thermal tests that occur at different levels of JWST assembly. After a brief description of the JWST mission and thermal architecture, a detailed description of the three aspects of the thermal verification and model validation plan is presented.

Cleveland, Paul E.↗