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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

The Empirical Investigation of Perspective-Based Reading

We consider reading techniques a fundamental means of achieving high quality software. Due to the lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with Perspective-Based Reading (PBR), a particular reading technique for requirements documents. The goal of PBR is to provide operational scenarios where members of a review team read a document from a particular perspective (e.g., tester, developer, user). Our assumption is that the combination of different perspectives provides better coverage of the document than the same number of readers using their usual technique.

Basili, Victor R.↗
NASA NTRS1995

The Empirical Investigation of Perspective-Based Reading

We consider reading techniques a fundamental means of achieving high quality software. Due to lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with Perspective Based Reading (PBR) a particular reading technique for requirement documents. The goal of PBR is to provide operation scenarios where members of a review team read a document from a particular perspective (eg., tester, developer, user). Our assumption is that the combination of different perspective provides better coverage of the document than the same number of readers using their usual technique. To test the efficacy of PBR, we conducted two runs of a controlled experiment in the environment of NASA GSFC Software Engineering Laboratory (SEL), using developers from the environment. The subjects read two types of documents, one generic in nature and the other from the NASA Domain, using two reading techniques, PBR and their usual technique. The results from these experiment as well as the experimental design, are presented and analyzed. When there is a statistically significant distinction, PBR performs better than the subjects' usual technique. However, PBR appears to be more effective on the generic documents than on the NASA documents.

Basili, Victor R.↗
NASA NTRS2002

Synthesizing Certified Code

Code certification is a lightweight approach to demonstrate software quality on a formal level. Its basic idea is to require producers to provide formal proofs that their code satisfies certain quality properties. These proofs serve as certificates which can be checked independently. Since code certification uses the same underlying technology as program verification, it also requires many detailed annotations (e.g., loop invariants) to make the proofs possible. However, manually adding theses annotations to the code is time-consuming and error-prone. We address this problem by combining code certification with automatic program synthesis. We propose an approach to generate simultaneously, from a high-level specification, code and all annotations required to certify generated code. Here, we describe a certification extension of AUTOBAYES, a synthesis tool which automatically generates complex data analysis programs from compact specifications. AUTOBAYES contains sufficient high-level domain knowledge to generate detailed annotations. This allows us to use a general-purpose verification condition generator to produce a set of proof obligations in first-order logic. The obligations are then discharged using the automated theorem E-SETHEO. We demonstrate our approach by certifying operator safety for a generated iterative data classification program without manual annotation of the code.

Whalen, Michael↗
NASA NTRS2002

Real-Time Embedded Software Verification and Validation 2001

As the space applications become more complex and timing constraints on control actions are more stringent, the task of integrating and testing NASA's real-time systems (such as X-38 Crew Return Vehicle, and certain International Space Station autonomous systems) has become a great challenge. A testing environment where can preserve consistent temporal behaviors as in the target execution must be established for system-level verification and software quality assurance. Our goal is to develop an analysis suite for validation and verification of real-time systems that are used to perform human- in-the-loop control operations during safety-critical missions. The suite will be able to carry out quantitative approaches of coverage diagnostic and temporal behavior evaluation in order to measure test coverage, to optimize test utilization, and to verify timing correctness.

Lee, Yann-Hang↗
NASA NTRS2002

An interfaces approach to TES ground data system processing design with the Science Investigator-led Processing System (SIPS)

Developing production-quality software to process the large volumes of scientific data is the responsibility of the TES Ground Data System, which is being developed at the Jet Propulsion Laboratory together with support contractor Raytheon/ITSS. The large data volume and processing requirements of the TES pose significant challenges to the design.

TES TES SIPS↗
NASA NTRS2001

Incorporating cost-benefit analyses into software assurance planning

The objective is to use cost-benefit analyses to identify, for a given project, optimal sets of software assurance activities. Towards this end we have incorporated cost-benefit calculations into a risk management framework.

investment software quality software process impro↗
NASA NTRS1999

Panel: Practical Issues in Implementing Software Reliability Measurement

Many ways of estimating software systems' reliability, or reliability-related quantities, have been developed over the past several years. In this panel, we discuss practical issues to be addressed in implementing software reliabilty measurement techniques in a production development environment.

software reliability software measurement software↗
NASA NTRS2006

Building the Core Architecture of a Multiagent System Product Line: With an example from a future NASA Mission

The field of Software Product Lines (SPL) emphasizes building a core architecture for a family of software products from which concrete products can be derived rapidly. This helps to reduce time-to-market, costs, etc., and can result in improved software quality and safety. Current AOSE methodologies are concerned with developing a single Multiagent System. We propose an initial approach to developing the core architecture of a Multiagent Systems Product Line (MAS-PL), exemplifying our approach with reference to a concept NASA mission based on multiagent technology.

Pena, Joaquin↗
NASA NTRS2010

Space Shuttle Program Primary Avionics Software System (PASS) Success Legacy - Major Accomplishments and Lessons Learned Detail Historical Timeline Analysis

This presentation focuses on the Space Shuttle Primary Avionics Software System (PASS) and the people who developed and maintained this system. One theme is to provide quantitative data on software quality and reliability over a 30 year period. Consistent data relates to code break discrepancies. Requirements were supplied from external sources. Requirement inspections and measurements not implemented until later, beginning in 1985. Second theme is to focus on the people and organization of PASS. Many individuals have supported the PASS project over the entire period while transitioning from company to company and contract to contract. Major events and transitions have impacted morale (both positively and negatively) across the life of the project.

Orr, James K.↗
NASA NTRS2001

Space Shuttle Navigation in the GPS Era

The Space Shuttle navigation architecture was originally designed in the 1970s. A variety of on-board and ground based navigation sensors and computers are used during the ascent, orbit coast, rendezvous, (including proximity operations and docking) and entry flight phases. With the advent of GPS navigation and tightly coupled GPS/INS Units employing strapdown sensors, opportunities to improve and streamline the Shuttle navigation process are being pursued. These improvements can potentially result in increased safety, reliability, and cost savings in maintenance through the replacement of older technologies and elimination of ground support systems (such as Tactical Air Control and Navigation (TACAN), Microwave Landing System (MLS) and ground radar). Selection and missionization of "off the shelf" GPS and GPS/INS units pose a unique challenge since the units in question were not originally designed for the Space Shuttle application. Various options for integrating GPS and GPS/INS units with the existing orbiter avionics system were considered in light of budget constraints, software quality concerns, and schedule limitations. An overview of Shuttle navigation methodology from 1981 to the present is given, along with how GPS and GPS/INS technology will change, or not change, the way Space Shuttle navigation is performed in the 21 5 century.

Goodman, John L.↗
NASA NTRS2005

Semantic Metrics for Analysis of Software

A recently conceived suite of object-oriented software metrics focus is on semantic aspects of software, in contradistinction to traditional software metrics, which focus on syntactic aspects of software. Semantic metrics represent a more human-oriented view of software than do syntactic metrics. The semantic metrics of a given computer program are calculated by use of the output of a knowledge-based analysis of the program, and are substantially more representative of software quality and more readily comprehensible from a human perspective than are the syntactic metrics.

Etzkorn, Letha H.↗
NASA NTRS2014

Preparing GMAT for Operational Maneuver Planning of the Advanced Composition Explorer (ACE)

The General Mission Analysis Tool (GMAT) is an open-source space mission design, analysis and trajectory optimization tool. GMAT is developed by a team of NASA, private industry, public and private contributors. GMAT is designed to model, optimize and estimate spacecraft trajectories in flight regimes ranging from low Earth orbit to lunar applications, interplanetary trajectories and other deep space missions. GMAT has also been flight qualified to support operational maneuver planning for the Advanced Composition Explorer (ACE) mission. ACE was launched in August, 1997 and is orbiting the Sun-Earth L1 libration point. The primary science objective of ACE is to study the composition of both the solar wind and the galactic cosmic rays. Operational orbit determination, maneuver operations and product generation for ACE are conducted by NASA Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF). This paper discusses the entire engineering lifecycle and major operational certification milestones that GMAT successfully completed to obtain operational certification for the ACE mission. Operational certification milestones such as gathering of the requirements for ACE operational maneuver planning, gap analysis, test plans and procedures development, system design, pre-shadow operations, training to FDF ACE maneuver planners, shadow operations, Test Readiness Review (TRR) and finally Operational Readiness Review (ORR) are discussed. These efforts have demonstrated that GMAT is flight quality software ready to support ACE mission operations in the FDF.

Trajectory analysis↗
NASA NTRS2019

Preparing General Mission Analysis Tool for Operational Maneuver Planning of the Advanced Composition Explorer Mission

The General Mission Analysis Tool (GMAT) is an open-source space mission design, analysis and trajectory optimization tool. GMAT is developed by a team of NASA, private industry, public and private contributors. GMAT is designed to model, optimize and estimate spacecraft trajectories in flight regimes ranging from low Earth orbit to lunar applications, interplanetary trajectories and other deep space missions. GMAT has also been flight qualified to support operational maneuver planning for the Advanced Composition Explorer (ACE) mission. ACE was launched in August, 1997 and is orbiting the Sun-Earth L1 libration point. The primary science objective of ACE is to study the composition of both the solar wind and the galactic cosmic rays. Operational orbit determination, maneuver operations and product generation for ACE are conducted by NASA Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF). This paper discusses the entire engineering lifecycle and major operational certification milestones that GMAT successfully completed to obtain operational certification for the ACE mission. Operational certification milestones such as gathering of the requirements for ACE operational maneuver planning, gap analysis, test plans and procedures development, system design, pre-shadow operations, training to FDF ACE maneuver planners, shadow operations, Test Readiness Review (TRR) and finally Operational Readiness Review (ORR) are discussed. These efforts have demonstrated that GMAT is flight quality software ready to support ACE mission operations in the FDF.

mission design↗
NASA NTRS2017

MONTE for Orbit Determination

Monte is the Jet Propulsion Laboratory’s (JPL) signature astrodynamic computing platform. Its main interface is a collection of Python-language libraries that can be used either for one-o analyses or to build high-quality software applications. Perhaps nowhere is Monte’s versatility and excellence better demonstrated than in its use for operational orbit determination (OD). Over the period from 2007 to 2016, Monte was the prime OD solution for fourteen JPL flight projects, and secondary for seven non-JPL projects. These missions span the range of Solar System destinations and operational protocols, yet each were successfully serviced by Monte’s flexible OD library. This paper reviews the missions on which Monte has been used for OD, with an eye toward pointing out the di erent ways it has been deployed to solve unique problems. It also gives an outline of the main elements of the orbit determination library and how they work together to navigate flight missions.

Martin-Mur, Tomas↗
NASA NTRS2024

High-Rate Delay Tolerant Networking (HDTN) Software Requirements Analysis

This document serves as a detailed analysis of the main networking protocols implemented by HDTN. Sources of the protocol specifications include Internet Engineering Task Force (IETF) Request for Comments (RFC) and Consultative Committee for Space Data Systems (CCSDS) standards. The focus of this report is to derive software requirements suitable for NASA Procedural Requirements 7150.2D Class B compliance, including requirements traceability and software verification and validation, from the source specifications. This analysis will be incorporated into the finalized HDTN Software Requirements Specification (SRS) but does not encompass the full scope of the HDTN SRS. Requirements in this document are considered draft. The complete requirements will include bundle application requirements, interface requirements, computer resource requirements, software quality factors, and additional requirements as determined by the project. This document is publicly released to the greater community to receive feedback and foster collaboration opportunities.

Rachel Dudukovich↗
NASA NTRS1992

The role of metrics and measurements in a software intensive total quality management environment

Paramax Space Systems began its mission as a member of the Rockwell Space Operations Company (RSOC) team which was the successful bidder on a massive operations consolidation contract for the Mission Operations Directorate (MOD) at JSC. The contract awarded to the team was the Space Transportation System Operations Contract (STSOC). Our initial challenge was to accept responsibility for a very large, highly complex and fragmented collection of software from eleven different contractors and transform it into a coherent, operational baseline. Concurrently, we had to integrate a diverse group of people from eleven different companies into a single, cohesive team. Paramax executives recognized the absolute necessity to develop a business culture based on the concept of employee involvement to execute and improve the complex process of our new environment. Our executives clearly understood that management needed to set the example and lead the way to quality improvement. The total quality management policy and the metrics used in this endeavor are presented.

Daniels, Charles B.↗