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In this paper, I describe software product lines and why a Ground Data Processing System should use one. I also describe how to develop a software product line, using examples from an imaginary Ground Data Processing System.
The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.
The investigations of the software evaluation laboratory into the software development process at NASA/Goddard are described. A data collection process for acquiring detailed histories of software development projects is outlined. The application of different sets of software methodologies to specific applications projects is summarized. The effect of the development methodology on productivity is discussed.
The paper discusses four reliability data gathering experiments which were conducted using a small sample of programs for two problems having ultrareliability requirements, n-version programming for fault detection, and repetitive run modeling for failure and fault rate estimation. The experimental results agree with those of Nagel and Skrivan in that the program error rates suggest an approximate log-linear pattern and the individual faults occurred with significantly different error rates. Additional analysis of the experimental data raises new questions concerning the phenomenon of interacting faults. This phenomenon may provide one explanation for software reliability decay. The fourth experiment underscored the difficulty in distinguishing between observations of deficiencies in the design of the algorithm and observations of software faults for real-time process control software. These experiments are a part of a program of serial experiments being pursued by the System Validation Methods of NASA-Langley Research Center to find a means of credibly performing reliability evaluations of flight control software.
The goal of this collaboration was to produce Flight Software Branch (FSB) process standards for software inspections which could be used across three new missions within the FSB. The standard was developed by Dr. Forrest Shull (Fraunhofer Center for Experimental Software Engineering, Maryland) using the Perspective-Based Inspection approach, (PBI research has been funded by SARP) , then tested on a pilot Branch project. Because the short time scale of the collaboration ruled out a quantitative evaluation, it would be decided whether the standard was suitable for roll-out to other Branch projects based on a qualitative measure: whether the standard received high ratings from Branch personnel as to usability and overall satisfaction. The project used for piloting the Perspective-Based Inspection approach was a multi-mission framework designed for reuse. This was a good choice because key representatives from the three new missions would be involved in the inspections. The perspective-based approach was applied to produce inspection procedures tailored for the specific quality needs of the branch. The technical information to do so was largely drawn through a series of interviews with Branch personnel. The framework team used the procedures to review requirements. The inspections were useful for indicating that a restructuring of the requirements document was needed, which led to changes in the development project plan. The standard was sent out to other Branch personnel for review. Branch personnel were very positive. However, important changes were identified because the perspective of Attitude Control System (ACS) developers had not been adequately represented, a result of the specific personnel interviewed. The net result is that with some further work to incorporate the ACS perspective, and in synchrony with the roll out of independent Branch standards, the PBI approach will be implemented in the FSB. Also, the project intends to continue its collaboration with the technology provider (Dr. Forrest Shull) past the end of the grant, to allow a more rigorous quantitative evaluation.
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.
The objective is to use cost-benefit analyses to identify, for a given project, optimal sets of software assurance activities.
The 2024 Software for the NASA Science Mission Directorate Workshop was the first workshop of its kind in over 10 years. The numerous attendees and high level of interaction in this hybrid workshop portrayed the untapped interest and energy in the NASA SMD community about software. Over 100 takeaways were collected from the hosted discussions in four key areas - Communication, Communities, Funding and Clarity - as summarized in this report. One takeaway was representative of all four categories: “Software is not hardware; it is organic and needs a different model. You often don't know which components will be Open-Source reusable until later in the development cycle.” For the communication category, this takeaway motivates the reduction of silos by shifting towards a model that better supports community collaboration on common challenges and a more streamlined and improved software release process. For the communities category, the same statement points to forming communities of practice with varying scopes and a new approach to recognition and incentives for open-source software contributions. Concerning funding, this statement motivates a more sustained and flexible funding model that better supports the software foundation needed for NASA’s long-term success, including the collaboration and infrastructure a good foundation requires. The new approach to clarity motivated by this statement calls for significant changes to the software release process and related policies to streamline compliance, align those policies with the open-source science culture NASA is promoting and with each other, and simplify use of the cloud. It is time to recognize software as a foundational component of NASA with an organic nature not properly supported by current approaches. Different models are needed in all four areas to shift the NASA SMD software community and governance structures into a more efficient, open, and collaborative ecosystem - one that enables ground-breaking science and daring exploration into the coming decades
This software automatically processes Sally Ride Science (SRS) delivered MoonKAM camera control files (ccf) into uplink products for the GRAIL-A and GRAIL-B spacecraft as part of an education and public outreach (EPO) extension to the Grail Mission. Once properly validated and deemed safe for execution onboard the spacecraft, MoonKommand generates the command products via the Automated Sequence Processor (ASP) and generates uplink (.scmf) files for radiation to the Grail-A and/or Grail-B spacecraft. Any errors detected along the way are reported back to SRS via email. With Moon Kommand, SRS can control their EPO instrument as part of a fully automated process. Inputs are received from SRS as either image capture files (.ccficd) for new image requests, or downlink/delete files (.ccfdl) for requesting image downlink from the instrument and on-board memory management. The Moon - Kommand outputs are command and file-load (.scmf) files that will be uplinked by the Deep Space Network (DSN). Without MoonKommand software, uplink product generation for the MoonKAM instrument would be a manual process. The software is specific to the Moon - KAM instrument on the GRAIL mission. At the time of this writing, the GRAIL mission was making final preparations to begin the science phase, which was scheduled to continue until June 2012.
The ultimate goal of this report was to integrate the powerful tools of artificial intelligence into the traditional process of software development. To maintain the US aerospace competitive advantage, traditional aerospace and software engineers need to more easily incorporate the technology of artificial intelligence into the advanced aerospace systems being designed today. The future goal was to transition artificial intelligence from an emerging technology to a standard technology that is considered early in the life cycle process to develop state-of-the-art aircraft automation systems. This report addressed the future goal in two ways. First, it provided a matrix that identified typical aircraft automation applications conducive to various artificial intelligence methods. The purpose of this matrix was to provide top-level guidance to managers contemplating the possible use of artificial intelligence in the development of aircraft automation. Second, the report provided a methodology to formally evaluate neural networks as part of the traditional process of software development. The matrix was developed by organizing the discipline of artificial intelligence into the following six methods: logical, object representation-based, distributed, uncertainty management, temporal and neurocomputing. Next, a study of existing aircraft automation applications that have been conducive to artificial intelligence implementation resulted in the following five categories: pilot-vehicle interface, system status and diagnosis, situation assessment, automatic flight planning, and aircraft flight control. The resulting matrix provided management guidance to understand artificial intelligence as it applied to aircraft automation. The approach taken to develop a methodology to formally evaluate neural networks as part of the software engineering life cycle was to start with the existing software quality assurance standards and to change these standards to include neural network development. The changes were to include evaluation tools that can be applied to neural networks at each phase of the software engineering life cycle. The result was a formal evaluation approach to increase the product quality of systems that use neural networks for their implementation.
The past ten years of research on computer vision have matured into a powerful real time system comprised of standardized commercial hardware, computers, and pipeline processing laboratory prototypes, supported by anextensive set of image processing algorithms. The software system was constructed to be transportable via the choice of a popular high level language (PASCAL) and a widely used computer (VAX-11/750), it comprises a whole realm of low level and high level processing software that has proven to be versatile for applications ranging from factory automation to space satellite tracking and grappling.
Only a few efforts are currently underway to develop an adequate technology base for the various themes. Particular attention must be given to software commonality and evolutionary capability, to increased system integrity and autonomy; and to improved communications among the program users, the program developers, and the programs themselves. There is a need for quantum improvement in software development methods and increasing the awareness of software by all concerned. Major thrusts identified include: (1) data and systems management; (2) software technology for autonomous systems; (3) technology and methods for improving the software development process; (4) advances related to systems of software elements including their architecture, their attributes as systems, and their interfaces with users and other systems; and (5) applications of software including both the basic algorithms used in a number of applications and the software specific to a particular theme or discipline area. The impact of each theme on software is assessed.
The software programming environment used in the development of Guidance and Control Software (GCS) implementations used in a software error studies experiment conducted by the Research Triangle Institute (RTI) and the NASA-Langley is described. The Radio Technical Commission for Aeronautics RTCA/DO-178A guidelines are fulfilled, and requirements for document number 9 in which the hardware, software, and processes used to develop and maintain the software for the GCS project are described. The software programming environment for GCS largely consists of tools that are included in Digital Equipment Corporations software layered product library or are a part of the VAX/VMS baseline system.
Concern over the limited intravehicular activity time has increased the interest in performing in-space assembly and construction operations with automated robotic systems. A technique being considered at LaRC is a supervised-autonomy approach, which can be monitored by an Earth-based supervisor that intervenes only when the automated system encounters a problem. A test-bed to support evaluation of the hardware and software requirements for supervised-autonomy assembly methods was developed. This report describes the design of the software system necessary to support the assembly process. The software is hierarchical and supports both automated assembly operations and supervisor error-recovery procedures, including the capability to pause and reverse any operation. The software design serves as a model for the development of software for more sophisticated automated systems and as a test-bed for evaluation of new concepts and hardware components.
The Operations Engineering Lab at JPL has developed a software architecture based on an integrated toolkit approach for simplifying and automating mission operations tasks.
The Operations Engineering Lab (OEL) at JPL has developed a software architecture based on an integrated toolkit approach for simplifying and automating mission operations tasks. The toolkit approach is based on building adaptable, reusable graphical tools that are integrated through a combination of libraries, scripts, and system-level user interface shells. The graphical interface shells are designed to integrate and visually guide a user through the complex steps in an operations process. They provide a user with an integrated system-level picture of an overall process, defining the required inputs and possible outputs through interactive on-screen graphics.
Version 2.0 of the autogen software has been released. "Autogen" (automated sequence generation) signifies both a process and software used to implement the process of automated generation of sequences of commands in a standard format for uplink to spacecraft. Autogen requires fewer workers than are needed for older manual sequence-generation processes and reduces sequence-generation times from weeks to minutes.
There is a need for simulation models of software development processes other than the waterfall because processes such as spiral development are becoming more and more popular. The use of a spiral process can make the inherently difficult job of cost and schedule estimation even more challenging due to its evolutionary nature, but this allows for a more flexible process that can better meet customers' needs. This paper will present a discrete event simulation model of spiral development that can be used to analyze cost and schedule effects of using such a process in comparison to a waterfall process.