Ada (trademark) projects at NASA. Runtime environment issues and recommendations

Ada practitioners should use this document to discuss and establish common short term requirements for Ada runtime environments. The major current Ada runtime environment issues are identified through the analysis of some of the Ada efforts at NASA and other research centers. The runtime environment characteristics of major compilers are compared while alternate runtime implementations are reviewed. Modifications and extensions to the Ada Language Reference Manual to address some of these runtime issues are proposed. Three classes of projects focusing on the most critical runtime features of Ada are recommended, including a range of immediately feasible full scale Ada development projects. Also, a list of runtime features and procurement issues is proposed for consideration by the vendors, contractors and the government

An operating system for future aerospace vehicle computer systems

The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure

Software Requirements Specification for Lunar Icecube

A thesis presented to the faculty of the College of Science at Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Michael R. Glaser-Garbrick on April 21, 2017

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

A survey on online monitoring approaches of computer-based systems

This report surveys forms of online data collection that are in current use (as well as being the subject of research to adapt them to changing technology and demands), and can be used as inputs to assessment of dependability and resilience, although they are not primarily meant for this use

Transportable Applications Environment (TAE) Plus: A NASA tool used to develop and manage graphical user interfaces

The Transportable Applications Environment (TAE) Plus was built to support the construction of graphical user interfaces (GUI's) for highly interactive applications, such as real-time processing systems and scientific analysis systems. It is a general purpose portable tool that includes a 'What You See Is What You Get' WorkBench that allows user interface designers to layout and manipulate windows and interaction objects. The WorkBench includes both user entry objects (e.g., radio buttons, menus) and data-driven objects (e.g., dials, gages, stripcharts), which dynamically change based on values of realtime data. Discussed here is what TAE Plus provides, how the implementation has utilized state-of-the-art technologies within graphic workstations, and how it has been used both within and without NASA

Evaluation of Algorithm-Based Fault Tolerance for Machine Learning and Computer Vision under Neutron Radiation

In the past decade, there has been a push for deployment of commercial-off-the-shelf (COTS) avionics due in part to cheaper costs and the desire for more performance. Traditional radiation-hardened processors are expensive and only provide limited processing power. With smaller mission budgets and the need for more computational power, low-cost and high-performance COTS solutions become more attractive for these missions. Due to the computational capacity enhancements provided by COTS technology, machine-learning and computer-vision applications are now being deployed on modern space missions. However, COTS electronics are highly susceptible to radiation environments. As a result, reliability in the underlying computations becomes a concern. Matrix multiplication is used in machine-learning and computer-vision applications as the main computation for decisions, making it a critical part of the application. Therefore, the large time and memory footprint of the matrix multiplication in machine-learning and computer-vision applications makes them even more susceptible to single-event upsets. In this thesis, algorithm-based fault tolerance (ABFT) is investigated to mitigate silent data errors in machine learning and computer vision. ABFT is a methodology of data error detection and correction using information redundancy contained in separate data structures from the primary data. In matrix multiplication, ABFT consists of storing checksum data in vectors separate from the matrix to use for error detection and correction. Fault injection into a matrix-multiplication kernel was performed prior to irradiation. Irradiation was then performed on the kernel under wide-spectrum neutrons at Los Alamos Neutron Science Center to observe the mitigation effects of ABFT. Fault injections targeted towards the general-purpose registers show a $48\times$ reduction in data errors using data-error mitigation with ABFT with a negligible change in run-time. Cross-section results from irradiation show a 5.3x improvement in reliability of using ABFT as opposed to no mitigation with a >99.9999 confidence level. The results of this experiment demonstrate that ABFT is a viable solution for run-time error correction in matrix multiplication for machine-learning and computer-vision applications in future spacecraft

Transportable Applications Environment (TAE) Plus: A NASA user interface development and management system

The transportable Applications Environment Plus (TAE Plus), developed at the NASA Goddard Space FLight Center, is a portable, What you see is what you get (WYSIWYG) user interface development and management system. Its primary objective is to provide an integrated software environment that allows interactive prototyping and development of graphical user interfaces, as well as management of the user interface within the operational domain. TAE Plus is being applied to many types of applications, and what TAE Plus provides, how the implementation has utilizes state-of-the-art technologies within graphic workstations, and how it has been used both within and without NASA are discussed