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NASA NTRS2008

Guidance and Control Software Project Data - Volume 4: Configuration Management and Quality Assurance Documents

The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes configuration management and quality assurance documents from the GCS project. Volume 4 contains six appendices: A. Software Accomplishment Summary for the Guidance and Control Software Project; B. Software Configuration Index for the Guidance and Control Software Project; C. Configuration Management Records for the Guidance and Control Software Project; D. Software Quality Assurance Records for the Guidance and Control Software Project; E. Problem Report for the Pluto Implementation of the Guidance and Control Software Project; and F. Support Documentation Change Reports for the Guidance and Control Software Project.

Hayhurst, Kelly J.↗

NASA NTRS2014

Use Of The Operational Air Quality Monitor (AQM) For In-Flight Water Testing Project

A primary requirement for manned spaceflight is Environmental Health which ensures air and water contaminants, acoustic profiles, microbial flora, and radiation exposures within the cabin are maintained to levels needed for crew health and for vehicle system functionality. The reliance on ground analyses of returned samples is a limitation in the current environmental monitoring strategy that will prevent future Exploration missions beyond low-Earth orbit. This proposal attempts to address this shortcoming by advancing in-flight analyses of water and air. Ground analysis of in-flight, air and water samples typically employ vapor-phase analysis by gas chromatography-mass spectrometry (GC-MS) to identify and quantify organic compounds present in the samples. We envision the use of newly-developed direct ionization approaches as the most viable avenue leading towards an integrated analytical platform for the monitoring of water, air, and, potentially bio-samples in the cabin environment. Development of an in-flight instrument capable of analyzing air and water samples would be the logical next step to meeting the environmental monitoring needs of Exploration missions. Currently, the Air Quality Monitor (AQM) on-board ISS provides this specific information for a number of target compounds in the air. However, there is a significant subset of common target compounds between air and water. Naturally, the following question arises, "Can the AQM be used for both air and water quality monitoring?" Previous directorate-level IR&D funding led to the development of a water sample introduction method for mass spectrometry using electrothermal vaporization (ETV). This project will focus on the integration of the ETV with a ground-based AQM. The capabilities of this integrated platform will be evaluated using a subset of toxicologically important compounds.

Macatangay, Ariel↗

NASA NTRS1966

Computer program searches characteristic data of diodes and transistors

Semiconductor information storage and retrieval system provides a comprehensive, accurate, and ready reference to characteristic data of diodes and transistors. The system can be used to supply a complete listing of technical component information necessary for circuit designers, reliability engineers, and quality assurance personnel.

Source record↗

NASA NTRS1968

Test control.

Environmental test control methods for improving quality and reducing costs, noting standardized specifications and information collection for administration

Dundas, H. R.↗

NASA NTRS1973

Results of precision processing (scene correction) of ERTS-1 images using digital image processing techniques

ERTS-1 MSS and RBV data recorded on computer compatible tapes have been analyzed and processed, and preliminary results have been obtained. No degradation of intensity (radiance) information occurred in implementing the geometric correction. The quality and resolution of the digitally processed images are very good, due primarily to the fact that the number of film generations and conversions is reduced to a minimum. Processing times of digitally processed images are about equivalent to the NDPF electro-optical processor.

Bernstein, R.↗

NASA NTRS1975

A complementary filtering technique for deriving aircraft velocity and position information

An onboard navigation system which employed complementary filtering was developed to provide velocity and position information. The inputs to the mix filter included both acceleration inputs, which provided high-frequency position and velocity information, and radar position inputs, which provided the low-frequency position and velocity information. Onboard aircraft instrumentation, including attitude reference gyros and body-mounted accelerometers, was used to provide the acceleration information. An in-flight comparison of signal quality and accuracy showed good agreement between the complementary filtering system and an aided inertial navigation system. Furthermore, the complementary filtering system was proven to be satisfactory in control and display system applications for both automatic and pilot-in-the-loop instrument approaches and landings.

Niessen, F. R.↗

NASA NTRS1982

Research advances in satellite-aided crop forecasting

The underlying concept of the technology is to estimate crop area and yield for specified regions and to multiply the two to obtain production at the regional level. The treatment here is mainly of area estimation. The approach to non-U.S. crop forecasting does not require ground observations. Among the problems hampering development are the need to estimate crop areas much earlier in the season and the need for information extraction methods that reduce the quantity and quality of the data required.

Erickson, J.↗

NASA NTRS1987

Earth Observing System - The earth research system of the 1990's

The Earth Observing Systems' objective of comprehensively studying the earth's change leads to an array of technological and implementational challenges. Included in those challenges are in the in-orbit maintenance of fifty instruments through periodic servicing and the development of an international ground information system which permits rapid access to high quality data. The paper describes these challenges and also discusses potential contributions from international and USA agencies, mission design and payload groupings strategies, as well as design approaches to the spacecraft itself.

Graf, James E.↗

NASA NTRS1988

A proposed tropical rainfall measuring mission (TRMM) satellite

The proposed Tropical Rainfall Measuring Mission (TRMM) satellite (presently in its third year of planning), is described. The TRMM satellite, planned for an operational duration of at least three years beginning in the mid-1990s, is intended to obtain high-quality measurements of tropical precipitation by means of information derived from a quantitative spaceborne radar, a multichannel passive microwave radiometer, and an AVHRR. The satellite's orbit will be low-altitude (320 km), for high resolution, and low-inclination (30 to 35 deg), for making it possible to visit each sampling area twice a day. Radar and passive microwave algorithms and rain-retrieval algorithms to be used in precipitation measurements are discussed together with cloud dynamical models designed to test these algorithms.

Simpson, Joanne↗

NASA NTRS1989

TRUSS: An intelligent design system for aircraft wings

Competitive leadership in the international marketplace, superiority in national defense, excellence in productivity, and safety of both private and public systems are all national defense goals which are dependent on superior engineering design. In recent years, it has become more evident that early design decisions are critical, and when only based on performance often result in products which are too expensive, hard to manufacture, or unsupportable. Better use of computer-aided design tools and information-based technologies is required to produce better quality United States products. A program is outlined here to explore the use of knowledge based expert systems coupled with numerical optimization, database management techniques, and designer interface methods in a networked design environment to improve and assess design changes due to changing emphasis or requirements. The initial structural design of a tiltrotor aircraft wing is used as a representative example to demonstrate the approach being followed.

Bates, Preston R.↗

NASA NTRS1990

Estimation of synoptic fields of middle atmosphere parameters from Nimbus-7 LIMS profile data

The most widely used version of the Nimbus-7 middle atmosphere dataset is the set of high quality, daily, and zonal Fourier coefficients that resolve information out to six wavenumbers at 12 UTC. A Kalman filter algorithm was applied to the original profile data in order to generate those fields for the data archive or LAMAT product. The characteristics and implementation of the algorithm are described in some detail, along with examples of the output for each of the LIMS parameters.

Remsberg, Ellis E.↗

NASA NTRS1993

On the assessment of visual communication by information theory

This assessment of visual communication integrates the optical design of the image-gathering device with the digital processing for image coding and restoration. Results show that informationally optimized image gathering ordinarily can be relied upon to maximize the information efficiency of decorrelated data and the visual quality of optimally restored images.

Huck, Friedrich O.↗

NASA NTRS1994

General-Purpose Plotting Software

TADPLOT computer program gives researcher general-purpose plotting software package easy to use, quickly creates X-Y plots, and powerful enough to create full-feature publication-quality plots. Enables user to save selected plot information displayed subsequently on several different devices, including "hard-copy" plotters. Postprocessing features that enable user to manipulate and combine plots also available. Written in ANSI STANDARD FORTRAN 77.

Hammond, Dana P.↗

NASA NTRS1996

Requirement Metrics for Risk Identification

The Software Assurance Technology Center (SATC) is part of the Office of Mission Assurance of the Goddard Space Flight Center (GSFC). The SATC's mission is to assist National Aeronautics and Space Administration (NASA) projects to improve the quality of software which they acquire or develop. The SATC's efforts are currently focused on the development and use of metric methodologies and tools that identify and assess risks associated with software performance and scheduled delivery. This starts at the requirements phase, where the SATC, in conjunction with software projects at GSFC and other NASA centers is working to identify tools and metric methodologies to assist project managers in identifying and mitigating risks. This paper discusses requirement metrics currently being used at NASA in a collaborative effort between the SATC and the Quality Assurance Office at GSFC to utilize the information available through the application of requirements management tools.

Hammer, Theodore↗

NASA NTRS2000

National Transonic Facility Characterization Status

This paper describes the current status of the characterization of the National Transonic Facility. The background and strategy for the tunnel characterization, as well as the current status of the four main areas of the characterization (tunnel calibration, flow quality characterization, data quality assurance, and support of the implementation of wall interference corrections) are presented. The target accuracy requirements for tunnel characterization measurements are given, followed by a comparison of the measured tunnel flow quality to these requirements based on current available information. The paper concludes with a summary of which requirements are being met, what areas need improvement, and what additional information is required in follow-on characterization studies.

Bobbitt, C., Jr.↗

NASA NTRS2001

Orbit Determination of the Mars Global Surveyor Spacecraft Using Laser Altimetry

Many of the scientific investigations of the Mars Global Surveyor (MGS) mission require high precision orbital information and some are limited entirely by its quality. These include the laser altimeter (MOLA) the Mars gravity field and atmospheric occultation investigations by radio science, and the planetary dynamics and celestial mechanics investigations. The precision of the orbits can usually be assessed by comparing overlapping orbits for a given period; but these results tend to reflect the repeatability rather than the accuracy. The re-constructed orbits from the doppler and range tracking data on MGS are (to date) at the few meter level radially, and a few hundreds of meters horizontally, using the best gravity models, presently available. With the laser altimeter on MGS we have a mechanism to measure the quality and to actually make significant improvements in the orbital accuracy by incorporating the altimetry data as a tracking datatype. By adding the altimeter measurements at orbital cross-over locations we have been able to reduce die radial error to 1 meter of less on average and have reduced the along track and out of plane error by almost 2 orders of magnitude down to a few meters. It is apparent that the altimeter observation provides a geometric strength to the orbit that it is not possible to obtain from the present doppler and the range data alone. We discuss the results obtained for the first year of the MGS mapping orbit. This work is supported by the NASA Mars Program.

Smith, David E.↗

NASA NTRS2001

From Binary Notation to Gravitational Waves: Rocket Science Made Easy

The Space Place is a NASA educational outreach program open to all NASA missions, studies, and instruments. It uses diverse media (web, print, displays, hands-on activities) to deliver high-quality products through a highly leveraged infrastructure. Additional information is contained in the original extended abstract.

Fisher, Diane K.↗

NASA NTRS2001

Achieving QoS for Aeronautical Telecommunication Networks Over Differentiated Services

Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a stand alone network which implies building an expensive separate network for ATN However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

Bai, Haowei↗