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All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

STI Program Multimedia Initiative

This paper relates the experience of the NASA Scientific and Technical Information Program in introducing multimedia within the STI Program framework. A discussion of multimedia technology is included to provide context for the STI Program effort. The STI Program's Multimedia Initiative is discussed in detail. Parallels and differences between multimedia and traditional information systems project development are highlighted. Challenges faced by the program in initiating its multimedia project are summarized along with lessons learned. The paper concludes with a synopsis of the benefits the program hopes to provide its users through the introduction of multimedia illustrated by examples of successful multimedia projects.

Cotter, Gladys A.↗
NASA NTRS1992

Recent developments at the Goddard Engineering Test Bed

Work on the Flight Telerobotic Service (FTS) since that reported in Leake (1991) is examined, and initial work on a Hubble servicing mission is outlined. A state-of-the-art force reflecting teleoperation system that uses torque control at the joints of the slave manipulator has been implemented. The master rate/slave damper mode proposed by Langley has proved to be a very efficient operational mode, allowing force reflection ratios up to one to one. A software architecture for real-time Ada robotics systems has been proposed, and implementation has been launched. This architecture builds on the lessons learned from NASA Standard Reference Model Architecture and the prototype FTS effort. The Capaciflector sensor has been integrated into the system, and it has been used to perform a basic berthing task autonomously.

Leake, Stephen↗
NASA NTRS1992

NASA's telerobotics research program

In 1985, NASA instituted a research program in telerobotics to develop and provide the technology for applications of telerobotics to the United States space program. The authors describe the goals, organizing framework, and content of that endeavor. They review the actual tasks which comprise the content of the program which has evolved significantly in terms of its content, goals, and approach. The lessons learned in that time comprise the organizing framework of the current program. This organizing framework is described.

Weisbin, C. R.↗
NASA NTRS1991

Galileo environmental test and analysis program summary

This paper presents an overview of the Galileo Project's environmental test and analysis program during the spacecraft development phase - October 1978 through launch in October 1989. After describing the top-level objectives of the program, summaries of-the approach, requirements, and margins are provided. Examples of assembly- and system-level test results are given for both the pre-1986 (direct mission) testing and the post-1986 (Venus-Earth-Earth gravity assist mission) testing, including dynamic, thermal, electromagnetic compatibility (EMC), and magnetic. The approaches and results for verifying by analysis that the requirements of certain environments (e.g., radiation, micrometeoroids, and single event upsets) are satisfied are presented. The environmental program implemented on Galileo satisfied the spirit and intent of the requirements imposed by the Project during the spacecraft's development. The lessons learned from the Galileo environmental program are discussed in this paper.

Hoffman, A. R.↗
NASA NTRS1991

Testing - Smart strategy for safety and mission quality

The paper is concerned with the need for a comprehensive test plan for the Space Station Freedom (SST) that would fully verify specification compliance and be based on an error budget. In particular, attention is given to some lessons learned from other NASA programs and the principal challenges for SSF testing, including phase C/D/E agreements, testing parameters, phase testing, and the human element. The importance of close teamwork between the NASA/Contractor systems engineers and assurance engineers is emphasized.

Rodney, George A.↗
NASA NTRS1991

Vibration testing of large structures (CLAES Instrument)

The vibration testing performed on the Cryogenic Limb Array Etalon Spectrometer (CLAES) Instrument, installed on the Upper Atmosphere Research Satellite, is discussed. The tests discussed include random vibration, model verification using random vibration, and structural verification using a low frequency sine burst. Particular attention is given to the use of the sine burst test method to verify the structural integrity. Lessons learned from the program are summarized.

Newkirk, Roger↗
NASA NTRS1993

Experiences with thin film filter development for the Extreme Ultraviolet Explorer

The design, development, and optimization of the thin film filters used on the Extreme Ultraviolet Explorer (EUVE) Satellite to define the EUV wavelength bandpasses of the individual instruments was a complicated task. The bandpasses had to be optimized for the astrophysical goals of the EUVE mission and constrained by the strong geocoronal EUV background emission. Materials with optical constants that met these requirements had to be found and tested. In many cases these materials were not compatible or were not strong enough to survive the intense vibrations of a rocket launch. Other effects, such as photoelectron 'halo' produced in the filters, were not discovered until flight qualification. The final set of flight filters included: lexan/boron, aluminum/carbon, titanium/antimony/aluminum, and tin/silicon monoxide. This paper discusses the lessons learned in the development of these filters, including the optimization process, material interactions and problems, calibration techniques, vibration susceptibility, thermal tests, and photoelectron emission. We feel the experiences gained over the last 10 years creating the filter sets for EUVE will be invaluable for future missions that use thin film filters.

Vallerga, J. V.↗
NASA NTRS1992

Test results of the SHARE II Mid-deck Flight Experiment

The SHARE II (Space Station Advanced Radiator Experiment II) Mid-deck Experiment was flown on board the Space Shuttle (STS-37) from April 5 to 12, 1991. The purpose of the experiment was to demonstrate the operation of several design changes proposed for the NASA/Grumman SHARE II heat pipe as a result of the lessons learned during the first SHARE flight (STS-29) in March 1989. Two test articles flew during the mission. The first, the Bubble Management Test Article, was a Plexiglas model of the monogroove heat pipe. This test article was primarily used to evaluate the performance of two 0-g bubble management devices; the redesigned evaporator screen artery and the condenser bubble trap. The second, the Blended Manifold Priming Test Article, also constructed of Plexiglas, was used to demonstrate passive self-priming of a heat pipe blended manifold connecting three evaporator legs to a single condenser leg. Both test articles used a 50/50 mixture of ethanol and water as the working fluid. Overall, the experiment was highly successful, with all the major test objectives fulfilled, including blended manifold priming, condenser bubble trap operation, screen artery bubble ingestion, and elimination of hydraulic diameter mismatch.

Brown, Richard F.↗
NASA NTRS1992

Flight research on natural laminar flow applications

Natural laminar flow (NLF) is clearly one of the most potentially attractive drag reduction technologies by virtue of its relative simplicity. NLF is achieved passively, that is, by design of surface shapes to produce favorable pressure gradients. However, it is not without its challenges and limitations. This chapter describes the significant challenges to achieving and maintaining NLF and documents certain of the limitations for practical applications. A brief review of the history and of more recent NLF flight experiments is given, followed by a summary of lessons learned which are pertinent to future applications. The chapter also summarizes important progress in test techniques, particularly in flow visualization and hot-film techniques for boundary-layer measurements in flight.

Holmes, Bruce J.↗
NASA NTRS1993

Topex Microwave Radiometer thermal control - Post-system-test modifications and on-orbit performance

The Topex Microwave Radiometer has had an excellent thermal performance since launch. The instrument, however, went through a hardware modification right before launch to correct for a thermal design inadequacy that was uncovered during the spacecraft thermal vacuum test. This paper reports on how the initially obscure problem was tracked down, and how the thermal models were revised, validated, and utilized to investigate the solution options and guide the hardware modification decisions. Details related to test data interpretation, analytical uncertainties, and model-prediction vs. test-data correlation, are documented. Instrument/spacecraft interface issues, where the problem originated and where in general pitfalls abound, are dealt with specifically. Finally, on-orbit thermal performance data are presented, which exhibit good agreement with flight predictions, and lessons learned are discussed.

Lin, Edward I.↗
NASA NTRS1993

Review of NASA's Hypersonic Research Engine Project

The goals of the NASA Hypersonic Research Engine (HRE) Project, which began in 1964, were to design, develop, and construct a hypersonic research ramjet/scramjet engine for high performance and to flight-test the developed concept over the speed range from Mach 3 to 8. The project was planned to be accomplished in three phases: project definition, research engine development, and flight test using the X-15A-2 research aircraft, which was modified to carry hydrogen fuel for the research engine. The project goal of an engine flight test was eliminated when the X-15 program was canceled in 1968. Ground tests of engine models then became the focus of the project. Two axisymmetric full-scale engine models having 18-inch-diameter cowls were fabricated and tested: a structural model and a combustion/propulsion model. A brief historical review of the project with salient features, typical data results, and lessons learned is presented.

Andrews, Earl H.↗
NASA NTRS1993

Evolving directions in NASA's planetary rover requirements and technology

This paper reviews the evolution of NASA's planning for planetary rovers (i.e. robotic vehicles which may be deployed on planetary bodies for exploration, science analysis, and construction) and some of the technology that has been developed to achieve the desired capabilities. The program is comprised of a variety of vehicle sizes and types in order to accommodate a range of potential user needs. This includes vehicles whose weight spans a few kilograms to several thousand kilograms; whose locomotion is implemented using wheels, tracks, and legs; and whose payloads vary from microinstruments to large scale assemblies for construction. We first describe robotic vehicles, and their associated control systems, developed by NASA in the late 1980's as part of a proposed Mars Rover Sample Return (MRSR) mission. Suggested goals at that time for such an MRSR mission included navigating for one to two years across hundreds of kilometers of Martian surface; traversing a diversity of rugged, unknown terrain; collecting and analyzing a variety of samples; and bringing back selected samples to the lander for return to Earth. Subsequently, we present the current plans (considerably more modest) which have evolved both from technological 'lessons learned' in the previous period, and modified aspirations of NASA missions. This paper describes some of the demonstrated capabilities of the developed machines and the technologies which made these capabilities possible.

Weisbin, C. R.↗
NASA NTRS1990

Intelligent systems engineering methodology

An added challenge for the designers of large scale systems such as Space Station Freedom is the appropriate incorporation of intelligent system technology (artificial intelligence, expert systems, knowledge-based systems, etc.) into their requirements and design. This presentation will describe a view of systems engineering which successfully addresses several aspects of this complex problem: design of large scale systems, design with requirements that are so complex they only completely unfold during the development of a baseline system and even then continue to evolve throughout the system's life cycle, design that involves the incorporation of new technologies, and design and development that takes place with many players in a distributed manner yet can be easily integrated to meet a single view of the requirements. The first generation of this methodology was developed and evolved jointly by ISX and the Lockheed Aeronautical Systems Company over the past five years on the Defense Advanced Research Projects Agency/Air Force Pilot's Associate Program, one of the largest, most complex, and most successful intelligent systems constructed to date. As the methodology has evolved it has also been applied successfully to a number of other projects. Some of the lessons learned from this experience may be applicable to Freedom.

Fouse, Scott↗
NASA NTRS1992

Proceedings of the Seventeenth Annual Software Engineering Workshop

Proceedings of the Seventeenth Annual Software Engineering Workshop are presented. The software Engineering Laboratory (SEL) is an organization sponsored by NASA/Goddard Space Flight Center and created to investigate the effectiveness of software engineering technologies when applied to the development of applications software. Topics covered include: the Software Engineering Laboratory; process measurement; software reuse; software quality; lessons learned; and is Ada dying.

Source record↗
NASA NTRS1993

Visual Earth observation performance in the space environment. Human performance measurement 4: Flight experiments

A wide variety of secondary payloads have flown on the Space Transportation System (STS) since its first flight in the 1980's. These experiments have typically addressed specific issues unique to the zero-gravity environment. Additionally, the experiments use the experience and skills of the mission and payload specialist crew members to facilitate data collection and ensure successful completion. This paper presents the results of the Terra Scout experiment, which flew aboard STS-44 in November 1991. This unique Earth Observation experiment specifically required a career imagery analyst to operate the Spaceborne Direct-View Optical System (SpaDVOS), a folded optical path telescope system designed to mount inside the shuttle on the overhead aft flight deck windows. Binoculars and a small telescope were used as backup optics. Using his imagery background, coupled with extensive target and equipment training, the payload specialist was tasked with documenting the following: (1) the utility of the equipment; (2) his ability to acquire and track ground targets; (3) the level of detail he could discern; (4) the atmospheric conditions; and (5) other in-situ elements which contributed to or detracted from his ability to analyze targets. Special emphasis was placed on the utility of a manned platform for research and development of future spaceborne sensors. The results and lessons learned from Terra Scout will be addressed including human performance and equipment design issues.

Huth, John F.↗
NASA NTRS1993

Solar dynamic power system development for Space Station Freedom

The development of a solar dynamic electric power generation system as part of the Space Station Freedom Program is documented. The solar dynamic power system includes a solar concentrator, which collects sunlight; a receiver, which accepts and stores the concentrated solar energy and transfers this energy to a gas; a Brayton turbine, alternator, and compressor unit, which generates electric power; and a radiator, which rejects waste heat. Solar dynamic systems have greater efficiency and lower maintenance costs than photovoltaic systems and are being considered for future growth of Space Station Freedom. Solar dynamic development managed by the NASA Lewis Research Center from 1986 to Feb. 1991 is covered. It summarizes technology and hardware development, describes 'lessons learned', and, through an extensive bibliography, serves as a source list of documents that provide details of the design and analytic results achieved. It was prepared by the staff of the Solar Dynamic Power System Branch at the NASA Lewis Research Center in Cleveland, Ohio. The report includes results from the prime contractor as well as from in-house efforts, university grants, and other contracts. Also included are the writers' opinions on the best way to proceed technically and programmatically with solar dynamic efforts in the future, on the basis of their experiences in this program.

Source record↗
NASA NTRS1992

Spacecraft COst REduction Team (SCORE): TQM/CI on a massive scale

The business of building satellites and space systems has matured. Few missions require, or can afford, excellent performance at any price. The new paradigm is doing more with less, providing quality systems at lower cost--in other words, doing our job 'Faster-Better-Cheaper.' The TRW Spacecraft COst REduction (SCORE) initiative was launched in 1990 by Daniel S. Goldin, then general manager of TRW's Space & Technology Group. The SCORE mission is to apply continuous improvement (CI) techniques to effect major reductions in the cost (our primary goal) and span time (as a corollary) required for the production of spacecraft. SCORE is a multi-year initiative that is having a profound effect on both the procedural and the cultural aspects of how we do business. The objectives of this initiative are being realized. The focus of this paper is not on the results of SCORE per se, but rather on the things we have leaned about how to do continuous improvement on a massive scale, with multilevel (hierarchical) CI teams. The following sections summarize the chronology of the SCORE initiative, from team formation to development of the year-end report for 1991. Lessons learned, the core of this presentation, are discussed--with particular focus on the unique aspects of SCORE. The SCORE initiative is continuing and, as a part of our evolving culture, will never end. It has resulted in profound insights into the way we do work and (the topic at hand) how to do CI for large and complex multidisciplinary development activities.

Bullard, Jerry D.↗
NASA NTRS1992

NASA/contractor partnership on the second TDRSS ground terminal program: Breaking barriers

The Second Tracking and Data Relay Satellite System (TDRSS) Ground Terminal (STGT) Program from its technical and programmatic backgrounds is introduced and then several techniques to enhance communication and empower the NASA Contractor team are described. A major factor in our success was an approach used to shorten the time span of the Critical Design Review phase. This approach is described. The relationships involving NASA's O&M contractor are discussed. A set of lessons learned is included.

Tierney, Paul G.↗