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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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A number of missions have recently been proposed that aim to take advantage of the growing scientific interest in the region of space near libration points in the Sun-Earth system. In support of missions that include increasingly complex trajectories and incorporate libration point orbits, more efficient techniques and new philosophies for design must be considered.
This study deals with aircraft material and structural requirements, advantages of composites, airframe and engine applications, design procedures, problem areas, and future trends in civil aircraft. The selection of materials and design of structure for any given component or part must be made not only on the basis of the mechanical and structural functions, but must also consider the operational and cost parameters for civil aircraft. Composites have caused the orientation to shift from a metal-based philosophy for design, where only incremental improvements could be anticipated, to one where substantial changes in design approaches are possible. Future designs are likely to include a combination of new approaches and composite materials.
A design study of commercial V/STOL transport airplanes for a 1985 operational time period has been made. The baseline mission considered was 400 nmi at a cruise speed of M = 0.75 and a 100-passenger payload with VTOL. Variations from the baseline included mission distance, payload, cruise speed, and propulsion system failure philosophy. All designs used propulsion systems consisting of multiple gas generators driving remote tip turbine lift and lift/cruise fans. By considering the fan to be designed for operational reliability, significant simplication of the airplane systems and reduction in airplane size and cost can be achieved.
The revolution and application of dexterous robotics in the undersea energy production industry and how this mature technology has affected planned SSF dexterous robotic tasks are examined. Undersea telerobotics, or Remotely Operated Vehicles (ROV's), have evolved in design and use since the mid-1970s. Originally developed to replace commercial divers for both planned and unplanned tasks, they are now most commonly used to perform planned robotic tasks in all phases of assembly, inspection, and maintenance of undersea structures and installations. To accomplish these tasks, the worksites, the tasks themselves, and the tools are now engineered with both the telerobot's and the diver's capabilities in mind. In many cases, this planning has permitted a reduction in telerobot system complexity and cost. The philosophies and design practices that have resulted in the successful incorporation of telerobotics into the highly competitive and cost conscious offshore production industry have been largely ignored in the space community. Cases where these philosophies have been adopted or may be successfully adopted in the near future are explored.
An approach is outlined for the development of ultrareliable avionics for civil air transports using a design-for-validation philosophy that includes rigorous application of formal methods. The basic concept of the methodology is introduced, and the role of formal methods is explored. The impact of the design-for-validation philosophy on the system design process is then demonstrated by two simple examples. More details about the design-for-validation methodology are then given.
PySCF is a Python-based general-purpose electronic structure platform that supports first-principles simulations of molecules and solids as well as accelerates the development of new methodology and complex computational workflows. Here, we explain the design and philosophy behind PySCF that enables it to meet these twin objectives. With several case studies, we show how users can easily implement their own methods using PySCF as a development environment. We then summarize the capabilities of PySCF for molecular and solid-state simulations. Finally, we describe the growing ecosystem of projects that use PySCF across the domains of quantum chemistry, materials science, machine learning, and quantum information science.
Fermilab, the birthplace of many scientific discoveries in physics and particle accelerator sciences, is in the midst of a widescale modernization effort. The Accelerator Control Operations Research Network (ACORN project’s goal is to modernize the accelerator control system by replacing end-of-life power supplies and enhance future operations of the Fermilab accelerator complex with megawatt particle beams. Within ACORN, opportunities for process improvement concerning software development, human-system interface design, and task performance are also being considered. Human factors researchers from Idaho National Laboratory in collaboration with usability experts from Fermilab, are currently investigating human-centered design improvements for the accelerator control system. For example, substantial tribal knowledge and memory recall are required to effectively operate the accelerator system. This contributes to high cognitive workload and potential burnout of accelerator operators. Developing guidance for consistent visual and functional design enables a more intuitive interaction and relieves operators of cognitive burden. Additionally, developing more intuitive and integrated interfaces can also lead to improved accelerator efficacy by empowering operators with greater understanding and control of the systems. The challenge in developing such interfaces is in designing for a wide variety of user goals, system specifications, and level of experience in users. The challenges need to be met while e also considering the maintainability of the control system. The purpose of this paper is to detail the human factors process and design within the ACORN project, describe results gathered thus far, and discuss the larger implications for this work.
Reexamination of jet engine, heat pipes, thermionic diode, Rankine cycle space power systems, discussing redesign possibilities
An investigation was made to formulate and evaluate heat pipe applications for the space shuttle orbiter. Of the twenty-seven specific applications which were identified, a joint evaluation resulted in the selection of five of the most promising ones for prototype development. The formulation process is described, along with the applications which evolved. The bulk of the discussion deals with the top five applications: (1) heat pipe augmented cold rail; (2) avionics heat pipe circuit; (3) heat pipe/phase change material modular sink; (4) air-to-heat-pipe heat exchanger; and (5) heat pipe radiator for compartment temperature control. The philosophy, physical design details, and performance data are presented for each concept along with a comparison to the baseline design where applicable. A sixth application, heat pipe space radiator for waste heat rejection, was also recommended for prototype development.
Discussion of six specific applications for heat pipe (HP) devices on the space shuttle. These applications were chosen from 27 concepts formulated as part of a study to evaluate the potential benefits associated with HP use. The formulation process is briefly described along with the applications which evolved. The bulk of the discussion deals with the 'top' six - namely, HP radiators for waste heat rejection, an HP augmented cold rail, an HP circuit for electronic equipment cooling, modular heat sink for control of remote packages, an HP temperature control for compartments, and air-cooled equipment racks. The philosophy, physical design details, and performance data are presented for each concept along with a comparison with the baseline design where applicable.
The Pioneer 6 to 9 interplanetary spacecraft were launched in 1965, 66, 67, and 68. All continued to operate in orbits about the sun, gathering data on the solar system environment near one astronomical unit (AU) from the sun. Pioneer 10 was launched in March 1972, returned information about the planet Jupiter which it encountered in December 1973, and is now operating at six AU from the sun on a solar system escape trajectory. Pioneer 11, launched in April 1973, will encounter Jupiter in December 1974. The long-term mission success and performance of these programs (with emphasis on Pioneers 10 and 11) is reviewed in terms of these factors: philosophy of design for uncertain environments, simplicity in operation, redundancy, the test program, and the actual environment encountered.
As future LTA vehicles will be doomed right from the start if they do not fill a real need, some differences in transport philosophy between design engineers on the one hand and freight forwarders on the other are discussed. Watching rising costs of energy necessary to transport our cargo from A to B, and realizing that this price of energy is always included in the product's selling price at B, the apparent correlation between installed specific tractive force per unit of cargo weight and pure freighting cost are contemplated. Very speedy and progressive Airship designs are mistrusted, because the key to any low cost transport tool is to design it for its given task only, without any unnecessary sophistication.
In modern fighter aircraft air-to-air missile launch acceptable ranges (LARs) are provided to the pilot for his launch decision. These LARs are calculated in the avionic software, using very simple algebraic equations and algorithms, that attempt to model complex missile behavior. Frequently these algorithms are revised to reflect inaccuracies discovered, when comparisons are made with missile six degree-of-freedom (6-DOF) simulations. The process of modifying this software has become expensive. In the past, these simple LAR generators were modified based only on subjective judgmental approach, with little regard to the missile range design limits. With reduced budgets a more rational methodology should be taken to assess whether or not simple fighter LAR generators need to be modified. Any LAR generator can produce large amounts of range (minimum and maximum) data over the board engagement limits of modem fighter and air-to-air missiles. This infinite population lends itself to some statistical methodology to access simple LAR accuracy and the need for software modification. The methodology should produce statistical parameters for use in the decision making process of modifying a simple fighter LAR generator. This paper presents a regression method, based on a missile range design limit philosophy. Acceptance criteria from the regression method are given that provide simple statistical parameters to aid in this decision making process.
The development and utilization of informational archives and databases started, in the Italian Astronet Project, in the middle of 1983. In that year, a small group of astronomers and some more technical people met together in an Astronet working group, with a common, painful experience in managing astronomical catalogues and archives with computers. Nowadays, some years later, some software packages and the contents of both, a relative general database and several local databases represent the work and the effort of the group. The systems have been conceived and developed keeping in mind the original goal of the group: to allow the single atronomer to make a free use of original data. The main package (DIRA) was rewritten, after some years of use, to fully take advantage of the several suggestions of the astronomer that used it and gathered experiences in the astronomical catalog's management. A more technical goal was to install the whole system, born and developed in the vms environment, on unix and unix-like systems. This new version, DIRA2, has a new user interface, a query language with SQL style commands supporting numerical and character functions also and a set of commands to create new catalogues from existing data. The graphics commands are also more powerful with respect to the previous version. DIRA (and DIRA2 of course) philosophy and design are very simple and proved to be very appreciated by astronomers, namely, to normalize and homogenize, at minimum, astronomical catalogues, to collect satisfactory astronomical documentation on their contents and, finally, to allow an astronomical approach to the dialogue with the database. DIRA2 is currently used in most Italian astronomical institutes to retrieve data from a still growing database of about 140 well documented and controlled astronomical catalogues, for the identification of objects and the preparation of a 'medium size' survey, in astrometry and in the creation of new catalogues.
While systems engineering process is a program formal management technique and contractually binding, the design process is the informal practice of achieving the design project requirements throughout all design phases of the systems engineering process. The design process and organization are systems and component dependent. Informal reviews include technical information meetings and concurrent engineering sessions, and formal technical discipline reviews are conducted through the systems engineering process. This paper discusses and references major philosophical principles in the design process, identifies its role in interacting systems and disciplines analyses and integrations, and illustrates the process application in experienced aerostructural designs.
Friction Stir Welding (FSW) is a new and innovative solid-state joining process which can be applied to difficult-to- weld aluminum alloys. However, the large forces involved with the process have posed a production tooling challenge. Lockheed Martin Michoud Space Systems has overcome many of these challenges on the Super Lightweight External Tank (ET) program. Utilizing Aluminum-Copper-Lithium alloy 2195 in the form of plate and extrusions, investigations of FSW process parameters have been completed. Major loading mechanisms are discussed in conjunction with deflection measurements. Since the ET program is a cryogenic application, a brief comparison of cryogenic material properties with room temperature material properties is offered for both FSW and fusion welds. Finally, a new approach to controlling the FSW process from a load perspective is introduced. Emphasis will be put on tooling development, as well as the impact of tooling design and philosophy on Friction Stir Weld success probability.
Current trends in spacecraft development include the use of advanced technologies while maintaining the "faster, better, cheaper" philosophy. Spacecraft designers are continually designing with smaller and faster electronics as well as lighter and thinner materials providing better performance, lower weight, and ultimately lower costs. Given this technology trend, spacecraft will become increasingly susceptible to the harsh space environments, causing damaging or even disabling effects on space systems. NASA's Space Environments and Effects (SEE) Program defines the space environments and provides advanced technology development to support the design, development, and operation of spacecraft systems that will accommodate or mitigate effects due to the harsh space environments. This Program provides a comprehensive and focused approach to understanding the space environment, to define the best techniques for both flight and ground-based experimentation, to update the models which predict both the environments and the environmental effects on spacecraft, and finally to ensure that this multitudinous information is properly maintained and inserted into spacecraft design programs. A description of the SEE Program, its accomplishments, and future activities is provided.
Thermal images, or infrared images, are representations of the world based on heat, instead of visible light. Research has shown that the resulting thermal image results in perceptual differences leading to difficulties in interpretation (e.g., the determination of slope angle, concavity/convexity), or increased identification latencies. A joint research project between the United States (NASA and U.S. Army) and Israel (Ministry of Defense and Israel Air Force) has resulted in the development of a prototype part-task trainer for the acquisition of perceptual skills associated with thermal imaging usage. This prototype system is videodisk-based under computer control, using recordings of thermal images. A lesson section introduces declarative knowledge, in which the basic physics and heuristics of thermal imagery are taught. An exercise section teaches procedural knowledge, with the user viewing dynamic, actual imagery, with an interactive detection/location determination task. The general philosophy and design of the trainer will be demonstrated.