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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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Program plans are given for an integrating controller for space station autonomy as well as for controls and displays. The technical approach, facility requirements and candidate facilities, development schedules, and resource requirements estimates are given.
An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. The test engine delivered 78kW indicated power from 1007cc displacement, operating at 3500 RPM on Schnuerle loop scavenged two-stroke cycle. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude, in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit design of a multicylinder engine for eventual flight applications; including injection system requirement, turbocharging, heat rejection, breathing, scavenging, and structural requirements. The multicylinder engine concept is configured to operate with an augmented turbocharger, but with no primary scavenge blower. The test program is oriented to provide a balanced turbocharger compressor to turbine power balance without an auxiliary scavenging system. Engine cylinder heat rejection to the ambient air has been significantly reduced and the minimum overall turbocharger efficiency required is within the range of commercially available turbochargers. Analytical studies and finite element modeling is made of insulated configurations of the engines - including both ceramic and metallic versions. A second generation test engine is designed based on current test results.
An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit a design of a multicylinder engine for eventual flight applications.
An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit design of a multicylinder engine for eventual flight applications.
The present discussion of the X-29A forward-swept wing experimental aircraft's functional flight program and concept evaluation program gives attention to the program management structure for a test team that encompasses NASA, the U.S. Air Force, and the prime contractor for the X-29A. The preflight, flight-functional, envelope-expansion and flight research test objectives of the program are also noted, together with the qualitative characterizations obtained to date for both a limited envelope flight control system and one for an expanded envelope.
The paper discusses the design of a tiltrotor blade for application to the XV-15 research demonstration aircraft. The design features 43 deg nonlinear twist and nonuniform tapered planform. The structure is composite with extensive use of graphite in the primary structure. Instrumentation and wiring is encapsulated in the composite structure during the cure cycle. The tip shell is removable, providing access to the tracking and balance weights. This feature provides research facility of alternate tip configurations. The cuff is similarly removable. The graphite epoxy system used is high strain American Cyanamid's Celion 6000ST/Cycom 950. This is the first application of this material in rotor blades.
A set of quantitative approaches is presented for evaluating software development methods and tools. The basic idea is to generate a set of goals which are refined into quantifiable questions which specify metrics to be collected on the software development and maintenance process and product. These metrics can be used to characterize, evaluate, predict, and motivate. They can be used in an active as well as passive way by learning form analyzing the data and improving the methods and tools based upon what is learned from that analysis. Several examples were given representing each of the different approaches to evaluation. The cost of the approaches varied inversely with the level of confidence in the interpretation of the results.
The motivations, features and expected benefits and applications of the NASA SMART program are summarized. SMART is intended to push the state of the art in automation and robotics, a goal that Public Law 98-371 mandated be an inherent part of the Space Station program. The effort would first require tests of sensors, manipulators, computers and other subsystems as seeds for the evolution of flight-qualified subsystems. Consideration is currently being given to robotics systems as add-ons to the RMS, MMU and OMV and a self-contained automation and robotics module which would be tended by astronaut visits. Probable experimentation and development paths that would be pursued with the equipment are discussed, along with the management structure and procedures for the program. The first hardware flight is projected for 1989.
The need for advances in ceramic techniques in order to manufacture reliable cost-effective ceramic components for automotive gas turbine engines, in particular in the hot section of the engine, is examined. The objectives of the ATTAP is to establish the reliability of ceramic component designs and materials in automotive gas turbines; to expand the experimental data base in the operation environment; and to complete the development of analytical tools needed to support industry in the successful application of ceramics to long-life turbine engines. The role of industry and the government in the development of the gas turbine engine is discussed.
The paper reports the ongoing development of a telerobot demonstrator. The demonstrator is implemented as a laboratory-based research testbed, and will show proof-of-concept for supervised automation of space assembly, servicing, and repair operations. The demonstrator system features a hierarchically layered intelligent control architecture which enables automated planning and run-time sequencing of complex tasks by a supervisory human operator. The demonstrator also provides a full bilateral force-reflecting hand control teleroperations capability. The operator may switch smoothly between the automated and teleroperated tasking modes in run-time, either on a preplanned or operator-designated basis.
The objectives were to identify the space station waste gases and their characteristics, and to investigate compressor and dryer types, as well as transport and storage requirements with tradeoffs leading to a preliminary system definition.
The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions.
Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.
An overview of the Vented Tank Resupply Experiment (VTRE) program is presented in outline and graphical form. The goal of the program is to develop, design, build and provide flight and post flight support for a Shuttle Hitchhiker Experiment to investigate and demonstrate vented tank venting in space. Program schedules and experiment subsystem schematics are presented and specific technical objectives, power requirements, payload assemblies, Hitchhiker canister integration, and orbiter mission approach are addressed.
A 650 Mbps laser communications testbed under construction for the development of flight qualifiable hardware suitable for near-term operation on geosynchronous-to-geosynchronous crosslink missions is presented. The program's primary purpose is to develop and optimize laser communications unique subsystems. Requirements for the testbed experiments are to optimize the acquisition processes, to fully simulate the long range (up to 21,000 km) and the fine tracking characteristics of two narrow-beam laser communications terminals, and to fully test communications performance which will include average and burst bit error rates, effects of laser diode coalignment, degradation due to internal and external stray light, and the impact of drifts in the optical components.
This is a one year contract starting on April 1, 2001 to design the Rapid Infrared and Visible Multiple Object Spectrometer (RIVMOS) and its auxiliary dispersing elements, design and fabricate silicon grisms, and reduce testing data with silicon grisms. Here I report our progress made during the funding period.
This is a one-year program starting on April 15,2003 to develop two infrared silicon grism for Rapid Visible and Infrared Multiple Object Spectrometer (RIVMOS) for observations in 1.1 - 5 microns.
Solar Sailcraft, the stuff of dreams of the H.G. Wells generation, is now a rapidly maturing reality. The promise of unlimited propulsive power by harnessing stellar radiation is close to realization. Currently, efforts are underway to build, prototype and test two configurations. These sails are designed to meet a 20m sail requirement, under guidance of the In-Space Propulsion (ISP) technology program office at MSFC. While these sails will not fly , they are the first steps in improving our understanding of the processes and phenomena at work. As part of the New Millennium Program (NMP) the ST9 technology validation mission hopes to launch and fly a solar sail by 2010 or sooner. Though the Solar Sail community has been studying and validating various concepts over two decades, it was not until recent breakthroughs in structural and material technology, has made possible to build sails that could be launched. With real sails that can be tested (albeit under earth conditions), the real task of engineering a viable spacecraft has finally commenced. Since it is not possible to accurately or practically recreate the actual operating conditions of the sailcraft (zero-G, vacuum and extremely low temperatures), much of the work has focused on developing accurate models that can be used to predict behavior in space, and for sails that are 6-10 times the size of currently existing sails. Since these models can be validated only with real test data under "earth" conditions, the process of modeling and the identification of uncertainty due to model assumptions and scope need to be closely considered. Sailcraft models that exist currently, are primarily focused on detailed physical representations at the component level, these are intended to support prototyping efforts. System level models that cut across different sail configurations and control concepts while maintaining a consistent approach are non-existent. Much effort has been focused on the areas of thrust performance, solar radiation prediction, and sail membrane behavior vis-a-vis their reflective geometry, such as wrinkling/folding/furling as it pertains to thrust prediction. A parallel effort has been conducted on developing usable models for developing attitude control systems (ACS), for different sail configurations in different regimes. There has been very little by way of a system wide exploration of the impact of the various control schemes, thrust prediction models for different sail configurations being considered.