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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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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Aerospace Safety Advisory Panel

An assessment of NASA's safety performance for 1983 affirms that NASA Headquarters and Center management teams continue to hold the safety of manned flight to be their prime concern, and that essential effort and resources are allocated for maintaining safety in all of the development and operational programs. Those conclusions most worthy of NASA management concentration are given along with recommendations for action concerning; product quality and utility; space shuttle main engine; landing gear; logistics and management; orbiter structural loads, landing speed, and pitch control; the shuttle processing contractor; and the safety of flight operations. It appears that much needs to be done before the Space Transportation System can achieve the reliability necessary for safe, high rate, low cost operations.

Source record↗
NASA NTRS1993

The Bunny: A simulated commercial air transportation study

The Bunny is a single-engine, 100 passenger commercial transport designed to serve the high density short-to-medium range markets in AEROWORLD. The aircraft's design range is 10,000 feet at a cruise velocity of 30 ft/s. The aircraft features a low wing which incorporates polyhedral for roll control. Yaw and pitch control are accomplished by a rudder and elevator, respectively. Propulsion is provided by a nose-mounted Astro 15 electric motor powered by thirteen 1.2 V, 1000 mah batteries with a Zinger 12-6 propeller. The aircraft is structurally designed with a safety factor of 1.5 and is constructed primarily of balsa, bass, and birch wood. Passenger seating is arranged on two levels, with three-abreast on the lower level and two-abreast on the upper level. The factors which had the most significant influence on the final design were the direct operating cost and the take-off distance. The primary strength of The Bunny is its ability to compete economically with the HB-40. At full capacity and mid-range fuel costs, the cost per seat per thousand feet (CPSK) of this aircraft is 25% less than the HB-40. Another principal strength is its ability to operate in all airports in AEROWORLD. Also, The Bunny's two-piece removable wing is an advantage from a transportability standpoint.

Fulton, David↗
NASA NTRS1999

Autonomous Navigation Using Celestial Objects

In the twenty-first century, National Aeronautics and Space Administration (NASA) Enterprises envision frequent low-cost missions to explore the solar system, observe the universe, and study our planet. Satellite autonomy is a key technology required to reduce satellite operating costs. The Guidance, Navigation, and Control Center (GNCC) at the Goddard Space Flight Center (GSFC) currently sponsors several initiatives associated with the development of advanced spacecraft systems to provide autonomous navigation and control. Autonomous navigation has the potential both to increase spacecraft navigation system performance and to reduce total mission cost. By eliminating the need for routine ground-based orbit determination and special tracking services, autonomous navigation can streamline spacecraft ground systems. Autonomous navigation products can be included in the science telemetry and forwarded directly to the scientific investigators. In addition, autonomous navigation products are available onboard to enable other autonomous capabilities, such as attitude control, maneuver planning and orbit control, and communications signal acquisition. Autonomous navigation is required to support advanced mission concepts such as satellite formation flying. GNCC has successfully developed high-accuracy autonomous navigation systems for near-Earth spacecraft using NASA's space and ground communications systems and the Global Positioning System (GPS). Recently, GNCC has expanded its autonomous navigation initiative to include satellite orbits that are beyond the regime in which use of GPS is possible. Currently, GNCC is assessing the feasibility of using standard spacecraft attitude sensors and communication components to provide autonomous navigation for missions including: libration point, gravity assist, high-Earth, and interplanetary orbits. The concept being evaluated uses a combination of star, Sun, and Earth sensor measurements along with forward-link Doppler measurements from the command link carrier to autonomously estimate the spacecraft's orbit and reference oscillator's frequency. To support autonomous attitude determination and control and maneuver planning and control, the orbit determination accuracy should be on the order of kilometers in position and centimeters per second in velocity. A less accurate solution (one hundred kilometers in position) could be used for acquisition purposes for command and science downloads. This paper provides performance results for both libration point orbiting and high Earth orbiting satellites as a function of sensor measurement accuracy, measurement types, measurement frequency, initial state errors, and dynamic modeling errors.

Folta, David↗
NASA NTRS2000

Using Model-Based Reasoning for Autonomous Instrument Operation

Multiprobe missions are an important part of NASA's future: Cluster, Magnetospheric Multi Scale, Global Electrodynamics and Magnetospheric Constellation are representatives from the Sun-Earth Connections Theme. To make such missions robust, reliable, and affordable, ideally the many spacecraft of a constellation must be at least as easy to operate as one spacecraft is today. To support this need for scalability, science instrumentation must become increasingly easy to operate, even as this same instrumentation becomes more capable and advanced. Communication and control resources will be at a premium for future instruments. Many missions will be out of contact with ground operators for extended periods either to reduce operations cost or because of orbits that limit communication to weekly perigee transits. Autonomous capability is necessary if such missions are to effectively achieve their operational objectives. An autonomous system is one that acts given its situation in a mission appropriate manner without external direction to achieve mission goals. To achieve this capability autonomy must be built into the system through judicious design or through a built-in intelligence that recognizes system state and manages system response. To recognize desired or undesired system states, the system must have an implicit or explicit understanding of its expected states given its history and self observations. The systems we are concerned with, science instruments, can have stringent requirements for system state knowledge in addition to requirements driven by health and safety concerns. Without accurate knowledge of the system state, the usefulness of the science instrument may be severely limited. At the same time, health and safety concerns often lead to overly conservative instrument operations further reducing the effectiveness of the instrument. These requirements, coupled with overall mission requirements including lack of communication opportunities and tolerance of environmental hazards, frame the problem of constructing autonomous science instruments. we are developing a model of the Low Energy Neutral Atom instrument (LENA) that is currently flying on board the Imager for Magnetosphere-to-Aurora Global Exploration (IMAGE) spacecraft. LENA is a particle detector that uses high voltage electrostatic optics and time-of-flight mass spectrometry to image neutral atom emissions from the denser regions of the Earth's magnetosphere. As with most spacecraft borne science instruments, phenomena in addition to neutral atoms are detected by LENA. Solar radiation and energetic particles from Earth's radiation belts are of particular concern because they may help generate currents that may compromise LENA's long term performance. An explicit model of the instrument response has been constructed and is currently in use on board IMAGE to dynamically adapt LENA to the presence or absence of energetic background radiations. The components of LENA are common in space science instrumentation, and lessons learned by modelling this system may be applied to other instruments. This work demonstrates that a model-based approach can be used to enhance science instrument effectiveness. Our future work involves the extension of these methods to cover more aspects of LENA operation and the generalization to other space science instrumentation.

Johnson, Mike↗
NASA NTRS2001

A Study of the Economic Benefit Potential of Intermodal Transports

A conceptual study was conducted to determine the benefit potential of an Intermodal Transport in which quick change payload modules are used to reduce the cost of air travel by increasing daily utilization. Three basic concepts varying the degree of modularity were investigated for a 122,000 pounds payload 3,000 NM range regional wide body transport. The profit potential for operating as a passenger transport during the day and as a freighter at night was assessed. Assuming current levels of profitability, Intermodal operations could offer an operating cost reduction potential up to 20%. Enabling technology needs are identified as very quiet aircraft for expanded night operations, distributed load carrying quick disconnect latching, and configuration dependent safety issues. Recommendations are made to explore if additional benefits are possible from alternative mission and usage modules.

Nelson, J. M.↗
NASA NTRS1986

Design concepts to improve high performance solar simulator

By improving several important components of the well known off-axis solar simulator system, a considerable step forward was made. The careful mathematical studies on the optics and the thermal side of the problem lead to a highly efficient system with low operational costs and a high reliability. The actual performance of the simulator is significantly better than the specified one, and the efficiency is outstanding. No more than 12 lamps operating at 18 kW are required to obtain one Solar Constant in the 6 m beam. It is now known that by using sophisticated optics, even larger facilities of high performance can be designed without leaving the proven off-axis concept and using a spherical mirror. Using high performance optics is a means of reducing costs at a given size of beam because the number of lamps is one of the most cost driving factors in the construction of a solar simulator.

Juranek, H. J.↗
NASA NTRS1983

New Directions: 1982-2000

The major objective of the Deep Space Network in the period 1983-2000 is the fulfillment of the extremely diverse telecommunications requirements of the known and anticipated users. Deep space exploration projects will continue to occupy a dominant role, although in the mid-1980s, with the completion of the Networks Consolidation Program, high Earth orbiter projects will become substantial users of the Network. Also playing an increasingly important role in the Network of the next decade will be non-flight projects, such as Geodynamics, Radio Astronomy, Radar Astronomy, and the Search for Extraterrestrial Intelligence (SETI). The major challenge in meeting the primary Network objective of the next decade will be that of providing increased performance as required by users at costs which can be borne by NASA in an environment of limited resources. Emphasis will be on increased commonality, flexibility, and automation to reduce maintenance and operations costs, and lower mission costs.

Renzetti, N. A.↗
NASA NTRS1985

Energy Efficient Engine Program Advanced Turbofan Nacelle Definition Study

Advanced, low drag, nacelle configurations were defined for some of the more promising propulsion systems identified in the earlier Benefit/Cost Study, to assess the benefits associated with these advanced technology nacelles and formulate programs for developing these nacelles and low volume thrust reversers/spoilers to a state of technology readiness in the early 1990's. The study results established the design feasibility of advanced technology, slim line nacelles applicable to advanced technology, high bypass ratio turbofan engines. Design feasibility was also established for two low volume thrust reverse/spoiler concepts that meet or exceed the required effectiveness for these engines. These nacelle and thrust reverse/spoiler designs were shown to be applicable in engines with takeoff thrust sizes ranging from 24,000 to 60,000 pounds. The reduced weight, drag, and cost of the advanced technology nacelle installations relative to current technology nacelles offer a mission fuel burn savings ranging from 3.0 to 4.5 percent and direct operating cost plus interest improvements from 1.6 to 2.2 percent.

Howe, David C.↗
NASA NTRS2012

The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

Robuck, Mark↗
NASA NTRS1996

Decision-Aiding and Optimization for Vertical Navigation of Long-Haul Aircraft

Most decisions made in the cockpit are related to safety, and have therefore been proceduralized in order to reduce risk. There are very few which are made on the basis of a value metric such as economic cost. One which can be shown to be value based, however, is the selection of a flight profile. Fuel consumption and flight time both have a substantial effect on aircraft operating cost, but they cannot be minimized simultaneously. In addition, winds, turbulence, and performance x,ary widely with altitude and time. These factors make it important and difficult for pilots to (a) evaluate the outcomes associated with a particular trajectory before it is flown and (b) decide among possible trajectories. The two elements of this problem considered here are (1) determining, what constitutes optimality, and (2) finding optimal trajectories. Pilots and dispatchers from major U.S. airlines were surveyed to determine which attributes of the outcome of a flight they considered the most important. Avoiding turbulence-for passenger comfort topped the list of items which were not safety related. Pilots' decision making about the selection of flight profile on the basis of flight time, fuel burn, and exposure to turbulence was then observed. Of the several behavioral and prescriptive decision models invoked to explain the pilots' choices, utility maximization is shown to best reproduce the pilots' decisions. After considering more traditional methods for optimizing trajectories, a novel method is developed using a genetic algorithm (GA) operating on a discrete representation of the trajectory search space. The representation is a sequence of command altitudes, and was chosen to be compatible with the constraints imposed by Air Traffic Control, and with the training given to pilots. Since trajectory evaluation for the GA is performed holistically, a wide class of objective functions can be optimized easily. Also, using the GA it is possible to compare the costs associated with different airspace design and air traffic management policies. A decision aid is proposed which would combine the pilot's notion of optimility with the GA-based optimization, provide the pilot with a number of alternative pareto-optimal trajectories, and allow him to consider un-modelled attributes and constraints in choosing among them. A solution to the problem of displaying alternatives in a multi-attribute decision space is also presented.

Patrick, Nicholas J. M.↗
NASA NTRS1996

Decision-Aiding and Optimization for Vertical Navigation of Long-Haul Aircraft

Most decisions made in the cockpit are related to safety, and have therefore been proceduralized in order to reduce risk. There are very few which are made on the basis of a value metric such as economic cost. One which can be shown to be value based, however, is the selection of a flight profile. Fuel consumption and flight time both have a substantial effect on aircraft operating cost, but they cannot be minimized simultaneously. In addition, winds, turbulence, and performance vary widely with altitude and time. These factors make it important and difficult for pilots to (a) evaluate the outcomes associated with a particular trajectory before it is flown and (b) decide among possible trajectories. The two elements of this problem considered here are: (1) determining what constitutes optimality, and (2) finding optimal trajectories. Pilots and dispatchers from major u.s. airlines were surveyed to determine which attributes of the outcome of a flight they considered the most important. Avoiding turbulence-for passenger comfort-topped the list of items which were not safety related. Pilots' decision making about the selection of flight profile on the basis of flight time, fuel burn, and exposure to turbulence was then observed. Of the several behavioral and prescriptive decision models invoked to explain the pilots' choices, utility maximization is shown to best reproduce the pilots' decisions. After considering more traditional methods for optimizing trajectories, a novel method is developed using a genetic algorithm (GA) operating on a discrete representation of the trajectory search space. The representation is a sequence of command altitudes, and was chosen to be compatible with the constraints imposed by Air Traffic Control, and with the training given to pilots. Since trajectory evaluation for the GA is performed holistically, a wide class of objective functions can be optimized easily. Also, using the GA it is possible to compare the costs associated with different airspace design and air traffic management policies. A decision aid is proposed which would combine the pilot's notion of optimality with the GA-based optimization, provide the pilot with a number of alternative pareto-optimal trajectories, and allow him to consider unmodelled attributes and constraints in choosing among them. A solution to the problem of displaying alternatives in a multi-attribute decision space is also presented.

Patrick, Nicholas J. M.↗
NASA NTRS1989

An economic model for evaluating high-speed aircraft designs

A Class 1 method for determining whether further development of a new aircraft design is desirable from all viewpoints is presented. For the manufacturer the model gives an estimate of the total cost of research and development from the preliminary design to the first production aircraft. Using Wright's law of production, one can derive the average cost per aircraft produced for a given break-even number. The model will also provide the airline with a good estimate of the direct and indirect operating costs. From the viewpoint of the passenger, the model proposes a tradeoff between ticket price and cruise speed. Finally all of these viewpoints are combined in a Comparative Aircraft Seat-kilometer Economic Index.

Vandervelden, Alexander J. M.↗
NASA NTRS1994

DSN co-observing operations to support space VLBI missions

Reliable radio astronomy support of space very long baseline interferometry (VLBI) missions by ground radio telescopes is mandatory in order to achieve a high scientific return from the missions. The 70 m DSN antennas along with other ground radio telescopes will perform as the ground segment of the earth-space interferometer. Improvements of radio astronomy VLBI operations at the DSN to achieve higher reliability, efficiency, flexibility, and lower operations costs is a major goal in preparing for radio astronomy support of SVLBI. To help realize this goal, a remote control and monitoring mode for radio astronomy operations at the DSN has been developed.

Altunin, Valery I.↗
NASA NTRS2007

Integrating Automation into a Multi-Mission Operations Center

NASA Goddard Space Flight Center's Space Science Mission Operations (SSMO) Project is currently tackling the challenge of minimizing ground operations costs for multiple satellites that have surpassed their prime mission phase and are well into extended mission. These missions are being reengineered into a multi-mission operations center built around modern information technologies and a common ground system infrastructure. The effort began with the integration of four SMEX missions into a similar architecture that provides command and control capabilities and demonstrates fleet automation and control concepts as a pathfinder for additional mission integrations. The reengineered ground system, called the Multi-Mission Operations Center (MMOC), is now undergoing a transformation to support other SSMO missions, which include SOHO, Wind, and ACE. This paper presents the automation principles and lessons learned to date for integrating automation into an existing operations environment for multiple satellites.

Surka, Derek M.↗
NASA NTRS1973

Low cost space.

It is pointed out that a contradiction between boundless space and limited resources has put the space program in the distressing position of cutting good and worthy projects from its activities during this decade. One approach to ameliorate the situation is to increase the productivity of space activities by greater utilization of the equipment developed for its projects. The Space Shuttle constitutes the first big step in that direction. The reusable character of the Shuttle orbiter will cut operational costs by permitting recovery and reuse of payload equipment through routine round-trip operations to space.

Tischler, A. O.↗
NASA NTRS1990

Automated procedure execution for space vehicle autonomous control

Increased operational autonomy and reduced operating costs have become critical design objectives in next-generation NASA and DoD space programs. The objective is to develop a semi-automated system for intelligent spacecraft operations support. The Spacecraft Operations and Anomaly Resolution System (SOARS) is presented as a standardized, model-based architecture for performing High-Level Tasking, Status Monitoring and automated Procedure Execution Control for a variety of spacecraft. The particular focus is on the Procedure Execution Control module. A hierarchical procedure network is proposed as the fundamental means for specifying and representing arbitrary operational procedures. A separate procedure interpreter controls automatic execution of the procedure, taking into account the current status of the spacecraft as maintained in an object-oriented spacecraft model.

Broten, Thomas A.↗
NASA NTRS2003

Contingency Power Study for Short Haul Civil Tiltrotor

AlliedSignal Engines (AE) defined a number of concepts that significantly increased the horsepower of a turboshaft engine to accommodate the loss of an engine and enable the safe landing of a twin-engined, 40-passenger, short haul civil tiltrotor. From these concepts, "Water/Methanol Injection," a "Better Power Turbine Than Required," and a "Secondary Combustor For Interturbine Reheat" were chosen, based on system safety and economics, for more detailed examination. Engine performance, mission, and cost analysis of these systems indicated contingency power levels of 26 to 70 percent greater than normal rated takeoff could be attained for short durations, thus enabling direct operating cost savings between 2 and 6 percent.

Eisenberg, Joseph D.↗
NASA NTRS2006

Transforming Our SMEX Organization by Way of Innovation, Standardization, and Automation

NASA's Small Explorer (SMEX) Flight Operations Team (FOT) is currently tackling the challenge of supporting ground operations for several satellites that have surpassed their designed lifetime and have a dwindling budget. At Goddard Space Flight Center (GSFC), these missions are presently being reengineered into a fleet-oriented ground system. When complete, this ground system will provide command and control of four SMEX missions, and will demonstrate fleet automation and control concepts as a pathfinder for additional mission integrations. A goal of this reengineering effort is to demonstrate new ground-system technologies that show promise of supporting longer mission lifecycles and simplifying component integration. In pursuit of this goal, the SMEX organization has had to examine standardization, innovation, and automation. A core technology being demonstrated in this effort is the GSFC Mission Services Evolution Center (GMSEC) architecture. The GMSEC architecture focuses on providing standard interfaces for ground system applications to promote application interoperability. Building around commercial Message Oriented Middleware and providing a common messaging standard allows GMSEC to provide the capabilities necessary to support integration of new software components into existing missions and increase the level of interaction within the system. For SMS, GMSEC has become the technology platform to transform flight operations with the innovation and automation necessary to reduce operational costs. The automation technologies supported in SMEX are built upon capabilities provided by the GMSEC architecture that allows the FOT to further reduce the involvement of the console, operator. Initially, SMEX is automating only routine operations, such as safety and health monitoring, basic commanding, and system recovery. The operational concepts being developed here will reduce the need for staffed passes and are a necessity for future fleet management. As this project continues to evolve, additional innovations beyond GMSEC and automation have, and will continue to be developed. The team developed techniques for migrating ground systems of existing on-orbit assets. The tools necessary to monitor and control software failures were integrated and tailored for operational environments. All this was done with a focus of extending fleet operations to mission beyond SMU. The result of this work is the foundation for a broader fleet-capable ground system that will include several missions supported by the Space Science Mission Operations Project.

Madden, Maureen↗