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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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The reported activity covers laboratory scale experiments on twelve bituminous, sub-bituminous and lignite coals, and preliminary design and specifications for bench-scale and mini-pilot plant equipment.
The HEAO (High Energy Astronomy Observatory) Program consists of three large automated scientific observatories launched between 1977 and 1979 to observe from near-earth orbit stellar X-ray and gamma-ray sources and to measure incoming cosmic ray particles. The HEAO-2 and HEAO-3 spacecraft are expected to exceed their design lifetimes by a factor of three, as did HEAO-1, which operated for 18 months. All three missions are considered successful in that target dates have essentially been met, launch and flight operations have been relatively smooth, instrumentation has performed well, and there have been no cost overruns. The paper lists ten factors contributing to the missions' success, among them a thorough definition before program start, commonality of spacecraft design, redundancy of mission critical equipment, ample design margins, and tight control of system changes. Specific mission parameters are included in the paper as well as the technological advances engendered by the HEAO Program in such areas as high-resolution X-ray optics and solid-state spectrometry.
Pair of documents describe mechanism allowing astronaut to capture in extravehicular activity small artificial satellite for retrieval and return to Earth. Mechanism operates by insertion of probe in nozzle of rocket motor on satellite, followed by expansion of inserted probe end to grasp motor inside nozzle and thereby capture satellite. Designed for specific satellite, but operating principle adapted to almost any satellite equipped with rocket motor or possibly used in retrieval of hollow-shaped objects in marine and other salvage operations.
Since 1985, the Naval Ocean Systems Center has been identifying and developing needed technology for flexible manufacturing of hybrid microelectronic assemblies. Specific projects have been accomplished through contracts with manufacturing companies, equipment suppliers, and joint efforts with other government agencies. The resulting technology has been shared through semi-annual meetings with government, industry, and academic representatives who form an ad hoc advisory panel. More than 70 major technical capabilities have been identified for which new development is needed. Several of these developments have been completed and are being shared with industry.
The six studies which are addressed are entitled: Design Modularity and Commonality; Modification of Existing Hardware (COTS) vs. New Hardware Build Cost Analysis; Automation Cost vs. Crew Utilization; Hardware Miniaturization versus Cost; Space Station Freedom/Spacelab Modules Compatibility vs. Cost; and Prototype Utilization in the Development of Space Hardware. The product of these six studies was intended to provide a knowledge base and methodology that enables equipment produced for the Space Biology Initiative program to meet specific design and functional requirements in the most efficient and cost effective form consistent with overall mission integration parameters. Each study promulgates rules of thumb, formulas, and matrices that serves has a handbook for the use and guidance of designers and engineers in design, development, and procurement of Space Biology Initiative (SBI) hardware and software.
The six studies which are the subjects of this report are entitled: Design Modularity and Commonality; Modification of Existing Hardware (COTS) vs. New Hardware Build Cost Analysis; Automation Cost vs. Crew Utilization; Hardware Miniaturization versus Cost; Space Station Freedom/Spacelab Modules Compatibility vs. Cost; and Prototype Utilization in the Development of Space Hardware. The product of these six studies was intended to provide a knowledge base and methodology that enables equipment produced for the Space Biology Initiative program to meet specific design and functional requirements in the most efficient and cost effective form consistent with overall mission integration parameters. Each study promulgates rules of thumb, formulas, and matrices that serves as a handbook for the use and guidance of designers and engineers in design, development, and procurement of Space Biology Initiative (SBI) hardware and software.
California Polytechnic State University's design project for the 1990-91 school year was the design of a close air support aircraft. There were eight design groups that participated and were given requests for proposals. These proposals contained mission specifications, particular performance and payload requirements, as well as the main design drivers. The mission specifications called for a single pilot weighing 225 lb with equipment. The design mission profile consisted of the following: (1) warm-up, taxi, take off, and accelerate to cruise speed; (2) dash at sea level at 500 knots to a point 250 nmi from take off; (3) combat phase, requiring two combat passes at 450 knots that each consist of a 360 deg turn and an energy increase of 4000 ft. - at each pass, half of air-to-surface ordnance is released; (4) dash at sea level at 500 knots 250 nmi back to base; and (5) land with 20 min of reserve fuel. The request for proposal also specified the following performance requirements with 50 percent internal fuel and standard stores: (1) the aircraft must be able to accelerate from Mach 0.3 to 0.5 at sea level in less than 20 sec; (2) required turn rates are 4.5 sustained g at 450 knots at sea level; (3) the aircraft must have a reattack time of 25 sec or less (reattack time was defined as the time between the first and second weapon drops); (4) the aircraft is allowed a maximum take off and landing ground roll of 2000 ft. The payload requirements were 20 Mk 82 general-purpose free-fall bombs and racks; 1 GAU-8A 30-mm cannon with 1350 rounds; and 2 AIM-9L Sidewinder missiles and racks. The main design drivers expressed in the request for proposal were that the aircraft should be survivable and maintainable. It must be able to operate in remote areas with little or no maintenance. Simplicity was considered the most important factor in achieving the former goal. In addition, the aircraft must be low cost both in acquisition and operation. The summaries of the aircraft configurations developed by the eight groups are presented.
A compilation of basic information on pyrotechnically actuated devices/systems used in NASA aerospace and aeronautic applications was formatted into a catalog. The intent is to provide (1) a quick reference digest of the types of operational pyro mechanisms and (2) a source of contacts for further details. Data on these items was furnished by the NASA Centers that developed and/or utilized such devices to perform specific functions on spacecraft, launch vehicles, aircraft, and ground support equipment. Information entries include an item title, user center name, commercial contractor/vendor, identifying part number(s), a basic figure, briefly described purpose and operation, previous usage, and operational limits/requirements.
As on-board satellite systems continue to increase in ability to perform self diagnostic checks, it will become more important for satellites to initiate ground communications contact. Currently, the NASA Space Network requires users to pre-arranged times for satellite communications links through the Tracking and Data Relay Satellite (TDRS). One of the challenges in implementing an on-demand access protocol into the Space Network, is the fact that a low Earth orbiting (LEO) satellite's communications will be subject to a doppler shift which is outside the capability of the NASA ground station to lock onto. In a prearranged system, the satellite's doppler is known a priori, and the ground station is able to lock onto the satellite's signal. This paper describes the development of a high speed analog to digital interface into a Digital Signal Processor (DSP). This system will be used for identifying the doppler shift of a LEO satellite through the Space Network, and aiding the ground station equipment in locking onto the signal. Although this interface is specific to one application, it can be used as a basis for interfacing other devices with a DSP.
NASA's James Webb Space Telescope (JWST) faces difficult technical and budgetary challenges to overcome before it is scheduled launch in 2010. The Integrated Science Instrument Module (ISIM), shares these challenges. The major challenge addressed in this paper is the data network used to collect, process, compresses and store Infrared data. A total of 114 Mbps of raw information must be collected from 19 sources and delivered to the two redundant data processing units across a twenty meter deployed thermally restricted interface. Further data must be transferred to the solid-state recorder and the spacecraft. The JWST detectors are kept at cryogenic temperatures to obtain the sensitivity necessary to measure faint energy sources. The Focal Plane Electronics (FPE) that sample the detector, generate packets from the samples, and transmit these packets to the processing electronics must dissipate little power in order to help keep the detectors at these cold temperatures. Separating the low powered front-end electronics from the higher-powered processing electronics, and using a simple high-speed protocol to transmit the detector data minimize the power dissipation near the detectors. Low Voltage Differential Signaling (LVDS) drivers were considered an obvious choice for physical layer because of their high speed and low power. The mechanical restriction on the number cables across the thermal interface force the Image packets to be concentrated upon two high-speed links. These links connect the many image packet sources, Focal Plane Electronics (FPE), located near the cryogenic detectors to the processing electronics on the spacecraft structure. From 12 to 10,000 seconds of raw data are processed to make up an image, various algorithms integrate the pixel data Loss of commands to configure the detectors as well as the loss of science data itself may cause inefficiency in the use of the telescope that are unacceptable given the high cost of the observatory. This combination of requirements necessitates a redundant, fault tolerant, high- speed, low mass, low power network with a low Bit error Rate(1E-9- 1E-12). The ISIM systems team performed many studies of the various network architectures that meeting these requirements. The architecture selected uses the Spacewire protocol, with the addition of a new transport and network layer added to implement end-to-end reliable transport. The network and reliable transport mechanism must be implemented in hardware because of the high average information rate and the restriction on the ability of the detectors to buffer data due to power and size restrictions. This network and transport mechanism was designed to be compatible with existing Spacewire links and routers so that existing equipment and designs may be leveraged upon. The transport layer specification is being coordinated with European Space Agency (ESA), Spacewire Working Group and the Consultative Committee for Space Data System (CCSDS) PlK Standard Onboard Interface (SOIF) panel, with the intent of developing a standard for reliable transport for Spacewire. Changes to the protocol presented are likely since negotiations are ongoing with these groups. A block of RTL VHDL that implements a multi-port Spacewire router with an external user interface will be developed and integrated with an existing Spacewire Link design. The external user interface will be the local interface that sources and sinks packets onto and off of the network (Figure 3). The external user interface implements the network and transport layer and handles acknowledgements and re-tries of packets for reliable transport over the network. Because the design is written in RTL, it may be ported to any technology but will initially be targeted to the new Actel Accelerator series (AX) part. Each link will run at 160 Mbps and the power will be about 0.165 Watt per link worst case in the Actel AX.
There are many ways to send humans to Mars. Credible technical reports can be traced to the 1950's. More recently, NASA has funded major studies that depict a broad variety of trajectories, technologies, stay times, and costs. Much of this data is still valid with direct application to today's exploration planning. This paper presents results comparing these studies with particular emphasis on the in-space transportation aspects of the mission. Specifically, comparisons are made on propulsion systems used for getting the crew and mission equipment from Earth orbit to Mars orbit, descending and ascending from the surface, and returning to Earth orbit. Areas of comparison for each of these phases include crew size, mission mass, propellant mass, delta v, specific impulse, transit time, surface stay time, aero-braking, and others. Data is analyzed to demonstrate either strong trends toward particular technologies or diverging solutions.
The Virtual Interactive Classroom (VIC) allows Internet users, specifically students, to remotely control and access data from scientific equipment. This is a significant advantage to school systems that cannot afford experimental equipment, have Internet access, and are seeking to improve science and math scores with current resources. A VIC Development Lab was established at Lewis to demonstrate that scientific equipment can be controlled by remote users over the Internet. Current projects include a wind tunnel, a room camera, a science table, and a microscope.
The scope of this task is to perform a comparative analysis of the various Environmental Control Life Support System (ECLSS) options for different growth scenarios. The Space Station Freedom ECLSS design and existing ground-based clean room facilities are used as a baseline for comparison. Specifically addressed here are the ground based clean room facilities at the Marshall Space Flight Center (MSFC). Given here is an evaluation of the facilities, equipment, technologies, and procedures used to maintain specified environments in typical aerospace industrial areas. Twenty-five specific clean rooms are evaluated. The objectives were to collect, compare, and catalog data for each specified facility in the areas of engineering and design, construction materials, work stations, contamination control, particulate elimination, entry systems, and instrumentation, and to make recommendations concerning enhancements required to assure an efficient and orderly evolution of MSFC clean room environmental control facilities.
Progress is reported on the mission support plan and those support activities envisioned to be applicable and necessary during premission and postmission phases of the Spacelab program. The purpose, role, and requirements of the contamination control operations for the first two missions of the Spacelab equipped Space Transportation System are discussed. The organization of the contamination control operation and its relationship to and interfaces with other mission support functions is also discussed. Some specific areas of contamination to be investigated are treated. They are: (1) windows and viewports, (2) experiment equipment, (3) thermal control surfaces, (4) the contaminant induced atmosphere (as differentiated from the normal ambient atmosphere at the orbit altitude), and (5) optical navigation instruments.
Vector modulators are used to impose baseband modulation on RF signals, but non-ideal behavior limits the overall performance. The non-ideal behavior of the vector modulator is compensated using data collected with the use of an automated test system driven by a LabVIEW program that systematically applies thousands of control-signal values to the device under test and collects RF measurement data. The technology innovation automates several steps in the process. First, an automated test system, using computer controlled digital-to-analog converters (DACs) and a computer-controlled vector network analyzer (VNA) systematically can apply different I and Q signals (which represent the complex number by which the RF signal is multiplied) to the vector modulator under test (VMUT), while measuring the RF performance specifically, gain and phase. The automated test system uses the LabVIEW software to control the test equipment, collect the data, and write it to a file. The input to the Lab - VIEW program is either user-input for systematic variation, or is provided in a file containing specific test values that should be fed to the VMUT. The output file contains both the control signals and the measured data. The second step is to post-process the file to determine the correction functions as needed. The result of the entire process is a tabular representation, which allows translation of a desired I/Q value to the required analog control signals to produce a particular RF behavior. In some applications, corrected performance is needed only for a limited range. If the vector modulator is being used as a phase shifter, there is only a need to correct I and Q values that represent points on a circle, not the entire plane. This innovation has been used to calibrate 2-GHz MMIC (monolithic microwave integrated circuit) vector modulators in the High EIRP Cluster Array project (EIRP is high effective isotropic radiated power). These calibrations were then used to create correction tables to allow the commanding of the phase shift in each of four channels used as a phased array for beam steering of a Ka-band (32-GHz) signal. The system also was the basis of a breadboard electronic beam steering system. In this breadboard, the goal was not to make systematic measurements of the properties of a vector modulator, but to drive the breadboard with a series of test patterns varying in phase and amplitude. This is essentially the same calibration process, but with the difference that the data collection process is oriented toward collecting breadboard performance, rather than the measurement of output from a network analyzer.
A gas-controlled variable-conductance heat pipe was qualified for flight aboard orbiting astronomical observatory (OAO3). Experiments were conducted to determine the performance and reliability of the pipe in the vacuum environment of space, and to demonstrate in a specific engineering application its effectiveness in providing temperature stability for spacecraft equipment which experiences varying electronic duty cycles and changing thermal boundary conditions. System design and hardware are discussed in detail.
The TDRSS will consist initially of two geosynchronous satellites and a common ground station at White Sands, New Mexico. According to current schedules, operations are to begin in November 1980. The overall TDRSS will provide high and low bit-rate telemetry, commands, and satellite-to-satellite tracking services. Each Tracking and Data Relay Satellite (TDRS) will have four antenna systems for NASA use. The common ground station at White Sands will have three 18-meter K-band antennas. The tracking equipment at the ground station is required to meet the following specifications: (1) 0.1-radian root-mean-square (rms) phase noise on nondestruct Doppler measurements; (2) 10-nanosecond rms range noise; (3) 50-nanosecond maximum systematic range error. Attention is given to two-way range and Doppler measurements, the bilateration tracking of TDRS, and an experiment using differenced one-way Doppler measurements.
Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.