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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 829 records · Page 46

Mixed mode missions - Designing payloads to match flight opportunities

Shuttle missions have usually been viewed as being devoted to a single mission mode. But full utilization of the STS capabilities as a platform for space research dictates a flexible strategy toward payload integration and mission design. Simple interfaces, single disciplines, and large design and resource margins point the way toward larger payload integration and operation costs. Payloads for early missions (i.e., OSTA-1, OSS-1, and MEA) are used as illustrations to support this argument. The implications of this approach for future NASA plans as well as for new STS operational concepts are considered.

Noblitt, B. G.↗

Circuit Counts Carbon Fibers

Carbon fibers are counted when they fall on high-voltage grid. An arc discharge vaporizes fiber and triggers timer. The equal-duration pulses from timer are integrated by operational amplifier, giving an output voltage that is proportional to the number of fibers incident after reset switch was opened. If two or more fibers arrive at grid simultaneously, they are vaporized one at a time; thus all of them are counted.

Yang, L. C.↗

Hybrid A/D converter for 200 deg C operation

A 12 bit A/D converter was designed and developed which will operate at 200 C with .05 linearity, 1/accuracy, 350 WSec conversion time, and only 455 mW power consumption. This product also necessitated the development of a unique three metal system in which aluminum wire bonding is done utilizing aluminum bonding pads, gold wire bonding to all gold areas, and employment of a nickel interface between gold and aluminum connections. This system totally eliminates the formation of a intermetallics at the bonding interface which can lead to bond failure. This product represents an advancement in electronics as it proved the operation of integrated circuits at high temperature, as well as providing information about both the electrical and mechanical reliability of hybrid circuits at 200 C.

Sullivan, M. R.↗

Role of TDRSS in tracking and data acquisition

The integration and operation of the Tracking Data Relay Satellite System (TDRSS) into the NASA Communications Network (NASCOM) equipment and services is described. The system concept employs spacecraft in geosynchronous orbit, operating as communications front-ends, and a single ground terminal, which provides primary tracking and data acquisition services for earth-orbiting user satellites and for the Space Shuttle. The TDRSS system is further characterized by real-time throughput of user data and a high degree of automation.

Spearing, R. E.↗

High stability amplifier

An electrical RF signal amplifier for providing high temperature stability and RF isolation and comprised of an integrated circuit voltage regulator, a single transistor, and an integrated circuit operational amplifier mounted on a circuit board such that passive circuit elements are located on side of the circuit board while the active circuit elements are located on the other side is described. The active circuit elements are embedded in a common heat sink so that a common temperature reference is provided for changes in ambient temperature. The single transistor and operational amplifier are connected together to form a feedback amplifier powered from the voltage regulator with transistor implementing primarily the desired signal gain while the operational amplifier implements signal isolation. Further RF isolation is provided by the voltage regulator which inhibits cross-talk from other like amplifiers powered from a common power supply. Input and output terminals consisting of coaxial connectors are located on the sides of a housing in which all the circuit components and heat sink are located.

Adams, W. A.↗

Space environment effects on fiber optics systems

The performance survivability of hardened fiber optic data link design for application in future spacecraft systems was assessed. The effects of space environmental conditions on link performance was analyzed. The integration and operation of new fiber optic link components exhibiting increased hardening to radiation environments is emphasized. The opportunity to expose operational fiber optic data links to an actual space environment for 6 months or longer and to retrieve the data links for analysis are discussed. Reliable design criteria for future spacecraft application, relative to the long term low dose space radiation effects as a function of temperature are outlined.

Taylor, E. W.↗

Space station needs, attributes and architectural options: Mission requirements

Various mission requirements for the proposed space station are examined. Subjects include modelling methodology, science applications, commercial opportunities, operations analysis, integrated mission requirements, and the role of man in space station functions and activities. The information is presented through the use of graphs.

Source record↗

A high energy stage for the National Space Transporation System

The Shuttle/Centaur is an expendable hydrogen/oxygen cryogenic upper stage for use with the National Space Transportation System. It is a modification of the existing Atlas/Centaur which was used by NASA since 1966 to launch interplanetary and Earth orbital payloads for numerous organizations. Two configurations of the Shuttle/Centaur are being developed. Vehicle capability includes placing approximately 4500 kg (10,000 lb) in geostationary orbit, and initial applications will be for the interplanetary Galileo and Ulysses Missions in 1986. The Shuttle/Centaur development program is discussed, the configurations and performance are described, and the unique integration and operations requirements related to the Shuttle are indicated. Design changes to the current Atlas/Centaur required for Shuttle operation are described here, and include those related to Orbiter cargo bay dimensions, environment, and safety considerations.

Stofan, A. J.↗

An implicit form for the Osher upwind scheme

Conservative upwind schemes for the Euler equations, such as the Osher scheme, accurately resolve flow discontinuities and correctly model the physics of the problem. However, these schemes require many more arithmetic operations per integration step than simple central-difference schemes and hence result in large computing times. An implicit version of the first-order- and second-order-accurate Osher schemes in two spatial dimensions and generalized coordinates is developed in this study. Because implicit schemes permit the use of large integration steps, in many cases they require fewer integration steps to reach steady-state (especially in calculations on grids with widely varying mesh-cell sizes). The implicit scheme developed in this study accelerated convergence speeds by almost an order of magnitude in the problems considered. Test cases include quasi-one-dimensional nozzle flow and supersonic flow past a cylinder.

Rai, M. M.↗

Solid-State Detector for Trace Materials

Detector for trace chemicals senses as few as 10 to the 12th power molecules of given material on surface. Contains no moving parts, amenable to large-scale integration, and operates at room temperature. Potential applications in industrial process control and in environmental analysis. Characteristic signals indicate presence of certain chemicals.

Lambe, J. J.↗

Data Requirement (DR) MA-03: Payload missions integration

Project management and payload integration requirements definition activities are reported. Mission peculiar equipment; systems integration; ground operations analysis and requirement definition; safety and quality assurance; and support systems development are examined for payloads planned for the following missions: EOM-1; SL-2; Sl-3 Astro-1; MSL-2; EASE/ACCESS; MPESS; and the middeck ADSF flight.

Source record↗

Selected tether applications in space: Phase 2. Executive summary

The application of tether technology has the potential to increase the overall performance efficiency and capability of the integrated space operations and transportation systems through the decade of the 90s. The primary concepts for which significant economic benefits were identified are dependent on the space station as a storage device for angular momentum and as an operating base for the tether system. Concepts examined include: (1) tether deorbit of shuttle from space station; (2) tethered orbit insertion of a spacecraft from shuttle; (3) tethered platform deployed from space station; (4) tether-effected rendezvous of an OMV with a returning OTV; (5) electrodynamic tether as an auxiliary power source for space station; and (6) tether assisted launch of an OTV mission from space station.

Thorson, M. H.↗

Spacelab Hitchhiker, a quick reaction carrier

It is pointed out that NASA is developing a new way to get payloads into orbit in a short time and at a low cost. The 'Spacelab Hitchhiker' is the carrier program which will accomplish this objective. The Spacelab Hitchhiker carrier is a Shuttle payload. The primary application of the considered program will be related to science and technology payloads. Attention is given to the Hitchhiker concept, details regarding the Hitchhiker-G and Hitchhiker-M, aspects of integration and operations, Orbiter resources and STS interfaces, the conduction of Hitchhiker flights as 'flights of opportunity', questions of payload selection, and organizational interfaces.

James, E. F.↗

A high energy stage for the National Space Transportation System

The Shuttle/Centaur is an expendable hydrogen/oxygen cryogenic upper stage for use with the National Space Transportation System. It is a modification of the existing Atlas/Centaur which was used by NASA since 1966 to launch interplanetary and earth orbital payloads for numerous organizations. Two configurations of the Shuttle/Centaur are being developed. Vehicle capability includes placing approximately 4500 kg (10,000 lb) in geostationary orbit, and initial applications will be for the interplanetary Galileo and Ulysses Missions in 1986. The Shuttle/Centaur development program is discussed, the configurations and performance are described, and the unique integration and operations requirements related to the Shuttle are indicated. Design changes to the current Atlas/Centaur required for Shuttle operation are described here, and include those related to Orbiter cargo bay dimensions, environment, and safety considerations.

Stofan, A. J.↗

STS retrieval of satellites

The Space Transportation System (STS) provides the capability to retrieve satellites from space. This capability was demonstrated on flights STS 41-C and STS 51-A, and will be demonstrated again on a future flight with the retrieval of the Long Duration Exposure Facility (LDEF). This paper describes the activity required to ensure a successful retrieval from initial flight planning to actual flight operations. Attention is given to retrieval hardware necessary for success and manifest. Discussion of flight design to meet all constraints placed on the manifested cargo is included. Flightcrew and flight control team training are addressed. Flight rules, techniques, and procedures development are described and examples given. Mission Control Center (MCC) and Payload Operations Control Center (POCC) operations for integrated testing and actual flight support will be presented.

Bruce, T. N.↗

Construction of a 2- by 2-foot transonic adaptive-wall test section at the NASA Ames Research Center

The development of a new production-size, two-dimensional, adaptive-wall test section with ventilated walls at the NASA Ames Research Center is described. The new facility incorporates rapid closed-loop operation, computer/sensor integration, and on-line interference assessment and wall corrections. Air flow through the test section is controlled by a series of plenum compartments and three-way slide vales. A fast-scan laser velocimeter was built to measure velocity boundary conditions for the interference assessment scheme. A 15.2-cm- (6.0-in.-) chord NACA 0012 airfoil model will be used in the first experiments during calibration of the facility.

Morgan, Daniel G.↗

Technology advances for Space Shuttle processing

One of the major initial tasks of the Space Systems Integration and Operations Research Applications (SIORA) Program was the application of automation and robotics technology to all aspects of the Shuttle tile processing and inspection system. The SIORA Program selected a nonlinear systems engineering methodology which emphasizes a team approach for defining, developing, and evaluating new concepts and technologies for the operational system. This is achieved by utilizing rapid prototyping testbeds whereby the concepts and technologies can be iteratively tested and evaluated by the team. The present methodology has clear advantages for the design of large complex systems as well as for the upgrading and evolution of existing systems.

Wiskerchen, M. J.↗

Acceleration ground test program to verify GAS payload No. 559 structure/support avionics and experiment structural integrity

Acceleration ground tests were conducted on the Get Away Special (GAS) payload 559 to verify the structural integrity of the structure/support avionics and two of the planned three flight experiments. The ITA (Integrated Test Area) Standardized Experiment Module (ISEM) structure was modified to accommodate the experiments for payload 559. The ISEM avionics consisted of a heavy duty sliver zinc power supply, three orthogonal-mounted low range microgravity accelerometers, a tri-axis high range accelerometer, a solid state recorder/programmer sequencer, and pressure and temperature sensors. The tests were conducted using the Gravitational Plant Physiology Laboratory Centrifuge of the University City Science Center in Philadelphia, PA. The launch-powered flight steady state acceleration profile of the shuttle was simulated from lift-off through jettison of the External Tank (3.0 g's). Additional tests were conducted at twice the nominal powered flight acceleration levels (6 g's) and an over-test condition of four times the powered flight loads to 12.6 g's. The present test program has demonstrated the value of conducting ground tests to verify GAS payload experiment integrity and operation before flying on the shuttle.

Cassanto, John M.↗