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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Space Station multidisciplinary analysis capability - IDEAS2

A computer-aided engineering tool now in use at NASA for systems engineering and integration analysis of the Space Station is described. This tool, called IDEAS2, combines the spacecraft-specific analysis software from NASA IDEAS (truss synthesizer, rigid body controls, plume impingement, orbital lifetime, orbit heat loads, and life support systems) with the interactive graphics, geometric database, solids modeler, structural and thermal analysis capability of the SDRC I-DEAS to obtain an integrated package suitable for Space Station design. This integrated package was applied to a very recent study of growth scenarios of the Space Station dual keel configuration, in which a comparison was made between designs using a combination of photovoltaic solar arrays and solar dynamic collectors, and those using only solar dynamic collectors.

Baker, M.↗
NASA NTRS1986

Space Station tethered refueling facility operations

The space-based orbital transfer vehicle will require a large cryogenic fuel storage facility at the Space Station. An alternative to fuel storage onboard the Space Station, is on a tethered orbital refueling facility (TORF) which is separated from the Space Station by a sufficient distance to induce a gravity gradient to settle the propellants. Facility operations are a major concern associated with a tethered LO2/LH2 storage depot. A study was carried out to analyze these operations so as to identify the preferred TORF deployment direction (up or down) and whether the TORF should be permanently or intermittently deployed. The analyses considered safety, contamination, rendezvous, servicing, transportation rate, communication, and viewing. An upwardly, intermittently deployed facility is the preferred configuration for a tethered cryogenic fuel storage.

Kiefel, E. R.↗
NASA NTRS1986

Predictive momentum management for the Space Station

Space station control moment gyro momentum management is addressed by posing a deterministic optimization problem with a performance index that includes station external torque loading, gyro control torque demand, and excursions from desired reference attitudes. It is shown that a simple analytic desired attitude solution exists for all axes with pitch prescription decoupled, but roll and yaw coupled. Continuous gyro desaturation is shown to fit neatly into the scheme. Example results for pitch axis control of the NASA power tower Space Station are shown based on predictive attitude prescription. Control effector loading is shown to be reduced by this method when compared to more conventional momentum management techniques.

Hatis, P. D.↗
NASA NTRS1986

Verification of post permanently manned configuration Space Station elements

An account is given of the techniques and ground systems designed to fulfill post permanently manned configuration (PMC) Space Station verification tasks. Consideration is given to analysis using computer math models and computer-aided interface verification systems, testing using simulators and interface mixtures, and special inspection. It is noted that an initial Space Station design that accommodates and facilitates verification is crucial to an effective verification program as well as proper instrumentation, built-in test capability, and a precise configuration management, control and record system. It is concluded that post PMC verification should be accounted for both in the initial Space Station design and in the subsequent development of initial assembly flight verification techniques and capabilities.

Scully, E. J.↗
NASA NTRS1986

EOS production on the Space Station

The paper discusses a conceptual integration of the equipment for EOS (Electrophoresis Operations/Space) on the Space Station in the early 1990s. Electrophoresis is a fluid-constituent separation technique which uses forces created by an electrical field. Aspects covered include EOS equipment and operations, and Space Station installations involving a pressurized module, a resupply module, utility provisions and umbilicals and crew involvement. Accommodation feasibility is generally established, and interfaces are defined. Space Station production of EOS-derived pharmaceuticals will constitute a significant increase in capability compared to precursor flights on the Shuttle in the 1980s.

Runge, F. C.↗
NASA NTRS1986

Space Station technology experiments and uses

The use of the proposed Space Station for technological experimentation is discussed. The general objectives and capabilities of the Station and the status of planning are reviewed; the external and internal environmental conditions at the 500-km 28.5-deg-inclination Station orbit are described; and six conceptual Technology Development Missions designed by NASA and included in the Mission Requirements Data Base are briefly characterized and illustrated with drawings. The missions considered concern spacecraft-materials performance, solar dynamic power, data transfer and processing microelectronics, long-term cryogenic-fluid storage, active-optics technology, and cryogenic-propellant transfer, storage, and reliquefaction.

Breckenridge, R. A.↗
NASA NTRS1985

An evaluation of the performance of Umkehr stations by Solar Backscattered Ultraviolet (SBUV) experiment

Until recently, Umkehr data taken by 20 Dobson stations around the world have been the principal source of information about the behavior of upper stratospheric ozone. Umkehr results are used also for detecting drifts in satellite instruments and for determining intersatellite biases. However, a systematic evaluation of the quality of Umkehr data taken by the various stations has been lacking. Five years of ozone profile data from the Solar Backscattered Ultraviolet (SBUV) have been used to examine and intercompare the quality of Umkehr stations, and to assess the degradation of their performance after the El Chichon volcano eruption in southern Mexico. In contrast to Umkehr, the SBUV ozone measurments in layers 7 through 9 (1-8 mb) were unaffected by the massive amounts of dust and gases ejected by El Chichon.

Bhartia, P. K.↗
NASA NTRS1986

Fluid management and its role in the future of Space Station

Technological challenges and suggested plans for meeting them pertaining to fluid management in the Space Station are discussed. A short overview is given of the major Space Station systems and operations which employ or rely on fluid management, followed by a description of the general system issues and challenges encountered in managing fluids in space. Examples of some current and near term activities directed toward providing the understanding and technologies necessary to overcome relevant problems are presented. Finally, suggested plans for similar but longer range research and development activities are offered. These plans emphasize the requirements and benefits of expanded in-space experiments, with the ultimate aim of using the Space Station as a facility for fluid management research and technology development efforts.

Salzman, J.↗
NASA NTRS1985

A science perspective of the Space Station

On-orbit scientific research involving the presence of humans has been hampered during Shuttle flights due to the brevity of the missions and the limited power supplies and data management facilities. The solutions to these limitations are the Space Station and extended duration Orbiter, the latter offering 2.5 weeks on-orbit operations. The Space Station configuration is to include polar orbiting and co-orbiting unmanned platforms serviced, initially, by the Shuttle. The longer duration operations on the Space Station will permit lowering the amount of on-the-ground training in favor of on-orbit experience, thereby enhancing the flexibility of experimental opportunities and expanding the breadth of investigations. The goal of all the developments is to furnish groundside experimenters access to space, along with minimized adaptation of experimental procedures to exploit the space environment.

Black, D. C.↗
NASA NTRS1986

A space station Structures and Assembly Verification Experiment, SAVE

The Space Station structure has been baselined to be a 5 M (16.4 ft) erectable truss. This structure will provide the overall framework to attach laboratory modules and other systems, subsystems and utilities. The assembly of this structure represents a formidable EVA challenge. To validate this capability the Space Station Structures/Dynamics Technical Integration Panel (TIP) met to develop the necessary data for an integrated STS structures flight experiment. As a result of this meeting, the Langley Research Center initiated a joint Langley/Boeing Aerospace Company study which supported the structures/dynamics TIP in developing the preliminary definition and design of a 5 M erectable space station truss and the resources required for a proposed flight experiment. The purpose of the study was to: (1) devise methods of truss assembly by astronauts; (2) define a specific test matrix for dynamic characterization; (3) identify instrumentation and data system requirements; (4) determine the power, propulsion and control requirements for the truss on-orbit for 3 years; (5) study the packaging of the experiment in the orbiter cargo bay; (6) prepare a preliminary cost estimate and schedule for the experiment; and (7) provide a list of potential follow-on experiments using the structure as a free flyer. The results of this three month study are presented.

Russell, R. A.↗
NASA NTRS1986

Nickel-hydrogen batteries from Intelsat 5 to space station

The heritage of the Ni-H2 technology that makes the space station application feasible is discussed. It also describes a design for a potential space station Ni-H2 battery system. Specific design values presented here were developed by Ford Aerospace as part of the Rocketdyne team effort on the Phase B Definition and Preliminary Design of the Space Station Power System in support of NASA Lewis Research Center.

Vanommering, G.↗
NASA NTRS1986

Design, construction and utilization of a space station assembled from 5-meter erectable struts

Presented are the primary characteristics of the 5-meter erectable truss designated for the space station. The relatively large 5-meter truss dimension was chosen to provide a deep beam for high bending stiffness yet provide convenient mounting locations for space shuttle cargo bay size payloads which are 14.5 ft. (4.4 m) in diameter. Truss nodes and quick-attachment erectable joints are described which provide for evolutionary three-dimensional growth and for simple maintenance and repair. A mobile remote manipulator system is described which is provided to assist in station construction and maintenance. A discussion is also presented of the construction of the space station and the associated EVA time.

Mikulas, M. M., Jr.↗
NASA NTRS1986

Solar dynamic power systems for space station

The Parabolic Offset Linearly Actuated Reflector (POLAR) solar dynamic module was selected as the baseline design for a solar dynamic power system aboard the space station. The POLAR concept was chosen over other candidate designs after extensive trade studies. The primary advantages of the POLAR concept are the low mass moment of inertia of the module about the transverse boom and the compactness of the stowed module which enables packaging of two complete modules in the Shuttle orbiter payload bay. The fine pointing control system required for the solar dynamic module has been studied and initial results indicate that if disturbances from the station are allowed to back drive the rotary alpha joint, pointing errors caused by transient loads on the space station can be minimized. This would allow pointing controls to operate in bandwidths near system structural frequencies. The incorporation of the fine pointing control system into the solar dynamic module is fairly straightforward for the three strut concentrator support structure. However, results of structural analyses indicate that this three strut support is not optimum. Incorporation of a vernier pointing system into the proposed six strut support structure is being studied.

Irvine, Thomas B.↗
NASA NTRS1985

Advanced EVA system design requirements study: EVAS/space station system interface requirements

The definition of the Extravehicular Activity (EVA) systems interface requirements and accomodations for effective integration of a production EVA capability into the space station are contained. A description of the EVA systems for which the space station must provide the various interfaces and accomodations are provided. The discussion and analyses of the various space station areas in which the EVA interfaces are required and/or from which implications for EVA system design requirements are derived, are included. The rationale is provided for all EVAS mechanical, fluid, electrical, communications, and data system interfaces as well as exterior and interior requirements necessary to facilitate EVA operations. Results of the studies supporting these discussions are presented in the appendix.

Woods, T. G.↗
NASA NTRS1987

Dual keel space station control/structures interaction study

A study was made to determine the influence of truss bay size on the performance of the space station control system. The objective was to determine if any control problems existed during reboost and to assess the level of potential control/structures interaction during operation of the control moment gyros used for vertical stabilization. The models analyzed were detailed finite-element representations of the 5 meter and 9 foot growth versions of the 300 kW dual keel station. Results are presented comparing the performance of the reboost control system for both versions of the space station. Standards for comparison include flexible effects at the attitude control sensor locations and flexible contributions to pointing error at the solar collectors. Bode analysis results are presented for the attitude control system and control, structural, and damping sensitivities are examined.

Young, John W.↗
NASA NTRS1987

Concurrent communication among multi-transceiver stations over shared media

In order to increase a local-area network's throughput beyond a single bus data rate without using dedicated switching nodes, multiple buses and multitransceiver stations are required. The design space of single-hop interconnections is explored among such stations. Interconnections are presented whose throughput can grow quadratically with the number of transmitters and receivers per station. These are referred to as selective broadcast interconnections (SBIs). The performance of various SBIs are studied. A spread-spectrum channel can accommodate several current successful transmission, and a single-transceiver node can thus utilize only a small fraction of the channel capacity. In order to allocate the appropriate fraction of capacity to a busy node, it is proposed to equip it with several transmitters and receivers, thereby turning it into a supernode. Several architectures and operation policies for supernodes are suggested and compared. It is shown that a supernode can significantly outperform a collection of independent conventional nodes with the same total numbers of transmitters and receivers. Packet-radio networks with half-duplex nodes, as well as networks with full-duplex nodes, are considered.

Birk, Yitzhak↗
NASA NTRS1987

Space station: A program overview

An overview is presented of the NASA program for the development of the Space Station. A general representation of the initial Space Station complex is shown. The Space Station goals and program objectives are briefly reviewed, as well as the program schedule. An advanced development program and program management approach are also presented.

Ambrus, Judith H.↗
NASA NTRS1987

Design, construction, and utilization of a space station assembled from 5-meter erectable struts

The primary characteristics of the 5-meter erectable truss is presented, which was baselined for the Space Station. The relatively large 5-meter truss dimension was chosen to provide a deep beam for high bending stiffness yet provide convenient mounting locations for space shuttle cargo bay size payloads which are approx. 14.5 ft (4.4 m) in diameter. Truss nodes and quick attachment erectable joints are described which provide for evolutionary three dimensional growth and for simple maintenance and repair. A mobile remote manipulator system is described which is provided to assist in station construction and maintenance. A discussion is also presented of the construction of the Space Station and the associated extravehicular active (EVA) time.

Mikulas, Martin M., Jr.↗