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At least 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Space station propulsion technology

The progress on the Space Station Propulsion Technology Program is described. The objectives are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the Initial Operating Capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion to that required to support and interface with advanced station functions. The evaluation of concepts was completed. The accumulator module of the test bed was completed and, with the microprocessor controller, delivered to NASA-MSFC. An oxygen/hydrogen thruster was modified for use with the test bed and successfully tested at mixture ratios from 4:1 to 8:1.

Briley, G. L.↗
NASA NTRS1986

The space station power system

The manned space station is the next major NASA program. It presents many challenges to the power system designers. The power system in turn is a major driver on the overall configuration. In this paper, the major requirements and guidelines that affect the station configuration and the power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts, both fanciful and feasible, are described and linked to the present concept. The recently completed Phase B trade study selections of photovoltaic system technologies are described in detail. A summary of the present solar dynamic and power management and distribution systems is also given for completeness.

Baraona, C. R.↗
NASA NTRS1985

An analysis of low-thrust, resistojet reboost for the Space Station

This paper presents results of an analysis of low-thrust orbit maintenance of the Space Station. Propellant requirements and transfer times are given for reboost of the station through various altitude increments. The reboost can readily be accomplished with thrust levels that subject the station to an acceleration of less than the desired upper limit of 10 to the -5th g's. The variation in time and the probabilistic aspect of the predicted upper-atmospheric density as well as the variation in time of sun-pointing drag areas were taken into account. Estimates of the propellant requirements at different times during an 11-year solar cycle are given. It is shown that the amount of CO2 available from the station life-support system is sufficient, over most of the solar cycle, to provide the propellant for a resistojet orbit-maintenance system.

Penko, P. F.↗
NASA NTRS1985

Space Station operations

An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

Gray, R. H.↗
NASA NTRS1985

Planning for Space Station utilization

User requirements for the planned Space Station, and utilization planning to meet those needs, are discussed. The continual involvement of the customer in all aspects of the Space Station Program is to be achieved by identifying customers and by defining, refining, and integrating their requirements so as to stimulate the best possible design, development, and operations. Planning guidelines to be used in the Space Station definition process are shown and discussed, as is the Space Station Planning Schedule.

Raney, W.↗
NASA NTRS1985

Function, form, and technology - The evolution of Space Station in NASA

The history of major Space Station designs over the last twenty-five years is reviewed. The evolution of design concepts is analyzed with respect to the changing functions of Space Stations; and available or anticipated technology capabilities. Emphasis is given to the current NASA Space Station reference configuration, the 'power tower'. Detailed schematic drawings of the different Space Station designs are provided.

Fries, S. D.↗
NASA NTRS1985

Space stations and space platforms - Concepts, design, infrastructure, and uses

Topics discussed include space infrastructures and early Space Station and platform planning. Consideration is given to the supportive role of the Space Station and platform in future astronomy, earth observation, planetary, and communication space missions. Papers are presented on the history of the Space Station and space platform concepts, potential designs of space stations and space platforms, and long-range plans for space research.

Bekey, I.↗
NASA NTRS1986

Design drivers of the Space Station Propulsion System

The objective of this paper is to describe some of the factors that are being considered by NASA in the selection of the Space Station Propulsion System. The paper describes briefly several design alternatives under consideration. The emphasis of this paper is on understanding the criteria being used by NASA, rather than a quantitative evaluation of the design alternatives. Four system evaluation criteria are suggested: cost, safety, technical readiness, and opportunities for station evolution. Within the cost criteria, the impact of the design alternatives on maintenance and resupply costs is discussed. Safety is suggested to be determined more by the nature of the propellants than the possible loss of the propulsion function. Technical readiness is primarily an evaluation of the risk of schedule delay, more than a concern over a showstopper in the development of any of the systems. Finally, the opportunity for station evolution is described in terms of the development of an oxygen/hydrogen economy for the Space Station.

Graetch, J.↗
NASA NTRS1985

The challenge of the US Space Station

The U.S. Space Station program is described. The objectives of the present national space policy are reviewed. International involvement and commercial use of space are the two strategies involved in the development of the Space Station. The Space Station is to be a multifunctional, modular, permanent facility with manned and unmanned platforms. The functions of the Space Station for space research projects, such as material processing and electrophoresis, are examined. The infrastructure required for commercialization of space is analyzed. NASA's space policy aimed at stimulating space commerce is discussed. NASA's plans to reduce the financial, institutional, and technical risks of space research are studied.

Beggs, J. M.↗
NASA NTRS1985

Space Station life sciences guidelines for nonhuman experiment accommodation

Life scientists will utilize one of four habitable modules which constitute the initial Space Station configuration. This module will be initially employed for studies related to nonhuman and human life sciences. At a later date, a new module, devoted entirely to nonhuman life sciences will be launched. This report presents a description of the characteristics of a Space Station laboratory facility from the standpoint of nonhuman research requirements. Attention is given to the science rationale for experiments which support applied medical research and basic gravitational biology, mission profiles and typical equipment and subsystem descriptions, issues associated with the accommodation of nonhuman life sciences on the Space Station, and conceptual designs for the initial operational capability configuration and later Space Station life-sciences research facilities.

Arno, R.↗
NASA NTRS1986

The US Space Station program

International participation in the U.S. Space Station program is examined. Proposed Space Station mission studies to be conducted by Canada, Japan, and Europe are described; the establishment and implementation of these programs is discussed. The use of the Space Station as a laboratory, test center, and manufacturing area, and the commercial applicability of the Space Station are analyzed.

Freitag, R. F.↗
NASA NTRS1985

Space Station power system issues

Issues governing the selection of power systems for long-term manned Space Stations intended solely for earth orbital missions are covered briefly, drawing on trade study results from both in-house and contracted studies that have been conducted over nearly two decades. An involvement, from the Program Development Office at MSFC, with current Space Station concepts began in late 1982 with the NASA-wide Systems Definition Working Group and continued throughout 1984 in support of various planning activities. The premise for this discussion is that, within the confines of the current Space Station concept, there is good reason to consider photovoltaic power systems to be a venerable technology option for both the initial 75 kW and 300 kW (or much greater) growth stations. The issue of large physical size required by photovoltaic power systems is presented considering mass, atmospheric drag, launch packaging and power transmission voltage as being possible practicality limitations. The validity of searching for a cross-over point necessitating the introduction of solar thermal or nuclear power system options as enabling technologies is considered with reference to programs ranging from the 4.8 kW Skylab to the 9.5 gW Space Power Satellite.

Giudici, R. J.↗
NASA NTRS1985

Tethered nuclear power for the space station

A nuclear space power system the SP-100 is being developed for future missions where large amounts of electrical power will be required. Although it is primarily intended for unmanned spacecraft, it can be adapted to a manned space platform by tethering it above the station through an electrical transmission line which isolates the reactor far away from the inhabited platform and conveys its power back to where it is needed. The transmission line, used in conjunction with an instrument rate shield, attenuates reactor radiation in the vicinity of the space station to less than one-one hundredth of the natural background which is already there. This combination of shielding and distance attenuation is less than one-tenth the mass of boom-mounted or onboard man-rated shields that are required when the reactor is mounted nearby. This paper describes how connection is made to the platform (configuration, operational requirements) and introduces a new element the coaxial transmission tube which enables efficient transmission of electrical power through long tethers in space. Design methodology for transmission tubes and tube arrays is discussed. An example conceptual design is presented that shows SP-100 at three power levels 100 kWe, 300 kWe, and 1000 kWe connected to space station via a 2 km HVDC transmission line/tether. Power system performance, mass, and radiation hazard are estimated with impacts on space station architecture and operation.

Bents, D. J.↗
NASA NTRS1985

Power conditioning subsystems for photovoltaic central-station power plants - Technology and performance

Central-Station (CS) Photovoltaic (PV) systems have the potential of economically displacing significant amounts of centrally generated electricity. However, the technical viability and, to some extent, the economic viability of central-station PV generation technology will depend upon the availability of large power conditioners that are efficient, safe, reliable, and economical. This paper is an overview of the technical and cost requirements that must be met to develop economically viable power conditioning subsystems (PCS) for central-station power plants. The paper also examines various already commercially available PCS hardware that may be suitable for use in today's central PV power stations.

Krauthamer, S.↗
NASA NTRS1985

Space Station Advanced Development Program

The Space Station Advanced Development Program has the objective to transform promising new techniques into mature proven concepts to enable design options for the initial Space Station. It is pointed out that the options should improve system performance and reduce operational costs. Attention is given to the approach employed in the implementation of the program, the technology issues, aspects of Space Station evolution and growth, a Space Station technology overview, and subsystem technologies. The Advanced Development Power Program is considered along with the advanced development of auxiliary propulsion, the program dealing with attitude control and stabilization, and developments related to data management. Other developments are concerned with communication, system operation, manned systems technology, structures, and environmental control and life support.

Carlisle, R. F.↗
NASA NTRS1986

Space Station dynamic modeling, control and simulation

Dynamic disturbances of many orders of magnitude greater than those of conventional spacecraft will be routine for the Space Station. Accurate knowledge of inflight structural dynamics and disturbances will be lacking. System identification will reduce uncertainties. To deal with the remaining model errors and time-varying elements, adaptive control may be required. Dynamic models for two Space Station configurations are derived. A direct model reference adaptive control algorithm is synthesized and evaluated with respect to the station model parameter errors and plant dynamics truncations. Both the rigid body and the flexible modes are treated. Simulation results show that convergence of the adaptive algorithm can be achieved in 100 to about 300 seconds with reasonable performance even during Shuttle hard docking operations in which station mass and inertia are instantaneously changed by more than 100 percent.

Ih, C.-H. C.↗
NASA NTRS1985

The U.S. Space Station program

An overview is given of the U.S. Space Station program, beginning with President Reagan's directive to NASA 'to develop a permanently manned Space Station and to do it within a decade'. The international aspects of the project are emphasized, and fruitful cooperation between Italy and the U.S. in past and present space research is noted. The Station is to serve diverse functions, including that of a laboratory in space, a permanent observatory, a servicing facility, a transportation node, and assembly and manufacturing facility, a storage depot, and a staging base for future endeavors. Management-related and engineering-related guidelines are laid out. The plan is to make the Space Station a legacy from this century to the next, with the help of and to the benefit of all who share our goals.

Culbertson, P. E.↗
NASA NTRS1985

Astrophysics and the Space Station - Executive summary of the NASA Working Group

Current plans for astrophysics experiments using the Space Station are summarized. The planning history is briefly traced; the fundamental roles of the Station as observatory, assembly plant, and service point for free-flying astrophysics platforms are considered; the NASA astrophysics programs are described; the chief outstanding problems are listed; and the need for smaller experiments is stressed. Lists of desired Station performance parameters and charts showing projected completion dates for Station components are provided.

Pellerin, C. J.↗