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At least 199 records · Page 11

Utility and technology for a space central power station

The technological and economical impacts of a large central power station in Earth orbit on the performance and cost of future spacecraft and their orbital-transfer systems are examined. It is shown that beaming power to remote users cannot be cost-effective if the central power station uses the same power generation system that would be readily available for provision of on-board power. Laser transmitters/receivers to make central power stations feasible are considered. The cost-effectiveness of meeting Earth-orbiting spacecraft electrical demands from a central power station was analyzed, indicating that this application cannot justify the investment required for the central station. Key technology needs which must be met to enable a viable central power station in the future are identified.

Holloway, P. F.↗

Architectural options for space stations in the context of the space infrastructure

The role of space stations in the space element infrastructure anticipated for the end of the 20th century is discussed. Various architectures for space stations designed to function as part of the infrastructure are examined with respect to a set of potential objectives for the stations. Architectural options are described that range from a minimum station of low capability and cost to an expensive station with a full operations capability and high growth potential. The capabilities, growth potentials, and likely costs of the options are compared, and the association between functional capabilities and likely cost is considered. It is concluded that the cost of a space station is intimately related to its architecture and that a larger initial investment must be made to satisfy more ambitious objectives.

Bekey, I.↗

Performance requirements analysis for payload delivery from a space station

Operations conducted from a space station in low Earth orbit which have different constraints and opportunities than those conducted from direct Earth launch were examined. While a space station relieves many size and performance constraints on the space shuttle, the space station's inertial orbit has different launch window constraints from those associated with customary Earth launches which reflect upon upper stage capability. A performance requirements analysis was developed to provide a reference source of parametric data, and specific case solutions and upper stage sizing trade to assist potential space station users and space station and upper stage developers assess the impacts of a space station on missions of interest.

Friedlander, A. L.↗

Space station propulsion system trade study

This study evaluates alternative space station propulsion system options for a range of space station configurational and operational architectures. Space station propulsion requirements ranging from those representative of the first generation space station to those of an advanced space station with a space based OTV are considered. A methodology for comparing the candidate propulsion technologies is developed which considers design/development/qualification and operational costs, system mass, performance, reliability, and other relevant parameters. Advanced propulsion systems are shown to reduce space station costs by providing higher performance but to require a larger front end investment for development and qualification. This study indicates that if the full potential of such systems is to be realized, then low cost implementations of this technology must be developed.

Garrison, P. W.↗

Productivity in an evolutionary space station

Space station productivity is treated from a systems point of view, considering the functions and attributes of space station development, formation, and operation that affect productivity. An optimum planning method is needed to assure that the station will have mission flexibility, technology advancement, maintainability, and evolutionary capability. Advanced technology will be designed into the housekeeping and utility functions of the station. Greater risk taking may be allowed into designs if the potential benefits of the advanced system support the risk, and if the system can be buffered from causing a failure cascade throughout the station. A common data base is needed to store and track all designs, developments, and changes in the station subsystems. Systems that can be automated and free the human inhabitants for more productive work are favored, as are modular components that are highly fault-free. Human control must also be possible, especially during check-out and verification, and also for teaching the automated systems new or modified tasks.

Anderson, J. L.↗

A manned-machine space station construction concept

A design concept for the construction of a permanent manned space station is developed and discussed. The main considerations examined in developing the design concept are: (1) the support structure of the station be stiff enough to preclude the need for an elaborate on-orbit system to control structural response, (2) the station support structure and solar power system be compatible with existing technology, and (3) the station be capable of growing in a systematic modular fashion. The concept is developed around the assembly of truss platforms by pressure-suited astronauts operating in extravehicular activity (EVA), assisted by a machine (Assembly and Transport Vehicle, ATV) to position the astronauts at joint locations where they latch truss members in place. The ATV is a mobile platform that is attached to and moves on the station support structure using pegs attached to each truss joint. The operation of the ATV is described and a number of conceptual configurations for potential space stations are developed.

Mikulas, M. M., Jr.↗

Performance assessment of planetary missions as launched from an orbiting space station

Results presented are intended to assist planners and the mission analysis community in assessing the performance impact (pro or con) of launching planetary missions from an orbiting space station as compared to the usual, ground-based Shuttle launch of such missions. The analyses comprising this assessment include: (1) a basic understanding and description of the space station launch problem; (2) examination of alternative injection strategies and selection of the most appropriate strategy for minimizing performance penalties; and (3) quantitative comparison of station-launched and Shuttle-launched performance over a wide energy/mass range of planetary mission opportunities. Data for each mission covers a full 360 deg of possible nodal location of the space station orbit. The main results are that planetary missions can be launched from a space station within acceptable penalty bounds, and that the station serving as a staging base/propellant depot can benefit some missions requiring large payload mass or high injection energy.

Friedlander, A.↗

A study of space station needs, attributes and architectural options

The mission requirements, economic benefits, and time table of deployment of the space station are discussed. It is concluded that: (1) mission requirements overwhelmingly support the need for a space station; (2) a single space station is the way to begin; (3) the space station must evolve its capability; (4) the orbit transfer vehicle aspect of the space station will provide significant economic benefit; and (5) an early, affordable, effective way to start the space station program is needed.

Source record↗

Space Station Power System

The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

Baraona, C. R.↗

A dual spin space station design

A dual spin space station design is described. The space station has a cylindrical solar array that is spun to provide both gyroscopic stiffness to the space station and to stiffen the array structure. The platform is spun at the orbital angular rate. The space station is designed to have gravity gradient and aerodynamic restoring torques. An active control system is used to stabilize the station and store excess angular momentum until it can be removed from the station by magnetic torques.

Paluszek, M. A.↗

Space Station - Opportunity for international cooperation and utilization

In connection with his announcement regarding the development of a permanently manned Space Station, President Reagan invited the United States' friends and allies to join in the Space Station program. The President's invitation was preceded by more than two years of interaction between NASA and some of its potential partners in Space Station planning activities. Attention is given to international participation in Space Station planning, international cooperation on the Space Station, the guidelines for international cooperation, and the key challenges. Questions regarding quid pro quos are considered along with aspects of technology transfer, commercial use, problems of management, and the next steps concerning the Space Station program.

Pedersen, K. S.↗

Dynamic characteristics of two 300 kW class dual keel space station concepts

Results from an investigation of the dynamic behavior of a 300 kW class solar dynamic powered, dual kell space station are presented. The purpose of the investigation was to determine and assess the influence of space station truss bay size on station controllability during rigid body attitude adjustment and orbit reboost maneuvers. The dual keel space station concept is defined and two finite element models (one which has a truss bay size of 5m and another with a truss bay size of 9 feet) are described. Rigid and flexible body characteristics of the two space station models are also presented. Finally, results from a transient response analysis, where the stations are subjected to an orbit reboost maneuver, are summarized.

Dorsey, J. T.↗

Space Station utilization

The essential requirement of the Space Station that the customer be continually involved in all aspects of the program is considered. Potential users of the Space Station need both formal and informal channels into the program at an early stage of the definition process to secure their influence and participation in the development process. Only with this participation can users' needs and requirements be integrated into the design phase to produce 'user friendliness' in the Space Station. A Space Station that is easy and economical to use will generate more users that can take advantage of the available resources. The Space Station must be: a research facility; a satellite servicing and assembly facility; an observatory for terrestrial, solar, and astronomical viewing; and a transportation node for orbit transfer vehicles. NASA intends to see that the Space Station is developed and operated so as to serve its users.

Raney, W. P.↗

American experiences and perspectives - International cooperation on a permanently manned Space Station

In the late 1960s, NASA contemplated the establishment of a permanently manned Space Station along with the development of the Space Shuttle. After a temporary postponement of the Space Station project, it was finally decided to develop a Space Station and to have it operating by the early 1990s. This station is to serve in a variety of functions which are important for further advances with respect to the utilization of space. The Space Station could even serve as a staging base for trips to the moon and visits to Mars. An international approach is to be taken regarding the development and utilization of the Space Station, giving attention to a cooperation of the U.S. with Canada, Europe, and Japan. The implementation of such a cooperation requires that a number of problems are solved. Basic approaches suitable for achieving such a solution are discussed, taking into account the development of operational schemes which provide for efficient management, while permitting the exercise of diverse 'ownership' rights.

Pedersen, K. S.↗

Space station support of manned Mars missions

The assembly of a manned Mars interplanetary spacecraft in low Earth orbit can be best accomplished with the support of the space station. Station payload requirements for microgravity environments of .001 g and pointing stability requirements of less than 1 arc second could mean that the spacecraft may have to be assembled at a station-keeping position about 100 meters or more away from the station. In addition to the assembly of large modules and connective structures, the manned Mars mission assembly tasks may include the connection of power, fluid, and data lines and the handling and activation of components for chemical or nuclear power and propulsion systems. These assembly tasks will require the use of advanced automation and robotics in addition to Orbital Maneuvering Vehicle and Extravehicular Activity (EVA) crew support. Advanced development programs for the space station, including on-orbit demonstrations, could also be used to support manned Mars mission technology objectives. Follow-on studies should be conducted to identify space station activities which could be enhanced or expanded in scope (without significant cost and schedule impact) to help resolve key technical and scientific questions relating to manned Mars missions.

Holt, Alan C.↗

Space station interior noise analysis program

Documentation is provided for a microcomputer program which was developed to evaluate the effect of the vibroacoustic environment on speech communication inside a space station. The program, entitled Space Station Interior Noise Analysis Program (SSINAP), combines a Statistical Energy Analysis (SEA) prediction of sound and vibration levels within the space station with a speech intelligibility model based on the Modulation Transfer Function and the Speech Transmission Index (MTF/STI). The SEA model provides an effective analysis tool for predicting the acoustic environment based on proposed space station design. The MTF/STI model provides a method for evaluating speech communication in the relatively reverberant and potentially noisy environments that are likely to occur in space stations. The combinations of these two models provides a powerful analysis tool for optimizing the acoustic design of space stations from the point of view of speech communications. The mathematical algorithms used in SSINAP are presented to implement the SEA and MTF/STI models. An appendix provides an explanation of the operation of the program along with details of the program structure and code.

Stusnick, E.↗

Maintenance evaluation for space station liquid systems

Many of the thermal and environmental control life support subsystems as well as other subsystems of the space station utilize various liquids and contain components which are either expendables or are life-limited in some way. Since the space station has a 20-year minimum orbital lifetime requirement, there will also be random failures occurring within the various liquid-containing subsystems. These factors as well as the planned space station build-up sequence require that maintenance concepts be developed prior to the design phase. This applies to the equipment which needs maintenance as well as the equipment which may be required at a maintenance work station within the space station. This paper presents several maintenance concepts for liquid-containing items and a flight experiment program which would allow for evaluation and improvement of these concepts so they can be incorporated in the space station designs at the outset of its design phase.

Flugel, Charles↗

Speculations on future opportunities to evolve Brayton powerplants aboard the space station

The Space Station provides a unique, low-risk environment in which to evolve new capabilities. In this way, the Space Station will grow in capacity, in its range of capabilities, and its economy of operation as a laboratory and as a center for space operations. Although both Rankine and Brayton cycles, two concepts for solar dynamic power generation, now compete to power the station, this paper confines its attention to the Brayton cycle using a mixture of He and Xe as its working fluid. Such a Brayton powerplant to supply the station's increasing demands for both electric power and heat has the potential to gradually evolve higher and higher performance by exploiting already-evolved materials (ASTAR-811C and molten-Li heat storage), its peak cycle temperature rising ultimately to 1500 K. Adapting the station to exploit long tethers (200 to 300 km long) could yield increases in payloads to LEO, to GEO, and to distant destinations in the solar system. Such tethering of the Space Station would not only require additional power for electric propulsion but also would so increase nuclear safety that nuclear powerplants might provide this power. From an 8000-kWt SP-100 reactor, thermoelectric power generation could produce 300 kWe, or adapted solar-Brayton cycle, 2400 to 2800 kWe.

English, Robert E.↗