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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Development and testing of the S-band antenna subsystem for the Mariner Mars 1971 spacecraft

The Mariner Mars 1971 S-band antenna subsystem is used to transmit and receive S-band signals to and from the Deep Space Instrumentation Facility ground stations. The antenna subsystem consists of a low-gain antenna, a medium-gain antenna, a directional coupler, a high-gain antenna, and all transmission lines required to interconnect the antennas to the spacecraft radio frequency subsystem. The low-gain antenna is used to transmit signals during cruise and receive signals throughout the mission. The medium-gain antenna is coupled to the low-gain antenna via the directional coupler and is used to transmit and receive signals during Mars orbit insertion. The high-gain antenna is used to transmit high data rate signals primarily during Mars orbit.

Brejcha, A. G.↗
NASA NTRS1972

Pilot/vehicle control optimization using averaged operational mode and subsystem relative performance index sensitivities

A method is presented for designing optimal feedback controllers for systems having subsystem sensitivity constraints. Such constraints reflect the presence of subsystem performance indices which are in conflict with the performance index of the overall system. The key to the approach is the use of relative performance index sensitivity (a measure of the deviation of a performance index from its optimum value). The weighted sum of subsystem and/or operational mode relative performance index sensitivies is defined as an overall performance index. A method is developed to handle linear systems with quadratic performance indices and either full or partial state feedback. The usefulness of this method is demonstrated by applying it to the design of a stability augmentation system (SAS) for a VTOL aircraft. A desirable VTOL SAS design is one that produces good VTOL transient response both with and without active pilot control. The system designed using this method is shown to effect a satisfactory compromise solution to this problem.

Leininger, G. G.↗
NASA NTRS1972

Apollo experience report: Lunar module electrical power subsystem

The design and development of the electrical power subsystem for the lunar module are discussed. The initial requirements, the concepts used to design the subsystem, and the testing program are explained. Specific problems and the modifications or compromises (or both) imposed for resolution are detailed. The flight performance of the subsystem is described, and recommendations pertaining to power specifications for future space applications are made.

Campos, A. B.↗
NASA NTRS1972

Development of a biowaste resistojet propulsion system propellant management and control subsystem.

The subject subsystem is under development as the major portion of an overall biowaste resistojet system development program. The design is based on the Space Station model, but incorporates features compatible with all envisioned/anticipated advancements in the interfacing environmental control life support (EC/LS) system. Results to date, for system design, development plan, component selection, and system acceptance test will be presented. Subsystem usage in functional system tests to be performed at Langley Research Center, and its application to an envisioned and integrated system, and extended manned tests, are delineated. Expanded applications of the subsystem, to control/limit external contamination of manned spacecraft, are identified.-

Greco, R. V.↗
NASA NTRS1973

Ice pack heat sink subsystem - Phase 1, Volume 1

The design, development, fabrication, and test at one-g of a functional laboratory model (non-flight) ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions are discussed. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

Roebelen, G. J., Jr.↗
NASA NTRS1972

Autonomous power subsystem design for an Outer Planet Spacecraft.

This paper describes the overall design of the Thermoelectric Outer Planet Spacecraft (TOPS) power subsystem. It discusses the implementation of spacecraft requirements into a fault-tolerant design in which an on-board self-test and repair computer is utilized to provide autonomous operation. Development of a protected bus concept is discussed whereby electrical power supplied to essential spacecraft loads is maintained in the event of major on-board power blackouts. Particular attention is given to describing the interfaces and operation of the power subsystem with the spacecraft control computer subsystem. Autonomous power management operations are discussed where the on-board computer adjusts the spacecraft load demand to provide maximum utilization of source power for a given mission mode.

Andrews, R. E.↗
NASA NTRS1973

System design of the Pioneer Venus spacecraft. Volume 6: Power subsystem studies

Selection of a baseline power subsystem for the probe bus, orbiter, and large and small probes has been performed as a part of the Pioneer Venus Mission Systems Design Study. In each case the selection process has involved trades and incorporated the results of previous related studies. Factors considered primary in the selection of each subsystem approach were cost, and the ability of each of the proposed subsystems to perform reliably under the rigors of the space environment, temperature extremes, and high g loads. A trade was made to consider the advantages of an unregulated primary bus versus a regulated bus. The decision to use an unregulated bus was based on cost, weight, and the increase in load isolation achievable through the use of individual load regulators.

Prochaska, H. F.↗
NASA NTRS1973

System design of the Pioneer Venus spacecraft. Volume 10: Propulsion/orbit insertion subsystem studies

The Pioneer Venus orbiter and multiprobe missions require spacecraft maneuvers for successful accomplishment. This report presents the results of studies performed to define the propulsion subsystems required to perform those maneuvers. Primary goals were to define low mass subsystems capable of performing the required missions with a high degree of reliability for low cost. A review was performed of all applicable propellants and thruster types, as well as propellant management techniques. Based on this review, a liquid monopropellant hydrazine propulsion subsystem was selected for all multiprobe mission maneuvers, and for all orbiter mission maneuvers except orbit insertion. A pressure blowdown operating mode was selected using helium as the pressurizing gas. The forces associated with spacecraft rotations were used to control the liquid-gas interface and resulting propellant orientation within the tank.

Rosenstein, B. J.↗
NASA NTRS1974

Development of integrated, zero-G pneumatic transporter/rotating paddle incinerator/catalytic afterburner subsystem for processing human wastes on board spacecraft

A four component system was developed which consists of a particle size reduction mechanism, a pneumatic waste transport system, a rotating-paddle incinerator, and a catalytic afterburner to be integrated into a six-man, zero-g subsystem for processing human wastes on board spacecraft. The study included the development of different concepts or functions, the establishment of operational specifications, and a critical evaluation for each of the four components. A series of laboratory tests was run, and a baseline subsystem design was established. An operational specification was also written in preparation for detailed design and testing of this baseline subsystem.

Fields, S. F.↗
NASA NTRS1973

Ice Pack Heat Sink Subsystem - Phase I

This paper describes the design and test at one-g of a functional laboratory model (non-flight) Ice Pack Heat Sink Subsystem to be used eventually for astronaut cooling during manned space missions. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

Roebelen, G. J., Jr.↗
NASA NTRS1974

A statistical approach to deriving subsystem specifications

In order to produce cost effective environmental test programs, the test specifications must be realistic and to be useful, they must be available early in the life of a program. This paper describes a method for achieving such specifications for subsystems by utilizing the results of a statistical analysis of data acquired at subsystem mounting locations during system level environmental tests. The paper describes the details of this statistical analysis. The resultant recommended levels are a function of the subsystems' mounting location in the spacecraft. Methods of determining this mounting 'zone' are described. Recommendations are then made as to which of the various problem areas encountered should be pursued further.

Keegan, W. B.↗
NASA NTRS1974

Development of a six-man, self-contained carbon dioxide collection subsystem for spacecraft application

Life Systems, working with NASA, has developed an electrochemical, six-man, self-contained carbon dioxide concentrator subsystem (CX-6) designed to normally remove 13.2 lb/day of CO2 while maintaining the CO2 partial pressure (pCO2) of the cabin atmosphere at 3 mm Hg or less. The CX-6 was subjected to extensive parametric and endurance testing. The effects of operating conditions on CO2 removal and electrical efficiencies were determined, including effects of hydrogen (H2) flow rate, process airflow rate, pCO2, operating temperature and current density. A total of 209 days of operation was accumulated. The subsystem was designed with self-contained electronic control and monitoring instrumentation. The CX-6 was redesigned and repackaged into the CO2 collection subsystem for the air revitalization group of the space station prototype.

Schubert, F. H.↗
NASA NTRS1974

Mariner Mars 1971 attitude control subsystem

The Mariner Mars 1971 attitude control subsystem (ACS) is discussed. It is comprised of a sun sensor set, a Canopus tracker, an inertial reference unit, two cold gas reaction control assemblies, two rocket engine gimbal actuators, and an attitude control electronics unit. The subsystem has the following eight operating modes: (1) launch, (2) sun acquisition, (3) roll search, (4) celestial cruise, (5) all-axes inertial, (6) roll inertial, (7) commanded turn, and (8) thrust vector control. In the celestial cruise mode, the position control is held to plus or minus 0.25 deg. Commanded turn rates are plus or minus 0.18 deg/s. The attitude control logic in conjunction with command inputs from other spacecraft subsystems establishes the ACS operating mode. The logic utilizes Sun and Canopus acquisition signals generated within the ACS to perform automatic mode switching so that dependence of ground control is minimized when operating in the sun acquisition, roll search, and celestial cruise modes. The total ACS weight is 65.7 lb, and includes 5.4 lb of nitrogen gas. Total power requirements vary from 9 W for the celestial cruise mode to 54 W for the commanded turn mode.

Edmunds, R. S.↗
NASA NTRS1973

Automated biowaste sampling system urine subsystem operating model, part 1

The urine subsystem automatically provides for the collection, volume sensing, and sampling of urine from six subjects during space flight. Verification of the subsystem design was a primary objective of the current effort which was accomplished thru the detail design, fabrication, and verification testing of an operating model of the subsystem.

Fogal, G. L.↗
NASA NTRS1975

Cost analysis of life sciences experiments and subsystems

Cost estimates for experiments and subsystems flown in the Spacelab were established. Ten experiments were cost analyzed. Estimated cost varied from $650,000 for the hardware development of the SPE water electrolysis experiment to $78,500,000 for the development and operation of a representative life sciences laboratory program. The cost of subsystems for thermal, atmospheric and trace contaminants control of the Spacelab internal atmosphere was also estimated. Subsystem cost estimates were based on the utilization of existing components developed in previous space programs whenever necessary.

Yakut, M. M.↗
NASA NTRS1974

Solar electric propulsion spacecraft power subsystem for an Encke comet rendezvous mission

This paper presents the preliminary functional description of a solar electric propulsion spacecraft power subsystem for an Encke comet rendezvous mission in the 1980s. This description has been derived from the study of the mission requirements and constraints and the study of integrating a solar electric propulsion module with an existing spacecraft. Tradeoff studies performed in the process of selecting power subsystem parameters and performance characteristics are described. The power subsystem designs draw heavily on the designs for existing spacecraft and technology being developed in the electric propulsion research and development program supported by NASA.

Costogue, E. N.↗
NASA NTRS1974

The Atmosphere Explorer power subsystem

The present work describes the design and in-flight performance of the power subsystem for the first three Atmosphere Explorer (AE) spacecraft. The subsystem provides all electrical power to the spacecraft loads and consists of a solar array, three batteries, and a power supply electronics unit. Power from the solar array is supplied to the spacecraft loads through an unregulated power bus, which varies between -26 and -38 V. Loads which are normally on only during data collection phases of an orbit are fed from a tightly regulated -24.5 V bus. Power subsystem performance during the first three months in orbit has been nominal, except for an anomally in the shunt limiter protection circuitry. A malfunctioning shunt control amplifier was reconnected via ground command.

Obenschain, A.↗
NASA NTRS1974

The MIST /MIUS Integration and Subsystems Test/ laboratory - A testbed for the MIUS /Modular Integrated Utility System/ program

The MIUS (Modular Integrated Utility System) concept is to be an energy-conserving, economically feasible, integrated community utility system to provide five necessary services: electricity generation, space heating and air conditioning, solid waste processing, liquid waste processing, and residential water purification. The MIST (MIUS Integration and Subsystem Test) integrated system testbed constructed at the Johnson Space Center in Houston includes subsystems for power generation, heating, ventilation, and air conditioning (HVAC), wastewater management, solid waste management, and control and monitoring. The key design issues under study include thermal integration and distribution techniques, thermal storage, integration of subsystems controls and displays, incinerator performance, effluent characteristics, and odor control.

Beckham, W. S., Jr.↗