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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 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Space radiation shielding strategies and requirements for deep space missions

Methods for estimating crew exposure to radiation and for evaluating shield requirements for spacecraft equipment and crew are examined. The development status for deterministic space radiation transport computer codes and models of their nuclear interaction inputs, which are useful for estimating the composition and thickness of shield materials, is discussed. The relation between shield thickness and exposures is studied. Estimates of deep-space shield requirements are proposed. It is noted that an assessment of input parameter uncertainties reveals that a factor of 2 uncertainty in predicted dose equivalent could increase shield thickness by an order of magnitude of more.

Townsend, Lawrence W.↗
NASA NTRS1988

An overview of the space medicine program and development of the Health Maintenance Facility for Space Station

Because the prolonged stay on board the Space Station will increase the risk of possible inflight medical problems from that on Skylab missions, the Health Maintenance Facility (HMF) planned for the Space Station is much more sophisticated than the small clinics of the Skylab missions. The development of the HMF is directed by the consideration of three primary factors: prevention, diagnosis, and treatment of injuries and illnesses that may occur in flight. The major components of the HMF include the clinical laboratory, pharmacy, imaging system, critical-care system, patient-restraint system, data-management system, exercise system, surgical system, electrophysiologic-monitoring system, introvenous-fluid system, dental system, and hyperbaric-treatment-support system.

Pool, Sam Lee↗
NASA NTRS1991

Space Station Freedom coupling tasks: An evaluation of their space operational compatibility

The development of the Space Station Freedom tasks that are compatible with both telerobotic as well as extravehicular activity is a necessary redundancy in order to insure successful day to day operation. One task to be routinely performed aboard Freedom will be the changeout of various quick disconnect fluid connectors. In an attempt to resolve these potentially contradictory issues of compatibility, mock-ups of couplings suitable to both extravehicular as well as telerobotic activity were designed and built. An evaluation performed at the Remote Operator Interaction Laboratory at NASA's Johnson Space Center is discussed, which assessed the prototype couplings as well as three standard coupling designs. Data collected during manual and telerobotic manipulation of the couplings indicated that the custom coupling was in fact shown to be faster to operate and generally preferred over the standard coupling designs.

Sampaio, Carlos E.↗
NASA NTRS1991

Space water electrolysis: Space Station through advance missions

Static Feed Electrolyzer (SFE) technology can satisfy the need for oxygen (O2) and Hydrogen (H2) in the Space Station Freedom and future advanced missions. The efficiency with which the SFE technology can be used to generate O2 and H2 is one of its major advantages. In fact, the SFE is baselined for the Oxygen Generation Assembly within the Space Station Freedom's Environmental Control and Life Support System (ECLSS). In the conventional SFE process an alkaline electrolyte is contained within the matrix and is sandwiched between two porous electrodes. The electrodes and matrix make up a unitized cell core. The electrolyte provides the necessary path for the transport of water and ions between the electrodes, and forms a barrier to the diffusion of O2 and H2. A hydrophobic, microporous membrane permits water vapor to diffuse from the feed water to the cell core. This membrane separates the liquid feed water from the product H2, and, therefore, avoids direct contact of the electrodes by the feed water. The feed water is also circulated through an external heat exchanger to control the temperature of the cell.

Ronald J Davenport↗
NASA NTRS1990

A review of the habitability aspects of prior space flights from the flight crew perspective with an orientation toward designing Space Station Freedom

Habitability is a very important issue in long-duration spaceflight. With this concern, a review of much of the existing U.S. Skylab, Spacelab, and some Soviet literature on habitability aspects of long-duratioin space flight was completed for the Astronaut Space Station Support Office. The data were organized to follow as closely as possible the SSF distributed systems, such as Life Support, Data Management, etc. A new definition of habitability is proposed.

Stramler, J. H.↗
NASA NTRS1990

Space Station accommodation of the Space Exploration Initiative

It is pointed out that Space Station Freedom (SSF) will support the transportation, research, and development requirements of the Space Exploration Initiative through augmentation of its resources and initial capabilities. These augmentations include providing facilities for lunar and Mars vehicle testing, processing, and servicing; providing laboratories and equipment for such enabling research as microgravity countermeasures development; and providing for the additional crew that will be required to carry out these duties. It is noted that the best way to facilitate these augmentations is to ensure 'design-for-growth' capabilities by incorporating necessary design features in the baseline program. The critical items to be accommodated in the baseline design include provisions for future increased power-generation capability, the ability to add nodes and modules, and the ability to expand the truss structure to accommodate new facilities. The SSF program must also address the effect on nonexploration users (e.g., NASA experimenters, commercial users, university investigators, and international partners of the U.S.) of SSF facilities.

Ahlf, Peter↗
NASA NTRS1990

The Space Station Freedom Flight Telerobotic Servicer - The design and evolution of a dexterous space robot

The Flight Telerobotic Servicer (FTS) will provide a telerobotic capability to the Space Station in the early assembly phases of the program and will be used for assembly, maintenance, and inspection throughout the lifetime of the Station. Here, the FTS design approach to the development of autonomous capabilities is discussed. The FTS telerobotic workstations for the Shuttle and Space Station, and facility for on-orbit storage are examined. The rationale of the FTS with regard to ease of operation, operational versatility, maintainability, safety, and control is discussed.

Mccain, Harry G.↗
NASA NTRS1991

Oculomotor function during space flight and susceptibility to space motion sickness

Horizontal vestibulo-ocular reflex (VOR) and saccadic eye movements (SEM) were studied in 18 subjects before and during five Space Shuttle missions to evaluate the effects of weightlessness and correlations between results and susceptibility to and actual presence of space motion sickness (SMS). Active sinusoidal head oscillation was the stimulus for VOR tests with vision (VVOR), with eyes shaded (VOR-ES), and VOR suppression (VOR-S). Eye movements were recorded by electrooculography and head position by a potentiometer. No pathological nystagmus or other abnormal eye movements were seen. No significant in-flight changes were seen in the gain, phase shift or waveform of VVOR, VOR-ES or VOR-S. Statistically significant increases in saccadic latency and decreases in saccadic velocity were seen, with no change in saccadic accuracy. Preflight differences between SMS susceptible and nonsusceptible subjects were noted only in VOR-S, with less complete suppression in susceptible subjects, a finding also seen in flight. During flight, VVOR gain was significantly increased in three nonaffected subjects. Saccades of SMS-affected subjects showed increased latency and velocity and decreased accuracy compared to saccades of unaffected subjects.

Thornton, William E.↗
NASA NTRS1990

Interference effects on Space Station Freedom and Space Shuttle Orbiter Ku-band single access return links

In a Ku-band single access return (KSAR) communication link via the tracking and data relay satellite system (TDRSS), the interference between spacecraft can be discriminated by opposite antenna polarizations, pseudo-noise code, and by TDRSS antenna beam pointing. For the Space Station Freedom (SSF) KSAR and the Space Shuttle Orbiter (SSO) KSAR links, the pseudo-noise coding technique is not exploited. In addition, the two KSAR links use the same carrier frequency. Therefore, if the SSF and SSO are in close proximity, it is expected that mutual interference will be significant. Mutual interference effects on the SSO-KSAR I-channel and the SSF-KSAR links are analytically derived and compared to the simulation results. For the analysis, the channel is assumed ideally bandlimited and linear. It is demonstrated that a simplified (linear bandlimited channel) analytical approach yields results of adequate accuracy in an estimation of the signal degradation by interference.

Kwon, Hyuck M.↗
NASA NTRS1991

The NASA research and technology program on space power: A key element of the Space Exploration Initiative

In July 1989, President Bush announced his space exploration initiative of going back to the Moon to stay and then going to Mars. Building upon its ongoing research and technology base, NASA has established an exploration technology program to develop the technologies needed for piloted missions to the Moon and Mars. A key element for the flights and for the planned bases is power. The NASA research and technology program on space power encompasses power sources, energy storage, and power management.

Bennett, Gary L.↗
NASA NTRS1991

Beyond the Baseline 1991: Proceedings of the Space Station Evolution Symposium. Volume 2: Space Station Freedom, part 2

Individual presentations delivered at the Space Station Evolution Symposium in League City, Texas, on August 6, 7, and 8, 1991 are given in viewgraph form. Personnel responsible for Advanced Systems Studies and Advanced Development within the Space Station Freedom Program reported on the results of their work to date. Special attention is given to highlighting changes made during restructuring; a description of the growth paths through the follow-on and evolution stages; identification of the minimum impact provisions to allow flexibility in the baseline; and identification of enhancing and enabling technologies.

Source record↗
NASA NTRS1991

Beyond the Baseline 1991: Proceedings of the Space Station Evolution Symposium. Volume 1: Space Station Freedom, part 2

This report contains the individual presentations delivered at the Space Station Evolution Symposium. The results of Space Station Freedom Advanced Studies provide a road map for the evolution of Freedom in terms of user requirements, utilization and operations concepts, and growth options for distributed systems. Regarding these specific systems, special attention is given to: highlighting changes made during restructuring; description of growth paths through the follow-on and evolution phases; identification of minimum impact provisions to allow flexibility in the baseline; and identification of enhancing and enabling technologies.

Source record↗
NASA NTRS1991

Space transportation systems, launch systems, and propulsion for the Space Exploration Initiative: Results from Project Outreach

A number of transportation and propulsion options for Mars exploration missions are analyzed. As part of Project Outreach, RAND received and evaluated 350 submissions in the launch vehicle, space transportation, and propulsion areas. After screening submissions, aggregating those that proposed identical or nearly identical concepts, and eliminating from further consideration those that violated known physical princples, we had reduced the total number of viable submissions to 213. In order to avoid comparing such disparate things as launch vehicles and electric propulsion systems, six broad technical areas were selected to categorize the submissions: space transportation systems; earth-to-orbit (ETO) launch systems; chemical propulsion; nuclear propulsion; low-thrust propulsion; and other. To provide an appropriate background for analyzing the submissions, an extensive survey was made of the various technologies relevant to the six broad areas listed above. We discuss these technologies with the intent of providing the reader with an indication of the current state of the art, as well as the advances that might be expected within the next 10 to 20 years.

Garber, T.↗
NASA NTRS1992

Space Defense Initiative technologies and hardware can help resolve certain space exploration initiative weight and performance issues

The use of Space Defense Initiative (SDI) technologies and hardware in solving Space Exploration Initiative (SEI) problems is presented. The topics discussed include the following: Aerojet programs, SDI's technical focus, SDI technology weight savings, realized benefits, composite technologies, the Advanced Liquid Axial Stage (ALAS), propellant and pressurant tanks, lightweight engines, high performance helium tanks, hoop and helical fibers, ALAS's advanced carbon composite structure, and CLF5 performance issues. The discussion is presented in viewgraph form.

Relmer, Bryce↗
NASA NTRS1992

A proposal to demonstrate production of salad crops in the Space Station Mockup facility with particular attention to space, energy, and labor constraints

This research has continued along two lines, one at Marshall Space Flight Center with Salad Machine Rack development and the design and construction of a mockup for placement in the Huntsville Space Station Freedom mockup. The second avenue of research has addressed issues of relevance to the operation of the Salad Machine and Bioregenerative systems. These issues include plant species compatibility when grown on shared hydroponic systems and microbial populations of mixed species hydroponic systems. Significant progress is reported.

Brooks, Carolyn↗
NASA NTRS1992

The simulated space proton environment for radiation effects on Space Telescope Imaging Spectrograph (STIS)

The space telescope imaging spectrograph (STIS) is a second generation instrument planned for the Hubble Space Telescope (HST) which is currently in orbit. Candidate glasses and other transmitting materials are being considered for order sorters, in-flight calibration filters, detector windows, and calibration lamps. The glasses for in-flight calibration filters showed significant drop in UV transmission, but can probably still be used on STIS. The addressed topics include the Hubble radiation environment, simulation of orbital exposure at Harvard Cyclotron Laboratory, measurement of spectral transmission, and comments on individual samples.

Becher, Jacob↗
NASA NTRS1991

Space transportation options for the Space Exploration Initiative

The candidate architectures of space transportation vehicles designed for the Space Exploration Initiative are discussed together with the launch systems concepts. Special attention is given to the lunar mission and Mars mission scenarios and the launch- and transfer-vehicle options for Mars and moon missions.

Huber, William G.↗
NASA NTRS1991

State space representation of the open-loop dynamics of the Space Shuttle Main Engine

A parameter and structure estimation technique for multivariable systems is used to obtain state space representation of open loop dynamics of the Space Shuttle Main Engine (SSME). The parameterization being used is both minimal and unique. The simplified linear models may be used for fault detection studies and control system design and development.

Duyar, Ahmet↗