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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Space shuttle maneuvering engine reusable thrust chamber program. Task 11: Stability analyses and acoustic model testing data dump

The combustion stability characteristics of engines applicable to the Space Shuttle Orbit Maneuvering System and the adequacy of acoustic cavities as a means of assuring stability in these engines were investigated. The study comprised full-scale stability rating tests, bench-scale acoustic model tests and analysis. Two series of stability rating tests were made. Acoustic model tests were made to determine the resonance characteristics and effects of acoustic cavities. Analytical studies were done to aid design of the cavity configurations to be tested and, also, to aid evaluation of the effectiveness of acoustic cavities from available test results.

Oberg, C. L.↗
NASA NTRS1973

An experimental study of the motorcycle roll stabilization task

The work of Sharp represents the most complete theoretical analysis of the uncontrolled motorcycle presently available, and serves as a theoretical basis for the study described. Sharp's analysis included roll, yaw, lateral translation, and steering degrees of freedom, and the resulting equations are linear with constant coefficients. Tire aligning moments due to tire sideslip were added to Sharp's equations. Experimental results are presented, and related to the theoretical studies of Sharp and Weir.

Eaton, D. J.↗
NASA NTRS1975

Feasibility study of modern airships, phase 1. Volume 1: Summary and mission analysis (tasks 2 and 4)

The histroy, potential mission application, and designs of lighter-than-air (LTA) vehicles are researched and evaluated. Missions are identified to which airship vehicles are potentially suited. Results of the mission analysis are combined with the findings of a parametric analysis to formulate the mission/vehicle combinations recommended for further study. Current transportation systems are surveyed and potential areas of competition are identified as well as potential missions resulting from limitations of these systems. Potential areas of military usage are included.

Bloetscher, F.↗
NASA NTRS1975

Feasibility study of modern airships, phase 1. Volume 2: Parametric analysis (task 3)

Various types of lighter-than-air vehicles from fully buoyant to semibuoyant hybrids were examined. Geometries were optimized for gross lifting capabilities for ellipsoidal airships, modified delta planform lifting bodies, and a short-haul, heavy-lift vehicle concept. It is indicated that: (1) neutrally buoyant airships employing a conservative update of materials and propulsion technology provide significant improvements in productivity; (2) propulsive lift for VTOL and aerodynamic lift for cruise significantly improve the productivity of low to medium gross weight ellipsoidal airships; and (3) the short-haul, heavy-lift vehicle, consisting of a simple combination of an ellipsoidal airship hull and existing helicopter componentry, provides significant potential for low-cost, near-term applications for ultra-heavy lift missions.

Lancaster, J. W.↗
NASA NTRS1975

Head-eye tracking in two-dimensional pursuit tasks

The neurological control systems for the eye and head are studied by investigating dynamic eye and head rotations in two degrees of freedom using bandlimited, white noise stimuli, nominally wide field of view stimulus presentations of + or - 10 deg and power spectral analysis of the data to produce input/output transfer and coherence functions. Determined were frequency response characteristics of these systems, the linearity of the transfer functions in both coupled and decoupled vertical and horizontal stimulus/response reference axes and the amount of cross axis coupling present in system responses. A comparative study was also conducted to assess the differences in response characteristics between single axis and dual axis visual stimulation for the same subject.

Shirachi, D. K.↗
NASA NTRS1975

Vertex evoked potentials in a rating-scale detection task - Relation to signal probability

Results of vertex-evoked potential studies conducted to determine how decision confidence level and decision probability interact to determine P3 amplitude for both signal-present and signal-absent decisions. They support the contention that the form of the vertex-evoked response is closely correlated with the subject's psychophysical response regarding the presence or absence of a threshold-level signal.

Squires, K. C.↗
NASA NTRS1975

Shuttle LOX loading transient study. Task 2 milestone report. National space and technology laboratories (NSTL) LOX loading facility analysis

Transient thermodynamic analyses were made of the LOX loading system proposed for the space shuttle main propulsion test article (MPTA). This system is made up of a LOX replenish system and a main LOX line which include the barge tank, the lines, pumps, and valves between the barge and the orbiter (ORB) ground service equipment (GSE) interface, the MPTA fill system, the space shuttle main engine (SSME) chilldown bleed system, and the GSE vent system. System analyses include predictions of system performance sensitivity to operating sequence and LOX flowrate, temperature, and quality at the ORB/GSE interface. The transient thermodynamic conditions at the SSME feed line entrance, ET entrance (tank bottom), and the SSME bleed/GSE vent TEE are also included. The analyses are based on continuous SSME bleed flow during GSE facility chilldown.

Glasgow, V. L.↗
NASA NTRS1975

Task 3 Milestone Report, Kennedy Space Center (KSC) LOX Loading Facility Analyses

Transient thermodynamic analyses have been made for the Kennedy Space Center (KSC) LOX loading system proposed for the space shuttle. The primary objective of these analyses is to predict the sensitivity of system performance to operating procedures, flow rate, temperature, and quality at the orbiter (ORB)/ground service equipment (GSE) interface. A further objective is to establish required system chill-down times. These analyses also include the prediction of transient thermodynamic conditions for the facility vent line, shuttle main engine (SSME) feed line entrance, ORB/ET interface, and the ET entrance (tank bottom).

Glasgow, V. L.↗
NASA NTRS1975

Electrochemical carbon dioxide concentrator advanced technology tasks

Technology advancement studies are reported on the basic electrochemical CO2 removal process to provide a basis for the design of the next generation cell, module and subsystem hardware. An Advanced Electrochemical Depolarized Concentrator Module (AEDCM) is developed that has the characteristics of low weight, low volume, high CO2, removal, good electrical performance and low process air pressure drop. Component weight and noise reduction for the hardware of a six man capacity CO2 collection subsystem was developed for the air revitalization group of the Space Station Prototype (SSP).

Schneider, J. J.↗
NASA NTRS1975

Biomedical applications team tasks

The status of the biomedical applications team is discussed along with its activity in applications engineering. Various technology requests are summarized.

Laenger, C. J., Sr.↗
NASA NTRS1974

Technology forecasting for space communication. Task one report: Cost and weight tradeoff studies for EOS and TDRS

Weight and cost optimized EOS communication links are determined for 2.25, 7.25, 14.5, 21, and 60 GHz systems and for a 10.6 micron homodyne detection laser system. EOS to ground links are examined for 556, 834, and 1112 km EOS orbits, with ground terminals at the Network Test and Tracking Facility and at Goldstone. Optimized 21 GHz and 10.6 micron links are also examined. For the EOS to Tracking and Data Relay Satellite to ground link, signal-to-noise ratios of the uplink and downlink are also optimized for minimum overall cost or spaceborne weight. Finally, the optimized 21 GHz EOS to ground link is determined for various precipitation rates. All system performance parameters and mission dependent constraints are presented, as are the system cost and weight functional dependencies. The features and capabilities of the computer program to perform the foregoing analyses are described.

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NASA NTRS1975

Trade study for water and waste management concepts. Task 7: Support special analysis

Cost analyses and tradeoff studies are given for waste management in the Space Station, Lunar Surface Bases, and interplanetary space missions. Crew drinking water requirements are discussed and various systems to recycle water are examined. The systems were evaluated for efficiency and weight savings. The systems considered effective for urine water recovery were vapor compression, flash evaporation, and air evaporation with electrolytic pretreatment. For wash water recovery, the system of multifiltration was selected. A wet oxidation system, which can process many kinds of wastes, is also considered.

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