Zero-Gravity Atmospheric Cloud Physics Experiment Laboratory-engineering concepts/design tradeoffs. Volume 2: Detailed approaches
For abstract, see N75-10953.
Greco, R. V.↗
SEARCH · Search NASA
Results for “Zero Gravity”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Investigation of solidification in zero-gravity environment: M553 sphere forming experiment. Nickel-silver alloy evaluation
The processing of nickel-silver alloy specimens in space is discussed. Four specimens were melted only partially, while a fifth was melted completely and assumed after solidification a perfectly spherical shape. Growth of the solid was epitaxial on the unmelted material or on the retaining sting and occurred without undercooling. Solidification was dendritic in all cases with nonequilibrium silver particles forming monotectically between dendrite arms. Substantial loss of silver by evaporation took place. Evaporation of the silver within internal gas cavities on the melt was followed by surface condensation after completion of solidification and cooling, leading to a silver-rich lining in these cavities. The material gave no microstructural evidence of any reduction in liquid convection.
Kattamis, T. Z.↗
Zero-gravity atmospheric Cloud Physics Experiment Laboratory; Programmatics report
The programmatics effort included comprehensive analyses in four major areas: (1) work breakdown structure, (2) schedules, (3) costs, and (4) supporting research and technology. These analyses are discussed in detail in the following sections which identify and define the laboratory project development schedule, cost estimates, funding distributions and supporting research and technology requirements. All programmatics analyses are correlated among themselves and with the technical analyses by means of the work breakdown structure which serves as a common framework for program definition. In addition, the programmatic analyses reflect the results of analyses and plans for reliability, safety, test, and maintenance and refurbishment.
Source record↗
Study on processing immiscible materials in zero gravity
An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.
Reger, J. L.↗
Analysis of changes in leg volume parameters, and orthostatic tolerance in response to lower body negative pressure during 28-days exposure to zero gravity Skylab 2
The design of the leg volume measuring system employed for the M092 portion of the Skylab missions required the development of a system sensitive to large and small volume changes at the calf of the leg. These changes in volume were produced in response to the orthostatic stress of a Lower Body Negative Pressure Device (LBNPD) or by venous occlusion. The cardiovascular responses of the Apollo crewman associated with the postflight evaluations indicate varying decrements of orthostatic tolerance. The postflight changes indicate a slightly diminished ability of the cardiovascular system to function effectively against gravity following exposure to weightlessness. The objective of the Skylab LBNP experiments (M092) was to provide information about the magnitude and time course of the cardiovascular changes associated with prolonged periods of exposure to weightlessness. The equipment, signal processing, and analysis of the leg volume data obtained from the M092 experiment of the Skylab 2 Mission are described.
Barnett, R. D.↗
A zero-gravity demonstration of the collision and coalescence of water droplets
The mechanics of the collision and coalescence of liquid droplets is one of the main research areas in the fields of nuclear physics, astrophysics, meteorology and fluid mechanics. The crew members on the Skylab 3 and 4 missions were requested to perform demonstrations of the collision and coalescence of water droplets under the low gravity environment at orbital altitude. In Skylab 4 two water droplets with equal volumes, 30 cu cm each, were used. A dark colored droplet (contaminated with grape drink) moving with a velocity of 3.14 cm/sec collided with a stationary pink colored droplet (contaminated with strawberry drink) and coalescence occurred. Theoretical models are proposed to study the various stages of the collision-coalescence processes. Special considerations are concentrated in the investigation of the bounce-coalescence and coalescence-instability processes. The surface tension of the coalesced droplets was calculated to be 52 dynes/cm in perfect agreement with laboratory measurements made after the flight using a reproduction of the liquids.
Hung, R. J.↗
A photographic study of flow condensation in 1-g and zero-gravity environments
The test articles investigated include two full-scale radiator/condenser panels and a system of three parallel-connected fused quartz tubes. Testing was performed initially on the ground, with both horizontal and inclined flow passage orientations, and additionally in an aircraft flying 0-g trajectories. The photographic observations were made with two high speed cameras and a low speed camera. The flow regimes observed are compared with those predicted by the Baker chart (1954). The Baker chart is well in accord with physical reality in the annular flow region. However, a stratified-annular flow regime observed has no counterpart in the Baker categorization.
Keshock, E. G.↗
Zero gravity liquid propellant control by dielectrophoresis
Explore the source record for details and available documents.
Blackmon, J. B.↗
Analysis of changes in leg volume parameters, and orthostatic tolerance in response to lower body negative pressure during 59 days exposure to zero gravity Skylab 3
The cardiovascular responses of the Apollo crewmen associated with postflight evaluations indicate varying decrements of orthostatic tolerance. The postflight changes indicate a slightly diminished ability to the cardiovascular system to function effectively against gravity following exposure to weightlessness. The objective of the Skylab LBNP experiments (M092) was to provide information about the magnitude and time course of the cardiovascular changes associated with prolonged periods of exposure to weightlessness. This report details the equipment, signal processing and analysis of the leg volume data obtained from the M092 experiment of the Skylab 3 Mission.
Barnett, R. D.↗
Project Fog Drops 5. Task 1: A numerical model of advection fog. Task 2: Recommendations for simplified individual zero-gravity cloud physics experiments
A two-dimensional numerical model was used to investigate the formation of marine advection fog. The model predicts the evolution of potential temperature, horizontal wind, water vapor content, and liquid water content in a vertical cross section of the atmosphere as determined by vertical turbulent transfer and horizontal advection, as well as radiative cooling and drop sedimentation. The model is designed to simulate the formation, development, or dissipation of advection fog in response to transfer of heat and moisture between the atmosphere and the surface as driven by advection over horizontal discontinuities in the surface temperature. Results from numerical simulations of advection fog formation are discussed with reference to observations of marine fog. A survey of candidate fog or cloud microphysics experiments which might be performed in the low gravity environment of a shuttle-type spacecraft in presented. Recommendations are given for relatively simple experiments which are relevent to fog modification problems.
Rogers, C. W.↗
Solidification under zero gravity: A Long Duration Exposure Facility (LDEF) experiment for an early space shuttle mission
The preliminary design of two series of simple experiments the objectives of which are to determine the effect of an absence of gravity on (1) the general morphology of the structure, (2) location of ullage space, and (3) magnitude of surface tension driven convection, during the solidification of several metallic and nonmetallic systems is described. Details of the investigative approach, experimental procedure, experimental hardware, data reduction and analysis, and anticipated results are given.
Bailey, J. A.↗
Zero-gravity growth of NaF-NaCl eutectics in the NASA Skylab program
Continuous and discontinuous NaF fibers, embedded in a NaCl matrix, were produced in space and on earth. The production of continuous fibers in a eutectic mixture is attributed to the absence of convection current in the liquid during solidification in space. Image transmission and optical transmittance measurements of transverse sections of the space-grown and earth-grown ingots were made with a light microscope and a spectrometer. It is shown that better optical properties were obtained from samples grown in space. This was attributed to a better alignment of NaF fibers along the ingot axis. A new concept is advanced to explain the phenomenon of transmittance versus far infrared wavelength of the directionally solidified NaCl-NaF eutectic in terms of the two-dimensional Bragg Scattering and the polarization effect of Rayleigh scattering. This concept can be applied to other eutectic systems as long as the index of refraction of the matrix over a range of wavelengths is known. Experimental data are in agreement with the theoretical prediction.
Yue, A. S.↗
Feasibility of producing closed-cell metal foams in a zero-gravity environment from sputter deposited inert gas-bearing metals and alloys. Post-flight technical report, SPAR flight 2
Metallography from experiment 24-10 obtained on the second space processing applications rocket (SPAR) flight is discussed. Results are considered along with results from the related experiments on the first SPAR flight. Conclusions are presented.
Patten, J. W.↗
Electrophoretic separation of human kidney cells at zero gravity
Electrophoretic isolation of cells results in a loss of resolution power caused by the sedimentation of the cells in the media. The results of an experiment to extract urokinase from human embryos during the Apollo Soyuz mission are presented and discussed.
Barlow, G. H.↗
Zero-gravity growth of NaCl-LiF eutectic. Experiment MA-131
Continuous and discontinuous lithium fluoride fibers embedded in a sodium chloride matrix were produced in space and on earth, respectively. The production of continuous fibers in an eutectic mixture was attributed to the absence of convection current in the liquid during solidification in space. Image transmission and optical transmittance measurements of transverse sections of the space-grown and earth-grown ingots were made with a light microscope and a spectrometer. It was found that better optical properties were obtained from samples grown in space. This was attributed to a better alignment of lithium fluoride fibers along the growth direction.
Yue, A. S.↗
Fluid mass sensor for a zero gravity environment
A sensor for measuring the mass of fluids, is described which includes a housing having an inlet and outlet for receiving and dumping the fluid, a rotary impeller within the housing for imparting centrifugal motion to the fluid and a pressure sensitive transducer attached to the housing to sense the rotating fluid pressure. The fluid may be drawn into the housing by entrainment within a gas stream. The resulting mixture is then separated into two phases: gas and liquid. The gas is removed from the housing and the pressure of the liquid, under centrifugal motion, is sensed and correlated with the mass of the fluid.
Fogal, G. L.↗
Assessment of geophysical flows for zero-gravity simulation
The results of research relating to the feasibility of using a low gravity environment to model geophysical flows are presented. Atmospheric and solid earth flows are considered. Possible experiments and their required apparatus are suggested.
Winn, C. B.↗
Glass fining experiments in zero gravity
Ground based experiments were conducted to demonstrate that thermal migration actually operated in glass melts. Thermal migration consistent with the theory was found in one experiment on a borax melt, i.e., there was an approximately linear relation between the bubble diameter and bubble velocity for a given temperature and temperature gradient. It also appeared that nearby bubbles were attracted to one another, which could greatly aid fining. Interpretation of these results was not possible because of complications arising from gravity, i.e., floating of the bubbles, circulation currents due to buoyancy-driven natural connection, and flow of the melt out from the cell.
Smith, H. D.↗