A discussion of orbital workshop orientation and gravitational effects
Orbital work shop orientation and gravitational effects
Davis, B. G.↗
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Interstellar cloud shapes - A minimum-hypothesis account involving a purely gravitational effect
The effect produced by the anisotropic gravitational field on the shape of a nonspherical, self-gravitating interstellar cloud is examined. The projected axial ratios observed for molecular clouds can be accounted for if clouds are not generally in a state of strict dynamical equilibrium. For clouds having spectral line widths dominated by supersonic turbulent motions, this purely gravitational effect predicts a mean true axial ratio q about 0.3 for both oblate and prolate cloud geometries. Clouds having p less than about 0.3 are likely to be prolate and quite elongated. The observational data on molecular cloud cores, which have essentially thermal line widths, can be fitted equally well to either oblate or prolate spheroids having q between 0.1 and 0.4 with q about 0.2 providing the best match: highly elongated cores are again more likely to be prolate. While other processes certainly operate throughout the Galaxy to influence cloud shape, it appears plausible that at least some clouds may be shaped principally by their anisotropic gravitational field.
Fleck, Robert C., Jr.↗
Gravitational effects on electrochemical batteries
The existing work on gravitational effects on electrochemical batteries is summarized, certain conclusions are drawn, and recommendations are made for future activities in this field. The effects of sustained high-G environments on cycle silver-zinc and nickel-cadmium cells have been evaluated over four complete cycles in the region of 10 to 75 G. Although no effects on high current discharge performances or on ampere-hour capacity were noted, severe zinc migration and sloughing of active material from the zinc electrode were observed. This latter effect constitutes real damage, and over a long period of time would result in loss of capacity. It is recommended that a zero-G battery experiment be implemented. Both an orbiting satellite and a sounding rocket approach are being considered.
Meredith, R. E.↗
Orbital regression of synchronous satellites due to the combined gravitational effects of the sun, the moon and the oblate earth
Orbital regression of synchronous satellites due to combined gravitational effects of sun, moon, and oblate earth
GRAVITATIONAL EFFECT↗
Investigation of the earth's gravitational effects on the motion of near earth satellites
Earth gravitational effects on motion of near earth satellites
Yionoulis, S. M.↗
1998 Gordon Research Conference on Gravitational Effects on Living Systems
The Gordon Research Conference (GRC) on GRAVITATIONAL EFFECTS ON LIVING SYSTEMS was held at COLBY SAYWER 2 from 7/12/98 thru 7/17/98. The Conference was well-attended with 94 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, "free time" was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field. As you know, in the interest of promoting the presentation of unpublished and frontier-breaking research, Gordon Research Conferences does not permit publication of meeting proceedings.
Evans, Michael L.↗
1998 Gordon Research Conference on Gravitational Effects on Living Systems
The Gordon Research Conference (GRC) on GRAVITATIONAL EFFECTS ON LIVING SYSTEMS was held at COLBY SAYWER 2 from 7/12/98 thru 7/17/98. The Conference was well-attended with 94 participants. The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. A copy of the formal schedule and speaker program and the poster program is included. In addition to these formal interactions, "free time" was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.
Evans, Michael L.↗
Gravitational Effects on the Morphology and Kinetics of Photodeposition of Polydiacetylene Thin Films From Monomer Solutions
The goal of this proposed work is to study gravitational effects on the photodeposition of polydiacetylene thin films from monomer solutions onto transparent substrates. Polydiacetylenes have been an extensively studied class of organic polymers because they exhibit many unusual and interesting properties, including electrical conductivity and optical nonlinearity. Their long polymeric chains render polydiacetylenes readily conducive to thin film formation, which is necessary for many applications. These applications require thin polydiacetylene films possessing uniform thicknesses, high purity, minimal inhomogeneities and defects (such as scattering centers), etc. Also, understanding and controlling the microstructure and morphology of the films is important for optimizing their electronic and optical properties. The lack of techniques for processing polydiacetylenes into such films has been the primary limitation to their commercial use. We have recently discovered a novel method for the formation of polydiacetylene thin films using photo-deposition from monomer solutions onto transparent substrates with UV light. This technique is very simple to carry out, and can yield films with superior quality to those produced by conventional methods. Furthermore, these films exhibit good third-order properties and are capable of waveguiding. We have been actively studying the chemistry of diacetylene polymerization in solution and the photo-deposition of polydiacetylene thin films from solution. It is well-known that gravitational factors such as buoyancy-driven convection and sedimentation can affect chemical and mass transport processes in solution. One important aspect of polydiacetylene thin film photodeposition in solution, relevant to microgravity science, is that heat generated by absorption of UV radiation induces thermal density gradients that under the influence of gravity, can cause fluid flows (buoyancy-driven convection). Additionally, changes in the chemical composition of the solution during polymerization may cause solutal convection. These fluid flows affect transport of material to and from the film surface and thereby affect the kinetics of the growth process. This manifests itself in the morphology of the resulting films; films grown under the influence of convection tend to have less uniform thicknesses, and can possess greater inhomogeneities and defects. Specifically, polydiacetylene films photodeposited from solution, when viewed under a microscope, exhibit very small particles of solid polymer which get transported by convection from the bulk solution to the surface of the growing film and become embedded. Even when carried out under conditions designed to minimize unstable density gradients (i.e., irradiating the solution from the top), some fluid flow still takes place (particles remain present in the films). It is also possible that defect nucleation may be occurring within the films or on the surface of the substrate; this, too, can be affected by convection (as is the case with crystal growth). Hence films grown in 1-g will, at best, still possess some defects. The objective of this proposal is to investigate, both in 1-g and in low-g, the effects of gravitational factors (primarily convection) on the dynamics of these processes, and on the quality, morphology, and properties of the films obtained.
Paley, Mark S.↗
A marsupial model for the investigation of gravitational effects on early development
The application of the marsupial mouse to the study of gravitational effects on early development is discussed. The benefits provided to microgravity experiments by the unique development of the species are described. The uterogestation and exterogestation, and the formation of the vestibular and musculoskeletal systems in the marsupial mouse are examined.
Jurgelski, W.↗
Flow stability and gravitational effects in condenser tubes
Multitube condensers of various geometries, investigating tube flow stability, distribution and gravitational effects
Berenson, P. J.↗
Effects of plant growth hormones on plant development in the absence of gravitational effects Final report, Sep. 1, 1964 - Aug. 31, 1966
Radioactive auxin to study axial curvature in terrestrial plants, retarded growth of internodes on horizontal clinostats on seedlings, and plant growth without gravity
BIOLOGY↗
Interannual Atmospheric Oscillations and Their Gravitational Effects
Past studies have examined the effects of the interannual atmospheric oscillations (IAO), or often called teleconnection patterns, on the Earth's rotation, such as El Nino/Southern Oscillation (ENSO), the quasi-biennial oscillation, and to a lesser extent the North Atlantic Oscillation (NAO). The present study focuses on IAO's effects on the gravitational field and geocenter; the purpose is to be able to identify and isolate the contributions of each prominent IAO in relation to the total contribution of the atmosphere, in terms of their magnitudes, their geographical patterns, and their interannual time history. We use the 40-year NCEP reanalysis of the monthly, global atmospheric surface pressure field as our basic data set. The method we apply to isolate the IAOs is the empirical orthogonal function (EOF) decomposition which is widely used in meteorological investigations. We do the EOF analysis first on IAOs' seasonal signals (by "collapsing" the 40-year series into 12 mean-months for each grid point) and obtain estimates for their respective contributions. Then we remove these seasonal signals from the data to focus on the (broad-band) interannual EOFs. We examine ENSO, NAO, North Pacific Oscillation, and other less prominent IAOs that can be identified from our data set, and compute their respective contributions to the variation of global gravitational field and geocenter motion. Finally, we compare the results with the available observational data, and discuss the implications w.r.t. the upcoming space missions such as GRACE.
Chao, Benjamin F.↗
A Thermal Review of the Sample Cartridge Assembly (SCA) Gravitational Effect of Distortion in Sintering (GEDS) Experiment Flight Processing
NASA’s Sample Cartridge Assembly (SCA) first flight experiment, Gravitational Effect of Distortion in Sintering (GEDS), was processed on the International Space Station (ISS) between 2019 and 2020. The SCA was heated in the European Space Agency’s (ESA) Low Gradient Furnace (LGF) that is housed inside the Material Science Research Rack (MSRR) located in the U.S. Laboratory Module. This summary will give a review of the design and flight experiment development for the GEDS SCA. It describes flight processing and the role of thermal engineering support. Lessons learned and future Principle Investigators (PI) will be discussed.
Micro-gravity Science↗
A Thermal Review of the Sample Cartridge Assembly (SCA) Gravitational Effect of Distortion in Sintering (GEDS) Experiment Flight Processing
NASA’s Sample Cartridge Assembly (SCA) first flight experiment, Gravitational Effect of Distortion in Sintering (GEDS), was processed on the International Space Station (ISS) between 2019 and 2020. The SCA was heated in the European Space Agency’s (ESA) Low Gradient Furnace (LGF) that is housed inside the Material Science Research Rack (MSRR) located in the U.S. Laboratory Module. This summary will give a review of the design and flight experiment development for the GEDS SCA. It describes flight processing and the role of thermal engineering support. Lessons learned and future Principle Investigators (PI) will be discussed.
MIcro-gravity Science↗
Gravitational Effects on Signal Transduction
An understanding of the mechanisms by which individual cells perceive gravity and how these cells transduce and respond to gravitational stimuli is critical for the development of long-term manned space flight experiments. We now propose to use a well-characterized model erythroid cell system and to investigate gravitational perturbations of its erythropoietin (Epo) signaling pathway and gene regulation. Cells will be grown at 1-G and in simulated microgravity in the NASA Rotating Wall Vessel bioreactor (RWV). Cell growth and differentiation, the Epo-receptor, the protein kinase C pathway to the c-myc gene, and the protein phosphatase pathway to the c-myb gene will be studied and evaluated as reporters of gravitational stimuli. The results of these experiments will have impact on the problems of 1) gravitational sensing by individual cells, and 2) the anemia of space flight. This ground-based study also will serve as a Space Station Development Study in gravitational effects on intracellular signal transduction.
Sytkowski, Arthur J.↗
Gravitational effects on the extinction conditions for premixed flames
The four particular classes of premixed flames which are of special interest include freely propagating gaseous flames, burner stabilized premixed gaseous flames, freely propagating particle-cloud flames, and burner stabilized two-phase flames. Associated gravitational effects are related to upward flame propagation, downward flame propagation, and flame propagation in microgravity. The results of theoretical and experimental studies suggest that a comprehensive approach to representation of extinction limits must deal with the full range of existence limits observed for flames. Issues awaiting solution are related to the flammability limits, extinction limit relations, and flame theories for g = 0. Attention is given to theoretical considerations, nonadiabatic features of premixed lycopodium-air flames, and general comments on the extinction conditions for premixed flames.
Berlad, A. L.↗
Gravitational Effects on Liquefaction Systems for Lunar and Mars xploration
There is interest at NASA, other space agencies, and industry, in the liquefaction of fluids produced through in-situ processes on the surfaces of the Moon and Mars. A multi-center team at NASA recently considered multiple different refrigeration cycles and refrigeration integration methodologies and how these might fit into early liquefaction plants for NASA's exploration initiatives. The rate of liquefaction for these initiatives is quite slow in comparison to large scale terrestrial applications. These studies concluded that, for both structural and heat spreading reasons, integrating the refrigeration tubing on the surface of the storage tank wall is an attractive path to pursue in the near term. An analysis is performed of the condensation processes within the tank to determine the sensitivity of liquefaction to gravitational effects. The heat transfer mechanisms include forced convection heat removal to the refrigeration system (or cryocooler), conduction through the tank wall heat exchanger, and condensation on the inner tank wall. Gravity affects the liquefaction process via condensate liquid drainage, natural convection in the ullage, and the shape of the liquid-vapor interface in the tank. Analysis of these mechanisms shows that while there is some sensitivity to gravitational level in general, within the bounds of current interest (rate of liquefaction appropriate to Lunar and Martian applications), this sensitivity of liquefaction to gravity is quite small. Thus, system level testing on the Earth should suffice for the performance prediction and demonstration of liquefaction operations as applicable to lunar and Martian applications.
Cryogenics↗
Gravitational Effects on Liquefaction Systems for Lunar and Mars Exploration
There is interest at NASA, other space agencies, and industry, in the liquefaction of fluids produced through in-situ processes on the surfaces of the Moon and Mars. A multi-center team at NASA recently considered multiple different refrigeration cycles and refrigeration integration methodologies and how these might fit into early liquefaction plants for NASA's exploration initiatives. The rate of liquefaction for these initiatives is quite slow in comparison to large scale terrestrial applications. These studies concluded that, for both structural and heat spreading reasons, integrating the refrigeration tubing on the surface of the storage tank wall is an attractive path to pursue in the near term. In order to develop a technology development path and inform investors, it was desired to investigate the sensitivity of gravity of the processes involved. An analysis of the condensation processes within the tank is performed. The objective is to determine the sensitivity of liquefaction to gravitational effects. The heat transfer mechanisms include forced convection heat removal to the refrigeration system (or cryocooler), conduction through the tank wall heat exchanger, and convection and condensation on the inner tank wall. Gravity affects the liquefaction process via condensate liquid drainage, natural convection in the ullage, and the shape of the liquid-vapor interface within the tank. Analysis of these mechanisms shows that while there is some sensitivity to gravitational level in general, within the bounds of current interest (rate of liquefaction appropriate to Lunar and Martian applications, and cooling capacity of the cryocooler), this sensitivity of liquefaction to gravity is quite small. Thus, system level testing on the Earth should suffice for the performance prediction and demonstration of liquefaction operations as applicable to Lunar and Martian applications.
ISRU↗