ARCHIVE SEARCH RESULTS |
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| Austin Community College |
| 2007 |
| Centrifugal Microgravity Mass Assessment System |
| • In space, efforts to weigh samples are inhibited by a lack of gravitational force assisting in taking meas-urements. The gravitational force exhibited between the mass of a sample and the mass of the earth is easily measured on earth’s surface, but measuring this is complicated in conditions of microgravity. As has been demonstrated in numerous experiments, centrifugal force is analogous to gravitational force when acting in a direction orthogonal to the axis of rotation. This can be used in conjunction with force reading devices to gather the masses of samples in conditions of microgravity. By measuring the speed at which a centrifuge rotates, a computer system can gather and calculate the expected centripetal acceleration, compare it to the force exerted by the sample, and work out the mass by Newtonian mechanics.
• The proposed research is a proof of concept model that seeks to demonstrate these principles in practice, and show their efficacy in determining known masses independently of earth’s gravity. Uses for mass de-termination in conditions of microgravity include real-time feedback on the conditions of microorganisms on shuttle missions, dietary information for diagnosis of medical conditions for people and other life kept in space, measurement of productive output for agricultural plants kept in orbit, astrogeological analysis of samples collected in deep space, and a multitude of applications to chemical analyses.
• A microgravity environment is required for proper testing and operation of this device to counter weight and acceleration induced effects on the strain gauges and to eliminate weight related friction forces inhibit-ing the accuracy of measurement.
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| Brown University |
| 2007 |
| Fluid Experiments Across States: Explorations in Educational Applications |
| This proposal outlines three experiments that will investigate the effect of a micro-gravity environment on fundamental aspects of fluid behavior, building on previous work by the Brown University Space Club . Last year, our project was concerned with creating experiments which would facilitate effective outreach to an elementary school audience. We have used some video and results from last years experiments as presentation material at local schools, which have had a great effect. Our proposal this year is directed at collecting more quantitative data to be used for outreach at middle and high schools as well as collecting clearer video.
Our first test will once again test capillary action in microgravity. This year our goal is to build off of our qualitative results from last year, and in addition obtain quantitative data, measuring the rate and the height of the liquid as it moves up the tube, in an effort to appeal to older students, as well as examine applications of capillary flow for use in the zero- or low-gravity environment. We will look at a larger variety of capillary widths and configurations and predict the same, quick movement of fluid up the capillary.
Our second experiment again consists of mixing fluids. The experiment tested last year was not as successful as we had hoped; we ran into difficulties observing the mixing patterns between the dyed water. In an effort to examine the flow patterns of the input fluid, we will inject water into oil so that differentiation is visible.
Our third experiment consists of impacting precipitating fluids. Similar to an experiment run last year, two streams of fluids will be impacted in microgravity. Drawing from the experience gained last year, the fluids will have more room to react based on modification to the existing experiment apparatus, namely through changes to the fluid input mechanisms contained in the experiment chamber. In addition, the two fluids impacting will form a precipitate under normal gravity conditions. We predict that a precipitate will still form in microgravity, and observe its unique pattern of formation. As an expansion upon the principles of our volcano experiment last year, we are performing a common high school chemistry experiment in a microgravity environment to facilitate more active learning about the effects of zero-G.
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| City College of New York, CUNY |
| 2007 |
| Inflatable and Deflatable Modular Structure |
| Combining aerospace engineering and architecture promises an exciting array of technological innovations that have not been realized ever before. These innovations range from spaceports and launching pads on Earth to human settlements on Earth’s moon or Mars. Our teams experiences while working in collaboration with the science, engineering and architectural departments, aims to inspire the formation of a new generation of team efforts to explore space designs for extreme terrestrial environment habitation.
It is widely accepted that a human-tended base on the moon can serve as a stepping-stone for human space exploration and development beyond the Low Earth Orbit environment of the International Space Station. At present, this vision relies on the development of structures that are economically feasible and lightweight. NASA has also explored the advantages of inflatable structures in the past and their functionality and applicability for use as space structure alternatives has been favorably reviewed.
The increasingly complicated mission scenarios that astronauts have to undertake while having to spend increasing amounts of time outside the confines of the space shuttle, illustrate the need of portable-reusable structures as an emerging requirement. Our proposal represents an innovative concept that offers the advantages of lightweight easily reusable structures for mission applications where transportable shelter is required.
The team proposes to create inflatable structures of certain complexity, which are capable of being easily and rapidly deployed and then retracted to their initial compact, pre-inflated form automatically with no human interaction. This is an initial subscale demonstration of this technology, which hopes to establish and the possibility of such structures to be utilized in zero gravity. We aim to validate some of the technical advantages of such designs and discover and solve any unforeseen problems that have not been encountered while testing the technology in the confines of normal gravity.
Depending on the environmental condition the loads of the structure must be able to withstand at one atmospheric pressure between the interior and exterior as well as the required loading usage. The lightweight designs will be able to deceit loading conditions and it will adjust depending on the environment in which it is deployed.
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| Cornell University |
| 2007 |
| Low-Power, High-Agility Robotics Using control-moment gyroscopes:Testing the power requirements and torque outputs of a robotic arm actuated by control-moment gyroscopes in a zero-g environment |
| The purpose of this project is to build and demonstrate a two degree-of-freedom robotic arm for space applications with low power consumption and high actuator torque. The project addresses power consumption issues that limit the performance of current space manipulators. Control-moment gyroscopes (CMGs) are a unique solution to these problems. They generate large output torques but require less power than conventional actuators, such as direct-drive motors or reaction-wheel assemblies (RWAs). Our simulations show that CMG actuation requires only 1%-10% of the power normally used by robotic arms. Faster motions demand even less power from the CMG system than from a system that uses the more familiar reaction wheels. The CMG Research Team proposes to design, manufacture, and test a robotic arm capable of effectively validating our theoretical predictions. Validation must occur in a microgravity environment, because it is the only environment in which the zero-gravity aspect of the testing can be realized. |
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| Drury University |
| 2007 |
| Dynamics of a Planar Arm Model with Servo-regulated Viscoelastic Muscles in a Microgravity Environment |
| We intend to construct a mechanical arm model which will simulate vertical planar human arm motion with two degrees of freedom: shoulder joint rotation and elbow joint rotation. The arm will consist of a rigid upper arm and forearm, with elastic materials representing elasticity of muscles, servo-motors representing contraction of muscles, and computer hardware (the Acroname Brainstem) as the processor controlling the angles of rotation of the servo-motors. The servo-motors in turn will effect rotation of the elbow and shoulder joints through the tension incited in the muscles. The reason for creating this mechanical arm model is to observe and predict arm motion in the laboratory under normal earth gravity conditions and on NASA's aircraft under near zero gravity conditions, and thus to gain insight regarding how muscle contractions generate arm motions under the vastly different conditions of normal gravity and zero gravity. Last year we submitted a successful proposal, which included two additional degrees of freedom. However, the mechanical complexity of the proposed project led to its premature cancellation. We believe that reducing last year's proposed four-degree-of-freedom system to two degrees of freedom would be beneficial to understanding human arm mechanics as controlled by the brain, in a microgravity environment. Another advantage to working with only two degrees of freedom is that we will be able to test the motion of our device, prior to flight, in the laboratory effectively without the influence of gravity, by operating the arm in the horizontal plane. This will allow us to make predictions in a laboratory setting regarding what will occur when the experiment is performed in microgravity conditions. We believe testing our device on the NASA aircraft will give us the experience necessary to eventually develop and test a fully four-degree-of-freedom system. |
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| Fairfield University |
| 2007 |
| Splashless In Space: The Impact Behavior of Large Droplets on a Rigid Surface in Low-Atmosphere, Low-Gravity Environments |
| Our proposal is to investigate the physics of large scale liquid drop impacts upon a smooth dry surface. As a drop of liquid impacts a smooth dry surface, a crown shaped splash emerges as the drop collapses. A rather surprising phenomenon, however, was discovered in 2005: when the atmospheric pressure around the impact is decreased, the splash ceases to occur. There seems to exist a relationship between the splash characteristics and the atmospheric conditions. This relationship governs the threshold pressure, which is the atmospheric pressure at which a splash no longer results. One of the key parameters is the size of the drop. Previous ground based experiments have been limited in drop size due to the effects of gravity, which acts to detach a drop from an injector when the weight of the drop surpasses the adhesive force of the liquid. While strides are being made in understanding this phenomenon on Earth, particularly with smaller droplets, it has not been possible to test the threshold scaling with larger drops. We propose to use the microgravity environment onboard the DC-9 to scale the drop sizes much larger than is possible on a ground-based lab to verify and extend our understanding into the regime of large drop sizes. Using a variation on an experimental setup proven in a previous microgravity experiment, we will form drops up to 5 times the previously tested size, into the gravity limited drop size regime, and impact them on a smooth dry surface at constant velocity. This process will be repeated while capturing the impacts on a high speed camera, varying the atmospheric pressure by ±10% in 2% increments from the theoretically calculated threshold pressure (see Plot I.3.1). Follow-up image processing will let us confirm or reject the expectations. With many applications, ranging from printing and surface coating to wing icing on airplanes, verification and further refinement of this model would be a welcomed contribution to the science community. |
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| Florida Institute of Technology |
| 2007 |
| Electrochemical Deposition of CIS Experiment |
| The Electrochemical Deposition Experiment (EDEP) team is proposing an experiment to determine the effects of gravity on the deposition of thin films in solar cells and any correlation to efficiency that stems from this. Solar cells and the related energy technologies are a vital aspect of the current space program, and they hold the key to further success and advancement, not just of space exploration but the entire nation, by giving access to an almost limitless source of energy. Current solar cells have a theoretical efficiency for converting light to energy of about 72% (Friedfeld 1999). In use, though, solar cells have not reached over 20% efficiency. One known reason for the drop in efficiency is misplaced atoms in the structure, formed during deposition, and other such native defects. These structural errors change the semiconductor efficiency, since the defects reduce the carrier density. The use of annealing, the process of heating the thin film to 600°C so it becomes malleable and then and rapidly cooling it, causes the suture of the cell to become more reined but still deformities are present. We propose to use the microgravity environment aboard the C-9 to investigate the effects a reduced gravity environment on the deposition of copper indium Diselenide (CIS) polycrystalline thin films. CIS thin films are already one of the best materials used in solar cells. After being deposited under reduced gravity, the CIS thin films should be free of these natural defects of similar films formed under 1G and also ones that were annealed. This will be confirmed afterwards through the use of various processes, such as atomic force microscopy and scanning tunneling microscopy, scanning electron microscopy and though the creation of functioning solar cells. |
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| Jackson State University |
| 2007 |
| Flow characteristics of water under the influence of Far Infra Red (FIR) and mechanical vibration in zero gravity and ground level gravity |
| The movement of fluid flow depends on velocity of the fluid mass, the temperature and the energy flux. Less energy is required to move fluid in zero g when compared to that occurring at 1 x g. Furthermore, when the energy required to move the fluid in zero g and 1 x g is the same, the fluid moves faster in zero g than in 1 x g. However, in hypo-gravity under in-vivo conditions blood flow is decreased. Considering that the density of water (1.00 g/cc) and blood (1.077 g/cc) are similar, the cause of difference in the flow characteristics at zero x g for the two fluids is not clear. A consequence of decreased blood flow at zero gravity is that physical activities are hindered. Far infrared (FIR) is very helpful for blood circulation. FIR induces moderate hyperthermia (local temperature ~ 40 °C) and within physiological condition augments microvessel permeability. Muscle and bone mass loss is very prevalent in sustained space flight. Mechanical vibration is a possible solution to stimulate muscle and bone mass gain. Our hypothesis is that (i) FIR and /or (ii) mechanical vibration increases fluid flow in zero-gravity. We want to fill the knowledge gap between the increased flow of water at zero g and the decreased blood flow at zero g. We wish to characterize the energy flux, density, temperature and velocity of water fluid flow in a cylindrical vessel in the presence and absence of (i) FIR and/or (ii) mechanical vibration. The data will be collected using probes and video camera. The same experiment will be performed on the ground, and the data will be compared, analyzed and published. K-12 grades activities will be formulated to explain the effect of FIR and mechanical vibration on flow characteristics to inspire them into the science and engineering fields. |
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| Johns Hopkins University |
| 2007 |
| Surface Tension Impelled Low-Gravity Liquid Mixing Experiment Revisited |
| Synopsis:
The purpose of the Surface Tension Impelled Low-gravity Liquid Mixing Experiment Revisited is to correct for problems encountered in STILLMix (2003) in order to collect data on the mixing behavior of two liquids on a surface. Liquid mixing is driven primarily by gravity in a terrestrial environment, especially where the substances are of disparate densities. Liquids on a surface will be flattened and forced to spread laterally. In this instance, surface tension is only a secondary driving factor in mixing.
We theorize that in a microgravity environment, surface tension will be the primary driving factor in the mixing behavior of liquids on a surface. For testing, two liquids will be introduced to a surface simultaneously and at equal rates to a sample surface designed for optimum mixing, and to a smooth control surface. The results will be recorded in digital video an analyzed using a computer graphics program such as Adobe Photoshop®.
The results will consist of the shape of the mixing wave fronts and conclusions about the nature of surface-tension impelled mixing in microgravity.
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| Lamar University |
| 2007 |
| Disturbances of Lunar Soil Simulant under Vacuum and Lunar Gravity Conditions |
| We propose an experiment to impact lunar soil simulant with a spherical iron projectile at varying velocities under lunar gravity and vacuum conditions. The purpose of the experiment is to acquire visual data on the effects of impact on the distribution of lunar granular dust and depth of craters as a function of mass and impacting velocity. In addition we intend to agitate the simulant at high frequencies to determine the height and distribution of the disturbed granular dust under vacuum and lunar gravity conditions. The experiment should provide insights into secondary regolith-forming processes resulting from low velocity projectiles, as well as information regarding mechanical disturbances caused by equipment deployed on the lunar surface. The behavior of lunar granular dust under lunar vacuum and gravity conditions is of utmost importance to lunar return missions, especially for long-term habitation of a lunar outpost. The extremely fine grain (<50 ?m) component and its angular character found in real lunar soils, suggests that this dust may pose a threat to mechanical operations, pressure seals, and even health [1,2]. Thus understanding its behavior is of great interest, and NASA has several proposals for large vacuum chambers to simulate the behavior of lunar simulant under review [3]. Our small-scale experiment may provide insights about such issues. Unlike the large proposed chambers, our system will fit comfortably on the reduced gravity aircraft allowing our experiment to add the reduced gravity component to the observed behavior. Given the rather small scale of the experiment, a part of post-flight data analysis will be devoted scaling the dimensions of the results. |
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