3,229 research outputs found

    Project Artemis

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    The goals of Project Artemis are designed to meet the challege of President Bush to return to the Moon, this time to stay. The first goal of the project is to establish a permanent manned base on the Moon for the purposes of scientific research and technological development. The knowledge gained from the establishment and operations of the lunar base will then be used to achieve the second goal of Project Artemis, the establishment of a manned base on the Martian surface. Throughout both phases of the program, crew safety will be the number one priority. There are four main issues that have governed the entire program: crew safety and mission success, commonality, growth potential, and costing and scheduling. These issues are discussed in more detail

    Structural Assembly Demonstration Experiment (SADE)

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    The purpose of the Structural Assembly Demonstration Experiment (SADE) was to create a near-term Shuttle flight experiment focusing on the deployment and erection of structural truss elements. The activities of the MIT Space Systems Laboratory consist of three major areas: preparing and conducting neutral buoyancy simulation test series; producing a formal SADE Experiment plan; and studying the structural dynamics issues of the truss structure. Each of these areas is summarized

    Assessment of Fitts' Law for Quantifying Combined Rotational and Translational Movements

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    Objective: To develop a model for human performance in combined translational and rotational movements based on Fitts' law. Background: Fitts' law has been successfully applied to translational movements in the past, providing generalization beyond a specific task as well as performance predictions. For movements involving both translations and rotations, no equivalent theory exists, making comparisons of input devices for these movements more ambiguous. Method: The study consisted of three experiments. In the first two, participants performed either pure translational or pure rotational movements of 1 degree of freedom. The third experiment involved the same movements combined. Results: On average, the performance times for combined movements were equal to the sum of the times for equivalent separate rotational and translational movements. A simple Fitts' law equivalent for combined movements with a similar slope as the separate components was proposed. In addition, a significant degree of coordination of the combined movements was found. This had a strong bias toward a parallel execution in 12 out of 13 participants. Conclusion: Combined movements with rotations and translations of 1 degree of freedom can be approximated using a simple Fitts' law equivalent. The rotational and translational components appear to be coordinated by the central nervous system to generate a parallel execution. Application: The results may help drive human interface designs and provide insights into the coordination of combined movements. Future extensions may be possible for the movements of higher degrees of freedom used in robot teleoperation and virtual reality applications.This work was supported by the Institute for Dexterous Space Robotics (Grant No. NNX06AD23G).Publicad

    Rapid flipping of parametric phase states

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    Since the invention of the solid-state transistor, the overwhelming majority of computers followed the von Neumann architecture that strictly separates logic operations and memory. Today, there is a revived interest in alternative computation models accompanied by the necessity to develop corresponding hardware architectures. The Ising machine, for example, is a variant of the celebrated Hopfield network based on the Ising model. It can be realized with artifcial spins such as the `parametron' that arises in driven nonlinear resonators. The parametron encodes binary information in the phase state of its oscillation. It enables, in principle, logic operations without energy transfer and the corresponding speed limitations. In this work, we experimentally demonstrate flipping of parametron phase states on a timescale of an oscillation period, much faster than the ringdown time \tau that is often (erroneously) deemed a fundamental limit for resonator operations. Our work establishes a new paradigm for resonator-based logic architectures.Comment: 6 pages, 3 figure

    Environmental mastery and depression in older adults in residential care

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    This study investigated the association between environmental mastery and depression in a sample of 96 older adults (aged 64&ndash;98 years) in residential care. The participants completed a scale that assessed depression along with measures for risk factors for depression such as functional capacity, self-evaluated physical health, bereavement experiences and environmental mastery. The results showed that 49 per cent of the variance in participants&rsquo; scores in depression could be attributed to their self-reported level of environmental mastery. Given the complexity of depression and the likelihood of reduced environmental mastery among older adults in residential care, the construct was further assessed as a mediating variable between the risk factors and depression. With environmental mastery taken as such, the explained variance in depression increased to 56 per cent. It was concluded that environmental mastery may be one of the more important factors affecting the mental health of older adults living in residential care and that strategies for increasing the residents&rsquo; environmental mastery are important to their psychological wellbeing. The discussion notes that among the questions needing further investigation are whether older adults who experience high environmental mastery make the transition from community living to residential nursing home care more successfully than others, and whether perceived mastery diminishes over time or occurs at the point of transition from community independent living to dependent supported living.<br /

    BioBot: Innovative Offloading of Astronauts for More Effective Exploration

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    The BioBot concept consists of a robotic rover which is capable of traversing the same terrain as a spacesuited human. It carries the primary life support system for the astronaut, including consumables, atmosphere revitalization systems (e.g., CO2 scrubbing, humidity and temperature management, ventilation fan), power system (e.g., battery, power management and distribution),and thermal control system (e.g., water sublimator, cooling water pump), along with umbilical lines to connect to the supported astronaut. Although not technically part of life support, it would be logical for the BioBot to also provide long-range communications, video monitoring, tool and sample transport, and other functions to enable and enhance EVA productivity in planetary surface exploration.The design reference scenario for this concept is that astronauts involved in future lunar or Mars exploration will be on the surface for weeks or months rather than days, and will be involved in regular EVA operations. It is not unreasonable to think of geologists spending several days inEVA exploration each week over a prolonged mission duration, with far more ambitious operational objectives than were typical of Apollo. In this scenario, each astronaut will be accompanied by a "BioBot", which will transport their life support system and consumables, an extended umbilical and umbilical reel, and robotic systems capable of controlling the position and motion of the umbilical. The astronaut will be connected to the robot via the umbilical, carrying only a small emergency open-loop life support system similar to those contained in every PLSS. The robotic mobility base will be designed to be capable of traveling anywhere the astronaut can walk, and will also be useful as a transport for the EVA tools, science instrumentation, and collected samples. In addition, the BioBot can potentially carry the astronaut on traverses as well. Such a system will also be a significant enhancement to public engagement in these future exploration missions, as the robotic vehicles can also support high-resolution cameras and high bandwidth communications gear to providehigh-definition video coverage of each crew throughout each EVA sortie

    NIAC Phase I Final Report: On-Orbit, Collision-Free Mapping of Small Orbital Debris

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    Sub-centimeter orbital debris is currently undetectable using ground-based radar and optical methods. However, the pits in Space Shuttle windows produced by paint chips (e.g. the 3.8mm diameter pit produced by a 0.2mm paint chip on STS-7) demonstrate that small debris can cause serious damage to spacecraft. Recent analytical, computational and experimental work has shown that charged objects moving quickly through a plasma will cause the formation of solitons in the plasma density. Due to their exposure to the solar wind plasma environment, even the smallest space debris will be charged. Depending on the debris size, charge and velocity, the plasma signature of the solitons may be detected by simple instrumentation on spacecraft. We will describe the amplitude and velocity of solitons that may be produced by mm-cm scale orbital debris in LEO. We will discuss the feasibility of mapping sub-cm orbital debris using a fleet of CubeSats equipped with Langmuir probes. The time and fleet size required to map the debris will also be described. Plasma soliton detection would be the first collision-free method of mapping the small debris population

    Evaluation of a novel saliva-based epidermal growth factor receptor mutation detection for lung cancer: A pilot study.

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    BackgroundThis article describes a pilot study evaluating a novel liquid biopsy system for non-small cell lung cancer (NSCLC) patients. The electric field-induced release and measurement (EFIRM) method utilizes an electrochemical biosensor for detecting oncogenic mutations in biofluids.MethodsSaliva and plasma of 17 patients were collected from three cancer centers prior to and after surgical resection. The EFIRM method was then applied to the collected samples to assay for exon 19 deletion and p.L858 mutations. EFIRM results were compared with cobas results of exon 19 deletion and p.L858 mutation detection in cancer tissues.ResultsThe EFIRM method was found to detect exon 19 deletion with an area under the curve (AUC) of 1.0 in both saliva and plasma samples in lung cancer patients. For L858R mutation detection, the AUC of saliva was 1.0, while the AUC of plasma was 0.98. Strong correlations were also found between presurgery and post-surgery samples for both saliva (0.86 for exon 19 and 0.98 for L858R) and plasma (0.73 for exon 19 and 0.94 for L858R).ConclusionOur study demonstrates the feasibility of utilizing EFIRM to rapidly, non-invasively, and conveniently detect epidermal growth factor receptor mutations in the saliva of patients with NSCLC, with results corresponding perfectly with the results of cobas tissue genotyping

    The ParaShield Entry Vehicle Concept: Basic Theory and Flight Test Development

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    With the emergence of microsatellite launch vehicle technology and the development of interest in space commercialization, there is a renewed need for entry vehicle technology to return mass from low earth orbit. This paper documents the ParaShield concept of the Space Systems Laboratory, which is an ultra-low ballistic coefficient (ULβ) entry vehicle. Trajectory simulations show that as the ballistic coefficient is lowered into the range of 100-150 Pa (2-3lb/ft2) the total heat load and peak heating flux drop markedly due to primary deceleration in regions of extremely low dynamic pressure. In this range any of a number of ceramic or glass-based fabrics can withstand the entry dynamic pressures and heat loads. Incorporating an offset of the center of gravity from the symmetrical axis of the shield allows L/D, and thus peak deceleration loads, to be controlled. By using a titanium support truss and deployment mechanism, a very large heat shield can be deployed from an entry capsule prior to deorbit; since the shield survives entry the same rib-braced fabric structure results in aerodynamic deceleration to a nominal landing velocity of 10-15 m/sec. Thus the same structure that provides heating protection for hypersonic entry is also the terminal decelerator in the subsonic regime and either water splashdown or a mechanical decelerator is used for landing impact attenuation. Since the same structure acts as both the heat shield and the landing parachute, the term ParaShield has been adopted to describe this concept Results presented show the application of the ParaShield concept to a variety of entry capsules including advanced manned spacecraft. A test vehicle was prepared to take data on ULβ entry from a suborbital trajectory. This paper also summarizes the experience gained from the design construction, and integration of the Space Systems Laboratory ParaShield test vehicle on the American Rocket Company launch vehicle. With the failure of the launch vehicle, no flight test data was obtained; the test vehicle survived the launch incident, and is flight-capable for future suborbital missions. The development experience summarized in this paper has resulted in a sufficient knowledge base to allow the design and development of orbital ParaShield vehicles
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