184 research outputs found

    Commentary on the Principle Element in the Decline and Fall of The Human Race

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    Aerocapture Technologies

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    Aeroassist technology development is a vital part of the NASA In-Space Propulsion Technology (ISPT) Program. One of the main focus areas of ISPT is aeroassist technologies through the Aerocapture Technology (AT) Activity. Within the ISPT, the current aeroassist technology development focus is aerocapture. Aerocapture relies on the exchange of momentum with an atmosphere to achieve thrust, in this case a decelerating thrust leading to orbit capture. Without aerocapture, a substantial propulsion system would be needed on the spacecraft to perform the same reduction of velocity. This could cause reductions in the science payload delivered to the destination, increases in the size of the launch vehicle (to carry the additional fuel required for planetary capture) or could simply make the mission impossible due to additional propulsion requirements. The AT is advancing each technology needed for the successful implementation of aerocapture in future missions. The technology development focuses on both rigid aeroshell systems as well as the development of inflatable aerocapture systems, advanced aeroshell performance sensors, lightweight structure and higher temperature adhesives. Inflatable systems such as tethered trailing ballutes ('balloon parachutes'), clamped ballutes, and inflatable aeroshells are also under development. Aerocapture-specific computational tools required to support future aerocapture missions are also an integral part of the ATP. Tools include: engineering reference atmosphere models, guidance and navigation, aerothermodynamic modeling, radiation modeling and flight simulation. Systems analysis plays a key role in the AT development process. The NASA in-house aerocapture systems analysis team has been taken with multiple systems definition and concept studies to complement the technology development tasks. The team derives science requirements, develops guidance and navigation algorithms, as well as engineering reference atmosphere models and aeroheating specifications. The study team also creates designs for the overall mission spacecraft. Presentation slides are provided to further describe the aerocapture project

    THE USE OF COMPUTATIONAL FLUIDS DYNAMICS TO OPTIMISE UNDERWATER KICKING PERFORMANCE

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    Elite swimmers use a variety of underwater kicking patterns in current competition with little scientific information used in their selection. The current study sought to discriminate between 2 different patterns of underwater dolphin kick (large amplitude, slow kicks versus small amplitude, fast kicks) using computational fluid dynamics (CFD). Inputs into the CFD model included an accurate 3D mapping of an elite swimmer and detailed kinematic information of the underwater kicking from a 2D analysis. Initial results of the static CFD model were in agreement with previous empirical testing of passive drag. Results of the dynamic CFD modelling and comparisons are still to be finalised

    Marshall Space Flight Center Research and Technology Report 2017

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    This report features over 60 technology development and scientific research efforts that collectively aim to enable new capabilities in spaceflight, expand the reach of human exploration, and reveal new knowledge about the universe in which we live. These efforts include a wide array of strategic developments: launch propulsion technologies that facilitate more reliable, routine, and cost effective access to space; in-space propulsion developments that provide new solutions to space transportation requirements; autonomous systems designed to increase our utilization of robotics to accomplish critical missions; life support technologies that target our ability to implement closed-loop environmental resource utilization; science instruments that enable terrestrial, solar, planetary and deep space observations and discovery; and manufacturing technologies that will change the way we fabricate everything from rocket engines to in situ generated fuel and consumables

    Radiation-Hardened Electronics for the Space Environment

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    RHESE covers a broad range of technology areas and products. - Radiation Hardened Electronics - High Performance Processing - Reconfigurable Computing - Radiation Environmental Effects Modeling - Low Temperature Radiation Hardened Electronics. RHESE has aligned with currently defined customer needs. RHESE is leveraging/advancing SOA space electronics, not duplicating. - Awareness of radiation-related activities through out government and industry allow advancement rather than duplication of capabilities

    Designing to encourage waste minimisation in the construction industry

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    The process of waste minimisation through ‘designing out waste’ is in its infancy. Many barriers and opportunities exist in developing waste minimisation strategies in design. The paper will summarise the initial findings of the authors’ recent research. It is intended to stimulate thought into the concept of designing out waste. By outlining the causative factors of waste through design and the principle strategies for waste reduction, the paper highlights the present status of this important subject and question whether adequate emphasis is being put on the initial stages of the waste hierarchy – reduce, reuse, recycle. The paper introduces the various options for waste minimisation in design, including designing for recycling, extended life, disassembly and designing out waste. It concludes by highlighting the links between ‘designing out waste’ and the future waste management and recycling industries, indicating where opportunities may exist

    Test and Evaluation of GRISSOM-1 CubeSat Communication Subsystem

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    The Grissom-1 mission (GM1), slated to launch in September 2022, is the first in a series of 6-Unit CubeSat satellites built and operated by the Air Force Institute of Technology’s (AFIT’s) Center for Space Research and Assurance (CSRA). Mission success for GM1 depends on a comprehensive campaign of testing and assessment to confirm the components, design, and assembly of all systems and subsystems within the satellite. This paper specifically focuses on the testing and analysis of all communication links between the spacecraft, the ground system, and the Satellite Operations Center (SOC) being hosted at the Air Force Instituteof Technology at Wright Patterson Air Force Base. Additionally, the paper will cover the potential for future missions for the GM1 based off the analysis of the current link. Specific to the GM1, analysis is performed on the spacecraft’s Cadet Plus software-defined radio (SDR), as developed by the Space Dynamics Laboratory, and its communication capabilities with the Mobile CubeSat Command and Control (MC3) network, the National Instruments USRP-2292 ground station SDR, and COSMOS Command and Control (C2) software. Testing and assessment occurred in both lab settings and simulated operational scenarios. This paper includes characterization of individual components, anechoic chamber downlink and uplink signal measurements and results, link margin calculations, plus direct point-to-point testing results. Experimental data describing the results of each test using the local instance of an MC3 ground station software. The research culminates in a full characterization of the Cadet Plus SDR, an analysis of the GM1 to MC3 communication interaction, and any limitations revealed as attributable to the 6U spacecraft

    Multilayer Dielectric Transmissive Optical Phase Modulator

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    A multilayer dielectric device has been fabricated as a prototype of a low-loss, low-distortion, transmissive optical phase modulator that would provide as much as a full cycle of phase change for all frequency components of a transmitted optical pulse over a frequency band as wide as 6.3 THz. Arrays of devices like this one could be an alternative to the arrays of mechanically actuated phase-control optics (adaptive optics) that have heretofore been used to correct for wave-front distortions in highly precise optical systems. Potential applications for these high-speed wave-front-control arrays of devices include agile beam steering, optical communications, optical metrology, optical tracking and targeting, directional optical ranging, and interferometric astronomy. The device concept is based on the same principle as that of band-pass interference filters made of multiple dielectric layers with fractional-wavelength thicknesses, except that here there is an additional focus on obtaining the desired spectral phase profile in addition to the device s spectral transmission profile. The device includes a GaAs substrate, on which there is deposited a stack of GaAs layers alternating with AlAs layers, amounting to a total of 91 layers. The design thicknesses of the layers range from 10 nm to greater than 1 micrometer. The number of layers and the thickness of each layer were chosen in a computational optimization process in which the wavelength dependences of the indices of refraction of GaAs and AlAs were taken into account as the design was iterated to maximize the transmission and minimize the group-velocity dispersion for a wavelength band wide enough to include all significant spectral components of the pulsed optical signal to be phase modulated

    Emerging Propulsion Technologies

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    The Emerging Propulsion Technologies (EPT) investment area is the newest area within the In-Space Propulsion Technology (ISPT) Project and strives to bridge technologies in the lower Technology Readiness Level (TRL) range (2 to 3) to the mid TRL range (4 to 6). A prioritization process, the Integrated In-Space Transportation Planning (IISTP), was developed and applied in FY01 to establish initial program priorities. The EPT investment area emerged for technologies that scored well in the IISTP but had a low technical maturity level. One particular technology, the Momentum-eXchange Electrodynamic-Reboost (MXER) tether, scored extraordinarily high and had broad applicability in the IISTP. However, its technical maturity was too low for ranking alongside technologies like the ion engine or aerocapture. Thus MXER tethers assumed top priority at EPT startup in FY03 with an aggressive schedule and adequate budget. It was originally envisioned that future technologies would enter the ISP portfolio through EPT, and EPT developed an EPT/ISP Entrance Process for future candidate ISP technologies. EPT has funded the following secondary, candidate ISP technologies at a low level: ultra-lightweight solar sails, general space/near-earth tether development, electrodynamic tether development, advanced electric propulsion, and in-space mechanism development. However, the scope of the ISPT program has focused over time to more closely match SMD needs and technology advancement successes. As a result, the funding for MXER and other EPT technologies is not currently available. Consequently, the MXER tether tasks and other EPT tasks were expected to phased out by November 2006. Presentation slides are presented which provide activity overviews for the aerocapture technology and emerging propulsion technology projects

    Analysis of the Development of Youth Football Throwing Mechanics

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    Football coaches currently use qualitative measures to describe how a quarterback should throw and can only describe the optimal throw verbally through what the naked eye can observe. The goal of this research was to analyze the development of middle school and high school quarterback (QB) throwing mechanics over consecutive seasons using motion capture technology. To analyze the development of these subjects, interviews were conducted with middle school and high school coaches to determine the most common pass types for the respective levels and common aspects of the throwing motion that coaches use to teach what they believe to be the optimal throwing motion as references for the analysis. Two separate years of analysis were used in this research to analyze the development of subject sets. Two time points from a total of eight subjects were analyzed to track the development of mechanics with physical development. Improvements of the throwing mechanics of the subjects with multiple time points were observed. The improvements were based on what was described by coaches as optimal throwing mechanics. In conclusion the training techniques used by the coaches were effective in improving the coaching points deemed as common from interviews with middle school and high school coaches
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