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At least 127 records · Page 7

Study program for design improvements of the X-3060 klystron. Phase 3: Electron gun fabrication and beam analyzer evaluation. Phase 4: Klystron prototype fabrication and testing

A full scale model was produced to verify suggested design changes. Through beam analyzer study, the correct electron beam diameter and cross sectional profile were established in conjunction with the desired confining magnetic field. Comparative data on the performance of the X-3060 klystron, design predictions for the improved klystron, and performance data taken during acceptance testing of the prototype VKS-8274 JPL are presented.

Goldfinger, A.↗

Development and testing of a portable wind sensitive directional air sampler

A portable wind-sensitive directional air sampler has been developed as part of an air pollution source identification system. The system is designed to identify sources of air pollution based on the directional collection of field air samples and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. Functional testing of a prototype sampler is described; all items exhibited performance and life sufficient to carry out field performance test operations. Life testing of the wind direction sensor and the directional porting valves, which are critical to reliable operation, was emphasized with successful results.

Deyo, J.↗

Evaporative Cooling and Dehumidification Garment for Portable Life Support Systems

This paper describes the design and development of an innovative thermal and humidity control system for future space suits. The system comprises an evaporation cooling and dehumidification garment (ECDG) and a lithium chloride absorber radiator (LCAR). The ECDG absorbs heat and water vapor from inside the suit pressure garment, while the LCAR rejects heat to space without venting water vapor. The ECDG is built from thin, flexible patches with coversheets made of non-porous, water-permeable membranes that -enclose arrays of vapor flow passages. Water vapor from inside the spacesuit diffuses across the water permeable membranes, enters the vapor flow channels, and then flows to the LCAR, thus dehumidifying the internal volume of the space suit pressure garment. Additional water evaporation inside the ECDG provides cooling for sensible heat loads. -The heat released from condensation and absorption in the LCAR is rejected to the environment by thermal radiation. We have assembled lightweight and flexible ECDG pouches from prototypical materials and measured their performance in a series of separate effects tests under well-controlled, prototypical conditions. Sweating hot plate tests at typical space suit pressures show that ECDG pouches can absorb over 60 W/ft of latent heat and 20 W/ft of sensible heat from the pressure garment environment. These results are in good agreement with the predictions of our analysis models.

Izenson, Michael↗

High Density Vertiplex - Scalable Autonomous Operations - Flight Test Report

This Technical Memorandum describes the approach taken within the High Density Vertiplex Project to perform rapid prototyping and assessment of the UAM Ecosystem including representative: Onboard Autonomous Systems, Ground Control and Fleet Management Systems, Airspace Management Systems, and Vertiport Automation Systems (VAS). Small Uncrewed Aerial Systems (sUAS) were employed as effective low risk and inexpensive surrogates for larger proposed UAM aircraft to accelerate the prototyping effort, ensure safety, greatly mitigate costs, and accelerate progress. Flight testing performed included multivehicle operations where usability Human Factors (HF) data was collected on the operators.

Jacob Schaefer↗

Performance evaluation of Space Shuttle SRB parachutes from air drop and scaled model wind tunnel tests

The aerodynamic performance characteristics have been determined for the Space Shuttle Solid Rocket Booster drogue, main, and pilot parachutes. The performance evaluation on the 20-degree conical ribbon parachutes is based primarily on air drop tests of full scale prototype parachutes. In addition, parametric wind tunnel tests were performed and used in parachute configuration development and preliminary performance assessments. The wind tunnel test data are compared to the drop test results and both sets of data are used to determine the predicted performance of the Solid Rocket Booster flight parachutes. Data from other drop tests of large ribbon parachutes are also compared with the Solid Rocket Booster parachute performance characteristics. Parameters assessed include full open terminal drag coefficients, reefed drag area, opening characteristics, clustering effects, and forebody interference.

Moog, R. D.↗

The Design, Fabrication, and Testing of Composite Heat Exchange Coupons

Several heat exchanger (HX) test panels were designed, fabricated and tested at the NASA Glenn Research Center to explore the fabrication and performance of several designs for composite heat exchangers. The development of these light weight, high efficiency air-liquid test panels was attempted using polymer composites and carbon foam materials. The fundamental goal of this effort was to demonstrate the feasibility of the composite HX for various space exploration and thermal management applications including Orion CEV and Altair. The specific objectives of this work were to select optimum materials, designs, and to optimize fabrication procedures. After fabrication, the individual design concept prototypes were tested to determine their thermal performance and to guide the future development of full-size engineering development units (EDU). The overall test results suggested that the panel bonded with pre-cured composite laminates to KFOAM Grade L1 scored above the other designs in terms of ease of manufacture and performance.

Quade, Derek J.↗

USDC based rapid penetrator of packed soil

Environment protection requires more testing and analysis tools. To detect buried chemical containers or other objects embedded in soil and avoid possible damages of them, a penetrator of packed soil operated using low pushing force was developed. The design was based on a novel driving mechanism of the ultrasonic/sonic driller/corer (USDC) device developed in the NDEAA lab at JPL [Bar-Cohen et al 2001, Bao et al 2003]. In the penetrator, a small free-flying mass is energized by a piezoelectric transducer and impacts a rod probe on its shoulder at frequencies of hundreds times per second. The impacts help the probe to penetrate the packed soil rapidly. A great reduction of the needed pushing force for penetration was achieved. The details of the design of the prototype penetrator and the results of performance tests are presented.

sampling↗

The Orion Atmosphere Revitalization Technology in Manned Ambient Pressure Space Suit Testing

An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Atmosphere Revitalization System (ARS) for moderate duration missions of the Orion Multipurpose Crew Vehicle. The Orion ARS is designed to support not only open-cabin operations, tests of which have been reported in previous years at this conference, but also closed space suit-loop operations. A previous low-pressure suit loop test was performed with a human metabolic simulator, and humans wearing emergency masks were tested in a closed-loop configuration before that. In late 2011, simple tests were performed in a suit-loop configuration with human test subjects in prototype space suits with prototype umbilicals at ambient and two slightly above-ambient pressures. Trace contaminant filters and a prototype blower were also incorporated into the test rig. This paper discusses the performance of the ARS technology in that 2011 test configuration.

Button, Amy↗

Space Suit Environment Testing of the Orion Atmosphere Revitalization Technology

An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). In three previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of this technology. That testing was performed in a sea-level pressure environment with both simulated and real human metabolic loads, and in both open and closed-loop configurations. The Orion ARS is designed to also support space-suited operations in a depressurized cabin, so the next step in developmental testing at JSC was to test the ARS technology in a typical closed space suit-loop environment with low-pressure oxygen inside the process loop and vacuum outside the loop. This was the first instance of low-pressure, high-oxygen, closed-loop testing of the Orion ARS technology, and it was conducted with simulated human metabolic loads in March 2009. The test investigated pressure drops and flow balancing through two different styles of prototype suit umbilical connectors. General swing-bed performance was tested with both umbilical configurations, as well as with a short jumper line installed in place of the umbilicals. Other interesting results include observations on the thermal effects of swing-bed operation in a vacuum environment and a recommendation of cycle time to maintain acceptable suit atmospheric CO2 and moisture levels.

Button, Amy B.↗

Design and Conduct of a Windshear Detection Flight Experiment

A description of the design and conduct of a series of flight experiments which tested the performance of candidate windshear detection devices is presented. With prototype windshear sensors installed, a NASA Boeing 737 test aircraft conducted numerous low altitude penetrations of microburst windshear conditions. These tests were preceded by extensive preparations which included piloted simulations, determination of safe operating limits, and the development of unique flight test hardware, displays, and procedures. The test aircraft and more than 50 research and support personnel were deployed to Orlando, Florida, and Denver, Colorado, during June and July 1991 for field testing. Upon receiving a forecast of developing weather activity, the aircraft crew launched and proceeded to the storm location, guided by uplinked ground radar information and voice communications with ground weather personnel. The tests required constant monitoring of numerous factors including aircraft flight parameters, ground obstructions, windshear magnitude, lightning, escape routes, ATC coordination, storm cell development, and others. The flight tests were extremely successful, safely recording more than 25 low altitude microburst windshear and strong gust front approaches and penetrations, along with completing a full test matrix of additional requirements related to windshear sensor performance. Data quality from the tests was excellent and indicates strong potential for airborne remote sensors to accurately predict and warn the flight crew of hazardous windshear conditions with ample time for precautionary crew action.

Flight Testing↗

Ceiling and visibility instrumentation within government agencies

The key systems requirements for ceilometer systems are described. The following items are included: range must be 10,000 ft.; laser emission must conform to the bureau of radiological health class I performance; system must detect two lowest cloud layers; display must be in either English or metric units; and system must be capable of self monitoring and testing performance. Based upon the requirements competitive prototype cloud height indicator systems are to be built.

Bonner, R. S.↗

Design, development and evaluation of Stanford/Ames EVA prehensors

Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation.

Leifer, Larry J.↗

The Energetic Trans-Iron Composition Experiment (ENTICE) on the Heavy Nuclei Explorer (HNX) Mission

The ENTICE experiment is one of two instruments that make up the HNX mission. The experimental goal of ENTICE is to measure with high precision the elemental abundances of all nuclei with Z between 10 and 82. This will enable us to determine if the injection mechanism for the cosmic ray accelerator is controlled by FIP or Volatility and to study the mix of nucleosynthetic processes that contribute to the galactic cosmic ray source. The ENTICE experiment utilizes the dE/dx-C method of charge determination and consists of silicon dE/dx detectors, Cherenkov detectors with two different refractive indices, and a fiber hodoscope. We will describe the instrument and its performance based on beam tests of a prototype instrument.

Israel, M. H.↗

Asynchronous Message Service for Deep Space Mission Operations

While the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) provides internationally standardized file transfer functionality that can offer significant benefits for deep space mission operations, not all spacecraft communication requirements are necessarily best met by file transfer. In particular, continuous event-driven asynchronous message exchange may also be useful for communications with, among, and aboard spacecraft. CCSDS has therefore undertaken the development of a new Asynchronous Message Service (AMS) standard, designed to provide common functionality over a wide variety of underlying transport services, ranging from shared memory message queues to CCSDS telemetry systems. The present paper discusses the design concepts of AMS, their applicability to deep space mission operations problems, and the results of preliminary performance testing obtained from exercise of a prototype implementation.

asynchronous message exchanges↗

Results of NASA/DARPA Automatic Probe and Drogue Refueling Flight Test

This presentation reports the results of the NASA/DARPA automatic probe and drogue refueling flight test. The program met several of its objectives including the design, development and successful testing of a prototype system to autonomously perform probes to drogue refueling; demonstrated acquisition and tracking capability of the video tracking system; demonstrated autonomous rendezvous capability; demonstrated ability to plug in a turn; and, demonstrated ability to plug in mild turbulence.

Schweikhard, Keith↗

Applications of a Forward-Looking Interferometer for the On-board Detection of Aviation Weather Hazards

The Forward-Looking Interferometer (FLI) is a new instrument concept for obtaining measurements of potential weather hazards to alert flight crews. The FLI concept is based on high-resolution Infrared (IR) Fourier Transform Spectrometry (FTS) technologies that have been developed for satellite remote sensing, and which have also been applied to the detection of aerosols and gases for other purposes. It is being evaluated for multiple hazards including clear air turbulence (CAT), volcanic ash, wake vortices, low slant range visibility, dry wind shear, and icing, during all phases of flight. Previous sensitivity and characterization studies addressed the phenomenology that supports detection and mitigation by the FLI. Techniques for determining the range, and hence warning time, were demonstrated for several of the hazards, and a table of research instrument parameters was developed for investigating all of the hazards discussed above. This work supports the feasibility of detecting multiple hazards with an FLI multi-hazard airborne sensor, and for producing enhanced IR images in reduced visibility conditions; however, further research must be performed to develop a means to estimate the intensities of the hazards posed to an aircraft and to develop robust algorithms to relate sensor measurables to hazard levels. In addition, validation tests need to be performed with a prototype system.

West, Leanne↗

Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

methane↗

NASA Advanced Space Suit Pressure Garment System Status and Development Priorities 2019

This paper discusses the current focus of NASA's Advanced Space Suit Pressure Garment Technology Development team's efforts, the status of that work, and a summary of longer term technology development priorities and activities. The Exploration Extra-vehicular Activity Unit (xEMU) project's International Space Station Demonstration Suit (xEMU Demo) project continues to be the team's primary customer and effort. In 2018 the team was engaged in addressing hardware design changes identified in the Z-2 pressure garment prototype Neutral Buoyancy Laboratory (NBL) test results. These changes will be discussed. Additionally components whose first iterations were produced in 2018 will be discussed. A full pressure garment prototype, termed Z-2.5, was assembled that is composed of updated and first prototype iteration hardware. Z-2.5 NBL testing, performed from October 2018 through April 2019 will inform final design iterations in preparation for the xEMU Demo preliminary design review planned to occur in the third quarter of government fiscal year 2019. A primary objective of the Z-2.5 NBL testing is to validate changes made to the hard upper torso geometry, which depart from the planetary walking suit upper torso geometry that has been used over the last 30 years. The team continues to work technology development, with GFY2018 work being used to supplement and feed the gaps left by the scope defined for the xEMU Demo. Specifically, a Phase IIx Small Business Innovative Research Grant to mature durable bearings that are compatible with a dust environment and a grant funded by the Science Technology Mission Directorate, Lightweight and Robust Exploration Space Suit (LARESS) project, to mature planetary impact requirements and hardware will be described. Finally, a brief review of longer-term pressure garment challenges and technology gaps will be presented to provide an understanding of the advanced pressure garment team's technology investment priorities and needs.

Ross, Amy↗