Physiological and technological considerations for Mars mission extravehicular activity

NASA Technical Reports Server (NTRS)

Waligora, James M.; Sedej, Melaine M.

1986-01-01

The nature of the suit is a function of the needs of human physiology, the ambient environment outside the suit, and the type of activity to be accomplished while in the suit. The physiological requirements that must be provided for in the Martian Extravehicular Activity (EVA) suit will be reviewed. The influence of the Martian environment on the EVA suit and EVA capabilities is elaborated, and the Martian environment is compared with the lunar environment. The differences that may influence the EVA design are noted. The type, nature, and duration of activities to be done in transit to Mars and on the Martian surface will be evaluated and the impact of these activities on the requirements for EVA systems will be discussed. Furthermore, the interaction between Martian surface transportation systems and EVA systems will be covered. Finally, options other than EVA will be considered such as robotics, nonanthropometric suits, and vehicles with anthropometric extremities or robotic end effectors.

Assessment of Scheduling and Plan Execution of Apollo 14 Lunar Surface Operations

NASA Technical Reports Server (NTRS)

Marquez, Jessica J.

2010-01-01

Although over forty years have passed since first landing on the Moon, there is not yet a comprehensive, quantitative assessment of Apollo extravehicular activities (EVAs). Quantitatively evaluating lunar EVAs will provide a better understanding of the challenges involved with surface operations. This first evaluation of a surface EVA centers on comparing the planned and the as-ran timeline, specifically collecting data on discrepancies between durations that were estimated versus executed. Differences were summarized by task categories in order to gain insight as to the type of surface operation activities that were most challenging. One Apollo 14 EVA was assessed utilizing the described methodology. Selected metrics and task categorizations were effective, and limitations to this process were identified.

Astronaut Ronald Evans is suited up for EVA training

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Ronald E. Evans, command module pilot of the Apollo 17 lunar landing mission, is assisted by technicians in suiting up for extravehicular activity (EVA) training in a water tank in bldg 5 at the Manned Spacecraft Center (49970); Evans participates in EVA training in a water tank in bldg 5 at the Manned Spacecraft Center. The structure in the picture simulates the Scientific Instrument Module (SIM) bay of the Apollo 17 Service Module (49971).

Adhesion Strength Study of EVA Encapsulants on Glass Substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F. J.; Glick, S. H.

2003-05-01

An extensive peel-test study was conducted to investigate the various factors that may affect the adhesion strength of photovoltaic module encapsulants, primarily ethylene-vinyl acetate (EVA), on glass substrates of various laminates based on a common configuration of glass/encapsulant/backfoil. The results show that"pure" or"absolute" adhesion strength of EVA-to-glass was very difficult to obtain because of tensile deformation of the soft, semi-elastic EVA layer upon pulling. A mechanically"strong enough" backing foil on the EVA was critical to achieving the"apparent" adhesion strength. Peel test method with a 90-degree-pull yielded similar results to a 180-degree-pull. The 90-degree-pull method better revealed the four stages ofmore » delamination failure of the EVA/backfoil layers. The adhesion strength is affected by a number of factors, which include EVA type, formulation, backfoil type and manufacturing source, glass type, and surface priming treatment on the glass surface or on the backfoil. Effects of the glass-cleaning method and surface texture are not obvious. Direct priming treatments used in the work did not improve, or even worsened, the adhesion. Aging of EVA by storage over~5 years reduced notably the adhesion strength. Lower adhesion strengths were observed for the blank (unformulated) EVA and non-EVA copolymers, such as poly(ethylene-co-methacrylate) (PEMA) or poly(ethylene-co-butylacrylate) (PEBA). Their adhesion strengths increased if the copolymers were cross-linked. Transparent fluoropolymer superstrates such as TefzelTM and DureflexTM films used for thin-film PV modules showed low adhesion strengths to the EVA at a level of~2 N/mm.« less

Energy Expenditure During Extravehicular Activity: Apollo Skylab Through STS-135

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

The importance of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to conduct an EVA over-tasked the crewmember and exceeded the capabilities of vehicle and space suit life support systems. Energy expenditure was closely evaluated through the Apollo lunar surface EVAs, resulting in modifications to space suit design and EVA operations. After the Apollo lunar surface missions were completed, the United States shifted its focus to long duration human space flight, to study the human response to living and working in a microgravity environment. This paper summarizes the energy expenditure during EVA from Apollo Skylab through STS-135.

STS-134 crew members Mike Fincke, Drew Feustel and Greg Chamitoff performing EVA Tile Repair Training.

NASA Image and Video Library

2010-01-28

JSC2010-E-014766 (28 Jan. 2010) --- NASA astronaut Michael Fincke (left), STS-134 mission specialist, participates in an EVA tile repair training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Instructor John Ray assisted Fincke.

ASTRONAUT KERWIN, JOSEPH P. - EXTRAVEHICULAR ACTIVITY (EVA) - SKYLAB (SL)-2

NASA Image and Video Library

1973-06-01

S73-27562 (June 1973) --- Scientist-astronaut Joseph P. Kerwin, Skylab 2 science pilot, performs extravehicular activity (EVA) at the Skylab 1 and 2 space station cluster in Earth orbit, as seen in this reproduction taken from a color television transmission made by a TV camera aboard the station. Kerwin is just outside the Airlock Module. Kerwin assisted astronaut Charles Conrad Jr., Skylab 2 commander, during the successful EVA attempt to free the stuck solar array system wing on the Orbital Workshop. Photo credit: NASA

Extravehicular Activity Technology Development Status and Forecast

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Westheimer, David T.

2011-01-01

The goal of NASA s current EVA technology effort is to further develop technologies that will be used to demonstrate a robust EVA system that has application for a variety of future missions including microgravity and surface EVA. Overall the objectives will be to reduce system mass, reduce consumables and maintenance, increase EVA hardware robustness and life, increase crew member efficiency and autonomy, and enable rapid vehicle egress and ingress. Over the past several years, NASA realized a tremendous increase in EVA system development as part of the Exploration Technology Development Program and the Constellation Program. The evident demand for efficient and reliable EVA technologies, particularly regenerable technologies was apparent under these former programs and will continue to be needed as future mission opportunities arise. The technological need for EVA in space has been realized over the last several decades by the Gemini, Apollo, Skylab, Space Shuttle, and the International Space Station (ISS) programs. EVAs were critical to the success of these programs. Now with the ISS extension to 2028 in conjunction with a current forecasted need of at least eight EVAs per year, the EVA hardware life and limited availability of the Extravehicular Mobility Units (EMUs) will eventually become a critical issue. The current EMU has successfully served EVA demands by performing critical operations to assemble the ISS and provide repairs of satellites such as the Hubble Space Telescope. However, as the life of ISS and the vision for future mission opportunities are realized, a new EVA systems capability will be needed and the current architectures and technologies under development offer significant improvements over the current flight systems. In addition to ISS, potential mission applications include EVAs for missions to Near Earth Objects (NEO), Phobos, or future surface missions. Surface missions could include either exploration of the Moon or Mars. Providing an EVA capability for these types of missions enables in-space construction of complex vehicles or satellites, hands on exploration of new parts of our solar system, and engages the public through the inspiration of knowing that humans are exploring places that they have never been before. This paper offers insight into what is currently being developed and what the potential opportunities are in the forecast.

Extravehicular Activity (EVA) Technology Development Status and Forecast

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Westheimer, David T.

2010-01-01

Beginning in Fiscal Year (FY) 2011, Extravehicular activity (EVA) technology development became a technology foundational domain under a new program Enabling Technology Development and Demonstration. The goal of the EVA technology effort is to further develop technologies that will be used to demonstrate a robust EVA system that has application for a variety of future missions including microgravity and surface EVA. Overall the objectives will be reduce system mass, reduce consumables and maintenance, increase EVA hardware robustness and life, increase crew member efficiency and autonomy, and enable rapid vehicle egress and ingress. Over the past several years, NASA realized a tremendous increase in EVA system development as part of the Exploration Technology Development Program and the Constellation Program. The evident demand for efficient and reliable EVA technologies, particularly regenerable technologies was apparent under these former programs and will continue to be needed as future mission opportunities arise. The technological need for EVA in space has been realized over the last several decades by the Gemini, Apollo, Skylab, Space Shuttle, and the International Space Station (ISS) programs. EVAs were critical to the success of these programs. Now with the ISS extension to 2028 in conjunction with a current forecasted need of at least eight EVAs per year, the EVA technology life and limited availability of the EMUs will become a critical issue eventually. The current Extravehicular Mobility Unit (EMU) has vastly served EVA demands by performing critical operations to assemble the ISS and provide repairs of satellites such as the Hubble Space Telescope. However, as the life of ISS and the vision for future mission opportunities are realized, a new EVA systems capability could be an option for the future mission applications building off of the technology development over the last several years. Besides ISS, potential mission applications include EVAs for missions to Near Earth Objects (NEO), Phobos, or future surface missions. Surface missions could include either exploration of the Moon or Mars. Providing an EVA capability for these types of missions enables in-space construction of complex vehicles or satellites, hands on exploration of new parts of our solar system, and engages the public through the inspiration of knowing that humans are exploring places that they have never been before. This paper offers insight into what is currently being developed and what the potential opportunities are in the forecast

Mars Surface Tunnel Element Concept

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.

2016-01-01

How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

Extravehicular activity at geosynchronous earth orbit

NASA Technical Reports Server (NTRS)

Shields, Nicholas, Jr.; Schulze, Arthur E.; Carr, Gerald P.; Pogue, William

1988-01-01

The basic contract to define the system requirements to support the Advanced Extravehicular Activity (EVA) has three phases: EVA in geosynchronous Earth orbit; EVA in lunar base operations; and EVA in manned Mars surface exploration. The three key areas to be addressed in each phase are: environmental/biomedical requirements; crew and mission requirements; and hardware requirements. The structure of the technical tasks closely follows the structure of the Advanced EVA studies for the Space Station completed in 1986.

EVA-SCRAM operations

NASA Technical Reports Server (NTRS)

Flanigan, Lee A.; Tamir, David; Weeks, Jack L.; Mcclure, Sidney R.; Kimbrough, Andrew G.

1994-01-01

This paper wrestles with the on-orbit operational challenges introduced by the proposed Space Construction, Repair, and Maintenance (SCRAM) tool kit for Extra-Vehicular Activity (EVA). SCRAM undertakes a new challenging series of on-orbit tasks in support of the near-term Hubble Space Telescope, Extended Duration Orbiter, Long Duration Orbiter, Space Station Freedom, other orbital platforms, and even the future manned Lunar/Mars missions. These new EVA tasks involve welding, brazing, cutting, coating, heat-treating, and cleaning operations. Anticipated near-term EVA-SCRAM applications include construction of fluid lines and structural members, repair of punctures by orbital debris, refurbishment of surfaces eroded by atomic oxygen, and cleaning of optical, solar panel, and high emissivity radiator surfaces which have been degraded by contaminants. Future EVA-SCRAM applications are also examined, involving mass production tasks automated with robotics and artificial intelligence, for construction of large truss, aerobrake, and reactor shadow shield structures. Realistically achieving EVA-SCRAM is examined by addressing manual, teleoperated, semi-automated, and fully-automated operation modes. The operational challenges posed by EVA-SCRAM tasks are reviewed with respect to capabilities of existing and upcoming EVA systems, such as the Extravehicular Mobility Unit, the Shuttle Remote Manipulating System, the Dexterous End Effector, and the Servicing Aid Tool.

Control of biofilm formation by poly-ethylene-co-vinyl acetate films incorporating nisin.

PubMed

Nostro, Antonia; Scaffaro, Roberto; Ginestra, Giovanna; D'Arrigo, Manuela; Botta, Luigi; Marino, Andreana; Bisignano, Giuseppe

2010-06-01

The aim of this study was to evaluate the effect of poly-ethylene-co-vinyl acetate (EVA) films incorporating different concentrations (0.1%, 0.5% and 1%) of nisin on the biofilm-forming ability of Listeria monocytogenes ATCC 7644, Staphylococcus aureus 815 and Staphylococcus epidermidis ATCC 35984. Nisin was incorporated into two grades of EVA (EVA14 and EVA28) in the melt during a common film-blowing operation. The efficacy of EVA/nisin films was evaluated by biofilm biomass measurements and Live/Dead staining in combination with fluorescence microscopy. In order to evaluate whether the nisin incorporation could modify the film surface properties, contact angle measurements and scanning electron microscopy were performed. The results revealed the efficacy of EVA14/nisin films in reducing biofilm formation on their surfaces with more evident effect for S. epidermidis than L. monocytogenes and S. aureus strains. In contrast, EVA28/nisin films showed unsatisfactory activity. Fluorescence microscopy confirmed poor biofilm formation on EVA14/nisin films, also characterised by the presence of dead cells. The data presented in this study offer new potential applications for developing strategies aimed to improve the effect of antimicrobial agents.

View of Mission Control during lunar surface Apollo 11 EVA

NASA Image and Video Library

1969-07-20

Overall view of the Mission Operations Control Room in the Mission Control Center, bldg 30, during the lunar surface extravehicular activity (EVA) of Apollo 11 Astronauts Neil A. Armstrong and Edwin E. Aldrin Jr.

Baseline tests of the EVA change-of-pace coupe electric passenger vehicle

NASA Technical Reports Server (NTRS)

Bozek, J. M.; Maslowski, E. A.; Dustin, M. O.

1977-01-01

The EVA Change-of-Pace Coupe, is an electric passenger vehicle, to characterize the state-of-the-art of electric vehicles. The EVA Change-of-Pace Coupe is a four passenger sedan that has been coverted to an electric vehicle. It is powered by twenty 6 volt traction batteries through a silicon controlled rectifier chopper controller actuated by a foot throttle to change the voltage applied to the series wound, direct current motor. Braking is accomplished with a vacuum assist hydraulic braking system. Regenerative braking is also provided.

Apollo 16 time and motion study

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.; Saxon, S. C.

1972-01-01

A time and motion study is presented of astronaut lunar surface activity on Apollo 16 which consists of five distinct analyses: an evaluation of lunar mobility, a comparison of task performance in 1-g training and lunar EVA, a study of metabolic costs and adaptation, a discussion of falls, and retrieval of fallen objects. Two basic mobility patterns, the hop or canter and the traditional walking gait, were consistently utilized in longer traverses. The metabolic rates associated with these two mobility types, each used by a different astronaut, were relatively equivalent. The time to perform tasks on the lunar surface was significantly longer (on the order of 70%) than the time to perform the same tasks during the last 1-g training session. These results corroborated the findings on Apollo 15 and were not significantly different from them. There was general improvement in lunar EVA performance upon repetition of tasks. Metabolic rate (BTU/hr.) and metabolic cost (BTU) decreased over successive EVAs. Specifically, the metabolic rate associated with riding the lunar roving vehicle (LRV) decreased by approximately 18% from EVA 1 to EVA 2 and by 15% from EVA 2 to EVA 3.

Photovoltaics module interface: General purpose primers

NASA Technical Reports Server (NTRS)

Boerio, J.

1985-01-01

The interfacial chemistry established between ethylene vinyl acetate (EVA) and the aluminized back surface of commercial solar cells was observed experimentally. The technique employed is called Fourier Transform Infrared (FTIR) spectroscopy, with the infrared signal being reflected back from the aluminum surface through the EVA film. Reflection infrared (IR) spectra are given and attention is drawn to the specific IR peak at 1080/cm which forms on hydrolytic aging of the EVA/aluminum system. With this fundamental finding, and the workable experimental techniques, candidate silane coupling agents are employed at the interface, and their effects on eliminating or slowing hydrolytic aging of the EVA/aluminum interface are monitored.

Effect of oxidation agent on wood biomass in ethylene vinyl acetate conductive polymer: tensile properties, tensile fracture surface and electrical properties

NASA Astrophysics Data System (ADS)

Hanif, M. P. M.; Supri, A. G.; Rozyanty, A. R.; Tan, S. J.

2017-10-01

The wood fiber (WF) type of Pulverised Wood Filler obtained by combustion process at temperature under 700 °C for 3 hours was characterized and coated with ferric chloride (FeCl3) by ethanol solution. Both carbonized wood fiber (CWF) and carbonized wood fiber-ferric chloride (CWF-FeCl3) were used as filler in ethylene vinyl acetate (EVA) conductive polymer. The filler was coated with FeCl3 to enhance the properties of the CWF to achieve progressive mechanical and electrical properties. The CWF and CWF-FeCl3 loading were varied from 2.5 to 10.0 wt%. EVA/CWF and EVA/CWF-FeCl3 conductive polymer were processed by using Brabender Plasticoder at 160 °C with 50 rpm rotor speed for 10 min. The mechanical properties were investigated by tensile testing and the tensile fractured surface of conductive polymers was analyzed by scanning electron microscopy (SEM) analysis. Then, the electrical conductivity of conductive polymer was determined by four-point probe I-V measurement system. The EVA/CWF-FeCl3 conductive polymer showed greater electrical conductivity and tensile strength but lower elongation at break than EVA/CWF conductive polymer. SEM morphology displayed rougher surface between CWF-FeCl3 and EVA phases compared to EVA/CWF conductive polymer.

Utilization of ISS to Develop and Test Operational Concepts and Hardware for Low-Gravity Terrestrial EVA

NASA Technical Reports Server (NTRS)

Gast, Matthew A.

2010-01-01

NASA has considerable experience in two areas of Extravehicular Activities (EVA). The first can be defined as microgravity, orbital EVAs. This consists of everything done in low Earth orbit (LEO), from the early, proof of concept EVAs conducted during the Gemini program of the 1960s, to the complex International Space Station (ISS) assembly tasks of the first decade of the 21st century. The second area of expertise is comprised of those EVAs conducted on the lunar surface, under a gravitational force one-sixth that of Earth. This EVA expertise encapsulates two extremes - microgravity and Earthlike gravitation - but is insufficient as humans expand their exploration purview, most notably with respect to spacewalks conducted on very low-gravity bodies, such as near- Earth objects (NEO) and the moons of Mars. The operational and technical challenges of this category of EVA have yet to be significantly examined, and as such, only a small number of operational concepts have been proposed thus far. To ensure mission success, however, EVA techniques must be developed and vetted to allow the selection of operational concepts that can be utilized across an assortment of destinations whose physical characteristics vary. This paper examines the utilization of ISS-based EVAs to test operational concepts and hardware in preparation for a low-gravity terrestrial EVA. While the ISS cannot mimic some of the fundamental challenges of a low-gravity terrestrial EVA - such as rotation rate and surface composition - it may be the most effective test bed available.

EVA Robotic Assistant Project: Platform Attitude Prediction

NASA Technical Reports Server (NTRS)

Nickels, Kevin M.

2003-01-01

The Robotic Systems Technology Branch is currently working on the development of an EVA Robotic Assistant under the sponsorship of the Surface Systems Thrust of the NASA Cross Enterprise Technology Development Program (CETDP). This will be a mobile robot that can follow a field geologist during planetary surface exploration, carry his tools and the samples that he collects, and provide video coverage of his activity. Prior experiments have shown that for such a robot to be useful it must be able to follow the geologist at walking speed over any terrain of interest. Geologically interesting terrain tends to be rough rather than smooth. The commercial mobile robot that was recently purchased as an initial testbed for the EVA Robotic Assistant Project, an ATRV Jr., is capable of faster than walking speed outside but it has no suspension. Its wheels with inflated rubber tires are attached to axles that are connected directly to the robot body. Any angular motion of the robot produced by driving over rough terrain will directly affect the pointing of the on-board stereo cameras. The resulting image motion is expected to make tracking of the geologist more difficult. This will either require the tracker to search a larger part of the image to find the target from frame to frame or to search mechanically in pan and tilt whenever the image motion is large enough to put the target outside the image in the next frame. This project consists of the design and implementation of a Kalman filter that combines the output of the angular rate sensors and linear accelerometers on the robot to estimate the motion of the robot base. The motion of the stereo camera pair mounted on the robot that results from this motion as the robot drives over rough terrain is then straightforward to compute. The estimates may then be used, for example, to command the robot s on-board pan-tilt unit to compensate for the camera motion induced by the base movement. This has been accomplished in two ways: first, a standalone head stabilizer has been implemented and second, the estimates have been used to influence the search algorithm of the stereo tracking algorithm. Studies of the image motion of a tracked object indicate that the image motion of objects is suppressed while the robot crossing rough terrain. This work expands the range of speed and surface roughness over which the robot should be able to track and follow a field geologist and accept arm gesture commands from the geologist.

Crosscutting Development- EVA Tools and Geology Sample Acquisition

NASA Technical Reports Server (NTRS)

2011-01-01

Exploration to all destinations has at one time or another involved the acquisition and return of samples and context data. Gathered at the summit of the highest mountain, the floor of the deepest sea, or the ice of a polar surface, samples and their value (both scientific and symbolic) have been a mainstay of Earthly exploration. In manned spaceflight exploration, the gathering of samples and their contextual information has continued. With the extension of collecting activities to spaceflight destinations comes the need for geology tools and equipment uniquely designed for use by suited crew members in radically different environments from conventional field geology. Beginning with the first Apollo Lunar Surface Extravehicular Activity (EVA), EVA Geology Tools were successfully used to enable the exploration and scientific sample gathering objectives of the lunar crew members. These early designs were a step in the evolution of Field Geology equipment, and the evolution continues today. Contemporary efforts seek to build upon and extend the knowledge gained in not only the Apollo program but a wealth of terrestrial field geology methods and hardware that have continued to evolve since the last lunar surface EVA. This paper is presented with intentional focus on documenting the continuing evolution and growing body of knowledge for both engineering and science team members seeking to further the development of EVA Geology. Recent engineering development and field testing efforts of EVA Geology equipment for surface EVA applications are presented, including the 2010 Desert Research and Technology Studies (Desert RATs) field trial. An executive summary of findings will also be presented, detailing efforts recommended for exotic sample acquisition and pre-return curation development regardless of planetary or microgravity destination.

EVA 2 activity on Flight Day 5 to survey the HST solar array panels

NASA Image and Video Library

1997-02-15

STS082-719-002 (14 Feb. 1997) --- Astronaut Joseph R. Tanner (right) stands on the end of Discovery's Remote Manipulator System (RMS) arm and aims a camera at the solar array panels on the Hubble Space Telescope (HST) as astronaut Gregory J. Harbaugh assists. The second Extravehicular Activity (EVA) photograph was taken with a 70mm camera from inside Discovery's cabin.

Performance Evaluation and Software Design for EVA Robotic Assistant Stereo Vision Heads

NASA Technical Reports Server (NTRS)

DiPaolo, Daniel

2003-01-01

The purpose of this project was to aid the EVA Robotic Assistant project by evaluating and designing the necessary interfaces for two stereo vision heads - the TracLabs Biclops pan-tilt-verge head, and the Helpmate Zebra pan-tilt-verge head. The first half of the project consisted of designing the necessary software interface so that the other modules of the EVA Robotic Assistant had proper access to all of the functionalities offered by each of the stereovision heads. This half took most of the project time, due to a lack of ready-made CORBA drivers for either of the heads. Once this was overcome, the evaluation stage of the project began. The second half of the project was to take these interfaces and to evaluate each of the stereo vision heads in terms of usefulness to the project. In the key project areas such as stability and reliability, the Zebra pan-tilt-verge head came out on top. However, the Biclops did have many more advantages over the Zebra, such as: lower power consumption, faster communications, and a simpler, cleaner API. Overall, the Biclops pan-tilt-verge head outperformed the Zebra pan-tilt-verge head.

FY13 High Performance EVA Glove (HPEG) Collaboration: Glove Injury Data Mining Effort - Training Data Overview

NASA Technical Reports Server (NTRS)

Reid, Christopher; Benson, Elizabeth; England, Scott; Charvat, Jacqueline; Norcross, Jason; McFarland, Shane; Rajulu, Sudhakar

2014-01-01

From the time hand-intensive tasks were first created for EVAs, discomforts and injuries have been noted.. There have been numerous versions of EVA gloves for US crew over the past 50 years, yet pain and injuries persist. The investigation team was tasked with assisting in a glove injury assessment for the High Performance EVA Glove (HPEG) project.center dot To aid in this assessment, the team was asked to complete the following objectives: - First, to develop the best current understanding of what glove-related injuries have occurred to date, and when possible, identify the specific mechanisms that caused those injuries - Second, to create a standardized method for comparison of glove injury potential from one glove to another. center dot The overall goal of the gloved hand injury assessment is to utilize ergonomics in understanding how these glove injuries are occurring, and to propose mitigations to current designs or design changes in the next generation of EVA gloves.

Astronaut David Scott using Apollo Lunar Surface Drill during second EVA

NASA Image and Video Library

1971-08-01

S71-41501 (1 Aug. 1971) --- Astronaut David R. Scott, Apollo 15 commander, is seen carrying the Apollo Lunar Surface Drill (ALSD) during the second lunar surface extravehicular activity (EVA) in this black and white reproduction taken from a color transmission made by the RCA color television camera mounted on the Lunar Roving Vehicle (LRV). This transmission was the fourth made during the mission.

View - Mission Control Center (MCC) - Lunar Surface - Apollo XI Extravehicular Activity (EVA) - MSC

NASA Image and Video Library

1969-07-20

S69-39815 (20 July 1969) --- Interior view of the Mission Operations Control Room (MOCR) in the Mission Control Center (MCC) during the Apollo 11 lunar extravehicular activity (EVA). The television monitor shows astronauts Neil A. Armstrong and Edwin E. Aldrin Jr. on the surface of the moon.

STS-64 extravehicular activity training view

NASA Image and Video Library

1993-06-21

S93-37890 (October 1993) --- Astronaut Jerry M. Linenger, STS-64 mission specialist, is assisted by Steve Voyles and Kari Rueter of Boeing Aerospace prior to participating in a rehearsal for a contingency extravehicular activity (EVA). Crewmates Mark C. Lee and Carl J. Meade have used the nearby 25-feet deep pool to rehearse a spacewalk designed to test and evaluate new EVA equipment. Photo credit: NASA or National Aeronautics and Space Administration

CDR Altman and MS Massimino in airlock prior to EVA 4

NASA Image and Video Library

2002-03-07

STS109-E-5688 (7 March 2002) --- Astronaut Scott D. Altman, mission commander, assists astronaut Michael J. Massimino, mission specialist, with suit-donning tasks prior to the STS-109 mission's fourth space walk (EVA-4). Astronauts Massimino and James H. Newman went on to install the new Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). The image was recorded with a digital still camera.

View of Mission Control Center (MCC) - Lunar Surface - Apollo XI - Extravehicular Activity (EVA) - MSC

NASA Image and Video Library

1969-07-20

S69-39817 (20 July 1969) --- Interior view of the Mission Operations Control Room (MOCR) in the Mission Control Center (MCC), Building 30, during the Apollo 11 lunar extravehicular activity (EVA). The television monitor shows astronauts Neil A. Armstrong and Edwin E. Aldrin Jr. on the surface of the moon.

Astronaut Alan Bean deploys ALSEP during first Apollo 12 EVA on moon

NASA Technical Reports Server (NTRS)

1969-01-01

Astronaut Alan L. Bean, Apollo 12 lunar module pilot, deploys components of the Apollo Lunar Surface Experiments Package (ALSEP) during the first Apollo 12 extravehicular activity (EVA) on the moon. The photo was made by Astronaut Charles Conrad Jr., Apollo 12 commander, using a 70mm handheld Haselblad camera modified for lunar surface usage.

Mars EVA Suit Airlock (MESA)

NASA Astrophysics Data System (ADS)

Ransom, Stephen; Böttcher, Jörg; Steinsiek, Frank

The Astrium Space Infrastructure Division has begun an in-house research activity of an Earth-based simulation facility supporting future manned missions to Mars. This research unit will help to prepare and support planned missions in the following ways: 1) to enable the investigation and analysis of contamination issues in advance of a human visit to Mars; 2) as a design tool to investigate and simulate crew operations; 3) to simulate crew operation during an actual mission; 4) to enable on-surface scientific operations without leaving the shirt-sleeve habitation environment ("glove box principle"). The MESA module is a surface EVA facility attached to the main habitation or laboratory module, or mobile pressurized rover. It will be sealed, but not pressurized, and provide protection against the harsh Martian environment. This module will include a second crew airlock for safety reasons. The compartment can also be used to provide an external working bench and experiment area for the crew. A simpler MESA concept provides only an open shelter against wind and dust. This concept does not incorporate working and experimental areas. The principle idea behind the MESA concept is to tackle the issue of contamination by minimizing the decontamination processes needed to clean surface equipment and crew suit surfaces after an EVA excursion prior to the astronaut re-entering the habitable area. The technical solution envisages the use of a dedicated crew suit airlock. This airlock uses an EVA suit which is externally attached by its back-pack to the EVA compartment area facing the Martian environment. The crew donns the suit from inside the habitable volume through the airlock on the back of the suit. The surface EVA can be accomplished after closing the back-pack and detaching the suit. A special technical design concept foresees an extendable suit back-pack, so that the astronaut can operate outside and in the vincinity of the module. The key driver in the investigation is the problem of contamination of the habitable volume by EVA and sampling activities and the transport of Earth-generated contaminants to Mars.

One hundred US EVAs: a perspective on spacewalks.

PubMed

Wilde, Richard C; McBarron, James W; Manatt, Scott A; McMann, Harold J; Fullerton, Richard K

2002-01-01

In the 36 years between June 1965 and February 2001, the US human space flight program has conducted 100 spacewalks, or extravehicular activities (EVAs), as NASA officially calls them. EVA occurs when astronauts wearing spacesuits travel outside their protective spacecraft to perform tasks in the space vacuum environment. US EVA started with pioneering feasibility tests during the Gemini Program. The Apollo Program required sending astronauts to the moon and performing EVA to explore the lunar surface. EVA supported scientific mission objectives of the Skylab program, but may be best remembered for repairing launch damage to the vehicle and thus saving the program. EVA capability on Shuttle was initially planned to be a kit that could be flown at will, and was primarily intended for coping with vehicle return emergencies. The Skylab emergency and the pivotal role of EVA in salvaging that program quickly promoted Shuttle EVA to an essential element for achieving mission objectives, including retrieving satellites and developing techniques to assemble and maintain the International Space Station (ISS). Now, EVA is supporting assembly of ISS. This paper highlights development of US EVA capability within the context of the overarching mission objectives of the US human space flight program. c2002 International Astronautical Federation. Published by Elsevier Science Ltd. All rights reserved.

An Effective Division of Labor Between Human and Robotic Agents Performing a Cooperative Assembly Task

NASA Technical Reports Server (NTRS)

Rehnmark, Fredrik; Bluethmann, William; Rochlis, Jennifer; Huber, Eric; Ambrose, Robert

2003-01-01

NASA's Human Space Flight program depends heavily on spacewalks performed by human astronauts. These so-called extra-vehicular activities (EVAs) are risky, expensive and complex. Work is underway to develop a robotic astronaut's assistant that can help reduce human EVA time and workload by delivering human-like dexterous manipulation capabilities to any EVA worksite. An experiment is conducted to evaluate human-robot teaming strategies in the context of a simplified EVA assembly task in which Robonaut, a collaborative effort with the Defense Advanced Research Projects Agency (DARPA), an anthropomorphic robot works side-by-side with a human subject. Team performance is studied in an effort to identify the strengths and weaknesses of each teaming configuration and to recommend an appropriate division of labor. A shared control approach is developed to take advantage of the complementary strengths of the human teleoperator and robot, even in the presence of significant time delay.

NASA Research Announcement Phase 2 Final Report for the Development of a Power Assisted Space Suit Glove

NASA Technical Reports Server (NTRS)

Lingo, Robert; Cadogan, Dave; Sanner, Rob; Sorenson, Beth

1997-01-01

The main goal of this program was to develop an unobtrusive power-assisted EVA glove metacarpalphalangeal (MCP) joint that could provide the crew member with as close to nude body performance as possible, and to demonstrate the technology feasibility of power assisted space suit components in general. The MCP joint was selected due to its being representative of other space suit joints, such as the shoulder, hip and carpometacarpal joint, that would also greatly benefit from this technology. In order to meet this objective, a development team of highly skilled and experienced personnel was assembled. The team consisted of two main entities. The first was comprised of ILC's experienced EVA space suit glove designers, who had the responsibility of designing and fabricating a low torque MCP joint which would be compatible with power assisted technology. The second part of the team consisted of space robotics experts from the University of Maryland's Space Systems Laboratory. This team took on the responsibility of designing and building the robotics aspects of the power-assist system. Both parties addressed final system integration responsibilities.

Astronaut Alan Bean deploys ALSEP during first Apollo 12 EVA on moon

NASA Image and Video Library

1969-11-19

AS12-47-6919 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot, deploys components of the Apollo Lunar Surface Experiments Package (ALSEP) during the first Apollo 12 extravehicular activity (EVA) on the moon. The photo was made by astronaut Charles Conrad Jr., commander, using a 70mm handheld Hasselblad camera modified for lunar surface usage.

Simulation of the «COSMONAUT-ROBOT» System Interaction on the Lunar Surface Based on Methods of Machine Vision and Computer Graphics

NASA Astrophysics Data System (ADS)

Kryuchkov, B. I.; Usov, V. M.; Chertopolokhov, V. A.; Ronzhin, A. L.; Karpov, A. A.

2017-05-01

Extravehicular activity (EVA) on the lunar surface, necessary for the future exploration of the Moon, involves extensive use of robots. One of the factors of safe EVA is a proper interaction between cosmonauts and robots in extreme environments. This requires a simple and natural man-machine interface, e.g. multimodal contactless interface based on recognition of gestures and cosmonaut's poses. When travelling in the "Follow Me" mode (master/slave), a robot uses onboard tools for tracking cosmonaut's position and movements, and on the basis of these data builds its itinerary. The interaction in the system "cosmonaut-robot" on the lunar surface is significantly different from that on the Earth surface. For example, a man, dressed in a space suit, has limited fine motor skills. In addition, EVA is quite tiring for the cosmonauts, and a tired human being less accurately performs movements and often makes mistakes. All this leads to new requirements for the convenient use of the man-machine interface designed for EVA. To improve the reliability and stability of human-robot communication it is necessary to provide options for duplicating commands at the task stages and gesture recognition. New tools and techniques for space missions must be examined at the first stage of works in laboratory conditions, and then in field tests (proof tests at the site of application). The article analyzes the methods of detection and tracking of movements and gesture recognition of the cosmonaut during EVA, which can be used for the design of human-machine interface. A scenario for testing these methods by constructing a virtual environment simulating EVA on the lunar surface is proposed. Simulation involves environment visualization and modeling of the use of the "vision" of the robot to track a moving cosmonaut dressed in a spacesuit.

Fogging Control on LDPE/EVA Coextruded Films: Wettability Behavior and Its Correlation with Electric Performance.

PubMed

Waldo-Mendoza, Miguel A; Quiñones-Jurado, Zoe V; Pérez-Medina, Juan C; Yañez-Soto, Bernardo; Ramírez-González, Pedro E

2017-02-22

The transformation of fog at a non-visible water layer on a membrane of low-density polyethylene (LDPE) and ethylene-vinyl acetate (EVA) was evaluated. Nonionic surfactants of major demand in the polyolefin industry were studied. A kinetic study using a hot fog chamber showed that condensation is controlled by both the diffusion and permanency of the surfactant more than by the change of the surface energy developed by the wetting agents. The greatest permanency of the anti-fog effect of the LDPE/EVA surface was close to 3000 h. The contact angle results demonstrated the ability of the wetting agent to spread out to the surface. Complementarily, the migration of nonionic surfactants from the inside of the polymeric matrix to the surface was analyzed by Fourier transform infrared (FTIR) microscopy. Additionally, electrical measurement on the anti-fogging membrane at alternating currents and at a sweep frequency was proposed to test the conductivity and wetting ability of nonionic surfactants. We proved that the amphiphilic molecules had the ability to increase the conductivity in the polyolefin membrane. A correlation between the bulk electrical conductivity and the permanency of the fogging control on the LDPE/EVA coextruded film was found.

Fogging Control on LDPE/EVA Coextruded Films: Wettability Behavior and Its Correlation with Electric Performance

PubMed Central

Waldo-Mendoza, Miguel A.; Quiñones-Jurado, Zoe V.; Pérez-Medina, Juan C.; Yañez-Soto, Bernardo; Ramírez-González, Pedro E.

2017-01-01

The transformation of fog at a non-visible water layer on a membrane of low-density polyethylene (LDPE) and ethylene-vinyl acetate (EVA) was evaluated. Nonionic surfactants of major demand in the polyolefin industry were studied. A kinetic study using a hot fog chamber showed that condensation is controlled by both the diffusion and permanency of the surfactant more than by the change of the surface energy developed by the wetting agents. The greatest permanency of the anti-fog effect of the LDPE/EVA surface was close to 3000 h. The contact angle results demonstrated the ability of the wetting agent to spread out to the surface. Complementarily, the migration of nonionic surfactants from the inside of the polymeric matrix to the surface was analyzed by Fourier transform infrared (FTIR) microscopy. Additionally, electrical measurement on the anti-fogging membrane at alternating currents and at a sweep frequency was proposed to test the conductivity and wetting ability of nonionic surfactants. We proved that the amphiphilic molecules had the ability to increase the conductivity in the polyolefin membrane. A correlation between the bulk electrical conductivity and the permanency of the fogging control on the LDPE/EVA coextruded film was found. PMID:28241433

802.16e System Profile for NASA Extra-Vehicular Activities

NASA Technical Reports Server (NTRS)

Foore, Lawrence R.; Chelmins, David T.; Nguyen, Hung D.; Downey, Joseph A.; Finn, Gregory G.; Cagley, Richard E.; Bakula, Casey J.

2009-01-01

This report identifies an 802.16e system profile that is applicable to a lunar surface wireless network, and specifically for meeting extra-vehicular activity (EVA) data flow requirements. EVA suit communication needs are addressed. Design-driving operational scenarios are considered. These scenarios are then used to identify a configuration of the 802.16e system (system profile) that meets EVA requirements, but also aim to make the radio realizable within EVA constraints. Limitations of this system configuration are highlighted. An overview and development status is presented by Toyon Research Corporation concerning the development of an 802.16e compatible modem under NASA s Small Business Innovative Research (SBIR) Program. This modem is based on the recommended system profile developed as part of this report. Last, a path forward is outlined that presents an evolvable solution for the EVA radio system and lunar surface radio networks. This solution is based on a custom link layer, and 802.16e compliant physical layer compliant to the identified system profile, and a later progression to a fully interoperable 802.16e system.

The Effect of Nano Loading and Ultrasonic Compounding of EVA/LDPE/Nano-magnesium Hydroxide on Mechanical Properties and Distribution of Nano Particles

NASA Astrophysics Data System (ADS)

Azman, I. A.; Salleh, R. M.; Alauddin, S. M.; Shueb, M. I.

2018-05-01

Blends of Ethylene Vinyl Acetate (EVA) and Low-Density Polyethylene (LDPE) are promising composite which have good mechanical properties to environmental stress cracking. However, they lack fire resistant properties, which limits it usage in wire and cable industry. In order to improve flame retardancy ability, a range of nano-magnesium hydroxide (nano-MH) loading which is from 0 phr to maximum of 20 phr with ultrasonic extrusion 0-100 kHz frequencies have been introduced. Ultrasonic extrusion was used to improve the distribution of nano-MH. It was found that, 10 phr of nano loading with 100 kHz ultrasonic assisted has greater tensile strength compared to the nanocomposite without ultrasonication. Further increase of nano MH loading, will decrease the tensile properties. Better elongation at break was observed at10 phr nano-MH with the frequency of 50 kHz. The sample of 20 phr of nanoMH assisted with 50 kHz ultrasonic exhibits good flexural properties while 10 phr of nano-MH without the ultrasonic assisted demonstrates good in izod impact properties. From the evaluation of mechanical properties studied, it was found that 10 phr of nano-MH has shown the best performance among all the samples tested for EVA/LDPE/nano-MH composites. Transmission Electron Microscopy (TEM) has been conducted on 10 phr sample with different frequencies in order to observe the distribution of nano-MH particles. The sample with 100 kHz frequency shows more uniform dispersion of nano-MH in EVA/LDPE composites. This investigation indicates that the ultrasonic technology can enhance the mechanical properties studied as well as the dispersion of nano particles in the composite.

STS-48 MS Gemar dons EMU with technicians' assistance prior to JSC WETF dive

NASA Technical Reports Server (NTRS)

1991-01-01

STS-48 Mission Specialist (MS) Charles D. Gemar, wearing an extravehicular mobility unit (EMU) and communications carrier assembly (CCA), smiles as he watches technicians adjust his sleeves prior to donning his EMU gloves. Gemar is preparing for an underwater extravehicular activity (EVA) training session in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Once underwater, Gemar will practice contingency EVA operations for his upcoming mission aboard Discovery, Orbiter Vehicle (OV) 103.

MS Jones and MS Curbeam suited in EMU in the A/L for EVA 3

NASA Image and Video Library

2001-02-07

STS098-349-004 (7-20 February 2001) --- Astronauts Thomas D. Jones (second left) and Robert L. Curbeam, both mission specialists, prepare for one of the three STS-98 sessions of extravehicular activity (EVA). Astronauts Kenneth D. Cockrell (lower left), mission commander, and Mark L. Polansky, mission specialist, assist Jones and Curbeam as they don their Extravehicular Mobility Unit (EMU) space suits in the airlock of the Space Shuttle Atlantis.

Achieving an adequate minute volume through a 2 mm transtracheal catheter in simulated upper airway obstruction using a modified industrial ejector.

PubMed

Hamaekers, A E W; Götz, T; Borg, P A J; Enk, D

2010-03-01

Needle cricothyrotomy and subsequent transtracheal jet ventilation (TTJV) is one of the last options to restore oxygenation while managing an airway emergency. However, in cases of complete upper airway obstruction, conventional TTJV is ineffective and dangerous. We transformed a small, industrial ejector into a simple, manual ventilator providing expiratory ventilation assistance (EVA). An ejector pump was modified to allow both insufflation of oxygen and jet-assisted expiration through an attached 75 mm long transtracheal catheter (TTC) with an inner diameter (ID) of 2 mm by alternately occluding and releasing the gas outlet of the ejector pump. In a lung simulator, the modified ejector pump was tested at different compliances and resistances. Inspiration and expiration times were measured and achievable minute volumes (MVs) were calculated to determine the effect of EVA. The modified ejector pump shortened the expiration time and an MV up to 6.6 litre min(-1) could be achieved through a 2 mm ID TTC in a simulated obstructed airway. The principle of ejector-based EVA seems promising and deserves further evaluation.

Acoustic Behavior of Subfloor Lightweight Mortars Containing Micronized Poly (Ethylene Vinyl Acetate) (EVA).

PubMed

Brancher, Luiza R; Nunes, Maria Fernanda de O; Grisa, Ana Maria C; Pagnussat, Daniel T; Zeni, Mára

2016-01-15

This paper aims to contribute to acoustical comfort in buildings by presenting a study about the polymer waste micronized poly (ethylene vinyl acetate) (EVA) to be used in mortars for impact sound insulation in subfloor systems. The evaluation method included physical, mechanical and morphological properties of the mortar developed with three distinct thicknesses designs (3, 5, and 7 cm) with replacement percentage of the natural aggregate by 10%, 25%, and 50% EVA. Microscopy analysis showed the surface deposition of cement on EVA, with preservation of polymer porosity. The compressive creep test estimated long-term deformation, where the 10% EVA sample with a 7 cm thick mortar showed the lowest percentage deformation of its height. The impact noise test was performed with 50% EVA samples, reaching an impact sound insulation of 23 dB when the uncovered slab was compared with the 7 cm thick subfloor mortar. Polymer waste addition decreased the mortar compressive strength, and EVA displayed characteristics of an influential material to intensify other features of the composite.

Plasma Surface Modification of Polymer Backsheets: Origins of Future Interfacial Barrier/Backsheet Failure (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pankow, J. W.; Glick, S. H.

2006-05-01

Flexible polymer substrates coated with inorganic oxide moisture barriers are a potential replacement for glass backsheets in thin-film PV (photovoltaic) modules. Silicon oxynitride (SiO{sub x}N{sub y}) deposited by plasma enhanced chemical vapor deposition (PECVD) on polyethylene terephthalate (PET) represents one potential new backsheet candidate. Barrier deposition runs at NREL have included a nitrogen-rich plasma pretreatment prior to barrier deposition with the intention of cleaning the PET surface and enhancing adhesion of the SiO{sub x}N{sub y} barrier film to PET; however, test coupons of PET/barrier/EVA/TPE failed after damp-heat exposure. (EVA is ethylene vinyl acetate and TPE is Tedlar{reg_sign}-PET-EVA). PET substrates exposedmore » to plasma conditions similar to those used in pretreatment were examined by X-ray photoelectron spectroscopy (XPS) to reveal that new low molecular weight PET fragments were created at the PET surface. These fragments are responsible for barrier/PET interfacial failure and barrier transfer to the EVA encapsulant side following damp heat exposure.« less

Electrical Currents and Adhesion of Edge-Delete Regions of EVA-to-Glass Module Packaging: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMahon, T. J.; Jorgensen, G. J.

2001-10-01

Presented at the 2001 NCPV Program Review Meeting: Electrical conductivity pathways from the grounded frame to the cell area in a PV module are reviewed here. Electrical conductivity pathways from the grounded frame to the cell area in a PV module are reviewed here. Measurements are made on 4 inch x 8 inch soda lime (SL) glass substrates with contact patterns defined using 3-mil and 10-mil diameter bead-blast removal of the SnO{sub 2} coating to study the dominant path, which is the EVA/glass interface. The remaining SnO{sub 2} contact strips are separated by what would simulate the module edge deletemore » regions. EVA encapsulated bead-blast surface resistances are 8 x 10{sup 15} ohm/sq compared to 8 x 10{sup 12} ohm/sq for native SL glass surfaces. Adhesion strengths to bead-blast surfaces are 25 to 30 lbs/in. Stress test results on these interfaces after removal from damp heat suggest corrosion of the glass at the glass-EVA interface.« less

Space Shuttle Projects

NASA Image and Video Library

1984-01-01

The Space Shuttle Challenger, making its fourth space flight, highlights the 41B insignia. The reusable vehicle is flanked in the oval by an illustration of a Payload Assist Module-D solid rocket motor (PAM-D) for assisted satellite deployment; an astronaut making the first non-tethered extravehicular activity (EVA); and eleven stars.

Enhanced Adhesion of EVA Laminates to Primed Glass Substrates Subjected to Damp-Heat Exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F. J.; Jorgensen, G. J.

2005-02-01

We investigated the effectiveness of glass-surface priming to promote enhanced adhesion of EVA laminates during damp-heat exposure at 85 C and 85% relative humidity. The primary objective was to develop advanced encapsulant formulations by incorporation of various primer formulations that exhibit improved adhesion during damp-heat exposure. Several primer formulations were identified that greatly enhanced the EVA adhesion strength, including to the extent that peeling could not be initiated, even for the laminates of the glass substrate/fast-cure EVA15295P/TPE backsheet (a Tedlar/polyester/EVA tri-laminate) that were exposed in a damp-heat test chamber for more than 750 h. The results show that a synergisticmore » increase in the interfacial hydrophobicity, siloxane density, and cross-linking density are the key attributes to the improvement in the EVA adhesion strength.« less

Preparation and Properties of Ethylene Vinyl Acetate Copolymer/Silica Nanocomposites in Presence of EVA-g-Acrylic Acid.

PubMed

Tham, Do Quang; Tuan, Vu Manh; Thanh, Dinh Thi Mai; Chinh, Nguyen Thuy; Giang, Nguyen Vu; Trang, Nguyen Thi Thu; Hang, To Thi Xuan; Huong, Ho Thu; Dung, Nguyen Thi Kim; Hoang, Thai

2015-04-01

Here we report a facile approach to enhance the dispersibility of ethylene vinyl acetate copolymer (EVA)/silica nanocomposites (for the EVA/silica nanocomposites and interaction between silica nanoparticles (nanosilica) and EVA by adding EVA-g-acrylic acid (EVAgAA) as a compatibilizer, which was formed by grafting acrylic acid onto EVA chains with the aid of dicumyl peroxide). The above nanocomposites with and without EVAgAA were prepared by melt mixing in a Haake intermixer with different contents of silica and EVAgAA. Their structure and morphology were characterized by Fourier transform infra-red (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and the mechanical, rheological, dielectrical, and flammability properties of the nanocomposites were also investigated. The FT-IR spectra of the nanocomposites confirmed the formation of hydrogen bonds between the surface silanol groups of nanosilica and C=O groups of EVA and/or EVAgAA. The presence of EVAgAA remarkably increased the intensity of hydrogen bonding between nanosilica and EVA which not only enhanced the dispersion of nanosilica in EVA matrix but also increased the mechanical, viscosity and storage modulus of EVA/silica nanocomposites. In addition, the flammability of EVA/silica nanocomposites is also significantly reduced after the functionalization with EVAgAA. However, the mechanical properties of EVA/silica nanocomposites tended to level off when its content was above 1.5 wt.%. It has also been found that the dielectric constant value of the EVA/EVAgAA/silica nanocomposites is much lower than that of the EVA/silica nanocomposites, which is another evidence of the hydrogen bonding formation between EVAgAA and nanosilica.

STS-134 crew during EVA TPS Overview training in the TPS/PABF

NASA Image and Video Library

2009-12-15

JSC2009-E-284897 (15 Dec. 2009) --- STS-134 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA?s Johnson Space Center. Pictured from the right are NASA astronauts Andrew Feustel, Greg Chamitoff, Michael Fincke, all mission specialists; along with NASA astronaut Gregory H. Johnson, pilot; and European Space Agency astronaut Roberto Vittori, mission specialist. John Ray (left) assisted the crew members.

Baseline tests of the EVA contractor electric passenger vehicle

NASA Technical Reports Server (NTRS)

Bozek, J. M.; Tryon, H. B.; Slavick, R. J.

1977-01-01

The EVA Contactor four door sedan, an electric passenger vehicle, was tested to characterize the state-of-the-art of electric vehicles. It is a four passenger sedan that was converted to an electric vehicle. It is powered by 16 series connected 6 volt electric vehicle batteries through a four step contactor controller actuated by a foot accelerator pedal. The controller changes the voltage applied to the separately excited DC motor. The braking system is a vacuum assisted hydraulic braking system. Regenerative braking was also provided.

Eva Physiology, Systems, and Performance (EPSP) Project Overview

NASA Technical Reports Server (NTRS)

Gernhardt, Michael L.

2007-01-01

Extravehicular activity (EVA) is any activity performed by astronauts outside their space vehicle or habitat. EVA may be performed on orbit, such as outside the Space Shuttle or the International Space Station, or on a planetary surface such as Mars or on the moon. Astronauts wear a pressurized suit that provides environmental protection, mobility, life support, and communications while they work in the harsh conditions of a microgravity environment. Exploration missions to the moon and Mars may last many days and will include many types of EVAs; exploration, science, construction and maintenance. The effectiveness and success of these EVA-filled missions is dependent on the ability to perform tasks efficiently. The EVA Physiology, Systems and Performance (EPSP) project will conduct a number of studies to understand human performance during EVA, from a molecular level to full-scale equipment and suit design aspects, with the aim of developing safe and efficient systems for Exploration missions and the Constellation Program. The EPSP project will 1) develop Exploration Mission EVA suit requirements for metabolic and thermal loading, optional center of gravity location, biomedical sensors, hydration, nutrition, and human biomedical interactions; 2) develop validated EVA prebreathe protocols that meet medical, vehicle, and habitat constraints while minimizing crew time and thus increasing EVA work efficiency; and 3) define exploration decompression sickness (DCS) risks, policy, and mission success statistics and develop a DCS risk definition report.

Extravehicular Activity Asteroid Exploration and Sample Collection Capability

NASA Technical Reports Server (NTRS)

Sipila, Stephanie A.; Scoville, Zebulon C.; Bowie, Jonathan T.; Buffington, Jesse A.

2014-01-01

One of the challenging primary objectives associated with NASA's Asteroid Redirect Crewed Mission (ARCM) is to demonstrate deep space Extravehicular Activity (EVA) and tools and to obtain asteroid samples to return to Earth for further study. Prior Shuttle and International Space Station (ISS) spacewalks have benefited from engineered EVA interfaces which have been designed and manufactured on Earth. Rigid structurally mounted handrails, and tools with customized interfaces and restraints optimize EVA performance. For ARCM, EVA complexity increases due to the uncertainty of the asteroid properties. The variability of rock size, shape and composition, as well as behavior of the asteroid capture mechanism will complicate EVA translation, tool restraint, and body stabilization. The unknown asteroid hardness and brittleness will complicate tool use. The rock surface will introduce added safety concerns for cut gloves and debris control. Feasible solutions to meet ARCM EVA objectives were identified using experience gained during Apollo, Shuttle, and ISS EVAs, terrestrial mountaineering practices, NASA Extreme Environment Mission Operations (NEEMO) 16 mission, and during Neutral Buoyancy Laboratory testing in the Modified Advanced Crew Escape Suit (MACES) suit. This paper will summarize the overall operational concepts for conducting EVAs for the ARCM mission including translation paths and body restraint methods, potential tools used to extract the samples, design implications for the Asteroid Redirect Vehicle (ARV) for EVA, and the results of early development testing of potential EVA tasks.

Procedure for the systematic orientation of digitised cranial models. Design and validation.

PubMed

Bailo, M; Baena, S; Marín, J J; Arredondo, J M; Auría, J M; Sánchez, B; Tardío, E; Falcón, L

2015-12-01

Comparison of bony pieces requires that they are oriented systematically to ensure that homologous regions are compared. Few orientation methods are highly accurate; this is particularly true for methods applied to three-dimensional models obtained by surface scanning, a technique whose special features make it a powerful tool in forensic contexts. The aim of this study was to develop and evaluate a systematic, assisted orientation method for aligning three-dimensional cranial models relative to the Frankfurt Plane, which would be produce accurate orientations independent of operator and anthropological expertise. The study sample comprised four crania of known age and sex. All the crania were scanned and reconstructed using an Eva Artec™ portable 3D surface scanner and subsequently, the position of certain characteristic landmarks were determined by three different operators using the Rhinoceros 3D surface modelling software. Intra-observer analysis showed a tendency for orientation to be more accurate when using the assisted method than when using conventional manual orientation. Inter-observer analysis showed that experienced evaluators achieve results at least as accurate if not more accurate using the assisted method than those obtained using manual orientation; while inexperienced evaluators achieved more accurate orientation using the assisted method. The method tested is a an innovative system capable of providing very precise, systematic and automatised spatial orientations of virtual cranial models relative to standardised anatomical planes independent of the operator and operator experience. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Extravehicular Activity (EVA) Microbial Swab Tool

NASA Technical Reports Server (NTRS)

Rucker, Michelle

2015-01-01

When we send humans to search for life on Mars, we'll need to know what we brought with us versus what may already be there. To ensure our crewed spacecraft meet planetary protection requirements--and to protect our science from human contamination--we'll need to know whether micro-organisms are leaking/venting from our ships and spacesuits. This is easily done by swabbing external vents and surfaces for analysis, but there was no US EVA tool for that job. NASA engineers developed an EVA-compatible swab tool that can be used to collect data on current hardware, which will influence eventual Mars life support and EVA hardware designs.

Next Generation Life Support: High Performance EVA Glove

NASA Technical Reports Server (NTRS)

Walsh, Sarah K.

2015-01-01

The objectives of the High Performance EVA Glove task are to develop advanced EVA gloves for future human space exploration missions and generate corresponding standards by which progress may be quantitatively assessed. New technologies and manufacturing techniques will be incorporated into the new gloves to address finger and hand mobility, injury reduction and durability in nonpristine environments. Three prototypes will be developed, each focusing on different technological advances. A robotic assist glove will integrate a powered grasping system into the current EVA glove design to reduce astronaut hand fatigue and hand injuries. A mechanical counter pressure (MCP) glove will be developed to further explore the potential of MCP technology and assess its capability for countering the effects of vacuum or low pressure environments on the body by using compression fabrics or materials to apply the necessary pressure. A gas pressurized glove, incorporating new technologies, will be the most flight-like of the three prototypes. Advancements include the development and integration of aerogel insulation, damage sensing components, dust-repellant coatings, and dust tolerant bearings.

Astronaut Richard Gordon returns to hatch of spacecraft following EVA

NASA Technical Reports Server (NTRS)

1966-01-01

Astronaut Richard F. Gordon Jr., pilot for the Gemini 11 space flight, returns to the hatch of the spacecraft following extravehicular activity (EVA). This picture was taken over the Atlantic Ocean at approximately 160 nautical miles above the earth's surface.

Shape Analysis and Deployment of the ExaVolt Antenna

NASA Astrophysics Data System (ADS)

Baginski, Frank; Zhao, Kaiyu; Furer, Joshua; Landay, Justin; Bailoor, Shantanu; Gorham, Peter; Varner, Gary; Miki, Christian; Hill, Brian; Schoorlemmer, Harm; Nguyen, Liem; Romero-Wolf, Andrew; Liewer, Kurt; Sauder, Jonathan; Brakke, Kenneth; Beatty, Jim; Connolly, Amy; Allison, Patrick; Pfendner, Carl; Dailey, Brian; Fairbrother, Debra; Said, Magdi; Lang, Steven; Young, Leyland

The ExaVolt Antenna (EVA) is the next generation balloon-borne ultra-high energy (UHE) particle observatory under development for NASA’s suborbital super-pressure balloon program in Antarctica. Unlike a typical mission where the balloon lifts a gondola that carries the primary scientific instrument, the EVA mission is a first-of-its-kind in that the balloon itself is part of the science instrument. Specifically, a toroidal RF reflector is mounted onto the outside surface of a superpressure balloon (SPB) and a feed antenna is suspended inside the balloon, creating a high-gain antenna system with a synoptic view of the Antarctic ice sheet. The EVA mission presents a number of technical challenges. For example, can a stowed feed antenna be inserted through an opening in the top-plate? Can the feed antenna be deployed during the ascent? Once float altitude is achieved, how might small shape changes in the balloon shape affect the antenna performance over the life of the EVA mission? The EVA team utilized a combination of testing with a 1/20-scale physical model, mathematical modeling and numerical simulations to probe these and related questions. While the problems are challenging, they are solvable with current technology and expertise. Experiments with a 1/20-scale EVA physical model outline a pathway for inserting a stowed feed into a SPB. Analysis indicates the EVA system will ascend, deploy and assume a stable configuration at float altitude. Nominal shape changes in an Antarctic SPB are sufficiently small to allow the use of the surface of the balloon as a high-gain reflector.

Acoustic Behavior of Subfloor Lightweight Mortars Containing Micronized Poly (Ethylene Vinyl Acetate) (EVA)

PubMed Central

Brancher, Luiza R.; Nunes, Maria Fernanda de O.; Grisa, Ana Maria C.; Pagnussat, Daniel T.; Zeni, Mára

2016-01-01

This paper aims to contribute to acoustical comfort in buildings by presenting a study about the polymer waste micronized poly (ethylene vinyl acetate) (EVA) to be used in mortars for impact sound insulation in subfloor systems. The evaluation method included physical, mechanical and morphological properties of the mortar developed with three distinct thicknesses designs (3, 5, and 7 cm) with replacement percentage of the natural aggregate by 10%, 25%, and 50% EVA. Microscopy analysis showed the surface deposition of cement on EVA, with preservation of polymer porosity. The compressive creep test estimated long-term deformation, where the 10% EVA sample with a 7 cm thick mortar showed the lowest percentage deformation of its height. The impact noise test was performed with 50% EVA samples, reaching an impact sound insulation of 23 dB when the uncovered slab was compared with the 7 cm thick subfloor mortar. Polymer waste addition decreased the mortar compressive strength, and EVA displayed characteristics of an influential material to intensify other features of the composite. PMID:28787851

Science Support Room Operations During Desert RATS 2009

NASA Technical Reports Server (NTRS)

Lofgren, G. E.; Horz, F.; Bell, M. S.; Cohen, B. A.; Eppler,D. B.; Evans, C. a.; Hodges, K. V.; Hynek, B. M.; Gruener, J. E.; Kring, D. A.;

EVA dosimetry in manned spacecraft.

PubMed

Thomson, I

1999-12-06

Extra Vehicular Activity (EVA) will become a large part of the astronaut's work on board the International Space Station (ISS). It is already well known that long duration space missions inside a spacecraft lead to radiation doses which are high enough to be a significant health risk to the crew. The doses received during EVA, however, have not been quantified to the same degree. This paper reviews the space radiation environment and the current dose limits to critical organs. Results of preliminary radiation dosimetry experiments on the external surface of the BION series of satellites indicate that EVA doses will vary considerably due to a number of factors such as EVA suit shielding, temporal fluctuations and spacecraft orbit and shielding. It is concluded that measurement of doses to crew members who engage in EVA should be done on board the spacecraft. An experiment is described which will lead the way to implementing this plan on the ISS. It is expected that results of this experiment will help future crew mitigate the risks of ionising radiation in space.

Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn

2009-01-01

During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.

Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn C.

2010-01-01

During the Apollo program, the space suit outer layer fabrics were badly abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub -layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This Paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, and shares the results and conclusions of the testing.

Design Considerations for a Crewed Mars Ascent Vehicle

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.

2015-01-01

Exploration architecture studies identified the Mars Ascent Vehicle (MAV) as one of the largest "gear ratio" items in a crewed Mars mission. Because every kilogram of mass ascended from the Martian surface requires seven kilograms or more of ascent propellant, it is desirable for the MAV to be as small and lightweight as possible. Analysis identified four key factors that drive MAV sizing: 1) Number of crew: more crew members require more equipment-and a larger cabin diameter to hold that equipment-with direct implications to structural, thermal, propulsion, and power subsystem mass. 2) Which suit is worn during ascent: Extravehicular Activity (EVA) type suits are physically larger and heavier than Intravehicular Activity (IVA) type suits and because they are less flexible, EVA suits require more elbow-room to maneuver in and out of. An empty EVA suit takes up about as much cabin volume as a crew member. 3) How much time crew spends in the MAV: less than about 12 hours and the MAV can be considered a "taxi" with few provisions for crew comfort. However, if the crew spends more than 12 consecutive hours in the MAV, it begins to look like a Habitat requiring more crew comfort items. 4) How crew get into/out of the MAV: ingress/egress method drives structural mass (for example, EVA hatch vs. pressurized tunnel vs. suit port) as well as consumables mass for lost cabin atmosphere, and has profound impacts on surface element architecture. To minimize MAV cabin mass, the following is recommended: Limit MAV usage to 24 consecutive hours or less; discard EVA suits on the surface and ascend wearing IVA suits; Limit MAV functionality to ascent only, rather than dual-use ascent/habitat functions; and ingress/egress the MAV via a detachable tunnel to another pressurized surface asset.

STS-45 MS Foale in EMU is lowered into JSC's WETF pool for underwater test

NASA Image and Video Library

1991-02-26

S91-30197 (1 March 1991) --- A wider shot of astronaut C. Michael Foale, mission specialist, standing on a platform which is part of a system that will lower him into a 25-ft. deep pool. Foale used the pool in the weightless environment training facility (WET-F) to rehearse a contingency extravehicular activity (EVA). Two SCUBA-equipped swimmers assist. Astronauts wear pressurized spacesuits configured for achieving a neutrally buoyant condition in the water to simulate both planned and contingency EVAs.

STS-53 MS Clifford, in EMU, dons gloves with technicians' assistance at JSC

NASA Technical Reports Server (NTRS)

1992-01-01

STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Michael R.U. Clifford, wearing extravehicular mobility unit (EMU) and communications carrier assembly (CCA), dons gloves with assistance from two technicians. Clifford is preparing for an underwater contingency extravehicular activity (EVA) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

STS-53 MS Voss,in EMU, dons gloves with technicians' assistance at JSC's WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) James S. Voss, wearing extravehicular mobility unit (EMU) and communications carrier assembly (CCA), dons his gloves with assistance from two technicians. Voss is preparing for an underwater contingency extravehicular activity (EVA) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

Use MACES IVA Suit for EVA Mobility Evaluations

NASA Technical Reports Server (NTRS)

Watson, Richard D.

2014-01-01

The use of an Intra-Vehicular Activity (IVA) suit for a spacewalk or Extra-Vehicular Activity (EVA) was evaluated for mobility and usability in the Neutral Buoyancy Lab (NBL) environment. The Space Shuttle Advanced Crew Escape Suit (ACES) has been modified (MACES) to integrate with the Orion spacecraft. The first several missions of the Orion MPCV spacecraft will not have mass available to carry an EVA specific suit so any EVA required will have to be performed by the MACES. Since the MACES was not designed with EVA in mind, it was unknown what mobility the suit would be able to provide for an EVA or if a person could perform useful tasks for an extended time inside the pressurized suit. The suit was evaluated in multiple NBL runs by a variety of subjects including crewmembers with significant EVA experience. Various functional mobility tasks performed included: translation, body positioning, carrying tools, body stabilization, equipment handling, and use of tools. Hardware configurations included with and without TMG, suit with IVA gloves and suit with EVA gloves. Most tasks were completed on ISS mockups with existing EVA tools. Some limited tasks were completed with prototype tools on a simulated rocky surface. Major findings include: demonstration of the ability to weigh-out the suit, understanding the need to have subjects perform multiple runs prior to getting feedback, determination of critical sizing factors, and need for adjustment of suit work envelop. The early testing has demonstrated the feasibility of EVA's limited duration and limited scope. Further testing is required with more flight like tasking and constraints to validate these early results. If the suit is used for EVA, it will require mission specific modifications for umbilical management or PLSS integration, safety tether attachment, and tool interfaces. These evaluations are continuing through calendar year 2014.

Haughton-Mars Project/NASA 2006 Lunar Medical Contingency Simulation: Equipment and Methods for Medical Evacuation of an Injured Crewmember

NASA Technical Reports Server (NTRS)

Chappell, S. P.; Scheuring, R. A.; Jones, J. A.; Lee, P.; Comtois, J. M.; Chase, T.; Gernhardt M.; Wilkinson, N.

2007-01-01

Introduction: Achieving NASA's Space Exploration Vision scientific objectives will require human access into cratered and uneven terrain for the purpose of sample acquisition to assess geological, and perhaps even biological features and experiments. Operational risk management is critical to safely conduct the anticipated tasks. This strategy, along with associated contingency plans, will be a driver of EVA system requirements. Therefore, a medical contingency EVA scenario was performed with the Haughton-Mars Project/NASA to develop belay and medical evacuation techniques for exploration and rescue respectively. Methods: A rescue system to allow two rescuer astronauts to evacuate one in incapacitated astronaut was evaluated. The systems main components were a hard-bottomed rescue litter, hand-operated winch, rope, ground picket anchors, and a rover-winch attachment adapter. Evaluation was performed on 15-25deg slopes of dirt with embedded rock. The winch was anchored either by adapter to the rover or by pickets hammered into the ground. The litter was pulled over the surface by rope attached to the winch. Results: The rescue system was utilized effectively to extract the injured astronaut up a slope and to a waiting rover for transport to a simulated habitat for advanced medical care, although several challenges to implementation were identified and overcome. Rotational stabilization of the winch was found to be important to get maximize mechanical advantage from the extraction system. Discussion: Further research and testing needs to be performed to be able to fully consider synergies with the other Exploration surface systems, in conducting contingency operations. Structural attachment points on the surface EVA suits may be critical to assist in incapacitated evacuation. Such attach points could be helpful in microgravity incapacitated crewmember transport as well. Wheeled utility carts or wheels that may be attachable to a litter may also aid in extraction and transport. Utilizing parts of the rover (e.g. seats) to deploy as a litter may be considered. Testing in simulated 1/6-g to determine feasibility of winch operation and anchor establishment will further reduce implementation uncertainties.

Oxidative stress-mediated hemolytic activity of solvent exchange-prepared fullerene (C60) nanoparticles

NASA Astrophysics Data System (ADS)

Trpkovic, Andreja; Todorovic-Markovic, Biljana; Kleut, Duska; Misirkic, Maja; Janjetovic, Kristina; Vucicevic, Ljubica; Pantovic, Aleksandar; Jovanovic, Svetlana; Dramicanin, Miroslav; Markovic, Zoran; Trajkovic, Vladimir

2010-09-01

The present study investigated the hemolytic properties of fullerene (C60) nanoparticles prepared by solvent exchange using tetrahydrofuran (nC60THF), or by mechanochemically assisted complexation with macrocyclic oligosaccharide gamma-cyclodextrin (nC60CDX) or the copolymer ethylene vinyl acetate-ethylene vinyl versatate (nC60EVA-EVV). The spectrophotometrical analysis of hemoglobin release revealed that only nC60THF, but not nC60CDX or nC60EVA-EVV, was able to cause lysis of human erythrocytes in a dose- and time-dependent manner. Atomic force microscopy revealed that nC60THF-mediated hemolysis was preceded by erythrocyte shrinkage and increase in cell surface roughness. A flow cytometric analysis confirmed a decrease in erythrocyte size and demonstrated a significant increase in reactive oxygen species production in red blood cells exposed to nC60THF. The nC60THF-triggered hemolytic activity was efficiently reduced by the antioxidants N-acetylcysteine and butylated hydroxyanisole, as well as by serum albumin, the most abundant protein in human blood plasma. These data indicate that nC60THF can cause serum albumin-preventable hemolysis through oxidative stress-mediated damage of the erythrocyte membrane.

Automating CapCom Using Mobile Agents and Robotic Assistants

NASA Technical Reports Server (NTRS)

Clancey, William J.; Sierhaus, Maarten; Alena, Richard L.; Berrios, Daniel; Dowding, John; Graham, Jeffrey S.; Tyree, Kim S.; Hirsh, Robert L.; Garry, W. Brent; Semple, Abigail

2005-01-01

We have developed and tested an advanced EVA communications and computing system to increase astronaut self-reliance and safety, reducing dependence on continuous monitoring and advising from mission control on Earth. This system, called Mobile Agents (MA), is voice controlled and provides information verbally to the astronauts through programs called personal agents. The system partly automates the role of CapCom in Apollo-including monitoring and managing EVA navigation, scheduling, equipment deployment, telemetry, health tracking, and scientific data collection. EVA data are stored automatically in a shared database in the habitat/vehicle and mirrored to a site accessible by a remote science team. The program has been developed iteratively in the context of use, including six years of ethnographic observation of field geology. Our approach is to develop automation that supports the human work practices, allowing people to do what they do well, and to work in ways they are most familiar. Field experiments in Utah have enabled empirically discovering requirements and testing alternative technologies and protocols. This paper reports on the 2004 system configuration, experiments, and results, in which an EVA robotic assistant (ERA) followed geologists approximately 150 m through a winding, narrow canyon. On voice command, the ERA took photographs and panoramas and was directed to move and wait in various locations to serve as a relay on the wireless network. The MA system is applicable to many space work situations that involve creating and navigating from maps (including configuring equipment for local topology), interacting with piloted and unpiloted rovers, adapting to environmental conditions, and remote team collaboration involving people and robots.

Comparison Of Human Modelling Tools For Efficiency Of Prediction Of EVA Tasks

NASA Technical Reports Server (NTRS)

Dischinger, H. Charles, Jr.; Loughead, Tomas E.

1998-01-01

Construction of the International Space Station (ISS) will require extensive extravehicular activity (EVA, spacewalks), and estimates of the actual time needed continue to rise. As recently as September, 1996, the amount of time to be spent in EVA was believed to be about 400 hours, excluding spacewalks on the Russian segment. This estimate has recently risen to over 1100 hours, and it could go higher before assembly begins in the summer of 1998. These activities are extremely expensive and hazardous, so any design tools which help assure mission success and improve the efficiency of the astronaut in task completion can pay off in reduced design and EVA costs and increased astronaut safety. The tasks which astronauts can accomplish in EVA are limited by spacesuit mobility. They are therefore relatively simple, from an ergonomic standpoint, requiring gross movements rather than time motor skills. The actual tasks include driving bolts, mating and demating electric and fluid connectors, and actuating levers; the important characteristics to be considered in design improvement include the ability of the astronaut to see and reach the item to be manipulated and the clearance required to accomplish the manipulation. This makes the tasks amenable to simulation in a Computer-Assisted Design (CAD) environment. For EVA, the spacesuited astronaut must have his or her feet attached on a work platform called a foot restraint to obtain a purchase against which work forces may be actuated. An important component of the design is therefore the proper placement of foot restraints.

View of activity in Mission Control Center during Apollo 15 EVA

NASA Image and Video Library

1971-08-02

S71-41852 (2 Aug. 1971) --- Gerald D. Griffin, foreground, stands near his console in the Mission Operations Control Room (MOCR) during Apollo 15's third extravehicular activity (EVA) on the lunar surface. Griffin is Gold Team (Shift 1) flight director for the Apollo 15 mission. Astronauts David R. Scott and James B. Irwin can be seen on the large screen at the front of the MOCR as they participate in sample-gathering on the lunar surface.

Extruded/injection-molded composites containing unripe plantain flour, ethylene vinyl-alcohol and glycerol: Evaluation of color, mechanical property and biodegradability

USDA-ARS?s Scientific Manuscript database

Extruded/injection-molded composites were produced from plantain flour blended with ethylene vinyl-alcohol (EVA) and glycerol. Scanning electron microscopy showed composites had a smooth surface and excellent compatibility between plantain flour, EVA and glycerol. The impact of increased plantain fl...

Antifouling Thermoplastic Composites with Maleimide Encapsulated in Clay Nanotubes.

PubMed

Fu, Ye; Gong, Congcong; Wang, Wencai; Zhang, Liqun; Ivanov, Evgenii; Lvov, Yuri

2017-09-06

An antifouling ethylene-vinyl acetate copolymer (EVA) coating with halloysite clay nanotubes loaded with maleimide (TCPM) is prepared. Such antifoulant encapsulation allowed for extended release of TCPM and a long-lasting, efficient protection of the coated surface against marine microorganisms proliferation. Halloysite also induces the composite's anisotropy due to parallel alignment of the nanotubes. The maleimide loaded halloysite incorporated into the polymer matrix allowed for 12-month release of the bacterial inhibitor preventing fouling; it is much longer than the 2-3 month protection when TCPM is directly admixed into EVA. The antifouling properties of the EVA-halloysite nanocomposites were tested by monitoring surface adhesion and proliferation of marine V. natriegens bacteria with SEM. As compared to the composite directly doped with TCPM-antifoulant, there were much less bacteria accumulated on the EVA-halloysite-TCPM coating after a 2-month exposure to seawater. Field tests at South China Sea marine station further confirmed the formulation efficiency. The doping of 28 wt % TCPM loaded halloysite drastically enhanced material antifouling property, which promises wide applications for protective marine coating.

Extravehicular Activity Asteroid Exploration and Sample Collection Capability

NASA Technical Reports Server (NTRS)

Scoville, Zebulon; Sipila, Stephanie; Bowie, Jonathan

2014-01-01

NASA's Asteroid Redirect Crewed Mission (ARCM) is challenged with primary mission objectives of demonstrating deep space Extravehicular Activity (EVA) and tools, and obtaining asteroid samples to return to Earth for further study. Although the Modified Advanced Crew Escape Suit (MACES) is used for the EVAs, it has limited mobility which increases fatigue and decreases the crews' capability to perform EVA tasks. Furthermore, previous Shuttle and International Space Station (ISS) spacewalks have benefited from EVA interfaces which have been designed and manufactured on Earth. Rigid structurally mounted handrails, and tools with customized interfaces and restraints optimize EVA performance. For ARCM, some vehicle interfaces and tools can leverage heritage designs and experience. However, when the crew ventures onto an asteroid capture bag to explore the asteroid and collect rock samples, EVA complexity increases due to the uncertainty of the asteroid properties. The variability of rock size, shape and composition, as well as bunching of the fabric bag will complicate EVA translation, tool restraint and body stabilization. The unknown asteroid hardness and brittleness will complicate tool use. The rock surface will introduce added safety concerns for cut gloves and debris control. Feasible solutions to meet ARCM EVA objectives were identified using experience gained during Apollo, Shuttle, and ISS EVAs, terrestrial mountaineering practices, NASA Extreme Environment Mission Operations (NEEMO) 16 mission, and during Neutral Buoyancy Laboratory testing in the MACES suit. The proposed concept utilizes expandable booms and integrated features of the asteroid capture bag to position and restrain the crew at the asteroid worksite. These methods enable the capability to perform both finesse, and high load tasks necessary to collect samples for scientific characterization of the asteroid. This paper will explore the design trade space and options that were examined for EVA, the overall concept for the EVAs including translation paths and body restraint methods, potential tools used to extract the samples, design implications for the Asteroid Redirect Vehicle (ARV) for EVA, the results of early development testing of potential EVA tasks, and extensibility of the EVA architecture to NASA's exploration missions.

21st Century extravehicular activities: Synergizing past and present training methods for future spacewalking success

NASA Astrophysics Data System (ADS)

Moore, Sandra K.; Gast, Matthew A.

2010-10-01

Neil Armstrong's understated words, "That's one small step for man, one giant leap for mankind" were spoken from Tranquility Base forty years ago. Even today, those words resonate in the ears of millions, including many who had yet to be born when man first landed on the surface of the moon. By their very nature, and in the true spirit of exploration, extravehicular activities (EVAs) have generated much excitement throughout the history of manned spaceflight. From Ed White's first spacewalk in the June of 1965, to the first steps on the moon in 1969, to the expected completion of the International Space Station (ISS), the ability to exist, live and work in the vacuum of space has stood as a beacon of what is possible. It was NASA's first spacewalk that taught engineers on the ground the valuable lesson that successful spacewalking requires a unique set of learned skills. That lesson sparked extensive efforts to develop and define the training requirements necessary to ensure success. As focus shifted from orbital activities to lunar surface activities, the required skill set and subsequently the training methods changed. The requirements duly changed again when NASA left the moon for the last time in 1972 and have continued to evolve through the SkyLab, Space Shuttle, and ISS eras. Yet because the visits to the moon were so long ago, NASA's expertise in the realm of extra-terrestrial EVAs has diminished. As manned spaceflight again shifts its focus beyond low earth orbit, EVA's success will depend on the ability to synergize the knowledge gained over 40+ years of spacewalking to create a training method that allows a single crewmember to perform equally well, whether performing an EVA on the surface of the Moon, while in the vacuum of space, or heading for a rendezvous with Mars. This paper reviews NASA's past and present EVA training methods and extrapolates techniques from both to construct the basis for future EVA astronaut training.

21st Century Extravehicular Activities: Synergizing Past and Present Training Methods for Future Spacewalking Success

NASA Technical Reports Server (NTRS)

Moore, Sandra K.; Gast, Matthew A.

2009-01-01

Neil Armstrong's understated words, "That's one small step for man, one giant leap for mankind." were spoken from Tranquility Base forty years ago. Even today, those words resonate in the ears of millions, including many who had yet to be born when man first landed on the surface of the moon. By their very nature, and in the the spirit of exploration, extravehicular activities (EVAs) have generated much excitement throughout the history of manned spaceflight. From Ed White's first space walk in June of 1965, to the first steps on the moon in 1969, to the expected completion of the International Space Station (ISS), the ability to exist, live and work in the vacuum of space has stood as a beacon of what is possible. It was NASA's first spacewalk that taught engineers on the ground the valuable lesson that successful spacewalking requires a unique set of learned skills. That lesson sparked extensive efforts to develop and define the training requirements necessary to ensure success. As focus shifted from orbital activities to lunar surface activities, the required skill-set and subsequently the training methods, changed. The requirements duly changed again when NASA left the moon for the last time in 1972 and have continued to evolve through the Skylab, Space Shuttle; and ISS eras. Yet because the visits to the moon were so long ago, NASA's expertise in the realm of extra-terrestrial EVAs has diminished. As manned spaceflight again shifts its focus beyond low earth orbit, EVA success will depend on the ability to synergize the knowledge gained over 40+ years of spacewalking to create a training method that allows a single crewmember to perform equally well, whether performing an EVA on the surface of the Moon, while in the vacuum of space, or heading for a rendezvous with Mars. This paper reviews NASA's past and present EVA training methods and extrapolates techniques from both to construct the basis for future EVA astronaut training.

Apollo 15 time and motion study

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.

1972-01-01

A time and motion study of Apollo 15 lunar surface activity led to examination of four distinct areas of crewmen activity. These areas are: an analysis of lunar mobility, a comparative analysis of tasks performed in 1-g training and lunar EVA, an analysis of the metabolic cost of two activities that are performed in several EVAs, and a fall/near-fall analysis. An analysis of mobility showed that the crewmen used three basic mobility patterns (modified walk, hop, side step) while on the lunar surface. These mobility patterns were utilized as adaptive modes to compensate for the uneven terrain and varied soil conditions that the crewmen encountered. A comparison of the time required to perform tasks at the final 1-g lunar EVA training sessions and the time required to perform the same task on the lunar surface indicates that, in almost all cases, it took significantly more time (on the order of 40%) to perform tasks on the moon. This increased time was observed even after extraneous factors (e.g., hardware difficulties) were factored out.

Walking to Olympus: An EVA Chronology

NASA Technical Reports Server (NTRS)

Portree, David S. F.; Trevino, Robert C.

1997-01-01

Spacewalkers enjoy a view of Earth once reserved for Apollo, Zeus, and other denizens of Mt. Olympus. During humanity's first extravehicular activity (EVA), Alexei Leonov floated above Gibraltar, the rock ancient seafarers saw as the gateway to the great unknown Atlantic. The symbolism was clear, Leonov stepped past a new Gibraltar when he stepped into space. More than 32 years and 154 EVAs later, Jerry Linenger conducted an EVA with Vladimir Tsibliyev as part of International Space Station Phase 1. They floated together above Gibraltar. Today the symbolism has new meaning: humanity is starting to think of stepping out of Earth orbit, space travel's new Gibraltar, and perhaps obtaining a new olympian view, a close-up look at Olympus Mons on Mars. Walking to Olympus: An EVA Chronology chronicles the 154 EVAs conducted from March 1965 to April 1997. It is intended to make clear the crucial role played by EVA in the history of spaceflight, as well as to chronicle the large body of EVA "lessons learned." Russia and the U.S. define EVA differently. Russian cosmonauts are said to perform EVA any time they are in vacuum in a space suit. A U.S. astronaut must have at least his head outside his spacecraft before he is said to perform an EVA. The difference is based in differing spacecraft design philoso- phies. Russian and Soviet spacecraft have always had a specialized airlock through which the EVA cosmonaut egressed, leaving the main habitable volume of the spacecraft pressurized. The U.S. Gemini and Apollo vehicles, on the other hand, depressurized their entire habitable volume for egress. In this document, we apply the Russian definition to Russian EVAS, and the U.S. definition to U.S. EVAS. Thus, for example, Gemini 4 Command Pilot James McDivitt does not share the honor of being first American spacewalker with Ed White, even though he was suited and in vacuum when White stepped out into space. Non-EVA spaceflights are listed in the chronology to provide context and to display the large num- ber of flights in which EVA played a role. This approach also makes apparent significant EVA gaps, for example, the U.S. gap between 1985 and 1991 following the Challenger accident. This NASA History Monograph is an edited extract from an extensive EVA Chronology and Reference Book being produced by the EVA Project Office, NASA Johnson Space Center, Houston, Texas. The larger work will be published as part of the NASA Formal Series in 1998. The authors gratefully acknowledge the assistance rendered by Max Ary, Ashot Bakunts, Gert-Jan Bartelds, Frank Cepollina, Andrew Chaikin, Phillip Clark, Richard Fullerton, Steven Glenn, Linda Godwin, Jennifer Green, Greg Harris, Clifford Hess, Jeffrey Hoffman, David Homan, Steven Hopkins, Nicholas Johnson, Eric Jones, Neville Kidger, Joseph Kosmo, Alexei Lebedev, Mark Lee, James LeBlanc, Dmitri Leshchenskii, Jerry Linenger, Igor Lissov, James McBarron, Clay McCullough, Joseph McMann, Story Musgrave, Dennis Newkirk, James Oberg, Joel Powell, Lee Saegesser, Andy Salmon, Glen Swanson, Joseph Tatarewicz, Kathy Thornton, Chris Vandenberg, Charles Vick, Bert Vis, David Woods, Mike Wright, John Young, and Keith Zimmerman. Special thanks to Laurie Buchanan, John Charles, Janet Kovacevich, Joseph Loftus, Sue McDonald, Martha Munies, Colleen Rapp, and Jerry Ross. Any errors remain the responsibility of the authors.

STS-335 crew training, EVA TPS Overview with instructor John Ray

NASA Image and Video Library

2010-11-03

JSC2010-E-183513 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-335 crew training, EVA TPS Overview with instructor John Ray

NASA Image and Video Library

2010-11-03

JSC2010-E-183514 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-335 crew training, EVA TPS Overview with instructor John Ray

NASA Image and Video Library

2010-11-03

JSC2010-E-183512 (3 Nov. 2010) --- STS-135 crew members participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/ Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Pictured from the left are NASA astronauts Chris Ferguson, commander; Rex Walheim, mission specialist; Doug Hurley, pilot; and Sandy Magnus, mission specialist. John Ray (right) assisted the crew members. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-118 Astronauts Rick Mastracchio and Clay Anderson Perform EVA

NASA Technical Reports Server (NTRS)

2007-01-01

As the construction continued on the International Space Station (ISS), STS-118 astronaut and mission specialist Rick Mastracchio was anchored on the foot restraint of the Canadarm2 as he participated in the third session of Extra Vehicular Activity (EVA) for the mission. Assisting Mastracchio was Expedition 15 flight engineer Clay Anderson (out of frame). During the 5 hour, 28 minute space walk, the two relocated the S-band Antenna Sub-Assembly from the Port 6 (P6) truss to the Port 1 (P1) truss, installed a new transponder on P1 and retrieved the P6 transponder.

A mobile transporter concept for EVA assembly of future spacecraft

NASA Technical Reports Server (NTRS)

Watson, Judith J.; Bush, Harold G.; Heard, Walter L., Jr.; Lake, Mark S.; Jensen, J. Kermit

1990-01-01

This paper details the ground test program for the NASA Langley Research Center Mobile Transporter concept. The Mobile Transporter would assist EVA astronauts in the assembly of the Space Station Freedom. 1-g and simulated O-g (neutral buoyancy) tests were conducted to evaluate the use of the Mobile Transporter. A three-bay (44 struts) orthogonal tetrahedral truss configuration with a 15-foot-square cross section was repeatedly assembled by a single pair of pressure suited test subjects working from the Mobile Transporter astronaut positioning devices. The average unit assembly time was 28 seconds/strut. The results of these tests indicate that the use of a Mobile Transporter for EVA assembly of Space Station size structure is viable and practical. Additionally, the Mobile Transporter could be used to construct other spacecraft such as the submillimeter astronomical laboratory, space crane, and interplanetary (i.e., Mars and lunar) spacecraft.

Control of a free-flying robot manipulator system

NASA Technical Reports Server (NTRS)

Alexander, H.

1986-01-01

The development of and test control strategies for self-contained, autonomous free flying space robots are discussed. Such a robot would perform operations in space similar to those currently handled by astronauts during extravehicular activity (EVA). Use of robots should reduce the expense and danger attending EVA both by providing assistance to astronauts and in many cases by eliminating altogether the need for human EVA, thus greatly enhancing the scope and flexibility of space assembly and repair activities. The focus of the work is to develop and carry out a program of research with a series of physical Satellite Robot Simulator Vehicles (SRSV's), two-dimensionally freely mobile laboratory models of autonomous free-flying space robots such as might perform extravehicular functions associated with operation of a space station or repair of orbiting satellites. It is planned, in a later phase, to extend the research to three dimensions by carrying out experiments in the Space Shuttle cargo bay.

Astronaut Alan Bean with subpackages of the ALSEP during EVA

NASA Technical Reports Server (NTRS)

1969-01-01

Astronaut Alan L. Bean, lunar module pilot, traverses with the two subpackages of the Apollo Lunar Surface Experiments Package (ALSEP) during the first Apollo 12 extravehicular activity (EVA). Bean deployed the ALSEP components 300 feet from the Lunar Module (LM). The LM and deployed erectable S-band antenna can be seen in the background.

The Nomad Explorer assembly assist vehicle: An architecture for rapid global extraterrestrial base infrastructure establishment

NASA Technical Reports Server (NTRS)

Thangavelu, Madhu

1994-01-01

Traditional concepts of lunar bases describe scenarios where components of the bases are landed on the lunar surface, one at a time, and then put together to form a complete stationary lunar habitat. Recently, some concepts have described the advantages of operating a mobile or 'roving' lunar base. Such a base vastly improves the exploration range from a primary lunar base. Roving bases would also allow the crew to first deploy, test, operationally certify, and then regularly maintain, service, and evolve long life-cycle facilities like observatories or other science payload platforms that are operated far apart from each other across the extraterrestrial surface. The Nomad Explorer is such a mobile lunar base. This paper describes the architectural program of the Nomad Explorer, its advantages over a stationary lunar base, and some of the embedded system concepts which help the roving base to speedily establish a global extraterrestrial infrastructure. A number of modular autonomous logistics landers will carry deployable or erectable payloads, service, and logistically resupply the Nomad Explorer at regular intercepts along the traverse. Starting with the deployment of science experiments and telecommunication networks, and the manned emplacement of a variety of remote outposts using a unique EVA Bell system that enhances manned EVA, the Nomad Explorer architecture suggests the capability for a rapid global development of the extraterrestrial body. The Moon and Mars are candidates for this 'mission oriented' strategy. The lunar case is emphasized in this paper.

Overview of Human Factors and Habitability at NASA

NASA Technical Reports Server (NTRS)

Connolly, Janis; Arch, M.; Kaiser, Mary

2009-01-01

This slide presentation reviews the ongoing work on human factors and habitability in the development of the Constellation Program. The focus of the work is on how equipment, spacecraft design, tools, procedures and nutrition be used to improve the health, safety and efficiency of the crewmembers. There are slides showing the components of the Constellation Program, and the conceptual designs of the Orion Crew module, the lunar lander, (i.e., Altair) the microgravity EVA suit, and the lunar surface EVA suit, the lunar rover, and the lunar surface system infrastructure.

Exploring the Integration of Field Portable Instrumentation into Real-Time Surface Science Operations with the RIS4E SSERVI Team

NASA Astrophysics Data System (ADS)

Young, K. E.; Bleacher, J. E.; Rogers, D.; Garry, W. B.; McAdam, A.; Scheidt, S. P.; Carter, L. M.; Glotch, T. D.

2015-12-01

The Remote, In Situ, and Synchrotron Studies for Science (RIS4E) team represents one node of the Solar System Exploration Research Virtual Institute (SSERVI) program. While the RIS4E team consists of four themes, each dedicated to a different aspect of airless body exploration, this submission details the RIS4E work underway to maximize an astronaut's effectiveness while conducting surface science. The next generation of surface science operations will look quite different than the EVAs (extravehicular activities) conducted during Apollo. Astronauts will possess data of much higher resolution than the Apollo reconnaissance data, and the EVAs will thus be designed to answer targeted science questions. Additionally, technological advancements over the last several decades have made it possible to conduct in situ analyses of a caliber much greater than was achievable during Apollo. For example, lab techniques such as x-ray fluorescence, x-ray diffraction, and multi-spectral imaging are now available in field portable formats, meaning that astronauts can gain real-time geochemical awareness during sample collection. The integration of these instruments into EVA operations, however, has not been widely tested. While these instruments will provide the astronaut with a high-resolution look at regional geochemistry and structure, their implementation could prove costly to the already constrained astronaut EVA timeline. The RIS4E team, through fieldwork at the December 1974 lava flow at Kilauea Volcano, HI, investigates the incorporation of portable technologies into planetary surface exploration and explores the relationship between science value added from these instruments and the cost associated with integrating them into an EVA timeline. We also consider what an appropriate instrumentation suite would be for the exploration of a volcanic terrain using this ideal terrestrial analog (see Rogers et al., Young et al., Bleacher et al., and Yant et al., this meeting).

Advanced EVA Capabilities: A Study for NASA's Revolutionary Aerospace Systems Concept Program

NASA Technical Reports Server (NTRS)

Hoffman, Stephen J.

2004-01-01

This report documents the results of a study carried out as part of NASA s Revolutionary Aerospace Systems Concepts Program examining the future technology needs of extravehicular activities (EVAs). The intent of this study is to produce a comprehensive report that identifies various design concepts for human-related advanced EVA systems necessary to achieve the goals of supporting future space exploration and development customers in free space and on planetary surfaces for space missions in the post-2020 timeframe. The design concepts studied and evaluated are not limited to anthropomorphic space suits, but include a wide range of human-enhancing EVA technologies as well as consideration of coordination and integration with advanced robotics. The goal of the study effort is to establish a baseline technology "road map" that identifies and describes an investment and technical development strategy, including recommendations that will lead to future enhanced synergistic human/robot EVA operations. The eventual use of this study effort is to focus evolving performance capabilities of various EVA system elements toward the goal of providing high performance human operational capabilities for a multitude of future space applications and destinations. The data collected for this study indicate a rich and diverse history of systems that have been developed to perform a variety of EVA tasks, indicating what is possible. However, the data gathered for this study also indicate a paucity of new concepts and technologies for advanced EVA missions - at least any that researchers are willing to discuss in this type of forum.

APOLLO XIII CREW - MISSION OPERATIONS CONTROL ROOM (MOCR) - APOLLO XII - LUNAR EXTRAVEHICULAR ACTIVITY (EVA) - MSC

NASA Image and Video Library

1969-11-21

S69-59525 (19 Nov. 1969) --- Overall view of activity in the Mission Operations Control Room (MOCR) in the Mission Control Center (MCC), Building 30, during the Apollo 12 lunar landing mission. When this picture was made the first Apollo 12 extravehicular activity (EVA) was being televised from the surface of the moon. Photo credit: NASA

Apollo Medical Operations Project: Recommendations for EVA and Lunar Surface Operations

NASA Technical Reports Server (NTRS)

Scheuring, R. A.; Davis, J. R.; Duncan, J. M.; Polk, J. D.; Jones, J. A.; Gillis, D. B.; Novak, J.

2013-01-01

The potential risk of injury to crewmembers is inherent in aggressive surface activities, whether they be Moon-, Mars-, or asteroid-based. In December 2005, the Space Medicine Division at JSC requested a study to identify Apollo mission issues that had an impact to crew health or performance or both. This talk focused on the Apollo EVA suit and lunar surface operations concerning crew health and performance. There were roughly 20 recommendations from this study of Apollo for improving these two areas for future exploration missions, a few of which were incorporated into the Human Systems Integration Requirements (HSIR). Dr. Richard Scheuring covered these topics along with some of the analog work that has been done regarding surface operations and medical contingencies.

STS-45 MS Foale in EMU prepares for underwater exercises in JSC's WETF pool

NASA Image and Video Library

1991-02-26

S91-30196 (1 March 1991) --- Astronaut C. Michael Foale, mission specialist, and Kathryn D. Sullivan, payload commander (barely visible in background), stand on a platform (out of frame) which is part of a system that will lower them into a 25-ft. deep pool. The payload commander and mission specialist used the pool in the weightless environment training facility (WET-F) to rehearse a contingency extravehicular activity (EVA). Astronauts wear pressurized spacesuits configured for achieving a neutrally buoyant condition in the water to simulate both planned and contingency EVAs. Two SCUBA-equipped swimmers assisting the training are seen in the background.

STS-120 Mission Specialist Doug Wheelock During EVA

NASA Technical Reports Server (NTRS)

2007-01-01

Astronaut Doug Wheelock, STS-120 mission specialist, participated in the mission's fourth session of extravehicular activity (EVA) while Space Shuttle Discovery was docked with the International Space Station (ISS). During the 7-hour and 19-minute space walk, astronaut Scott Parazynski (out of frame), mission specialist, cut a snagged wire and installed homemade stabilizers designed to strengthen the structure and stability of the damaged P6 4B solar array wing. Wheelock assisted from the truss by keeping an eye on the distance between Parazynski and the array. Once the repair was complete, flight controllers on the ground successfully completed the deployment of the array.

Wheelock during Expedition 16/STS-120 EVA 4

NASA Image and Video Library

2007-11-03

ISS016-E-009179 (3 Nov. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, participates in the mission's fourth session of extravehicular activity (EVA) while Space Shuttle Discovery is docked with the International Space Station. During the 7-hour, 19-minute spacewalk, astronaut Scott Parazynski (out of frame), mission specialist, cut a snagged wire and installed homemade stabilizers designed to strengthen the damaged solar array's structure and stability in the vicinity of the damage. Wheelock assisted from the truss by keeping an eye on the distance between Parazynski and the array. Once the repair was complete, flight controllers on the ground successfully completed the deployment of the array.

Wheelock during Expedition 16/STS-120 EVA 4

NASA Image and Video Library

2007-11-03

ISS016-E-009192 (3 Nov. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, participates in the mission's fourth session of extravehicular activity (EVA) while Space Shuttle Discovery is docked with the International Space Station. During the 7-hour, 19-minute spacewalk, astronaut Scott Parazynski (out of frame), mission specialist, cut a snagged wire and installed homemade stabilizers designed to strengthen the damaged solar array's structure and stability in the vicinity of the damage. Wheelock assisted from the truss by keeping an eye on the distance between Parazynski and the array. Once the repair was complete, flight controllers on the ground successfully completed the deployment of the array.

STS-109 MS Newman replace Reaction Wheel assembly during EVA 2

NASA Image and Video Library

2002-03-05

STS109-E-5399 (5 March 2002) --- Astronaut James H. Newman, mission specialist, moves about in the Space Shuttle Columbia's cargo bay while working in tandem with astronaut Michael J. Massimino (out of frame), mission specialist, during the STS-109 mission's second day of extravehicular activity (EVA). Inside Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the Remote Manipulator System (RMS) to assist the two in their work on the Hubble Space Telescope (HST). Part of the giant telescope's base, latched down in the payload bay, can be seen just above Newman. The image was recorded with a digital still camera.

Initial Work Toward a Robotically Assisted EVA Glove

NASA Technical Reports Server (NTRS)

Rogers, J.; Peters, B.; McBryan, E.; Laske, E.

2016-01-01

The Space Suit RoboGlove is a device designed to provide additional grasp strength or endurance for an EVA crew member since gloved hand performance is a fraction of what the unencumbered human hand can achieve. There have been past efforts to approach this problem by employing novel materials and construction techniques to the glove design, as well as integrating powered assistance devices. This application of the NASA/GM RoboGlove technology uses a unique approach to integrate the robotic actuators and sensors into a Phase VI EVA glove. This design provides grasp augmentation to the glove user while active, but can also function as a normal glove when disabled. Care was taken to avoid adding excessive bulk to the glove or affecting tactility by choosing low-profile sensors and extrinsically locating the actuators. Conduits are used to guide robotic tendons from linear actuators, across the wrist, and to the fingers. The second generation of the SSRG includes updated electronics, sensors, and actuators to improve performance. The following discusses the electromechanical design, softgoods integration, and control system of the SSRG. It also presents test results from the first integration of a powered mobility element onto a space suit, the NASA Mark III. Early results show that sensor integration did not impact tactile feedback in the glove and the actuators show potential for reduction in grasp fatigue over time.

Astronaut Alan Bean with subpackages of the ALSEP during EVA

NASA Image and Video Library

1969-11-19

AS12-46-6807 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot, traverses with the two sub packages of the Apollo Lunar Surface Experiments Package (ALSEP) during the first Apollo 12 extravehicular activity (EVA). Bean deployed the ALSEP components 300 feet from the Lunar Module (LM). The LM and deployed erectable S-band antenna can be seen in the background.

View of the Lunar Module 'Orion' and Lunar Roving Vehicle during first EVA

NASA Technical Reports Server (NTRS)

1972-01-01

A view of the Lunar Module (LM) 'Orion' and Lunar Roving Vehicle (LRV), as photographed by Astronaut Charles M. Duke Jr., lunar module pilot, during the first Apollo 16 extravehicular activity (EVA-1) at the Descates landing site. Astronaut John W. Young, commander, can be seen directly behind the LRV. The lunar surface feature in the left background is Stone Mountain.

Apollo 16 astronauts take lunar soil sample from Station no.9 during EVA

NASA Technical Reports Server (NTRS)

1971-01-01

One of the Apollo 16 astronauts takes lunar soil sample at the base of a small boulder at Station no.9 during the second Apollo 16 extravehicular activity (EVA-2) at the Descartes landing site. Depressions to th right of the scoop were made when a surface sample was taken. This photograph was taken just before the boulder was rolled over.

Modified Advanced Crew Escape Suit Intravehicular Activity Suit for Extravehicular Activity Mobility Evaluations

NASA Technical Reports Server (NTRS)

Watson, Richard D.

2014-01-01

The use of an intravehicular activity (IVA) suit for a spacewalk or extravehicular activity (EVA) was evaluated for mobility and usability in the Neutral Buoyancy Laboratory (NBL) environment at the Sonny Carter Training Facility near NASA Johnson Space Center in Houston, Texas. The Space Shuttle Advanced Crew Escape Suit was modified to integrate with the Orion spacecraft. The first several missions of the Orion Multi-Purpose Crew Vehicle will not have mass available to carry an EVA-specific suit; therefore, any EVA required will have to be performed by the Modified Advanced Crew Escape Suit (MACES). Since the MACES was not designed with EVA in mind, it was unknown what mobility the suit would be able to provide for an EVA or whether a person could perform useful tasks for an extended time inside the pressurized suit. The suit was evaluated in multiple NBL runs by a variety of subjects, including crewmembers with significant EVA experience. Various functional mobility tasks performed included: translation, body positioning, tool carrying, body stabilization, equipment handling, and tool usage. Hardware configurations included with and without Thermal Micrometeoroid Garment, suit with IVA gloves and suit with EVA gloves. Most tasks were completed on International Space Station mock-ups with existing EVA tools. Some limited tasks were completed with prototype tools on a simulated rocky surface. Major findings include: demonstrating the ability to weigh-out the suit, understanding the need to have subjects perform multiple runs prior to getting feedback, determining critical sizing factors, and need for adjusting suit work envelope. Early testing demonstrated the feasibility of EVA's limited duration and limited scope. Further testing is required with more flight-like tasking and constraints to validate these early results. If the suit is used for EVA, it will require mission-specific modifications for umbilical management or Primary Life Support System integration, safety tether attachment, and tool interfaces. These evaluations are continuing through calendar year 2014.

An Onboard ISS Virtual Reality Trainer

NASA Technical Reports Server (NTRS)

Miralles, Evelyn

2013-01-01

Prior to the retirement of the Space Shuttle, many exterior repairs on the International Space Station (ISS) were carried out by shuttle astronauts, trained on the ground and flown to the station to perform these repairs. After the retirement of the shuttle, this is no longer an available option. As such, the need for the ISS crew members to review scenarios while on flight, either for tasks they already trained or for contingency operations has become a very critical subject. In many situations, the time between the last session of Neutral Buoyancy Laboratory (NBL) training and an Extravehicular Activity (EVA) task might be 6 to 8 months. In order to help with training for contingency repairs and to maintain EVA proficiency while on flight, the Johnson Space Center Virtual Reality Lab (VRLab) designed an onboard immersive ISS Virtual Reality Trainer (VRT), incorporating a unique optical system and making use of the already successful Dynamic Onboard Ubiquitous Graphical (DOUG) graphics software, to assist crew members with current procedures and contingency EVAs while on flight. The VRT provides an immersive environment similar to the one experienced at the VRLab crew training facility at NASA Johnson Space Center. EVA tasks are critical for a mission since as time passes the crew members may lose proficiency on previously trained tasks. In addition, there is an increased need for unplanned contingency repairs to fix problems arising as the ISS ages. The need to train and re-train crew members for EVAs and contingency scenarios is crucial and extremely demanding. ISS crew members are now asked to perform EVA tasks for which they have not been trained and potentially have never seen before.

Apollo 12 - Bean - Conrad - during geological field trip

NASA Image and Video Library

1969-10-24

S69-55667 (10 Oct. 1969) --- Astronauts Charles Conrad Jr. and Alan L. Bean train for their upcoming Apollo 12 lunar landing mission. Here they are entering a simulated lunar surface area near Flagstaff, Arizona. Both are wearing lunar surface cameras strapped to their bodies. Conrad (left), the Apollo 12 mission commander, is carrying some of the tools from the geological tool container. The geological tool container, being carried here by Bean, the lunar module pilot, is similar to the one which will be used during scheduled extravehicular activity (EVA) periods on Nov. 19 and 20, 1969, on the lunar surface. While astronauts Conrad and Bean conduct their scheduled EVA on the moon's surface, astronaut Richard F. Gordon Jr., command module pilot, will man the Command and Service Modules (CSM) in lunar orbit.

Understanding Skill in EVA Mass Handling. Volume 4; An Integrated Methodology for Evaluating Space Suit Mobility and Stability

NASA Technical Reports Server (NTRS)

McDonald, P. Vernon; Newman, Dava

1999-01-01

The empirical investigation of extravehicular activity (EVA) mass handling conducted on NASA's Precision Air-Bearing Floor led to a Phase I SBIR from JSC. The purpose of the SBIR was to design an innovative system for evaluating space suit mobility and stability in conditions that simulate EVA on the surface of the Moon or Mars. The approach we used to satisfy the Phase I objectives was based on a structured methodology for the development of human-systems technology. Accordingly the project was broken down into a number of tasks and subtasks. In sequence, the major tasks were: 1) Identify missions and tasks that will involve EVA and resulting mobility requirements in the near and long term; 2) Assess possible methods for evaluating mobility of space suits during field-based EVA tests; 3) Identify requirements for behavioral evaluation by interacting with NASA stakeholders;.4) Identify necessary and sufficient technology for implementation of a mobility evaluation system; and 5) Prioritize and select technology solutions. The work conducted in these tasks is described in this final volume of the series on EVA mass handling. While prior volumes in the series focus on novel data-analytic techniques, this volume addresses technology that is necessary for minimally intrusive data collection and near-real-time data analysis and display.

Biomedical Support of U.S. Extravehicular Activity

NASA Technical Reports Server (NTRS)

Gernhardt, Michael L.; Dervay, J. P.; Gillis, D.; McMann, H. J.; Thomas, K. S.

2007-01-01

The world's first extravehicular activity (EVA) was performed by A. A. Leonov on March 18, 1965 during the Russian Voskhod-2 mission. The first US EVA was executed by Gemini IV astronaut Ed White on June 3, 1965, with an umbilical tether that included communications and an oxygen supply. A hand-held maneuvering unit (HHMU) also was used to test maneuverability during the brief EVA; however the somewhat stiff umbilical limited controlled movement. That constraint, plus difficulty returning through the vehicle hatch, highlighted the need for increased thermal control and improved EVA ergonomics. Clearly, requirements for a useful EVA were interrelated with the vehicle design. The early Gemini EVAs generated requirements for suits providing micro-meteor protection, adequate visual field and eye protection from solar visual and infrared radiation, gloves optimized for dexterity while pressurized, and thermal systems capable of protecting the astronaut while rejecting metabolic heat during high workloads. Subsequent Gemini EVAs built upon this early experience and included development of a portable environmental control and life support systems (ECLSS) and an astronaut maneuvering unit. The ECLSS provided a pressure vessel and controller with functional control over suit pressure, oxygen flow, carbon dioxide removal, humidity, and temperature control. Gemini EVA experience also identified the usefulness of underwater neutral buoyancy and altitude chamber task training, and the importance of developing reliable task timelines. Improved thermal management and carbon dioxide control also were required for high workload tasks. With the Apollo project, EVA activity was primarily on the lunar surface; and suit durability, integrated liquid cooling garments, and low suit operating pressures (3.75 pounds per square inch absolute [psia] or 25.8 kilopascal [kPa],) were required to facilitate longer EVAs with ambulation and significant physical workloads with average metabolic rates of 1000 BTU/hr and peaks of up to 2200 BTU/hr. Mobility was further augmented with the Lunar Roving Vehicle. The Apollo extravehicular mobility unit (EMU) was made up of over 15 components, ranging from a biomedical belt for capturing and transmitting biomedical data, urine and fecal containment systems, a liquid cooling garment, communications cap, a modular portable life support system (PLSS), a boot system, thermal overgloves, and a bubble helmet with eye protection. Apollo lunar astronauts performed successful EVAs on the lunar surface from a 5 psia (34.4 kPa) 100% oxygen environment in the Lunar Lander. A maximum of three EVAs were performed on any mission. For Skylab a modified A7LB suit, used for Apollo 15, was selected. The Skylab astronaut life support assembly (ALSA) provided umbilical support through the life support umbilical (LSU) and used open loop oxygen flow, rather than closed-loop as in Apollo missions. Thermal control was provided by liquid water circulated by spacecraft pumps and electrical power also was provided from the spacecraft via the umbilical. The cabin atmosphere of 5 psia (34.4 kPa), 70% oxygen, provided a normoxic atmosphere and because of the very low nitrogen partial pressures, no special protocols were required to protect against decompression sickness (DCS) as was the case with the Apollo spacecraft with a 5 psi, 100% oxygen environment.

Advanced extravehicular activity systems requirements definition study

NASA Technical Reports Server (NTRS)

1988-01-01

A study to define the requirements for advanced extravehicular activities (AEVA) was conducted. The purpose of the study was to develop an understanding of the EVA technology requirements and to map a pathway from existing or developing technologies to an AEVA system capable of supporting long-duration missions on the lunar surface. The parameters of an AEVA system which must sustain the crewmembers and permit productive work for long periods in the lunar environment were examined. A design reference mission (DRM) was formulated and used as a tool to develop and analyze the EVA systems technology aspects. Many operational and infrastructure design issues which have a significant influence on the EVA system are identified.

Lunar Balance and Locomotion

NASA Technical Reports Server (NTRS)

Paloski, William H.

2008-01-01

Balance control and locomotor patterns were altered in Apollo crewmembers on the lunar surface, owing, presumably, to a combination of sensory-motor adaptation during transit and lunar surface operations, decreased environmental affordances associated with the reduced gravity, and restricted joint mobility as well as altered center-of-gravity caused by the EVA pressure suits. Dr. Paloski will discuss these factors, as well as the potential human and mission impacts of falls and malcoordination during planned lunar sortie and outpost missions. Learning objectives: What are the potential impacts of postural instabilities on the lunar surface? CME question: What factors affect balance control and gait stability on the moon? Answer: Sensory-motor adaptation to the lunar environment, reduced mechanical and visual affordances, and altered biomechanics caused by the EVA suit.

Crew Systems for Asteroid Exploration: Concepts for Lightweight & Low Volume EVA Systems

NASA Technical Reports Server (NTRS)

Mueller, Rob; Calle, Carlos; Mantovani, James

2013-01-01

This RFI response is targeting Area 5. Crew Systems for Asteroid Exploration: concepts for lightweight and low volume robotic and extra-vehicular activity (EVA) systems, such as space suits, tools, translation aids, stowage containers, and other equipment. The NASA KSC Surface Systems Office, Granular Mechanics and Regolith Operations (GMRO) Lab and the Electrostatics & Surface Physics Lab (ESPL) are dedicated to developing technologies for operating in regolith environments on target body surfaces. We have identified two technologies in our current portfolio that are highly relevant and useful for crews that will visit a re-directed asteroid in Cis-Lunar Space. Both technologies are at a high TRL of 5/6 and could be rapidly implemented in time for an ARM mission in this decade.

Computer-generated scenes depicting the HST capture and EVA repair mission

NASA Image and Video Library

1993-11-12

Computer generated scenes depicting the Hubble Space Telescope capture and a sequence of planned events on the planned extravehicular activity (EVA). Scenes include the Remote Manipulator System (RMS) arm assisting two astronauts changing out the Wide Field/Planetary Camera (WF/PC) (48699); RMS arm assisting in the temporary mating of the orbiting telescope to the flight support system in Endeavour's cargo bay (48700); Endeavour's RMS arm assisting in the "capture" of the orbiting telescope (48701); Two astronauts changing out the telescope's coprocessor (48702); RMS arm assistign two astronauts replacing one of the telescope's electronic control units (48703); RMS assisting two astronauts replacing the fuse plugs on the telescope's Power Distribution Unit (PDU) (48704); The telescope's High Resolution Spectrograph (HRS) kit is depicted in this scene (48705); Two astronauts during the removal of the high speed photometer and the installation of the COSTAR instrument (48706); Two astronauts, standing on the RMS, during installation of one of the Magnetic Sensing System (MSS) (48707); High angle view of the orbiting Space Shuttle Endeavour with its cargo bay doors open, revealing the bay's pre-capture configuration. Seen are, from the left, the Solar Array Carrier, the ORU Carrier and the flight support system (48708); Two astronauts performing the replacement of HST's Rate Sensor Units (RSU) (48709); The RMS arm assisting two astronauts with the replacement of the telescope's solar array panels (48710); Two astronauts replacing the telescope's Solar Array Drive Electronics (SADE) (48711).

Improved lung recruitment and oxygenation during mandatory ventilation with a new expiratory ventilation assistance device: A controlled interventional trial in healthy pigs.

PubMed

Schmidt, Johannes; Wenzel, Christin; Mahn, Marlene; Spassov, Sashko; Cristina Schmitz, Heidi; Borgmann, Silke; Lin, Ziwei; Haberstroh, Jörg; Meckel, Stephan; Eiden, Sebastian; Wirth, Steffen; Buerkle, Hartmut; Schumann, Stefan

2018-05-04

In contrast to conventional mandatory ventilation, a new ventilation mode, expiratory ventilation assistance (EVA), linearises the expiratory tracheal pressure decline. We hypothesised that due to a recruiting effect, linearised expiration oxygenates better than volume controlled ventilation (VCV). We compared the EVA with VCV mode with regard to gas exchange, ventilation volumes and pressures and lung aeration in a model of peri-operative mandatory ventilation in healthy pigs. Controlled interventional trial. Animal operating facility at a university medical centre. A total of 16 German Landrace hybrid pigs. The lungs of anaesthetised pigs were ventilated with the EVA mode (n=9) or VCV (control, n=7) for 5 h with positive end-expiratory pressure of 5 cmH2O and tidal volume of 8 ml kg. The respiratory rate was adjusted for a target end-tidal CO2 of 4.7 to 6 kPa. Tracheal pressure, minute volume and arterial blood gases were recorded repeatedly. Computed thoracic tomography was performed to quantify the percentages of normally and poorly aerated lung tissue. Two animals in the EVA group were excluded due to unstable ventilation (n=1) or unstable FiO2 delivery (n=1). Mean tracheal pressure and PaO2 were higher in the EVA group compared with control (mean tracheal pressure: 11.6 ± 0.4 versus 9.0 ± 0.3 cmH2O, P < 0.001 and PaO2: 19.2 ± 0.7 versus 17.5 ± 0.4 kPa, P = 0.002) with comparable peak inspiratory tracheal pressure (18.3 ± 0.9 versus 18.0 ± 1.2 cmH2O, P > 0.99). Minute volume was lower in the EVA group compared with control (5.5 ± 0.2 versus 7.0 ± 1.0 l min, P = 0.02) with normoventilation in both groups (PaCO2 5.4 ± 0.3 versus 5.5 ± 0.3 kPa, P > 0.99). In the EVA group, the percentage of normally aerated lung tissue was higher (81.0 ± 3.6 versus 75.8 ± 3.0%, P = 0.017) and of poorly aerated lung tissue lower (9.5 ± 3.3 versus 15.7 ± 3.5%, P = 0.002) compared with control. EVA ventilation improves lung aeration via elevated mean tracheal pressure and consequently improves arterial oxygenation at unaltered positive end-expiratory pressure (PEEP) and peak inspiratory pressure (PIP). These findings suggest the EVA mode is a new approach for protective lung ventilation.This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0.

Advanced Extravehicular Protective Systems (AEPS) study

NASA Technical Reports Server (NTRS)

Williams, J. L.; Copeland, R. J.; Webbon, B. W.

1971-01-01

A description is given of life support subsystem concepts for advanced extravehicular protective systems (AEPS) intended for use on future orbital, lunar surface, and Mars surface missions in the late 1970's and 1980's. Primary interest was centered around the thermal control and carbon dioxide control subsystems because they offer the greatest potential for total weight savings. Emphasis was placed on the generation of regenerable subsystem concepts; however, partially regenerable and expendable concepts were also considered. Previously conceived and developed subsystem concepts were included in the study. Concepts were evaluated on the basis of subsystem weight and volume, and subsystem contribution to parent vehicle weight and volume, which included spares, regeneration equipment, expendables, expandables storage penalty, power penalty, and process heating or cooling penalty. Results are presented showing total weight and volume penalty as a function of total mission extravehicular activity (EVA) hours, and showing EVA weight and volume as a function of EVA duration. Subsystem concepts are recommended for each life support function, and secondary concepts which should be developed are also identified.

STS-87 Mission Specialists Scott and Doi with EVA coordinator Laws participate in the CEIT for their

NASA Technical Reports Server (NTRS)

1997-01-01

Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center are STS-87 crew members, assisted by Glenda Laws, extravehicular activity (EVA) coordinator, Johnson Space Center, at left. Next to Laws is Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, who is looking on as Mission Specialist Winston Scott gets a hands-on look at some of the equipment. The STS-87 mission will be the fourth United States Microgravity Payload and flight of the Spartan-201 deployable satellite. During the mission, scheduled for a Nov. 19 liftoff from KSC, Dr. Doi and Scott will both perform spacewalks.

Towards a Mars base - Critical steps for life support on the moon and beyond

NASA Technical Reports Server (NTRS)

Rummel, John D.

1992-01-01

In providing crew life support for future exploration missions, overall exploration objectives will drive the life support solutions selected. Crew size, mission tasking, and exploration strategy will determine the performance required from life support systems. Human performance requirements, for example, may be offset by the availability of robotic assistance. Once established, exploration requirements for life support will be weighed against the financial and technical risks of developing new technologies and systems. Other considerations will include the demands that a particular life support strategy will make on planetary surface site selection, and the availability of precursor mission data to support EVA and in situ resource recovery planning. As space exploration progresses, the diversity of life support solutions that are implemented is bound to increase.

Simplified Abrasion Test Methodology for Candidate EVA Glove Lay-Ups

NASA Technical Reports Server (NTRS)

Rabel, Emily; Aitchison, Lindsay

2015-01-01

During the Apollo Program, space suit outer-layer fabrics were badly abraded after performing just a few extravehicular activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots that penetrated the outer-layer fabric into the thermal protection layers after less than 8 hrs of surface operations. Current plans for the exploration planetary space suits require the space suits to support hundreds of hours of EVA on a lunar or Martian surface, creating a challenge for space suit designers to utilize materials advances made over the last 40 years and improve on the space suit fabrics used in the Apollo Program. Over the past 25 years the NASA Johnson Space Center Crew and Thermal Systems Division has focused on tumble testing as means of simulating wear on the outer layer of the space suit fabric. Most recently, in 2009, testing was performed on 4 different candidate outer layers to gather baseline data for future use in design of planetary space suit outer layers. In support of the High Performance EVA Glove Element of the Next Generation Life Support Project, testing a new configuration was recently attempted in which require 10% of the fabric per replicate of that need in 2009. The smaller fabric samples allowed for reduced per sample cost and flexibility to test small samples from manufacturers without the overhead to have a production run completed. Data collected from this iteration was compared to that taken in 2009 to validate the new test method. In addition the method also evaluated the fabrics and fabric layups used in a prototype thermal micrometeoroid garment (TMG) developed for EVA gloves under the NASA High Performance EVA Glove Project. This paper provides a review of previous abrasion studies on space suit fabrics, details methodologies used for abrasion testing in this particular study, results of the validation study, and results of the TMG testing.

Probabilistic Risk Model for Organ Doses and Acute Health Effects of Astronauts on Lunar Missions

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Hu, Shaowen; Nounu, Hatem N.; Cucinotta, Francis A.

2009-01-01

Exposure to large solar particle events (SPEs) is a major concern during EVAs on the lunar surface and in Earth-to-Lunar transit. 15% of crew times may be on EVA with minimal radiation shielding. Therefore, an accurate assessment of SPE occurrence probability is required for the mission planning by NASA. We apply probabilistic risk assessment (PRA) for radiation protection of crews and optimization of lunar mission planning.

View of rim of South Ray crater on traverse up Stone Mountain during EVA

NASA Technical Reports Server (NTRS)

1972-01-01

A view of the rim of South Ray crater photographed with a 500mm lens from Station no.4 -- the highest point on the traverse up Stone Mountain -- during the second Apollo 16 extravehicular activity (EVA-2) at the Descartes landing site. South Ray crater was a 'fresh' source of angular ejecta in the Lunar Module-Apollo Lunar Surface Experiments Package area and for samples at Station No.8.

jsc2013e073504

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073507

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073509

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073510

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073506

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073495

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

jsc2013e073498

NASA Image and Video Library

2013-07-29

PHOTO DATE: 29 July 2013 LOCATION: Bldg. 9NW, Space Vehicle Mockup Training Facility - POGO SUBJECT: Expedition 42 crew member and astronaut Barry "Butch" Wilmore during ISS EVA POGO 1 training. Instructors Faruq Sabur (black shirt), Allissa Battocletti (red shirt), Sandy Fletcher (light blue shirt with glasses) and astronaut Shane Kimbrough assist. PHOTOGRAPHER: Mark Sowa

Barratt in the A/L during EVA-3 Preparation

NASA Image and Video Library

2009-07-22

S127-E-007698 (22 July 2009) --- Astronaut Mike Barratt, Expedition 20 flight engineer, assumes a waiting stance in the International Space Station's Quest airlock while assisting astronauts Dave Wolf and Christopher Cassidy in getting ready for the mission's third space walk to perform work on the orbital outpost.

Desert Research and Technology Study 2003 Trip Report/ICES Paper

NASA Technical Reports Server (NTRS)

Ross, Amy; Kosmo, Joseph J.; Janoiko, Barbara; Eppler, Dean

2004-01-01

The Advanced Extra-vehicular Activity (EVA) team of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD) participated in the Desert Research and Technology Study (RATS) in September 2003, at Meteor Crater, AZ. The Desert RATS is an integrated remote field site te t with team members from several NASA centers (Johnson Space Center; Glenn and Ames Research Centers) and universities (Bowling Green State University, University of Cincinnati, Massachusetts Institute of Technology) participating. Each week of the two-week field test had a primary focus. The primary test hardware for the first week was the I-Gravity Lunar Rover Training Vehicle, or Grover, which was on loan to NASA from the United States Geological Survey (USGS) Astrogeology Research Program. The 2003 Grover driving test results serve as a rover performance characterization baseline for the Science, Crew, Operation and Utility Testbed (SCOUT) project team, which will be designing and fabricating a next generation roving vehicle prototype in Fiscal Year (FY) 2004. The second week of testing focused on EVA geologic traverses that utilized a geologic sample field analysis science trailer and also focused on human-robotic interaction between the suited subjects and the EVA Robotic Assistant (ERA). This paper will review the Advanced EVA team's role in the context of the overall Desert RATS, as well as the EVA team results and lessons learned. For information regarding other test participants' results, the authors can refer interested parties to the test reports produced by those Desert RATS teams.

Simulation of Martian EVA at the Mars Society Arctic Research Station

NASA Astrophysics Data System (ADS)

Pletser, V.; Zubrin, R.; Quinn, K.

The Mars Society has established a Mars Arctic Research Station (M.A.R.S.) on Devon Island, North of Canada, in the middle of the Haughton crater formed by the impact of a large meteorite several million years ago. The site was selected for its similarities with the surface of the Mars planet. During the Summer 2001, the MARS Flashline Research Station supported an extended international simulation campaign of human Mars exploration operations. Six rotations of six person crews spent up to ten days each at the MARS Flashline Research Station. International crews, of mixed gender and professional qualifications, conducted various tasks as a Martian crew would do and performed scientific experiments in several fields (Geophysics, Biology, Psychology). One of the goals of this simulation campaign was to assess the operational and technical feasibility of sustaining a crew in an autonomous habitat, conducting a field scientific research program. Operations were conducted as they would be during a Martian mission, including Extra-Vehicular Activities (EVA) with specially designed unpressurized suits. The second rotation crew conducted seven simulated EVAs for a total of 17 hours, including motorized EVAs with All Terrain Vehicles, to perform field scientific experiments in Biology and Geophysics. Some EVAs were highly successful. For some others, several problems were encountered related to hardware technical failures and to bad weather conditions. The paper will present the experiment programme conducted at the Mars Flashline Research Station, the problems encountered and the lessons learned from an EVA operational point of view. Suggestions to improve foreseen Martian EVA operations will be discussed.

Astronaut John Young stands at ALSEP deployment site during first EVA

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, stands at the Apollo Lunar Surface Experiments Package (ALSEP) deployment site during the first Apollo 16 extravehicular activity (EVA-1) at the Descartes landing site. The components of the ALSEP are in the background. The lunar surface drill is just behind and to the right of Young. The drill's rack and bore stems are to the left. The three sensor Lunar Surface Magnetometer is beyond the rack. The dark object in the right background is the Radioisotope Thermoelectric Generator (RTG). Between the RTG and the drill is the Heat Flow Experiment. A part of the Central Station is at the right center edge of the picture. This photograph was taken by Astronaut Charles M. Duke Jr., lunar module pilot.

In situ electron microscopy of Braille microsystems: photo-actuation of ethylene vinyl acetate/carbon nanotube composites

NASA Astrophysics Data System (ADS)

Czaniková, Klaudia; Krupa, Igor; Račko, Dušan; Šmatko, Vasilij; Campo, Eva M.; Pavlova, Ewa; Omastová, Mária

2015-02-01

The development of new types of tactile displays based on the actuation of composite materials can aid the visually impaired. Micro/nano systems based on ethylene vinyl acetate (EVA) polymeric matrices enriched with multiwalled carbon nanotubes (MWCNT) can produce ensembles capable of light-induced actuation. In this report, we investigate two types of commercial EVA copolymers matrices containing 28 and 50 wt% vinyl-acetate (VA). Non-covalent modification of carbon nanotubes was achieved through a compatibilization technique that appends the pyrenenyl and cholesteryl groups on the carbon nanotubes (CNTs) surface. EVA/MWCNT nanocomposites were prepared by casting from a solution. These composites were shaped into Braille elements using molds. The deformation of the Braille element (BE) under light-emitting diode (LED) illumination was observed for the first time by in situ scanning electron microscopy (SEM). The superior actuation performance promoted by the EVA/MWCNT nanocomposites indicates that these materials will be useful in the future as light-driven micro/nano system actuators.

Impact of Solar Array Position on ISS Vehicle Charging

NASA Technical Reports Server (NTRS)

Alred, John; Mikatarian, Ronald; Koontz, Steve

2006-01-01

The International Space Station (ISS), because of its large structure and high voltage solar arrays, has a complex plasma interaction with the ionosphere in low Earth orbit (LEO). This interaction of the ISS US Segment photovoltaic (PV) power system with the LEO ionospheric plasma produces floating potentials on conducting elements of the ISS structure relative to the local plasma environment. To control the ISS floating potentials, two Plasma Contactor Units (PCUs) are installed on the Z1 truss. Each PCU discharges accumulated electrons from the Space Station structure, thus reducing the potential difference between the ISS structure and the surrounding charged plasma environment. Operations of the PCUs were intended to keep the ISS floating potential to 40 Volts (Reference 1). Exposed dielectric surfaces overlying conducting structure on the Space Station will collect an opposite charge from the ionosphere as the ISS charges. In theory, when an Extravehicular Activity (EVA) crewmember is tethered to structure via the crew safety tether or when metallic surfaces of the Extravehicular Mobility Unit (EMU) come in contact with conducting metallic surfaces of the ISS, the EMU conducting components, including the perspiration-soaked crewmember inside, can become charged to the Space Station floating potential. The concern is the potential dielectric breakdown of anodized aluminum surfaces on the EMU producing an arc from the EMU to the ambient plasma, or nearby ISS structure. If the EMU arcs, an electrical current of an unknown magnitude and duration may conduct through the EVA crewmember, producing an unacceptable condition. This electrical current may be sufficient to startle or fatally shock the EVA crewmember (Reference 2). Hence, as currently defined by the EVA community, the ISS floating potential for all nominal and contingency EVA worksites and translation paths must have a magnitude less than 40 volts relative to the local ionosphere at all times during EVA. Arcing from the EMU is classified as a catastrophic hazard, which requires two-failure tolerant controls, i.e., three hazard controls. Each PCU is capable of maintaining the ISS floating potential below the requirement during EVA. The two PCUs provide a single failure tolerant control of ISS floating potential. In the event of the failure of one or two PCUs, a combination of solar array shunting and turning the solar arrays into their own wakes will be used to supply control of the plasma hazard (Reference 3). The purpose of this paper is to present on-orbit information that shows that ISS solar array placement with respect to the ISS velocity vector can control solar array plasma charging, and hence, provide an operational control for the plasma hazard. Also, this paper will present on-orbit information that shows that shunting of the ISS solar arrays can control solar array plasma charging, and hence, provide an additional operational control for the plasma hazard.

Astronaut Joseph Tanner is assisted into his EMU during training

NASA Technical Reports Server (NTRS)

1994-01-01

Astronaut Joseph R. Tanner, STS-66 mission specialist, is assisted by Boeing suit expert Steve Voyles in donning the gloves for his extravehicular mobility unit (EMU) as he prepares to be submerged in a 25-feet deep pool at JSC's Weightless Environment Training Facility (WETF). Though no extravehicular activity (EVA) is planned for the mission, at least two astronauts are trained to perform tasks that would require a space walk in the event of failure of remote systems.

Chemical and Biological Substances Decontamination Study for Mars Missions and Terrestrial Applications

NASA Astrophysics Data System (ADS)

Pottage, Thomas; Walker, James; Bennett, Allan; Vrublevskis, John; Hovland, Scott

This study, funded by the European Space Agency (ESA) and undertaken by the Health Protec-tion Agency, UK supported by Systems Engineering and Assessment Ltd., was devised to select suitable current decontamination technologies for development for future manned missions to the Moon and Mars. There is a requirement to decontaminate the habitat module due to the concerns about astronaut ill health, microbial deterioration of materials and potential forward contamination in the case of Mars. In the case of the MIR space station, biodeterioration of components and materials occurred, and dangerous levels of airborne microorganisms were detected during air sampling procedures which lead to the introduction of microbial exposure limits (as MORD SSP 50260) to ensure the health of the crew. COSPAR planetary protection guidelines highlight the need to reduce any potential forward or backwards contamination issues that may occur through the use of Extra Vehicular Activity (EVA) suits whilst on Mars. Decontamination of the suit exterior must be completed before any EVA activity on Mars, whilst a further decontamination cycle must be completed after entry to the airlock following EVA. Technologies and techniques have also been investigated for the microbial reduction of the interior surfaces of the EVA suit to stop biodeterioration of the materials and protect the user from pathogenic microbe accumulation. The first work package reviewed the systems description and requirements as detailed in the statement of work. The requirements were broken down into 12 further requirement sections, where they were updated and expanded, resulted in Technical Note (TN) 1 which was then used as the base document for WP2 and WP3. WP2 investigated the current technologies available for the decontamination of the habitat module interior on missions of up to 6 months and missions that have durations of greater than 6 months. A comprehensive review was carried out for the different methods that could be employed singularly and in combination to decontaminate the habitat. From this review a trade off matrix was compiled scoring each technology on a determined set of parameters. The highest score indicated the most suitable technology. For missions up to 6 months surface cleaning using disinfectant wipes were recommended in combination with an air disinfection/filtration system. For missions greater than 6 months these techniques would be complemented by the addition of a gaseous decontamination system, which could be periodically used to reduce microbial load from inaccessible surfaces. WP3 reviewed the current technologies that could be used for the decontamination of the EVA suit, both external surfaces (after use on the Lunar and Martian surfaces) and internal surfaces. Trade off matrices were constructed to reflect the new parameters for these uses. Only physical decontamination of the exterior surface of the EVA suit is needed for Lunar mission, but for Martian missions this must be enhanced with a gaseous disinfection technology. The interior of the suit can be decontaminated using passive antimicrobial fabrics and active cleaning using disinfectant wipes. WP4 summarised the previous TNs, and included estimates of costs and timelines for the development, based on technology readiness levels, of technologies that need to be flight proven before use on a mission.

Fuel Oxidizer Reaction Products (FORP) Contamination of Service Module (SM) and Release of N-nitrosodimethylamine(NDMA)in a Humid Environment from Crew EVA Suits Contaminated with FORP

NASA Technical Reports Server (NTRS)

Schmidl, William; Mikatarian, Ron; Lam, Chiu-Wing; West, Bil; Buchanan, Vanessa; Dee, Louis; Baker, David; Koontz, Steve

2004-01-01

The Service Module (SM) is an element of the Russian Segment of the International Space Station (ISS). One of the functions of the SM is to provide attitude control for the ISS using thrusters when the U.S. Control Moment Gyros (CMG's) must be desaturated. Prior to an Extravehicular Activity (EVA) on the Russian Segment, the Docking Compartment (DC1) is depressurized, as it is used as an airlock. When the DC1 is depressurized, the CMG's margin of momentum is insufficient and the SM attitude control thrusters need to fire to desaturate the CMG's. SM roll thruster firings induce contamination onto adjacent surfaces with Fuel Oxidizer Reaction Products (FORP). FORP is composed of both volatile and non-volatile components. One of the components of FORP is the potent carcinogen N-nitrosdimethylamine (NDMA). Since the EVA crewmembers often enter the area surrounding the thrusters for tasks on the aft end of the SM and when translating to other areas of the Russian Segment, the presence of FORP is a concern. This paper will discuss FORP contamination of the SM surfaces, the release of NDMA in a humid environment from crew EVA suits, if they happen to be contaminated with FORP, and the toxicological risk associated with the NDMA release.

An Assessment of Dust Effects on Planetary Surface Systems to Support Exploration Requirements

NASA Technical Reports Server (NTRS)

Wagner, Sandy

2004-01-01

Apollo astronauts learned first hand how problems with dust impact lunar surface missions. After three days, lunar dust contamination on EVA suit bearings led to such great difficulty in movement that another EVA would not have been possible. Dust clinging to EVA suits was transported into the Lunar Module. During the return trip to Earth, when micro gravity was reestablished, the dust became airborne and floated through the cabin. Crews inhaled the dust and it irritated their eyes. Some mechanical systems aboard the spacecraft were damaged due to dust contamination. Study results obtained by Robotic Martian missions indicate that Martian surface soil is oxidative and reactive. Exposures to the reactive Martian dust will pose an even greater concern to the crew health and the integrity of the mechanical systems. As NASA embarks on planetary surface missions to support its Exploration Vision, the effects of these extraterrestrial dusts must be well understood and systems must be designed to operate reliably and protect the crew in the dusty environments of the Moon and Mars. The AIM Dust Assessment Team was tasked to identify systems that will be affected by the respective dust, how they will be affected, associated risks of dust exposure, requirements that will need to be developed, identified knowledge gaps, and recommended scientific measurements to obtain information needed to develop requirements, and design and manufacture the surface systems that will support crew habitation in the lunar and Martian outposts.

Planetary Dust: Cross-Functional Considerations

NASA Technical Reports Server (NTRS)

Wagner, Sandra

2006-01-01

Apollo astronauts learned first hand how problems with dust impact lunar surface missions. After three days, lunar dust contaminating on EVA suit bearings led to such great difficulty in movement that another EVA would not have been possible. Dust clinging to EVA suits was transported into the Lunar Module. During the return trip to Earth, when microgravity was reestablished, the dust became airborne and floated through the cabin. Crews inhaled the dust and it irritated their eyes. Some mechanical systems aboard the spacecraft were damaged due to dust contamination. Study results obtained by Robotic Martian missions indicate that Martian surface soil is oxidative and reactive. Exposures to the reactive Martian dust will pose an even greater concern to the crew health and the integrity of the mechanical systems. As NASA embarks on planetary surface missions to support its Exploration Vision, the effects of these extraterrestrial dusts must be well understood and systems must be designed to operate reliably and protect the crew in the dusty environments of the Moon and Mars. The AIM Dust Assessment Team was tasked to identify systems that will be affected by the respective dust, how they will be affected, associated risks of dust exposure, requirements that will need to be developed, identified knowledge gaps, and recommended scientific measurements to obtain information needed to develop requirements, and design and manufacture the surface systems that will support crew habitation in the lunar and Martian outposts.

View of Mount Hadley as photographed by Apollo 15 during EVA

NASA Image and Video Library

1971-07-31

AS15-87-11849 (31 July-2 Aug. 1971) --- An excellent view of Mount Hadley, fully lighted, showing abundant linear features, as photographed during the Apollo 15 lunar surface extravehicular activity (EVA). This view is looking north from the Apollo Lunar Surface Experiments Package (ALSEP) site. Mount Hadley rises about 4,500 meters (approximately 14,765 feet) above the plain. While astronauts David R. Scott, commander, and James B. Irwin, lunar module pilot, descended in the Apollo 15 Lunar Module (LM) "Falcon" to explore the Hadley-Apennine area of the moon, astronaut Alfred M. Worden, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit.

Automating CapCom Using Mobile Agents and Robotic Assistants

NASA Technical Reports Server (NTRS)

Clancey, William J.; Sierhuis, Maarten; Alena, Richard L.; Graham, Jeffrey S.; Tyree, Kim S.; Hirsh, Robert L.; Garry, W. Brent; Semple, Abigail; Shum, Simon J. Buckingham; Shadbolt, Nigel;

Creating a Lunar EVA Work Envelope

NASA Technical Reports Server (NTRS)

Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David

2009-01-01

A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.

Astronaut John Young at LRV prior to deployment of ALSEP during first EVA

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut John W. Young, commander of Apollo 16, is at the Lunar Roving Vehicle (LRV), just prior to deployment of the Apollo Lunar Surface Experiment Package (ALSEP) during the first extravehicular activity (EVA-1), on April 21, 1972. Note Ultraviolet Camera/Spectrometer at right of Lunar Module (LM) ladder. Also note pile of protective/thermal foil under the U.S. flag on the LM which the astronauts pulled away to get to the Modular Equipment Stowage Assembly (MESA) bay.

Interviews with Apollo Lunar Surface Astronauts in Support of EVA Systems Design

NASA Technical Reports Server (NTRS)

Eppler, Dean

2010-01-01

A 3-person team interviewed 8 of the 11 surviving Apollo crewmembers in a series of focused interviews to discuss their experiences on the lunar surface. Eppler presented the results of these interviews, along with recommendations for the design of future lunar surface systems.

Comparing Apollo and Mars Exploration Rover (MER) Operations Paradigms for Human Exploration During NASA Desert-Rats Science Operations

NASA Technical Reports Server (NTRS)

Yingst, R. A.; Cohen, B. A.; Ming, D. W.; Eppler, D. B.

2011-01-01

NASA's Desert Research and Technology Studies (D-RATS) field test is one of several analog tests that NASA conducts each year to combine operations development, technology advances and science under planetary surface conditions. The D-RATS focus is testing preliminary operational concepts for extravehicular activity (EVA) systems in the field using simulated surface operations and EVA hardware and procedures. For 2010 hardware included the Space Exploration Vehicles, Habitat Demonstration Units, Tri-ATHLETE, and a suite of new geology sample collection tools, including a self-contained GeoLab glove box for conducting in-field analysis of various collected rock samples. The D-RATS activities develop technical skills and experience for the mission planners, engineers, scientists, technicians, and astronauts responsible for realizing the goals of exploring planetary surfaces.

Astronaut John Young stands at ALSEP deployment site during first EVA

NASA Image and Video Library

1972-04-21

AS16-114-18388 (21 April 1972) --- Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, stands at the Apollo Lunar Surface Experiments Package (ALSEP) deployment site during the first Apollo 16 extravehicular activity (EVA) at the Descartes landing site. The components of the ALSEP are in the background. The lunar surface drill is just behind and to the right of astronaut Young. The drill's rack and bore stems are to the left. The three-sensor Lunar Surface Magnetometer is beyond the rack. The dark object in the right background is the Radioisotope Thermoelectric Generator (RTG). Between the RTG and the drill is the Heat Flow Experiment. A part of the Central Station is at the right center edge of the picture. This photograph was taken by astronaut Charles M. Duke Jr., lunar module pilot.

Life Sciences Implications of Lunar Surface Operations

NASA Technical Reports Server (NTRS)

Chappell, Steven P.; Norcross, Jason R.; Abercromby, Andrew F.; Gernhardt, Michael L.

2010-01-01

The purpose of this report is to document preliminary, predicted, life sciences implications of expected operational concepts for lunar surface extravehicular activity (EVA). Algorithms developed through simulation and testing in lunar analog environments were used to predict crew metabolic rates and ground reaction forces experienced during lunar EVA. Subsequently, the total metabolic energy consumption, the daily bone load stimulus, total oxygen needed, and other variables were calculated and provided to Human Research Program and Exploration Systems Mission Directorate stakeholders. To provide context to the modeling, the report includes an overview of some scenarios that have been considered. Concise descriptions of the analog testing and development of the algorithms are also provided. This document may be updated to remain current with evolving lunar or other planetary surface operations, assumptions and concepts, and to provide additional data and analyses collected during the ongoing analog research program.

Apollo 14 Mission image - Astronaut Edgar D. Mitchell, lunar module pilot for the Apollo 14 lunar landing mission, stands by the deployed U.S. flag on the lunar surface during the early moments of the first extravehicular activity (EVA-1) of the mission.

NASA Image and Video Library

1971-02-05

AS14-66-9233 (5 Feb. 1971) --- Astronaut Edgar D. Mitchell, lunar module pilot for the Apollo 14 lunar landing mission, stands by the deployed U.S. flag on the lunar surface during the early moments of the first extravehicular activity (EVA) of the mission. He was photographed by astronaut Alan B. Shepard Jr., mission commander, using a 70mm modified lunar surface Hasselblad camera. While astronauts Shepard and Mitchell descended in the Lunar Module (LM) "Antares" to explore the Fra Mauro region of the moon, astronaut Stuart A. Roosa, command module pilot, remained with the Command and Service Modules (CSM) "Kitty Hawk" in lunar orbit.

The Influence of Robotic Assistance on Reducing Neuromuscular Effort and Fatigue during Extravehicular Activity Glove Use

NASA Technical Reports Server (NTRS)

Madden, Kaci E.; Deshpande, Ashish D.; Peters, Benjamin J.; Rogers, Jonathan M.; Laske, Evan A.; McBryan, Emily R.

2017-01-01

The three-layered, pressurized space suit glove worn by Extravehicular Activity (EVA) crew members during missions commonly causes hand and forearm fatigue. The Spacesuit RoboGlove (SSRG), a Phase VI EVA space suit glove modified with robotic grasp-assist capabilities, has been developed to augment grip strength in order to improve endurance and reduce the risk of injury in astronauts. The overall goals of this study were to i) quantify the neuromuscular modulations that occur in response to wearing a conventional Phase VI space suit glove (SSG) during a fatiguing task, and ii) determine the efficacy of Spacesuit RoboGlove (SSRG) in reversing the adverse neuromuscular modulations and restoring altered muscular activity to barehanded levels. Six subjects performed a fatigue sequence consisting of repetitive dynamic-gripping interspersed with isometric grip-holds under three conditions: barehanded, wearing pressurized SSG, and wearing pressurized SSRG. Surface electromyography (sEMG) from six forearm muscles (flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), extensor digitorum (ED), extensor carpi radialis longus (ECRL), and extensor carpi ulnaris (ECU)) and subjective fatigue ratings were collected during each condition. Trends in amplitude and spectral distributions of the sEMG signals were used to derive metrics quantifying neuromuscular effort and fatigue that were compared across the glove conditions. Results showed that by augmenting finger flexion, the SSRG successfully reduced the neuromuscular effort needed to close the fingers of the space suit glove in more than half of subjects during two types of tasks. However, the SSRG required more neuromuscular effort to extend the fingers compared to a conventional SSG in many subjects. Psychologically, the SSRG aided subjects in feeling less fatigued during short periods of intense work compared to the SSG. The results of this study reveal the promise of the SSRG as a grasp-assist device that can improve astronaut performance and reduce the risk of injury by offsetting neuromuscular effort. Modifications to the experimental protocol are needed, however, to improve the outcome of the neuromuscular fatigue metrics and determine the effectiveness of SSRG in increasing astronaut endurance. Nevertheless, these findings will improve the understanding of astronaut-spacesuit interaction and provide direction toward designing improved spacesuit gloves and robotic-assist devices, like the SSRG.

Metabolic and Subjective Results Review of the Integrated Suit Test Series

NASA Technical Reports Server (NTRS)

Norcross, J.R.; Stroud, L.C.; Klein, J.; Desantis, L.; Gernhardt, M.L.

2009-01-01

Crewmembers will perform a variety of exploration and construction activities on the lunar surface. These activities will be performed while inside an extravehicular activity (EVA) spacesuit. In most cases, human performance is compromised while inside an EVA suit as compared to a crewmember s unsuited performance baseline. Subjects completed different EVA type tasks, ranging from ambulation to geology and construction activities, in different lunar analog environments including overhead suspension, underwater and 1-g lunar-like terrain, in both suited and unsuited conditions. In the suited condition, the Mark III (MKIII) EVA technology demonstrator suit was used and suit pressure and suit weight were parameters tested. In the unsuited conditions, weight, mass, center of gravity (CG), terrain type and navigation were the parameters. To the extent possible, one parameter was varied while all others were held constant. Tests were not fully crossed, but rather one parameter was varied while all others were left in the most nominal setting. Oxygen consumption (VO2), modified Cooper-Harper (CH) ratings of operator compensation and ratings of perceived exertion (RPE) were measured for each trial. For each variable, a lower value correlates to more efficient task performance. Due to a low sample size, statistical significance was not attainable. Initial findings indicate that suit weight, CG and the operational environment can have a large impact on human performance during EVA. Systematic, prospective testing series such as those performed to date will enable a better understanding of the crucial interactions of the human and the EVA suit system and their environment. However, work remains to be done to confirm these findings. These data have been collected using only unsuited subjects and one EVA suit prototype that is known to fit poorly on a large demographic of the astronaut population. Key findings need to be retested using an EVA suit prototype better suited to a larger anthropometric portion of the astronaut population, and elements tested only in the unsuited condition need to be evaluated with an EVA suit and appropriate analog environment.

Preparation and Characterization of a Superparamagnetic Polymer Nanocomposite

NASA Astrophysics Data System (ADS)

Brenner, N.; Isseroff, R.; Rafailovich, M.; Rudomen, G.; Gambino, R.; Liang, S. S.; Sunil, D.; Si, M.; Collazo, L.; Pernodet, N.; Fang, X.

2006-03-01

Fe(CO)5 decomposition produced ferro- and superparamagnetic polymer nanocomposites. Fe(CO)5 and Cloisite 20A clay were combined in a closed vial for 12 hours, then opened to air for 2 hours. Mössbauer analysis indicated formation of Fe2O3 on clay; mass analysis indicated 12% Fe in clay. A Brabender mixed Fe2O3/clays with PMMA and EVA at ratios by mass of 9:4:36 and 1:1:4 respectively (Fe(CO)5:clay:polymer). TEM displayed Fe2O3 nanoparticles, 3.3 ^+ 0.8 nm in diameter, adsorbed on exfoliated clay platelet surfaces in polymer matrices. VSM data indicated superparamagnetism with moments of 510.3 emu/g(Fe2O3) (PMMA) and 8.46 emu/g(Fe2O3) (EVA). DMA showed 37% decreased dynamic modulus (EVA) and 11% (PMMA) due to Fe2O3. TGA indicated PMMA stability to 400^oC (9.3% mass residual) and EVA to 435^oC (11% mass residual). Cell adhesion tests showed Fe2O3/clay enhanced proliferation, promising applications in bone implants.

Ethylene-Vinyl Acetate Potential Problems for Photovoltaic Packaging: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kempe, M. D.; Jorgensen, G. J.; Terwilliger, K. M.

2006-05-01

Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support, optical coupling, electrical isolation, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate, it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about ?15 C. Temperatures lower thanmore » this can be reached for extended periods of time in some climates. Because of increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL 1703.« less

Ethylene-Vinyl Acetate Potential Problems for Photovoltaic Packaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kempe, M. D.; Jorgensen, G. J.; Terwilliger, K. M.

2006-01-01

Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support, optical coupling, electrical isolation, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate, it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about -15 degC. Temperatures lower thanmore » this can be reached for extended periods of time in some climates. Because of increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL1703.« less

Potential Problems with Ethylene-Vinyl Acetate for Photovoltaic Packaging (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kempe, M. D.; Jorgensen, G. J.; Terwilliger, K, M.

2006-05-01

Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support electrical isolation, optical coupling, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about -15 C. Temperatures lower thanmore » this can be reached for extended periods of time in some climates. Due to increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL 1703.« less

STS115 Preflight Training at NBL

NASA Image and Video Library

2006-08-02

JSC2006-E-31904 (2 Aug. 2006) --- Astronaut Steven G. MacLean (seated), STS-115 mission specialist representing the Canadian Space Agency, observes training activities of his crewmates from the simulation control area in the Neutral Buoyancy Laboratory (NBL) at the Sonny Carter Training Facility (SCTF) near Johnson Space Center. EVA instructor John V. Ray stands nearby to offer assistance.

STS-55 MS3 Harris dons EMU with technician's assistance in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1991-01-01

STS-55 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist 3 (MS3) Bernard A. Harris, Jr, partially suited in his extravehicular mobility unit (EMU), and a technician take a break from suiting procedures to watch nearby activity (out of frame) in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Harris has donned the EMU upper and lower torsos which are not yet connected at the waist ring. Once fully suited in the EMU, Harris will be lowered into the WETF's 25-foot pool for an underwater contingency extravehicular activity (EVA) simulation. There is no scheduled EVA for the 1993 flight but each spaceflight crew includes astronauts trained for a variety of contingency tasks that could require exiting the shirt-sleeve environment of a Shuttle's cabin.

Developing Science Operations Concepts for the Future of Planetary Surface Exploration

NASA Astrophysics Data System (ADS)

Young, K. E.; Bleacher, J. E.; Rogers, A. D.; McAdam, A.; Evans, C. A.; Graff, T. G.; Garry, W. B.; Whelley, P. L.; Scheidt, S.; Carter, L.; Coan, D.; Reagan, M.; Glotch, T.; Lewis, R.

2017-02-01

Human exploration of other planetary bodies is crucial in answering critical science questions about our solar system. As we seek to put humans on other surfaces by 2050, we must understand the science operations concepts needed for planetary EVA.

Engineering design constraints of the lunar surface environment

NASA Technical Reports Server (NTRS)

Morrison, D. A.

1992-01-01

Living and working on the lunar surface will be difficult. Design of habitats, machines, tools, and operational scenarios in order to allow maximum flexibility in human activity will require paying attention to certain constraints imposed by conditions at the surface and the characteristics of lunar material. Primary design drivers for habitat, crew health and safety, and crew equipment are: ionizing radiation, the meteoroid flux, and the thermal environment. Secondary constraints for engineering derive from: the physical and chemical properties of lunar surface materials, rock distributions and regolith thicknesses, topography, electromagnetic properties, and seismicity. Protection from ionizing radiation is essential for crew health and safety. The total dose acquired by a crew member will be the sum of the dose acquired during EVA time (when shielding will be least) plus the dose acquired during time spent in the habitat (when shielding will be maximum). Minimizing the dose acquired in the habitat extends the time allowable for EVA's before a dose limit is reached. Habitat shielding is enabling, and higher precision in predicting secondary fluxes produced in shielding material would be desirable. Means for minimizing dose during a solar flare event while on extended EVA will be essential. Early warning of the onset of flare activity (at least a half-hour is feasible) will dictate the time available to take mitigating steps. Warning capability affects design of rovers (or rover tools) and site layout. Uncertainty in solar flare timing is a design constraint that points to the need for quickly accessible or constructible safe havens.

Engineering design constraints of the lunar surface environment

NASA Astrophysics Data System (ADS)

Morrison, D. A.

1992-02-01

Living and working on the lunar surface will be difficult. Design of habitats, machines, tools, and operational scenarios in order to allow maximum flexibility in human activity will require paying attention to certain constraints imposed by conditions at the surface and the characteristics of lunar material. Primary design drivers for habitat, crew health and safety, and crew equipment are: ionizing radiation, the meteoroid flux, and the thermal environment. Secondary constraints for engineering derive from: the physical and chemical properties of lunar surface materials, rock distributions and regolith thicknesses, topography, electromagnetic properties, and seismicity. Protection from ionizing radiation is essential for crew health and safety. The total dose acquired by a crew member will be the sum of the dose acquired during EVA time (when shielding will be least) plus the dose acquired during time spent in the habitat (when shielding will be maximum). Minimizing the dose acquired in the habitat extends the time allowable for EVA's before a dose limit is reached. Habitat shielding is enabling, and higher precision in predicting secondary fluxes produced in shielding material would be desirable. Means for minimizing dose during a solar flare event while on extended EVA will be essential. Early warning of the onset of flare activity (at least a half-hour is feasible) will dictate the time available to take mitigating steps. Warning capability affects design of rovers (or rover tools) and site layout. Uncertainty in solar flare timing is a design constraint that points to the need for quickly accessible or constructible safe havens.

Astronaut David Scott gives salute beside U.S. flag during EVA

NASA Image and Video Library

1971-08-01

AS15-88-11863 (1 Aug. 1971) --- Astronaut David R. Scott, commander, gives a military salute while standing beside the deployed United States flag during the Apollo 15 lunar surface extravehicular activity (EVA) at the Hadley-Apennine landing site. The flag was deployed toward the end of EVA-2. The Lunar Module (LM), "Falcon," is partially visible on the right. Hadley Delta in the background rises approximately 4,000 meters (about 13,124 feet) above the plain. The base of the mountain is approximately 5 kilometers (about three statue miles) away. This photograph was taken by astronaut James B. Irwin, lunar module pilot. While astronauts Scott and Irwin descended in the LM to explore the moon, astronaut Alfred M. Worden, command module pilot, remained in lunar orbit in the Command and Service Modules (CSM).

Extravehicular Activity Systems Education and Public Outreach in Support of NASA's STEM Initiatives

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

The exploration activities associated with NASA?s goals to return to the Moon, travel to Mars, or explore Near Earth Objects (NEOs) will involve the need for human-supported space and surface extravehicular activities (EVAs). The technology development and human element associated with these exploration missions provide fantastic content to promote science, technology, engineering, and math (STEM). As NASA Administrator Charles F. Bolden remarked on December 9, 2009, "We....need to provide the educational and experiential stepping-stones to inspire the next generation of scientists, engineers, and leaders in STEM fields." The EVA Systems Project actively supports this initiative by providing subject matter experts and hands-on, interactive presentations to educate students, educators, and the general public about the design challenges encountered as NASA develops EVA hardware for these missions. This paper summarizes these education and public efforts.

Lighting constraints on lunar surface operations

NASA Technical Reports Server (NTRS)

Eppler, Dean B.

1991-01-01

An investigation into the levels of ambient lighting on the lunar surface indicates that for most nearside locations, illumination will be adequate throughout most of the lunar night to conduct EVAs with only minor artificial illumination. The maximum lighting available during the lunar night from Earthshine will be similar to the light level on a July evening at approximately 8:00 pm in the southern United States (approximately 15 minutes after sunset). Because of the captured rotation of the Moon about the Earth, the location of the Earth will remain approximately constant throughout the lunar night, with consequent constant shadow length and angle. Variations in the level of Earthside illumination will be solely a function of Earth phase angle. Experience during the Apollo Program suggests that EVA activities during the period around the lunar noon may be difficult due to lack of surface definition caused by elimination of shadows.

View of javelin and golf ball on lunar surface during Apollo 14 EVA

NASA Technical Reports Server (NTRS)

1971-01-01

View shows the javelin and golf ball used by Astronaut Alan B. Shepard Jr., Apollo 14 commander, during the mission's second extravehicular activity (EVA-2) on Feb. 6, 1971. Just to the left of center lies the javelin, with the golf ball just below it, almost perpendicular to it. Dark colored trails are the results of tracks made by the lunar overshoes of the astronauts and the wheels of the Modularized Equipment Transporter (MET). This photograph was made through the right window of the Lunar Module, looking northwest.

Components of the ALSEP deployed during Apollo 14 first EVA

NASA Image and Video Library

1971-02-05

AS14-67-9376 (5 Feb. 1971) --- Several components of the Apollo lunar surface experiments package (ASLEP) are deployed in this photograph taken during the first Apollo 14 extravehicular activity (EVA). The larger object with antenna is the ALSEP central station (CS). The active seismic experiment (ASE) mortar package assembly is to the rear left of the CS. The charged particle lunar environment experiment (CPLEE) is to the right rear of the CS. A portion of the modularized equipment transporter (MET) can be seen in the left foreground.

Information Presentation

NASA Technical Reports Server (NTRS)

Holden, Kritina; Sandor, A.; Thompson, S. G.; McCann, R. S.; Kaiser, M. K.; Begault, D. R.; Adelstein, B. D.; Beutter, B. R.; Stone, L. S.

2008-01-01

The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew on flight vehicles, surface landers and habitats, and during extra-vehicular activities (EVA). Designers of displays and controls for exploration missions must be prepared to select the text formats, label styles, alarms, electronic procedure designs, and cursor control devices that provide for optimal crew performance on exploration tasks. The major areas of work, or subtasks, within the Information Presentation DRP are: 1) Controls, 2) Displays, 3) Procedures, and 4) EVA Operations.

An Onboard ISS Virtual Reality Trainer

NASA Technical Reports Server (NTRS)

Miralles, Evelyn

2013-01-01

Prior to the retirement of the Space Shuttle, many exterior repairs on the International Space Station (ISS) were carried out by shuttle astronauts, trained on the ground and flown to the Station to perform these specific repairs. With the retirement of the shuttle, this is no longer an available option. As such, the need for ISS crew members to review scenarios while on flight, either for tasks they already trained for on the ground or for contingency operations has become a very critical issue. NASA astronauts prepare for Extra-Vehicular Activities (EVA) or Spacewalks through numerous training media, such as: self-study, part task training, underwater training in the Neutral Buoyancy Laboratory (NBL), hands-on hardware reviews and training at the Virtual Reality Laboratory (VRLab). In many situations, the time between the last session of a training and an EVA task might be 6 to 8 months. EVA tasks are critical for a mission and as time passes the crew members may lose proficiency on previously trained tasks and their options to refresh or learn a new skill while on flight are limited to reading training materials and watching videos. In addition, there is an increased need for unplanned contingency repairs to fix problems arising as the Station ages. In order to help the ISS crew members maintain EVA proficiency or train for contingency repairs during their mission, the Johnson Space Center's VRLab designed an immersive ISS Virtual Reality Trainer (VRT). The VRT incorporates a unique optical system that makes use of the already successful Dynamic On-board Ubiquitous Graphics (DOUG) software to assist crew members with procedure reviews and contingency EVAs while on board the Station. The need to train and re-train crew members for EVAs and contingency scenarios is crucial and extremely demanding. ISS crew members are now asked to perform EVA tasks for which they have not been trained and potentially have never seen before. The Virtual Reality Trainer (VRT) provides an immersive 3D environment similar to the one experienced at the VRLab crew training facility at the NASA Johnson Space Center. VRT bridges the gap by allowing crew members to experience an interactive, 3D environment to reinforce skills already learned and to explore new work sites and repair procedures outside the Station.

Analysis of Three-Dimensional Roller Performance in a Micro-g Environment

NASA Technical Reports Server (NTRS)

Roberts, B.; Shook, L.; Hossaini, L.; Cohen, R.

1999-01-01

Approximately 960 hours of extravehicular activity (EVA), or spacewalks, are planned for the construction of the International Space Station over the next six years. This is over two-and-a-half times the total number of EVA hours accumulated by the National Aeronautics and Space Administration (NASA) in the past 35 years of U.S. spaceflight. Therefore, it is advantageous to explore ways to assist astronauts in being more efficient while working in space. The Space Systems Laboratory at the University of Maryland is investigating ways of improving conventional ratcheting tools that do not work effectively in confined spaces and have been seen to exhibit other limitations that restrict their use during EVA. By replacing the traditional ratchet mechanism with a NASA/Goddard Space Flight Center-developed three-dimensional (3-D) sprag and roller mechanism, ratcheting tools can be made more efficient. In October of 1998, a 3-D roller mechanism was flown on space shuttle mission STS-95 as part of the Space Experiment Module program. The goal of the experiment was to quantify the roller's performance when operating for an extended period in a micro-g environment. This paper discusses the design of the experiment, as well as the results obtained.

Wisconsin's study of manned Mars missions

NASA Technical Reports Server (NTRS)

1987-01-01

The design group focused on three topics: (1) Extravehicular Activities, (2) Sample Return Missions, and (3) Structural and Construction Considerations of a Manned Mars Habitat. Extravehicular Activities permit a Mars based astronaut to exit the habitat and perform mission activities in the harsh Mars environment. Today's spacesuit gloves are bulky, hard to manipulate and fatiguing. A mechanical assistance mechanism has been developed for the glove that will reduce user fatigue and increase the duration of EVA's. Oxygen supply systems are also being developed for the EVA astronaut. A scuba type system of tanked breathing air proves to be the most efficient system for short duration EVA's. A system that extracts the oxygen from atmospheric carbon dioxide can provide oxygen for long duration FVA's. Sample Return Missions require that samples be taken from several sites. Transportation considerations are addressed and two transportation schemes are proposed. The first scheme involves a lighter than air balloon. This system provides excellent range. The second design is a rover that uses tracks rather than wheels. Track rovers perform well in soft, sandy conditions. Engineering aspects of a habitat and domed greenhouse were investigated and plans for the habitat have been made. A configuration has been established and construction details have been made.

Extravehicular Activity (EVA) Hardware & Operations Overview

NASA Technical Reports Server (NTRS)

Moore, Sandra; Marmolejo, Jose

2014-01-01

The objectives of this presentation are to: Define Extravehicular Activity (EVA), identify the reasons for conducting an EVA, and review the role that EVA has played in the space program; Identify the types of EVAs that may be performed; Describe some of the U.S. Space Station equipment and tools that are used during an EVA, such as the Extravehicular Mobility Unit (EMU), the Simplified Aid For EVA Rescue (SAFER), the International Space Station (ISS) Joint Airlock and Russian Docking Compartment 1 (DC-1), and EVA Tools & Equipment; Outline the methods and procedures of EVA Preparation, EVA, and Post-EVA operations; Describe the Russian spacesuit used to perform an EVA; Provide a comparison between U.S. and Russian spacesuit hardware and EVA support; and Define the roles that different training facilities play in EVA training.

Human Exploration of Phobos

NASA Technical Reports Server (NTRS)

Abercromby, Andrew F. J.; Chappell, Steven P.; Gernhardt, Michael L.; Lee, David E.; Howe, A. Scott

2015-01-01

This study developed, analyzed, and compared mission architectures for human exploration of Mars' Moons within the context of an Evolvable Mars Campaign. METHODS: All trades assumed conjunction class missions to Phobos (approximately 500 days in Mars system) as it was considered the driving case for the transportation architecture. All architectures assumed that the Mars Transit Habitat would remain in a High Mars Orbit with crewmembers transferring between HMO and Phobos in a small crew taxi vehicle. A reference science / exploration program was developed including performance of a standard set of tasks at 55 locations on the Phobos surface. Detailed EVA timelines were developed using realistic flight rules to accomplish the reference science tasks using exploration systems ranging from jetpacks to multi-person pressurized excursion vehicles combined with Phobos surface and orbital (L1, L4/L5, 20km Distant Retrograde Orbit) habitat options. Detailed models of propellant mass, crew time, science productivity, radiation exposure, systems and consumables masses, and other figures of merit were integrated to enable quantitative comparison of different architectural options. Options for pre-staging assets using solar electric propulsion (SEP) vs. delivering all systems with the crew were also evaluated. Seven discrete mission architectures were evaluated. RESULTS: The driving consideration for habitat location (Phobos surface vs. orbital) was radiation exposure, with an estimated reduction in cumulative mission radiation exposure of up to 34% (vs. Mars orbital mission) when the habitat is located on the Phobos surface, compared with only 3-6% reduction for a habitat in a 20km DRO. The exploration utility of lightweight unpressurized excursion vehicles was limited by the need to remain within 20 minutes of Solar Particle Event radiation protection combined with complex GN&C systems required by the non-intuitive and highly-variable gravitational environment. Two-person pressurized excursion vehicles as well as mobile surface habitats offer significant exploration capability and operational benefits compared with unpressurized EVA mobility systems at the cost of increased system and propellant mass. Mechanical surface translation modes (i.e. hopping) were modeled and offer potentially significant propellant savings and the possibility of extended exploration operations between crewed missions. Options for extending the utilization of the crew taxi vehicle were examined, including use as an exploration asset for Phobos surface exploration (when combined with an alternate mobility system) and as an EVA platform, both on Phobos and for contingency EVA on the Mars Transit Habitat. CONCLUSIONS: Human exploration of Phobos offers a scientifically meaningful first step towards human Mars surface missions that develops and validates transportation, habitation, and exploration systems and operations in advance of the Mars landing systems.

Astronaut James Irwin gives salute beside U.S. flag during EVA

NASA Image and Video Library

1971-08-01

AS15-88-11866 (1 Aug. 1971) --- Astronaut James B. Irwin, lunar module pilot, gives a military salute while standing beside the deployed United States flag during the Apollo 15 lunar surface extravehicular activity (EVA) at the Hadley-Apennine landing site. The flag was deployed toward the end of EVA-2. The Lunar Module (LM) "Falcon" is in the center. On the right is the Lunar Roving Vehicle (LRV). This view is looking almost due south. Hadley Delta in the background rises approximately 4,000 meters (about 13,124 feet) above the plain. The base of the mountain is approximately 5 kilometers (about 3 statute miles) away. This photograph was taken by astronaut David R. Scott, Apollo 15 commander. While astronauts Scott and Irwin descended in the LM to explore the moon, astronaut Alfred M. Worden, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit.

Securing Safety with Sensors

NASA Technical Reports Server (NTRS)

2004-01-01

The Robot Systems Technology Branch at NASA's Johnson Space Center collaborated with the Defense Advanced Research Projects Agency to design Robonaut, a humanoid robot developed to assist astronauts with Extra Vehicular Activities (EVA) such as space structure assembly and repair operations. By working side-by-side with astronauts or going where risks are too great for people, Robonaut is expected to expand the Space Agency s ability for construction and discovery. NASA engineers equipped Robonaut with human-looking, dexterous hands complete with five fingers to accomplish its tasks. The Robonaut hand is one of the first being developed for space EVA use and is the closest in size and capability to a suited astronaut s hand. As part of the development process, an advanced sensor system was needed to provide an improved method to measure the movement and forces exerted by Robonaut s forearms and hands.

Sprint: The first flight demonstration of the external work system robots

NASA Technical Reports Server (NTRS)

Price, Charles R.; Grimm, Keith

1995-01-01

The External Works Systems (EWS) 'X Program' is a new NASA initiative that will, in the next ten years, develop a new generation of space robots for active and participative support of zero g external operations. The robotic development will center on three areas: the assistant robot, the associate robot, and the surrogate robot that will support external vehicular activities (EVA) prior to and after, during, and instead of space-suited human external activities respectively. The EWS robotics program will be a combination of technology developments and flight demonstrations for operational proof of concept. The first EWS flight will be a flying camera called 'Sprint' that will seek to demonstrate operationally flexible, remote viewing capability for EVA operations, inspections, and contingencies for the space shuttle and space station. This paper describes the need for Sprint and its characteristics.

On-orbit Passive Thermography

NASA Technical Reports Server (NTRS)

Howell, Patricia A.; Winfree, William P.; Cramer, K. Elliott

2008-01-01

On July 12, 2006, British-born astronaut Piers Sellers became the first person to conduct thermal nondestructive evaluation experiments in space, demonstrating the feasibility of a new tool for detecting damage to the reinforced carbon-carbon (RCC) structures of the Shuttle. This new tool was an EVA (Extravehicular Activity, or spacewalk) compatible infrared camera developed by NASA engineers. Data was collected both on the wing leading edge of the Orbiter and on pre-damaged samples mounted in the Shuttle s cargo bay. A total of 10 infrared movies were collected during the EVA totaling over 250 megabytes of data. Images were downloaded from the orbiting Shuttle to Johnson Space Center for analysis and processing. Results are shown to be comparable to ground-based thermal inspections performed in the laboratory with the same type of camera and simulated solar heating. The EVA camera system detected flat-bottom holes as small as 2.54cm in diameter with 50% material loss from the back (hidden) surface in RCC during this first test of the EVA IR Camera. Data for the time history of the specimen temperature and the capability of the inspection system for imaging impact damage are presented.

Desert Research and Technology Studies 2005 Report

NASA Technical Reports Server (NTRS)

Ross, Amy J.; Kosmo, Joseph J.; Janoiko, Barbara A.; Bernard, Craig; Splawn, Keith; Eppler, Dean B.

2006-01-01

During the first two weeks of September 2005, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2005 Research and Technology Studies (RATS). The Desert RATS field test activity is the culmination of the various individual science and advanced engineering discipline areas year-long technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The purpose of the RATS is to drive out preliminary exploration concept of operations EVA system requirements by providing hands-on experience with simulated planetary surface exploration extravehicular activity (EVA) hardware and procedures. The RATS activities also are of significant importance in helping to develop the necessary levels of technical skills and experience for the next generation of engineers, scientists, technicians, and astronauts who will be responsible for realizing the goals of the Constellation Program. The 2005 Desert RATS was the eighth RATS field test and was the most systems-oriented, integrated field test to date with participants from NASA field centers, the United States Geologic Survey (USGS), industry partners, and research institutes. Each week of the test, the 2005 RATS addressed specific sets of objectives. The first week focused on the performance of surface science astro-biological sampling operations, including planetary protection considerations and procedures. The second week supported evaluation of the Science, Crew, Operations, and Utility Testbed (SCOUT) proto-type rover and its sub-systems. Throughout the duration of the field test, the Communications, Avionics, and Infomatics pack (CAI-pack) was tested. This year the CAI-pack served to provide information on surface navigation, science sample collection procedures, and EVA timeline awareness. Additionally, 2005 was the first year since the Apollo program that two pressurized suited test subjects have worked together simultaneously. Another first was the demonstration of recharge of cryogenic life support systems while in-use by the suited test subjects. The recharge capability allowed the simulated EVA test duration to be doubled, facilitating SCOUT proto-type rover testing. This paper summarizes Desert RATS 2005 test hardware, detailed test objectives, test operations and test results.

View of javelin and golf ball on lunar surface during Apollo 14 EVA

NASA Image and Video Library

1971-02-06

AS14-66-9337 (6 Feb. 1971) --- This view shows the "javelin" and golf ball used by astronaut Alan B. Shepard Jr., commander, during the mission's second extravehicular activity (EVA) on Feb. 6, 1971. Just to the left of center lies the "javelin", with the golf ball just below it, almost perpendicular to it. Dark colored trails are the results of tracks made by the lunar overshoes of the astronauts and the wheels of the modular equipment transporter (MET). This photograph was made through the right window of the Lunar Module (LM), looking northwest.

Active personal radiation monitor for lunar EVA

NASA Astrophysics Data System (ADS)

Straume, Tore; Borak, Tom; Braby, L. A.; Lusby, Terry; Semones, Edward J.; Vazquez, Marcelo E.

As astronauts return to the Moon-and this time, work for extended periods-there will be a critical need for crew personnel radiation monitoring as they operate lunar rovers or otherwise perform a myriad of extravehicular activities (EVAs). Our focus is on development of a small personal radiation monitor for lunar EVA that responds to the complex radiation quality and changing dose rates on the Moon. Of particular concern are active monitoring capabilities that provide both early warning and radiation dosimetry information during solar particle events (SPEs). To accomplish this, we are developing small detectors integrated with modern high speed, low power microelectronics to measure dose-rate and dose-mean lineal energy in real time. The monitor is designed to perform over the range of dose rates and LETs expected from both GCR and SPE radiations during lunar EVA missions. The monitor design provides simultaneous measurement of dose-equivalent rates at two tissue-equivalent depths simulating skin and marrow. The compact personal monitor is estimated to be the size of a cell phone and would fit on an EVA spacesuit (e.g., in backpack) or in a toolbox. The four-year development effort (which began December 2007) will result in a prototype radiation monitor field tested and characterized for the major radiations expected on the surface of the Moon. We acknowledge support from NSBRI through grants to NASA Ames Research Center (T. Straume, PI) and Colorado State University (T. Borak, PI).

Russian EVA fit check

NASA Image and Video Library

2013-06-21

ISS036-E-009793 (21 June 2013) --- Russian cosmonauts Fyodor Yurchikhin (left) and Alexander Misurkin, both Expedition 36 flight engineers, participate in a suited exercise dry run in preparation for a spacewalk in their Russian Orlan spacesuits, which is scheduled for June 24 from the International Space Station’s Pirs docking compartment. Russian cosmonaut Pavel Vinogradov (mostly out of frame at right), Expedition 36 commander, assists Yurchikhin and Misurkin.

STS-135 crew during Ingress/Egress Timeline training in building 9NW space station mockups

NASA Image and Video Library

2011-04-29

JSC2011-E-043872 (29 April 2011) --- NASA astronauts Sandy Magnus and Rex Walheim, both STS-135 mission specialists, participate in an EVA Thermal Protection System (TPS) overview training session in the TPS/Precision Air Bearing Facility in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. A crew instructor (right) assisted Magnus and Walheim. Photo credit: NASA

Astronaut John Grunsfeld during EVA training in the WETF

NASA Technical Reports Server (NTRS)

1995-01-01

Astronaut John M. Grunsfeld, STS-67 mission specialist, gives a salute as he is about to be submerged in a 25-feet deep pool in JSC's Weightless Environment Training Facility (WETF). Wearing a special training version of the Extravehicular Mobility Unit (EMU) space suit and assisted by several JSC SCUBA-equipped divers, Grunsfeld was later using the pool to rehearse contingency space walk chores.

Mars Surface Tunnel Element Concept

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.; Mary, Natalie; Howe, A. Scott; Jeffries, Sharon

2016-01-01

How Mars surface crews get into their ascent vehicle has profound implications for Mars surface architecture. To meet planetary protection protocols, the architecture has get Intravehicular Activity (IVA)-suited crew into a Mars Ascent Vehicle (MAV) without having to step outside into the Mars environment. Pushing EVA suit don/doff and EVA operations to an element that remains on the surface also helps to minimize MAV cabin volume, which in turn can reduce MAV cabin mass. Because the MAV will require at least seven kilograms of propellant to ascend each kilogram of cabin mass, minimal MAV mass is desired. For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The "Minimum Functional Tunnel" is a conceptual design that performs a single function. Having established this baseline configuration, the next step is to trade design options, evaluate other applications, and explore alternative solutions.

The Effects of Lunar Dust on EVA Systems During the Apollo Missions

NASA Technical Reports Server (NTRS)

Gaier, James R.

2005-01-01

Mission documents from the six Apollo missions that landed on the lunar surface have been studied in order to catalog the effects of lunar dust on Extra-Vehicular Activity (EVA) systems, primarily the Apollo surface space suit. It was found that the effects could be sorted into nine categories: vision obscuration, false instrument readings, dust coating and contamination, loss of traction, clogging of mechanisms, abrasion, thermal control problems, seal failures, and inhalation and irritation. Although simple dust mitigation measures were sufficient to mitigate some of the problems (i.e., loss of traction) it was found that these measures were ineffective to mitigate many of the more serious problems (i.e., clogging, abrasion, diminished heat rejection). The severity of the dust problems were consistently underestimated by ground tests, indicating a need to develop better simulation facilities and procedures.

The Effects of Lunar Dust on EVA Systems During the Apollo Missions

NASA Technical Reports Server (NTRS)

Gaier, James R.

2007-01-01

Mission documents from the six Apollo missions that landed on the lunar surface have been studied in order to catalog the effects of lunar dust on Extra-Vehicular Activity (EVA) systems, primarily the Apollo surface space suit. It was found that the effects could be sorted into nine categories: vision obscuration, false instrument readings, dust coating and contamination, loss of traction, clogging of mechanisms, abrasion, thermal control problems, seal failures, and inhalation and irritation. Although simple dust mitigation measures were sufficient to mitigate some of the problems (i.e., loss of traction) it was found that these measures were ineffective to mitigate many of the more serious problems (i.e., clogging, abrasion, diminished heat rejection). The severity of the dust problems were consistently underestimated by ground tests, indicating a need to develop better simulation facilities and procedures.

EVA worksite analysis--use of computer analysis for EVA operations development and execution.

PubMed

Anderson, D

1999-01-01

To sustain the rate of extravehicular activity (EVA) required to assemble and maintain the International Space Station, we must enhance our ability to plan, train for, and execute EVAs. An underlying analysis capability has been developed to ensure EVA access to all external worksites as a starting point for ground training, to generate information needed for on-orbit training, and to react quickly to develop contingency EVA plans, techniques, and procedures. This paper describes the use of computer-based EVA worksite analysis techniques for EVA worksite design. EVA worksite analysis has been used to design 80% of EVA worksites on the U.S. portion of the International Space Station. With the launch of the first U.S. element of the station, EVA worksite analysis is being developed further to support real-time analysis of unplanned EVA operations. This paper describes this development and deployment of EVA worksite analysis for International Space Station (ISS) mission support.

Development of an EVA systems cost model. Volume 3: EVA systems cost model

NASA Technical Reports Server (NTRS)

1975-01-01

The EVA systems cost model presented is based on proposed EVA equipment for the space shuttle program. General information on EVA crewman requirements in a weightless environment and an EVA capabilities overview are provided.

International Space Station (ISS) Plasma Contactor Unit (PCU) Utilization Plan Assessment Update

NASA Technical Reports Server (NTRS)

Hernandez-Pellerano, Amri; Iannello, Christopher J.; Garrett, Henry B.; Ging, Andrew T.; Katz, Ira; Keith, R. Lloyd; Minow, Joseph I.; Willis, Emily M.; Schneider, Todd A.; Whittlesey, Edward J.;

Results from an Investigation into Extra-Vehicular Activity (EVA) Training Related Shoulder Injuries

NASA Technical Reports Server (NTRS)

Johnson, Brian J.; Williams, David R.

2004-01-01

The number and complexity of extravehicular activities (EVAs) required for the completion and maintenance of the International Space Station (ISS) is unprecedented. The training required to successfully complete this magnitude of space walks presents a real risk of overuse musculoskeletal injuries to the EVA crew population. There was mounting evidence raised by crewmembers, trainers, and physicians at the Johnson Space Center (JSC) between 1999 and 2002 that suggested a link between training in the Neutral - Buoyancy Lab (NBL) and the several reported cases of shoulder injuries. The short- and long-term health consequences of shoulder injury to astronauts in training as well as the potential mission impact associated with surgical intervention to assigned EVA crew point to this as a critical problem that must be mitigated. Thus, a multi-directorate tiger team was formed in December of 2002 led by the EVA Office and Astronaut Office at the JSC. The primary objectives of this Tiger Team were to evaluate the prevalence of these injuries and substantiate the relationship to training in the NBL with the crew person operating in the EVA Mobility Unit (EMU). Between December 2002 and June of 2003 the team collected data, surveyed crewmembers, consulted with a variety of physicians, and performed tests. The results of this effort were combined with the vast knowledge and experience of the Tiger Team members to formulate several findings and over fifty recommendations. This paper summarizes those findings and recommendations as well as the process by which these were determined. The Tiger Team concluded that training in the NBL was directly linked to several major and minor shoulder injuries that had occurred. With the assistance of JSC flight surgeons, outside consultants, and the lead crewmember/physician on the team, the mechanisms of injury were determined. These mechanisms were then linked to specific aspects of the hardware design, operational techniques, and the training environment. During the 1999 to 2003 time frame many variables converged to make it impossible to determine with any accuracy which one or two root causes were primarily involved. Therefore a broad range of recommendations was established to prevent future injury to crewmembers training in the NBL in the near term. Many of these recommendations are lessons learned that are essentially timeless and therefore should be passed on to future EVA endeavors to ensure that hardware designs and operational techniques utilized in the future consider the demands of training on the human body here on earth.

EVA Swab Tool to Support Planetary Protection and Astrobiology Evaluations

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.; Hood, Drew; Walker, Mary; Venkateswaran, Kasthuri J.; Schuerger, Andrew C.

2018-01-01

When we send humans to search for life on other planets, we'll need to know what we brought with us versus what may already be there. To ensure our crewed systems meet planetary protection requirements-and to protect our science from human contamination-we'll need to assess whether microorganisms may be leaking or venting from our spacecraft. Microbial sample collection outside of a pressurized spacecraft is complicated by temperature extremes, low pressures that preclude the use of laboratory standard (wetted) swabs, and operation either in bulky spacesuits or with robotic assistance. Engineers at the National Aeronautics and Space Administration (NASA) recently developed a swab kit for use in collecting microbial samples from the external surfaces of crewed spacecraft, including spacesuits. The Extravehicular Activity (EVA) Swab Kit consists of a single swab tool handle and an eight-canister sample caddy. The design team minimized development cost by re-purposing a heritage Space Shuttle tile repair handle that was designed to quickly snap into different tool attachments by engaging a mating device in each attachment. This allowed the tool handle to snap onto a fresh swab attachment much like popular shaving razor handles can snap onto a disposable blade cartridge. To disengage the handle from a swab, the user performs two independent functions, which can be done with a single hand. This dual operation mitigates the risk that a swab will be inadvertently released and lost in microgravity. Each swab attachment is fitted with commercially available foam swab tips, vendor-certified to be sterile for Deoxyribonucleic Acid (DNA). A microbial filter installed in the bottom of each sample container allows the container to outgas and repressurize without introducing microbial contaminants to internal void spaces. Extensive ground testing, post-test handling, and sample analysis confirmed the design is able to maintain sterile conditions as the canister moves between various pressure environments. To further minimize cost, the design team acquired extensive ground test experience in a relevant flight environment by piggy-backing onto suited crew training runs. These training runs allowed the project to validate tool interfaces with pressurized EVA gloves and collect user feedback on the tool design and function, as well as characterize baseline microbial data for different types of spacesuits. In general, test subjects found the EVA Swab Kit relatively straightforward to operate, but identified a number of design improvements that will be incorporated into the final design. Although originally intended to help characterize human forward contaminants, this tool has other potential applications, such as for collecting and preserving space-exposed materials to support astrobiology experiments.

A statistical model for predicting muscle performance

NASA Astrophysics Data System (ADS)

Byerly, Diane Leslie De Caix

The objective of these studies was to develop a capability for predicting muscle performance and fatigue to be utilized for both space- and ground-based applications. To develop this predictive model, healthy test subjects performed a defined, repetitive dynamic exercise to failure using a Lordex spinal machine. Throughout the exercise, surface electromyography (SEMG) data were collected from the erector spinae using a Mega Electronics ME3000 muscle tester and surface electrodes placed on both sides of the back muscle. These data were analyzed using a 5th order Autoregressive (AR) model and statistical regression analysis. It was determined that an AR derived parameter, the mean average magnitude of AR poles, significantly correlated with the maximum number of repetitions (designated Rmax) that a test subject was able to perform. Using the mean average magnitude of AR poles, a test subject's performance to failure could be predicted as early as the sixth repetition of the exercise. This predictive model has the potential to provide a basis for improving post-space flight recovery, monitoring muscle atrophy in astronauts and assessing the effectiveness of countermeasures, monitoring astronaut performance and fatigue during Extravehicular Activity (EVA) operations, providing pre-flight assessment of the ability of an EVA crewmember to perform a given task, improving the design of training protocols and simulations for strenuous International Space Station assembly EVA, and enabling EVA work task sequences to be planned enhancing astronaut performance and safety. Potential ground-based, medical applications of the predictive model include monitoring muscle deterioration and performance resulting from illness, establishing safety guidelines in the industry for repetitive tasks, monitoring the stages of rehabilitation for muscle-related injuries sustained in sports and accidents, and enhancing athletic performance through improved training protocols while reducing injury.

Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities

NASA Technical Reports Server (NTRS)

Koscheyev, V. S.; Leon, G. R.; Hubel, A.; Nelson, E. D.; Tranchida, D.

2000-01-01

BACKGROUND: Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. METHOD: Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. RESULTS: Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. CONCLUSIONS: Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities.

PubMed

Koscheyev, V S; Leon, G R; Hubel, A; Nelson, E D; Tranchida, D

2000-06-01

Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

Shuttle EVA description and design criteria

NASA Technical Reports Server (NTRS)

1983-01-01

The STS extravehicular mobility unit, orbiter EVA provisions, EVA equipment, factors affecting employment of EVA, EVA mission integration, baselined extravehicular activity are discussed. Design requirements are also discussed.

Risk Management in EVA

NASA Technical Reports Server (NTRS)

Hall, Jonathan; Lutomski, M.

2006-01-01

This viewgraph presentation reviews the use of risk management in Extravehicular Activities (EVA). The contents include: 1) EVA Office at NASA - JSC; 2) EVA Project Risk Management: Why and When; 3) EVA Office Risk Management: How; 4) Criteria for Closing a Risk; 5) Criteria for Accepting a Risk; 6) ISS IRMA Reference Card Data Entry Requirement s; 7) XA/ EVA Office Risk Activity Summary; 8) EVA Significant Change Summary; 9) Integrated Risk Management Application (XA) Matrix, March 31, 2004; 10) ISS Watch Item: 50XX Summary Report; and 11) EVA Project RM Usefulness

Astronaut Judith Resnik participates in WETF training

NASA Image and Video Library

1984-05-14

S84-33898 (21 May 1984) --- Astronaut Jon A. McBride, 41-G pilot, assists his crewmate, Astronaut Kathryn D. Sullivan with the glove portion of her extravehicular mobility unit (EMU) prior to Dr. Sullivan's underwater session in the Johnson Space Center's weightless environment training facility (WET-F). Mission specialists Sullivan and David C. Leestma are scheduled for extravehicular activity (EVA) on the Columbia for NASA's 17th scheduled flight.

Cosmonaut Sergei Krikalev receives assistance from suit technician

NASA Technical Reports Server (NTRS)

1994-01-01

Sergei Krikalev, alternative mission specialist for STS-63, gets help from Dawn Mays, a Boeing suit technician. The cosmonaut was about to participate in a training session at JSC's Weightless Environment Training Facility (WETF). Wearing the training version of the extravehicular mobility unit (EMU) space suit, weighted to allow neutral buoyancy in the 25 feet deep WETF pool, Krikalev minutes later was underwater simulating a contingency spacewalk, or extravehicular activity (EVA).

Suitport Feasibility - Development and Test of a Suitport and Space Suit for Human Pressurized Space Suit Donning Tests

NASA Technical Reports Server (NTRS)

Boyle, Robert M.; Mitchell, Kathryn; Allton, Charles; Ju, Hsing

2011-01-01

The suitport concept has been recently implemented as part of the small pressurized lunar rover (Currently the Space Exploration vehicle, or SEV) and the Multi-Mission Space Exploration Vehicle (MMSEV) concept demonstrator vehicle. Suitport replaces or augments the traditional airlock function of a spacecraft by providing a bulkhead opening, capture mechanism, and sealing system to allow ingress and egress of a spacesuit while the spacesuit remains outside of the pressurized volume of the spacecraft. This presents significant new opportunities to EVA exploration in both microgravity and surface environments. The suitport concept will enable three main improvements in EVA by providing reductions in: pre-EVA time from hours to less than thirty minutes; airlock consumables; contamination returned to the cabin with the EVA crewmember. To date, the first generation suitport has been tested with mockup suits on the rover cabins and pressurized on a bench top engineering unit. The work on the rover cabin has helped define the operational concepts and timelines, and has demonstrated the potential of suitport to save significant amounts of crew time before and after EVAs. The work with the engineering unit has successfully demonstrated the pressurizable seal concept including the ability to seal after the introduction and removal of contamination to the sealing surfaces. Using this experience, a second generation suitport was designed. This second generation suitport has been tested with a spacesuit prototype using the pressure differentials of the spacecraft. This test will be performed using the JSC B32 Chamber B, a human rated vacuum chamber. This test will include human rated suitports, the suitport compatible prototype suit, and chamber modifications. This test will bring these three elements together in the first ever pressurized donning of a rear entry suit through a suitport. This paper presents design of a human rated second generation suitport, modifications to the JSC human rated chamber B to accept a suitport, and a compatible space suit to support pressurized human donning of the pressurized suit through a suitport. Design challenges and solutions and compromises required to develop the system are presented. Initial human testing results are presented.

EVA Systems Technology Gaps and Priorities 2017

NASA Technical Reports Server (NTRS)

Johnson, Brian J.; Buffington, Jesse A.

2017-01-01

Performance of Extra-Vehicular Activities (EVA) has been and will continue to be a critical capability for human space flight. Human exploration missions beyond LEO will require EVA capability for either contingency or nominal activities to support mission objectives and reduce mission risk. EVA systems encompass a wide array of products across pressure suits, life support systems, EVA tools and unique spacecraft interface hardware (i.e. EVA Translation Paths and EVA Worksites). In a fiscally limited environment with evolving transportation and habitation options, it is paramount that the EVA community's strategic planning and architecture integration products be reviewed and vetted for traceability between the mission needs far into the future to the known technology and knowledge gaps to the current investments across EVA systems. To ascertain EVA technology and knowledge gaps many things need to be brought together, assessed and analyzed. This includes an understanding of the destination environments, various mission concept of operations, current state of the art of EVA systems, EVA operational lessons learned, and reference advanced capabilities. A combined assessment of these inputs should result in well-defined list of gaps. This list can then be prioritized depending on the mission need dates and time scale of the technology or knowledge gap closure plan. This paper will summarize the current state of EVA related technology and knowledge gaps derived from NASA's Exploration EVA Reference Architecture and Operations Concept products. By linking these products and articulating NASA's approach to strategic development for EVA across all credible destinations an EVA could be done in, the identification of these gaps is then used to illustrate the tactical and strategic planning for the EVA technology development portfolio. Finally, this paper illustrates the various "touch points" with other human exploration risk identification areas including human health and performance.

EVA-Compatible Microbial Swab Tool

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.

2016-01-01

When we send humans to search for life on Mars, we'll need to know what we brought with us versus what may already be there. To ensure our crewed spacecraft meet planetary protection requirements—and to protect our science from human contamination—we'll need to know whether micro-organisms are leaking/venting from our ships and spacesuits. This is easily done by swabbing external vents and suit surfaces for analysis, but requires a specialized tool for the job. Engineers at the National Aeronautics and Space Administration (NASA) recently developed an Extravehicular Activity (EVA)-compatible swab tool that can be used to sample current space suits and life support systems. Data collected now will influence Mars life support and EVA hardware early in the planning process, before design changes become difficult and expensive.NASA’s EVA swab tool pairs a Space Shuttle-era tool handle with a commercially available swab tip mounted into a custom-designed end effector. A glove-compatible release mechanism allows the handle to quickly switch between swab tips, much like a shaving razor handle can snap onto a disposable blade cartridge. Swab tips are stowed inside individual sterile containers, each fitted with a microbial filter that allows the container to equalize atmospheric pressure, but prevents cabin contaminants from rushing into the container when passing from the EVA environment into a pressurized cabin. A bank of containers arrayed inside a tool caddy allows up to six individual samples to be collected during a given spacewalk.NASA plans to use the tool in 2016 to collect samples from various spacesuits during ground testing to determine what (if any) human-borne microbial contamination leaks from the suit under simulated thermal vacuum conditions. Next, the tool will be used on board the International Space Station to assess the types of microbial contaminants found on external environmental control and life support system vents. Data will support advanced EVA and life support system maturation studies, helping to answer questions such as “how close can an EVA-suited crew member approach an area of scientific interest without compromising the science?”

Phase VI Glove Durability Testing

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn

2011-01-01

The current state-of-the-art space suit gloves, the Phase VI gloves, have an operational life of 25 -- 8 hour Extravehicular Activities (EVAs) in a dust free, manufactured microgravity EVA environment. Future planetary outpost missions create the need for space suit gloves which can endure up to 90 -- 8 hour traditional EVAs or 576 -- 45 minute suit port-based EVAs in a dirty, uncontrolled planetary environment. Prior to developing improved space suit gloves for use in planetary environments, it is necessary to understand how the current state-of-the-art performs in these environments. The Phase VI glove operational life has traditionally been certified through cycle testing consisting of International Space Station (ISS)-based EVA tasks in a clean environment, and glove durability while performing planetary EVA tasks in a dirty environment has not previously been characterized. Testing was performed in the spring of 2010 by the NASA Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD) to characterize the durability of the Phase VI Glove and identify areas of the glove design which need improvement to meet the requirements of future NASA missions. Lunar simulant was used in this test to help replicate the dirty lunar environment, and generic planetary surface EVA tasks were performed during testing. A total of 50 manned, pressurized test sessions were completed in the Extravehicular Mobility Unit (EMU) using one pair of Phase VI gloves as the test article. The 50 test sessions were designed to mimic the total amount of pressurized cycling the gloves would experience over a 6 month planetary outpost mission. The gloves were inspected periodically throughout testing, to assess their condition at various stages in the test and to monitor the gloves for failures. Additionally, motion capture and force data were collected during 18 of the 50 test sessions to assess the accuracy of the cycle model predictions used in testing and to feed into the development of improved cycle model tables. This paper provides a detailed description of the test hardware and methodology, shares the results of the testing, and provides recommendations for future work.

Augmented robotic device for EVA hand manoeuvres

NASA Astrophysics Data System (ADS)

Matheson, Eloise; Brooker, Graham

2012-12-01

During extravehicular activities (EVAs), pressurised space suits can lead to difficulties in performing hand manoeuvres and fatigue. This is often the cause of EVAs being terminated early, or taking longer to complete. Assistive robotic gloves can be used to augment the natural motion of a human hand, meaning work can be carried out more efficiently with less stress to the astronaut. Lightweight and low profile solutions must be found in order for the assistive robotic glove to be easily integrated with a space suit pressure garment. Pneumatic muscle actuators combined with force sensors are one such solution. These actuators are extremely light, yet can output high forces using pressurised gases as the actuation drive. Their movement is omnidirectional, so when combined with a flexible exoskeleton that itself provides a degree of freedom of movement, individual fingers can be controlled during flexion and extension. This setup allows actuators and other hardware to be stored remotely on the user's body, resulting in the least possible mass being supported by the hand. Two prototype gloves have been developed at the University of Sydney; prototype I using a fibreglass exoskeleton to provide flexion force, and prototype II using torsion springs to achieve the same result. The gloves have been designed to increase the ease of human movements, rather than to add unnatural ability to the hand. A state space control algorithm has been developed to ensure that human initiated movements are recognised, and calibration methods have been implemented to accommodate the different characteristics of each wearer's hands. For this calibration technique, it was necessary to take into account the natural tremors of the human hand which may have otherwise initiated unexpected control signals. Prototype I was able to actuate the user's hand in 1 degree of freedom (DOF) from full flexion to partial extension, and prototype II actuated a user's finger in 2 DOF with forces achieved comparable to those of a natural, healthy hand. The minimum mass held by the user on the hand was 240 g, with remote hardware, including a compressed air bottle, having a further mass of 1.6 kg. These results indicate that the design is able to augment human motion in a low profile, low mass package, and could be a valuable addition to a space suit during an EVA.

Active Solid State Dosimetry for Lunar EVA

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.; Chen, Liang-Yu.

2006-01-01

The primary threat to astronauts from space radiation is high-energy charged particles, such as electrons, protons, alpha and heavier particles, originating from galactic cosmic radiation (GCR), solar particle events (SPEs) and trapped radiation belts in Earth orbit. There is also the added threat of secondary neutrons generated as the space radiation interacts with atmosphere, soil and structural materials.[1] For Lunar exploration missions, the habitats and transfer vehicles are expected to provide shielding from standard background radiation. Unfortunately, the Lunar Extravehicular Activity (EVA) suit is not expected to afford such shielding. Astronauts need to be aware of potentially hazardous conditions in their immediate area on EVA before a health and hardware risk arises. These conditions would include fluctuations of the local radiation field due to changes in the space radiation field and unknown variations in the local surface composition. Should undue exposure occur, knowledge of the dynamic intensity conditions during the exposure will allow more precise diagnostic assessment of the potential health risk to the exposed individual.[2

Ethylene vinyl acetate based radiation grafted hydrophilic matrices: Process parameter standardization, grafting kinetics and characterization

NASA Astrophysics Data System (ADS)

Chaudhari, C. V.; Mondal, R. K.; Dubey, K. A.; Grover, V.; Panicker, L.; Bhardwaj, Y. K.; Varshney, L.

2016-08-01

A transparent, elastomeric, grafted matrix for several potential applications was synthesized by single-step simultaneous radiation grafting of methacrylic acid onto ethylene vinyl acetate (EVA). CuSO4 was found to be the most suitable homo-polymerization inhibitor among different inhibitors tried. The grafting kinetics was found to be a strong function of dose rate (D) and monomer content (M) and an equation relating grafting rate Rg=Kg [M]1.13D0.23 was deduced. Crystallinity of the grafted matrices as assessed from XRD and DSC measurements indicated decrease in crystalline content with increase in grafting yield, suggesting crystalline domain of EVA get disrupted on grafting. Elastic modulus increased linearly with the increase in grafting yield, though elongation at break decreased precipitously from 900% to 30% at even 9% grafting. Thermo-gravimetric analysis showed three step weight loss of the grafted EVA matrix. The grafting of MAA resulted in increase in surface energy mainly due to enhanced polar component.

Interviews with the Apollo lunar surface astronauts in support of planning for EVA systems design

NASA Technical Reports Server (NTRS)

Connors, Mary M.; Eppler, Dean B.; Morrow, Daniel G.

1994-01-01

Focused interviews were conducted with the Apollo astronauts who landed on the moon. The purpose of these interviews was to help define extravehicular activity (EVA) system requirements for future lunar and planetary missions. Information from the interviews was examined with particular attention to identifying areas of consensus, since some commonality of experience is necessary to aid in the design of advanced systems. Results are presented under the following categories: mission approach; mission structure; suits; portable life support systems; dust control; gloves; automation; information, displays, and controls; rovers and remotes; tools; operations; training; and general comments. Research recommendations are offered, along with supporting information.

MS Peterson and MS Musgrave in payload bay (PLB) during EVA

NASA Technical Reports Server (NTRS)

1983-01-01

Extravehicular mobility unit (EMU) suited Mission Specialist (MS) Peterson, designated EV2, translates from forward payload bay (PLB) to aft bulkhead worksite along port side sill longeron using tether and slidewire system while MS Musgrave, designated EV1, floats on a tether in center of PLB. Inertial Upper Stage (IUS) Airborne Support Equipment (ASE) forward frame and aft frame tilt actuator (AFTA) table appear in front and behind Musgrave and vertical tail and Orbital Maneuvering System (OMS) pods appear in background highlighted against the cloudy surface of Earth. EMU mini workstation extravehicular activity (EVA) crewmember safety tether reel floats on Musgrave's waist tether.

Estimating the value of volunteer-assisted community-based aging services: a case example.

PubMed

Scharlach, Andrew E

2015-01-01

This study demonstrates the use of a social return on investment (SROI) approach in estimating the financial and social value created by volunteer-assisted community-based aging services. An expanded value added statement (EVAS) analysis found that the total value of outputs produced by the Concierge Club of San Diego substantially exceeded the cost of the program, after considering likely secondary and tertiary benefits for a range of affected stakeholders-including elderly service recipients, family members, volunteers, and societal institutions. Additional research is needed regarding the direct and indirect costs and benefits of volunteer support services for vulnerable older adults and their families.

Energy utilization rates during shuttle extravehicular activities.

PubMed

Waligora, J M; Kumar, K V

1995-01-01

The work rates or energy utilization rates during EVA are major factors in sizing of life support systems. These rates also provide a measure of ease of EVA and its cost in crew fatigue. From the first Shuttle EVA on the STS-6 mission in 1983, we have conducted 59 man-EVA and 341 man-hours of EVA. Energy utilization rates have been measured on each of these EVA. Metabolic rate was measured during each EVA using oxygen utilization corrected for suit leakage. From 1981-1987, these data were available for average data over the EVA or over large segments of the EVA. Since 1987, EVA oxygen utilization data were available at 2-minute intervals. The average metabolic rate on Shuttle EVA (194 kcal/hr.) has been significantly lower than metabolic rates during Apollo and Skylab missions. Peak rates have been below design levels, infrequent, and of short duration. The data suggest that the energy cost of tasks may be inversely related to the degree of training for the task. The data provide insight on the safety margins provided by life support designs and on the energy cost of Station construction EVA.

Architectural development of an advanced EVA Electronic System

NASA Technical Reports Server (NTRS)

Lavelle, Joseph

1992-01-01

An advanced electronic system for future EVA missions (including zero gravity, the lunar surface, and the surface of Mars) is under research and development within the Advanced Life Support Division at NASA Ames Research Center. As a first step in the development, an optimum system architecture has been derived from an analysis of the projected requirements for these missions. The open, modular architecture centers around a distributed multiprocessing concept where the major subsystems independently process their own I/O functions and communicate over a common bus. Supervision and coordination of the subsystems is handled by an embedded real-time operating system kernel employing multitasking software techniques. A discussion of how the architecture most efficiently meets the electronic system functional requirements, maximizes flexibility for future development and mission applications, and enhances the reliability and serviceability of the system in these remote, hostile environments is included.

A Novel Recombinant Enterovirus Type EV-A89 with Low Epidemic Strength in Xinjiang, China

PubMed Central

Fan, Qin; Zhang, Yong; Hu, Lan; Sun, Qiang; Cui, Hui; Yan, Dongmei; Sikandaner, Huerxidan; Tang, Haishu; Wang, Dongyan; Zhu, Zhen; Zhu, Shuangli; Xu, Wenbo

2015-01-01

Enterovirus A89 (EV-A89) is a novel member of the EV-A species. To date, only one full-length genome sequence (the prototype strain) has been published. Here, we report the molecular identification and genomic characterization of a Chinese EV-A89 strain, KSYPH-TRMH22F/XJ/CHN/2011, isolated in 2011 from a contact of an acute flaccid paralysis (AFP) patient during AFP case surveillance in Xinjiang China. This was the first report of EV-A89 in China. The VP1 coding sequence of this strain demonstrated 93.2% nucleotide and 99.3% amino acid identity with the EV-A89 prototype strain. In the P2 and P3 regions, the Chinese EV-A89 strain demonstrated markedly higher identity than the prototype strains of EV-A76, EV-A90, and EV-A91, indicating that one or more recombination events between EV-A89 and these EV-A types might have occurred. Long-term evolution of these EV types originated from the same ancestor provides the spatial and temporal circumstances for recombination to occur. An antibody sero-prevalence survey against EV-A89 in two Xinjiang prefectures demonstrated low positive rates and low titres of EV-A89 neutralization antibody, suggesting limited range of transmission and exposure to the population. This study provides a solid foundation for further studies on the biological and pathogenic properties of EV-A89. PMID:26685900

A Novel Recombinant Enterovirus Type EV-A89 with Low Epidemic Strength in Xinjiang, China.

PubMed

Fan, Qin; Zhang, Yong; Hu, Lan; Sun, Qiang; Cui, Hui; Yan, Dongmei; Sikandaner, Huerxidan; Tang, Haishu; Wang, Dongyan; Zhu, Zhen; Zhu, Shuangli; Xu, Wenbo

2015-12-21

Enterovirus A89 (EV-A89) is a novel member of the EV-A species. To date, only one full-length genome sequence (the prototype strain) has been published. Here, we report the molecular identification and genomic characterization of a Chinese EV-A89 strain, KSYPH-TRMH22F/XJ/CHN/2011, isolated in 2011 from a contact of an acute flaccid paralysis (AFP) patient during AFP case surveillance in Xinjiang China. This was the first report of EV-A89 in China. The VP1 coding sequence of this strain demonstrated 93.2% nucleotide and 99.3% amino acid identity with the EV-A89 prototype strain. In the P2 and P3 regions, the Chinese EV-A89 strain demonstrated markedly higher identity than the prototype strains of EV-A76, EV-A90, and EV-A91, indicating that one or more recombination events between EV-A89 and these EV-A types might have occurred. Long-term evolution of these EV types originated from the same ancestor provides the spatial and temporal circumstances for recombination to occur. An antibody sero-prevalence survey against EV-A89 in two Xinjiang prefectures demonstrated low positive rates and low titres of EV-A89 neutralization antibody, suggesting limited range of transmission and exposure to the population. This study provides a solid foundation for further studies on the biological and pathogenic properties of EV-A89.

EVA1A inhibits GBM cell proliferation by inducing autophagy and apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Xue; Kan, Shifeng; Liu, Zhen

Eva-1 homolog A (EVA1A) is a novel lysosome and endoplasmic reticulum-associated protein involved in autophagy and apoptosis. In this study, we constructed a recombinant adenovirus 5-EVA1A vector (Ad5-EVA1A) to overexpress EVA1A in glioblastoma (GBM) cell lines and evaluated its anti-tumor activities in vitro and in vivo. We found that overexpression of EVA1A in three GBM cell lines (U251, U87 and SHG44) resulted in a suppression of tumor cell growth via activation of autophagy and induction of cell apoptosis in a dose- and time-dependent manner. EVA1A-mediated autophagy was associated with inactivation of the mTOR/RPS6KB1 signaling pathway. Furthermore in vivo, overexpression ofmore » EVA1A successfully inhibited tumor growth in NOD/SCID mice. Our data suggest that EVA1A-induced autophagy and apoptosis play a role in suppressing the development of GBM and their up-regulation may be an effective method for treating this form of cancer. - Highlights: • Overexpression of EVA1A suppresses GBM cell growth. • EVA1A induces autophagy through the mTOR/RPS6KB1 pathway. • EVA1A induces GBM cell apoptosis. • EVA1A inhibits the development of GBM in vivo.« less

Application of Shuttle EVA Systems to Payloads. Volume 2: Payload EVA Task Completion Plans

NASA Technical Reports Server (NTRS)

1976-01-01

Candidate payload tasks for EVA application were identified and selected, based on an analysis of four representative space shuttle payloads, and typical EVA scenarios with supporting crew timelines and procedures were developed. The EVA preparations and post EVA operations, as well as the timelines emphasizing concurrent payload support functions, were also summarized.

Advanced EVA system design requirements study: EVAS/space station system interface requirements

NASA Technical Reports Server (NTRS)

Woods, T. G.

1985-01-01

The definition of the Extravehicular Activity (EVA) systems interface requirements and accomodations for effective integration of a production EVA capability into the space station are contained. A description of the EVA systems for which the space station must provide the various interfaces and accomodations are provided. The discussion and analyses of the various space station areas in which the EVA interfaces are required and/or from which implications for EVA system design requirements are derived, are included. The rationale is provided for all EVAS mechanical, fluid, electrical, communications, and data system interfaces as well as exterior and interior requirements necessary to facilitate EVA operations. Results of the studies supporting these discussions are presented in the appendix.

Tracking Historical NASA EVA Training: Lifetime Surveillance of Astronaut Health (LSAH) Development of the EVA Suit Exposure Tracker (EVA SET)

NASA Technical Reports Server (NTRS)

Laughlin, Mitzi S.; Murray, Jocelyn D.; Lee, Lesley R.; Wear, Mary L.; Van Baalen, Mary

2017-01-01

During a spacewalk, designated as extravehicular activity (EVA), an astronaut ventures from the protective environment of the spacecraft into the vacuum of space. EVAs are among the most challenging tasks during a mission, as they are complex and place the astronaut in a highly stressful environment dependent on the spacesuit for survival. Due to the complexity of EVA, NASA has conducted various training programs on Earth to mimic the environment of space and to practice maneuvers in a more controlled and forgiving environment. However, rewards offset the risks of EVA, as some of the greatest accomplishments in the space program were accomplished during EVA, such as the Apollo moonwalks and the Hubble Space Telescope repair missions. Water has become the environment of choice for EVA training on Earth, using neutral buoyancy as a substitute for microgravity. During EVA training, an astronaut wears a modified version of the spacesuit adapted for working in water. This high fidelity suit allows the astronaut to move in the water while performing tasks on full-sized mockups of space vehicles, telescopes, and satellites. During the early Gemini missions, several EVA objectives were much more difficult than planned and required additional time. Later missions demonstrated that "complex (EVA) tasks were feasible when restraints maintained body position and underwater simulation training ensured a high success probability".1,2 EVA training has evolved from controlling body positioning to perform basic tasks to complex maintenance of the Hubble Space Telescope and construction of the International Space Station (ISS). Today, preparation is centered at special facilities built specifically for EVA training, such as the Neutral Buoyancy Laboratory (NBL) at NASA's Johnson Space Center ([JSC], Houston) and the Hydrolab at the Gagarin Cosmonaut Training Centre ([GCTC], Star City, outside Moscow). Underwater training for an EVA is also considered hazardous duty for NASA astronauts. This activity places astronauts at risk for decompression sickness and barotrauma as well as various musculoskeletal disorders from working in the spacesuit. The medical, operational and research communities over the years have requested access to EVA training data to better understand the risks. As a result of these requests, epidemiologists within the Lifetime Surveillance of Astronaut Health (LSAH) team have compiled records from numerous EVA training venues to quantify the exposure to EVA training. The EVA Suit Exposure Tracker (EVA SET) dataset is a compilation of ground-based training activities using the extravehicular mobility unit (EMU) in neutrally buoyant pools to enhance EVA performance on orbit. These data can be used by the current ISS program and future exploration missions by informing physicians, researchers, and operational personnel on the risks of EVA training in order that future suit and mission designs incorporate greater safety. The purpose of this technical report is to document briefly the various facilities where NASA astronauts have performed EVA training while describing in detail the EVA training records used to generate the EVA SET dataset.

A Human Machine Interface for EVA

NASA Astrophysics Data System (ADS)

Hartmann, L.

EVA astronauts work in a challenging environment that includes high rate of muscle fatigue, haptic and proprioception impairment, lack of dexterity and interaction with robotic equipment. Currently they are heavily dependent on support from on-board crew and ground station staff for information and robotics operation. They are limited to the operation of simple controls on the suit exterior and external robot controls that are difficult to operate because of the heavy gloves that are part of the EVA suit. A wearable human machine interface (HMI) inside the suit provides a powerful alternative for robot teleoperation, procedure checklist access, generic equipment operation via virtual control panels and general information retrieval and presentation. The HMI proposed here includes speech input and output, a simple 6 degree of freedom (dof) pointing device and a heads up display (HUD). The essential characteristic of this interface is that it offers an alternative to the standard keyboard and mouse interface of a desktop computer. The astronaut's speech is used as input to command mode changes, execute arbitrary computer commands and generate text. The HMI can respond with speech also in order to confirm selections, provide status and feedback and present text output. A candidate 6 dof pointing device is Measurand's Shapetape, a flexible "tape" substrate to which is attached an optic fiber with embedded sensors. Measurement of the modulation of the light passing through the fiber can be used to compute the shape of the tape and, in particular, the position and orientation of the end of the Shapetape. It can be used to provide any kind of 3d geometric information including robot teleoperation control. The HUD can overlay graphical information onto the astronaut's visual field including robot joint torques, end effector configuration, procedure checklists and virtual control panels. With suitable tracking information about the position and orientation of the EVA suit, the overlaid graphical information can be registered with the external world. For example, information about an object can be positioned on or beside the object. This wearable HMI supports many applications during EVA including robot teleoperation, procedure checklist usage, operation of virtual control panels and general information or documentation retrieval and presentation. Whether the robot end effector is a mobile platform for the EVA astronaut or is an assistant to the astronaut in an assembly or repair task, the astronaut can control the robot via a direct manipulation interface. Embedded in the suit or the astronaut's clothing, Shapetape can measure the user's arm/hand position and orientation which can be directly mapped into the workspace coordinate system of the robot. Motion of the users hand can generate corresponding motion of the robot end effector in order to reposition the EVA platform or to manipulate objects in the robot's grasp. Speech input can be used to execute commands and mode changes without the astronaut having to withdraw from the teleoperation task. Speech output from the system can provide feedback without affecting the user's visual attention. The procedure checklist guiding the astronaut's detailed activities can be presented on the HUD and manipulated (e.g., move, scale, annotate, mark tasks as done, consult prerequisite tasks) by spoken command. Virtual control panels for suit equipment, equipment being repaired or arbitrary equipment on the space station can be displayed on the HUD and can be operated by speech commands or by hand gestures. For example, an antenna being repaired could be pointed under the control of the EVA astronaut. Additionally arbitrary computer activities such as information retrieval and presentation can be carried out using similar interface techniques. Considering the risks, expense and physical challenges of EVA work, it is appropriate that EVA astronauts have considerable support from station crew and ground station staff. Reducing their dependence on such personnel may under many circumstances, however, improve performance and reduce risk. For example, the EVA astronaut is likely to have the best viewpoint at a robotic worksite. Direct access to the procedure checklist can help provide temporal context and continuity throughout an EVA. Access to station facilities through an HMI such as the one described here could be invaluable during an emergency or in a situation in which a fault occurs. The full paper will describe the HMI operation and applications in the EVA context in more detail and will describe current laboratory prototyping activities.

Constellation Architecture Team-Lunar: Lunar Habitat Concepts

NASA Technical Reports Server (NTRS)

Toups, Larry; Kennedy, Kriss J.

2008-01-01

This paper will describe lunar habitat concepts that were defined as part of the Constellation Architecture Team-Lunar (CxAT-Lunar) in support of the Vision for Space Exploration. There are many challenges to designing lunar habitats such as mission objectives, launch packaging, lander capability, and risks. Surface habitats are required in support of sustaining human life to meet the mission objectives of lunar exploration, operations, and sustainability. Lunar surface operations consist of crew operations, mission operations, EVA operations, science operations, and logistics operations. Habitats are crewed pressurized vessels that include surface mission operations, science laboratories, living support capabilities, EVA support, logistics, and maintenance facilities. The challenge is to deliver, unload, and deploy self-contained habitats and laboratories to the lunar surface. The CxAT-Lunar surface campaign analysis focused on three primary trade sets of analysis. Trade set one (TS1) investigated sustaining a crew of four for six months with full outpost capability and the ability to perform long surface mission excursions using large mobility systems. Two basic habitat concepts of a hard metallic horizontal cylinder and a larger inflatable torus concept were investigated as options in response to the surface exploration architecture campaign analysis. Figure 1 and 2 depicts the notional outpost configurations for this trade set. Trade set two (TS2) investigated a mobile architecture approach with the campaign focused on early exploration using two small pressurized rovers and a mobile logistics support capability. This exploration concept will not be described in this paper. Trade set three (TS3) investigated delivery of a "core' habitation capability in support of an early outpost that would mature into the TS1 full outpost capability. Three core habitat concepts were defined for this campaign analysis. One with a four port core habitat, another with a 2 port core habitat, and the third investigated leveraging commonality of the lander ascent module and airlock pressure vessel hard shell. The paper will describe an overview of the various habitat concepts and their functionality. The Crew Operations area includes basic crew accommodations such as sleeping, eating, hygiene and stowage. The EVA Operations area includes additional EVA capability beyond the suit-port airlock function such as redundant airlock(s), suit maintenance, spares stowage, and suit stowage. The Logistics Operations area includes the enhanced accommodations for 180 days such as closed loop life support systems hardware, consumable stowage, spares stowage, interconnection to the other Hab units, and a common interface mechanism for future growth and mating to a pressurized rover. The Mission & Science Operations area includes enhanced outpost autonomy such as an IVA glove box, life support, and medical operations.

Knockout of Eva1a leads to rapid development of heart failure by impairing autophagy

PubMed Central

Zhang, Shu; Lin, Xin; Li, Ge; Shen, Xue; Niu, Di; Lu, Guang; Fu, Xin; Chen, Yingyu; Cui, Ming; Bai, Yun

2017-01-01

EVA1A (Eva-1 homologue A) is a novel lysosome and endoplasmic reticulum-associated protein that can regulate cell autophagy and apoptosis. Eva1a is expressed in the myocardium, but its function in myocytes has not yet been investigated. Therefore, we generated inducible, cardiomyocyte-specific Eva1a knockout mice with an aim to determine the role of Eva1a in cardiac remodelling in the adult heart. Data from experiments showed that loss of Eva1a in the adult heart increased cardiac fibrosis, promoted cardiac hypertrophy, and led to cardiomyopathy and death. Further investigation suggested that this effect was associated with impaired autophagy and increased apoptosis in Eva1a knockout hearts. Moreover, knockout of Eva1a activated Mtor signalling and the subsequent inhibition of autophagy. In addition, Eva1a knockout hearts showed disorganized sarcomere structure and mitochondrial misalignment and aggregation, leading to the lack of ATP generation. Collectively, these data demonstrated that Eva1a improves cardiac function and inhibits cardiac hypertrophy and fibrosis by increasing autophagy. In conclusion, our results demonstrated that Eva1a may have an important role in maintaining cardiac homeostasis. PMID:28151473

Post-Shuttle EVA Operations on ISS

NASA Technical Reports Server (NTRS)

West, William; Witt, Vincent; Chullen, Cinda

2010-01-01

The expected retirement of the NASA Space Transportation System (also known as the Space Shuttle ) by 2011 will pose a significant challenge to Extra-Vehicular Activities (EVA) on-board the International Space Station (ISS). The EVA hardware currently used to assemble and maintain the ISS was designed assuming that it would be returned to Earth on the Space Shuttle for refurbishment, or if necessary for failure investigation. With the retirement of the Space Shuttle, a new concept of operations was developed to enable EVA hardware (Extra-vehicular Mobility Unit (EMU), Airlock Systems, EVA tools, and associated support hardware and consumables) to perform ISS EVAs until 2015, and possibly beyond to 2020. Shortly after the decision to retire the Space Shuttle was announced, the EVA 2010 Project was jointly initiated by NASA and the One EVA contractor team. The challenges addressed were to extend the operating life and certification of EVA hardware, to secure the capability to launch EVA hardware safely on alternate launch vehicles, to protect for EMU hardware operability on-orbit, and to determine the source of high water purity to support recharge of PLSSs (no longer available via Shuttle). EVA 2010 Project includes the following tasks: the development of a launch fixture that would allow the EMU Portable Life Support System (PLSS) to be launched on-board alternate vehicles; extension of the EMU hardware maintenance interval from 3 years (current certification) to a minimum of 6 years (to extend to 2015); testing of recycled ISS Water Processor Assembly (WPA) water for use in the EMU cooling system in lieu of water resupplied by International Partner (IP) vehicles; development of techniques to remove & replace critical components in the PLSS on-orbit (not routine); extension of on-orbit certification of EVA tools; and development of an EVA hardware logistical plan to support the ISS without the Space Shuttle. Assumptions for the EVA 2010 Project included no more than 8 EVAs per year for ISS EVA operations in the Post-Shuttle environment and limited availability of cargo upmass on IP launch vehicles. From 2010 forward, EVA operations on-board the ISS without the Space Shuttle will be a paradigm shift in safely operating EVA hardware on orbit and the EVA 2010 effort was initiated to accommodate this significant change in EVA evolutionary history. 1

Post-Shuttle EVA Operations on ISS

NASA Technical Reports Server (NTRS)

West, Bill; Witt, Vincent; Chullen, Cinda

2010-01-01

The EVA hardware used to assemble and maintain the ISS was designed with the assumption that it would be returned to Earth on the Space Shuttle for ground processing, refurbishment, or failure investigation (if necessary). With the retirement of the Space Shuttle, a new concept of operations was developed to enable EVA hardware (EMU, Airlock Systems, EVA tools, and associated support equipment and consumables) to perform ISS EVAs until 2016 and possibly beyond to 2020. Shortly after the decision to retire the Space Shuttle was announced, NASA and the One EVA contractor team jointly initiated the EVA 2010 Project. Challenges were addressed to extend the operating life and certification of EVA hardware, secure the capability to launch EVA hardware safely on alternate launch vehicles, and protect EMU hardware operability on orbit for long durations.

Space Station Freedom extravehicular activity systems evolution study

NASA Technical Reports Server (NTRS)

Rouen, Michael

1990-01-01

Evaluation of Space Station Freedom (SSF) support of manned exploration is in progress to identify SSF extravehicular activity (EVA) system evolution requirements and capabilities. The output from these studies will provide data to support the preliminary design process to ensure that Space Station EVA system requirements for future missions (including the transportation node) are adequately considered and reflected in the baseline design. The study considers SSF support of future missions and the EVA system baseline to determine adequacy of EVA requirements and capabilities and to identify additional requirements, capabilities, and necessary technology upgrades. The EVA demands levied by formal requirements and indicated by evolutionary mission scenarios are high for the out-years of Space Station Freedom. An EVA system designed to meet the baseline requirements can easily evolve to meet evolution demands with few exceptions. Results to date indicate that upgrades or modifications to the EVA system may be necessary to meet the full range of EVA thermal environments associated with the transportation node. Work continues to quantify the EVA capability in this regard. Evolution mission scenarios with EVA and ground unshielded nuclear propulsion engines are inconsistent with anthropomorphic EVA capabilities.

Blue Print to India’s Amphibious Forces

DTIC Science & Technology

2009-01-01

Commando Force Humanitarian Assistance and Disaster Relief Non-combatant Eva~uationOperations Indian Ocean Region Sea Lanes of Communication Indian P ~ace...security policy - all buttress each other." u This strategic outlook of India, in consonance with her economic, foreign and defense policies, guid~s...between 17,000 tons - 24,000 tons.51 The LPD can carry 720 troops and have a 24 bed medical facility with two operating rooms52 whilst ------ ------ 16

Effect of Rare Earth Ions on the Properties of Composites Composed of Ethylene Vinyl Acetate Copolymer and Layered Double Hydroxides

PubMed Central

Wang, Lili; Li, Bin; Zhao, Xiaohong; Chen, Chunxia; Cao, Jingjing

2012-01-01

Background The study on the rare earth (RE)-doped layered double hydroxides (LDHs) has received considerable attention due to their potential applications in catalysts. However, the use of RE-doped LDHs as polymer halogen-free flame retardants was seldom investigated. Furthermore, the effect of rare earth elements on the hydrophobicity of LDHs materials and the compatibility of LDHs/polymer composite has seldom been reported. Methodology/Principal Findings The stearate sodium surface modified Ni-containing LDHs and RE-doped Ni-containing LDHs were rapidly synthesized by a coprecipitation method coupled with the microwave hydrothermal treatment. The influences of trace amounts of rare earth ions La, Ce and Nd on the amount of water molecules, the crystallinity, the morphology, the hydrophobicity of modified Ni-containing LDHs and the adsorption of modifier in the surface of LDHs were investigated by TGA, XRD, TEM, contact angle and IR, respectively. Moreover, the effects of the rare earth ions on the interfacial compatibility, the flame retardancy and the mechanical properties of ethylene vinyl acetate copolymer (EVA)/LDHs composites were also explored in detail. Conclusions/Significance S-Ni0.1MgAl-La displayed more uniform dispersion and better interfacial compatibility in EVA matrix compared with other LDHs. Furthermore, the S-Ni0.1MgAl-La/EVA composite showed the best fire retardancy and mechanical properties in all composites. PMID:22693627

EVA Wiki - Transforming Knowledge Management for EVA Flight Controllers and Instructors

NASA Technical Reports Server (NTRS)

Johnston, Stephanie S.; Alpert, Brian K.; Montalvo, Edwin James; Welsh, Lawrence Daren; Wray, Scott; Mavridis, Costa

2016-01-01

The EVA Wiki was recently implemented as the primary knowledge database to retain critical knowledge and skills in the EVA Operations group at NASA's Johnson Space Center by ensuring that information is recorded in a common, easy to search repository. Prior to the EVA Wiki, information required for EVA flight controllers and instructors was scattered across different sources, including multiple file share directories, SharePoint, individual computers, and paper archives. Many documents were outdated, and data was often difficult to find and distribute. In 2011, a team recognized that these knowledge management problems could be solved by creating an EVA Wiki using MediaWiki, a free and open-source software developed by the Wikimedia Foundation. The EVA Wiki developed into an EVA-specific Wikipedia on an internal NASA server. While the technical implementation of the wiki had many challenges, one of the biggest hurdles came from a cultural shift. Like many enterprise organizations, the EVA Operations group was accustomed to hierarchical data structures and individually-owned documents. Instead of sorting files into various folders, the wiki searches content. Rather than having a single document owner, the wiki harmonized the efforts of many contributors and established an automated revision controlled system. As the group adapted to the wiki, the usefulness of this single portal for information became apparent. It transformed into a useful data mining tool for EVA flight controllers and instructors, as well as hundreds of others that support the EVA. Program managers, engineers, astronauts, flight directors, and flight controllers in differing disciplines now have an easier-to-use, searchable system to find EVA data. This paper presents the benefits the EVA Wiki has brought to NASA's EVA community, as well as the cultural challenges it had to overcome.

EVA Wiki - Transforming Knowledge Management for EVA Flight Controllers and Instructors

NASA Technical Reports Server (NTRS)

Johnston, Stephanie S.; Alpert, Brian K.; Montalvo, Edwin James; Welsh, Lawrence Daren; Wray, Scott; Mavridis, Costa

2016-01-01

The EVA Wiki was recently implemented as the primary knowledge database to retain critical knowledge and skills in the EVA Operations group at NASA's Johnson Space Center by ensuring that information is recorded in a common, easy to search repository. Prior to the EVA Wiki, information required for EVA flight controllers and instructors was scattered across different sources, including multiple file share directories, SharePoint, individual computers, and paper archives. Many documents were outdated, and data was often difficult to find and distribute. In 2011, a team recognized that these knowledge management problems could be solved by creating an EVA Wiki using MediaWiki, a free and open-source software developed by the Wikimedia Foundation. The EVA Wiki developed into an EVA-specific Wikipedia on an internal NASA server. While the technical implementation of the wiki had many challenges, one of the biggest hurdles came from a cultural shift. Like many enterprise organizations, the EVA Operations group was accustomed to hierarchical data structures and individually-owned documents. Instead of sorting files into various folders, the wiki searches content. Rather than having a single document owner, the wiki harmonized the efforts of many contributors and established an automated revision controlled system. As the group adapted to the wiki, the usefulness of this single portal for information became apparent. It transformed into a useful data mining tool for EVA flight controllers and instructors, as well as hundreds of others that support EVA. Program managers, engineers, astronauts, flight directors, and flight controllers in differing disciplines now have an easier-to-use, searchable system to find EVA data. This paper presents the benefits the EVA Wiki has brought to NASA's EVA community, as well as the cultural challenges it had to overcome.

Development of new EVA formulations for improved performance at NREL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.

1997-02-01

We review in chronological order the research stages and fundamental concepts involved in developing modified and new EVA formulations for improved performance against photo-induced degradation and discoloration. The new NREL EVA formulations use additives totally different from the present commercial formulations (EVA A9918 and EVA 15295). Validation of their long-term photostability and thermostability is presently under way. Together with UV-absorbing glass superstrates, they may offer better success in achieving a more reliable module performance and longer service life without significant EVA discoloration problems, which are commonly experienced with EVA A9918 and, at a lesser rate, EVA 15295. {copyright} {ital 1997more » American Institute of Physics.}« less

Astronaut Charles Duke examines surface of boulder at North Ray crater

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Charles M. Duke Jr., lunar module pilot of the Apollo 16 lunar landing mission, examines the surface of a large boulder at North Ray crater during the third Apollo 16 extravehicular activity (EVA-3) at the Descartes landing site. This picture was taken by Astronaut John W. Young, commander. Note the chest-mounted 70mm Hasselblad camera.

Effect of EVA on thermal stability, flammability, mechanical properties of HDPE/EVA/Mg(OH)2 composites

NASA Astrophysics Data System (ADS)

Cao, R.; Deng, Z. L.; Ma, Y. H.; Chen, X. L.

2017-06-01

In this work, ethylene vinyl acetate (EVA) is introduced to improve the properties of high-density polyethylene (HDPE)/magnesium hydroxide (MH) composites. The thermal stability, flame retardancy and mechanical properties of HDPE/EVA/MH composites are investigated and discussed. With increasing content of EVA, the limiting oxygen index (LOI) of the composites increases. The thermal stability analysis shows that the initial decomposition temperature begins at a low temperature; however, the residues of the composites at 600°C increase when HDPE is replaced by small amounts of EVA. The early degradation absorbs heat, dilute oxygen and residue. During this process, it protects the matrix inside. Compared with the HDPE/MH and EVA/MH composites, the ternary HDPE/EVA/MH composites exhibit better flame retardancy by increasing the LOI values, and reducing the heat release rate (HRR) and total heat release (THR). With increasing content of EVA, the mechanical properties can also be improved, which is attributed to the good affinity between EVA and MH particles.

Application of shuttle EVA systems to payloads. Volume 1: EVA systems and operational modes description

NASA Technical Reports Server (NTRS)

1976-01-01

Descriptions of the EVA system baselined for the space shuttle program were provided, as well as a compendium of data on available EVA operational modes for payload and orbiter servicing. Operational concepts and techniques to accomplish representative EVA payload tasks are proposed. Some of the subjects discussed include: extravehicular mobility unit, remote manipulator system, airlock, EVA translation aids, restraints, workstations, tools and support equipment.

The Utility of a Small Pressurized Rover with Suit Ports for Lunar Exploration: A Geologist's Perspective

NASA Technical Reports Server (NTRS)

Kring, David A.; Bleacher, Jacob E.; Garry, W. Brent; Love, Stanley G.; Young, Kelsey E.

2017-01-01

Rover trade study: As summarized recently, mission simulations at Black Point Lava Flow (Arizona) that included realistic extravehicular activity (EVA) tasking, accurate traverse timelines, and an in-loop science CAPCOM (or SciCOM) showed that a small pressurized rover (SPR) was a better mobility asset than an unpressurized rover (UPR). Traverses within the SPR were easier on crew than spending an entire day in a spacesuit, enhancing crew productivity at each station. The SPR, named Lunar Electric Rover (LER), and sometimes called the Space Exploration Vehicle (SEV), could also provide shelter during a suit malfunction, radiation event, or medical emergency that might occur on the Moon. Intravehicular activity (IVA) capabilities: From within the vehicle, crew could describe and photo-document distant features during drives between stations, as well as in the near-field, directly in front of the LER, providing an ability to begin EVA planning on approach to each outcrop prior to egress. The vehicle can rotate 360º without any lateral movement, providing views in all directions. It has high-visibility windows, a ForeCam, AftCam, port and starboard cameras, docking cameras, and a GigaPan camera. EVA capabilities: To reduce timeline, mass, and volumetric overhead, rapid egress and ingress were envisioned, replacing an airlock with lower cabin pressure than on the International Space Station and suit ports on the aft cabin wall [2]. When needed for closer inspection and sample collecting, crew could egress in about 10 minutes through suit ports. Crew use SuitCams for additional photo-documentation, transmit mobile observations verbally, and collect surface materials. Typical simulations involved 3 to 4 EVA stations/day and 2 to 3 hr/day of boots on the ground. This allowed crew to explore a far larger territory, with more complex geological and in situ resource utilization (ISRU) features, than would a single, longer-duration EVA at one location, while also minimizing crew time in a spacesuit. Additionally, the vehicle could be driven with crew locked into the suit ports. This approach could involve a driver in the cockpit with a suited crewmember in a suit port, or the vehicle could be driven from the aft deck with both crewmembers in their suit ports. This approach was used when distances between stops were short enough that vehicle ingress and egress were less efficient than remaining in the suits and driving. Utility of suit ports: The advantages of suit ports were clearly demonstrated in those field-based trade studies. To illustrate those advantages further, consider the consequences of a SPR without suit ports at the Apollo 17 landing site. At that site, the crew's second EVA was an approximately 18 km loop conducted in a UPR, called the Lunar Roving Vehicle (LRV), in 7 hr 36 min 56 s. The traverse was composed of 5 formal stations, plus 8 additional LRV stations where crew made brief scientific stops. In a scenario involving a SPR without suit ports, crew would go EVA through an airlock and probably be limited to a single EVA per day. In that case, crew could drive the SPR 9 km from the landing site to station 2, go EVA, and complete station 2 tasks. However, to conduct station 3 tasks, the crew would then need to walk approximately 3 km to station 3, while ground control in Houston tele-robotically drives the LER to station 3. A walk of approximately 3 km is possible, as that is what the Apollo 14 crew did before LRVs were deployed, but it is a lengthy and potentially grueling EVA. Assuming crew completes station 3 tasks, they would likely need to re-enter the SPR, ending the day's EVA, and return to the landing site. They would not be able to walk the additional distances to stations 4 and 5 (the latter being about 6 km from station 3). Thus, crew in an SPR without suit ports would require two days to accomplish the same tasks Apollo 17 crew completed in a single day. If a future crew is involved in long duration traverses on the lunar surface, the deployment of a vehicle with suit ports would probably be a better solution.

EVA Physiology and Medical Considerations Working in the Suit

NASA Technical Reports Server (NTRS)

Parazynski, Scott

2012-01-01

This "EVA Physiology and Medical Considerations Working in the Suit" presentation covers several topics related to the medical implications and physiological effects of suited operations in space from the perspective of a physician with considerable first-hand Extravehicular Activity (EVA) experience. Key themes include EVA physiology working in a pressure suit in the vacuum of space, basic EVA life support and work support, Thermal Protection System (TPS) inspections and repairs, and discussions of the physical challenges of an EVA. Parazynski covers the common injuries and significant risks during EVAs, as well as physical training required to prepare for EVAs. He also shares overall suit physiological and medical knowledge with the next generation of Extravehicular Mobility Unit (EMU) system designers.

Exploration EVA System

NASA Technical Reports Server (NTRS)

Kearney, Lara

2004-01-01

In January 2004, the President announced a new Vision for Space Exploration. NASA's Office of Exploration Systems has identified Extravehicular Activity (EVA) as a critical capability for supporting the Vision for Space Exploration. EVA is required for all phases of the Vision, both in-space and planetary. Supporting the human outside the protective environment of the vehicle or habitat and allow ing him/her to perform efficient and effective work requires an integrated EVA "System of systems." The EVA System includes EVA suits, airlocks, tools and mobility aids, and human rovers. At the core of the EVA System is the highly technical EVA suit, which is comprised mainly of a life support system and a pressure/environmental protection garment. The EVA suit, in essence, is a miniature spacecraft, which combines together many different sub-systems such as life support, power, communications, avionics, robotics, pressure systems and thermal systems, into a single autonomous unit. Development of a new EVA suit requires technology advancements similar to those required in the development of a new space vehicle. A majority of the technologies necessary to develop advanced EVA systems are currently at a low Technology Readiness Level of 1-3. This is particularly true for the long-pole technologies of the life support system.

Exploration Architecture Options - ECLSS, EVA, TCS Implications

NASA Technical Reports Server (NTRS)

Chambliss, Joe; Henninger, Don; Lawrence, Carl

2010-01-01

Many options for exploration of space have been identified and evaluated since the Vision for Space Exploration (VSE) was announced in 2004. Lunar architectures have been identified and addressed in the Lunar Surface Systems team to establish options for how to get to and then inhabit and explore the moon. The Augustine Commission evaluated human space flight for the Obama administration and identified many options for how to conduct human spaceflight in the future. This paper will evaluate the options for exploration of space for the implications of architectures on the Environmental Control and Life Support (ECLSS), ExtraVehicular Activity (EVA) and Thermal Control System (TCS) Systems. The advantages and disadvantages of each architecture and options are presented.

View of portion of "relatively fresh" crater as photographed by Apollo 15

NASA Image and Video Library

1971-07-31

AS15-82-11082 (2 Aug. 1971) --- A close-up view of a portion of a "relatively fresh" crater, looking southeast, as photographed during the third Apollo 15 lunar surface extravehicular activity (EVA), on Aug. 2, 1971, at EVA Station No. 9, near Scarp Crater. The crater pictured is unnamed. The Apennine Front is in the background, and Hadley Delta Mountain is in the right background. While astronauts David R. Scott, commander, and James B. Irwin, lunar module pilot, descended in the Lunar Module (LM) "Falcon" to explore the moon, astronaut Alfred M. Worden, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit.

View of the Lunar Module "Orion" and Lunar Roving Vehicle during first EVA

NASA Image and Video Library

1972-04-21

AS16-107-17436 (21 April 1972) --- An excellent view of the Lunar Module (LM) "Orion" and Lunar Roving Vehicle (LRV), as photographed by astronaut Charles M. Duke Jr., lunar module pilot, during the first Apollo 16 extravehicular activity (EVA) at the Descartes landing site. Astronaut John W. Young, commander, can be seen directly behind the LRV. The lunar surface feature in the left background is Stone Mountain. While astronauts Young and Duke descended in the LM to explore the Descartes highlands landing site on the moon, astronaut Thomas K. Mattingly II, command module pilot, remained with the Command and Service Modules (CSM) "Casper" in lunar orbit.

Exploration Architecture Options - ECLSS, TCS, EVA Implications

NASA Technical Reports Server (NTRS)

Chambliss, Joe; Henninger, Don

2011-01-01

Many options for exploration of space have been identified and evaluated since the Vision for Space Exploration (VSE) was announced in 2004. The Augustine Commission evaluated human space flight for the Obama administration then the Human Exploration Framework Teams (HEFT and HEFT2) evaluated potential exploration missions and the infrastructure and technology needs for those missions. Lunar architectures have been identified and addressed by the Lunar Surface Systems team to establish options for how to get to, and then inhabit and explore, the moon. This paper will evaluate the options for exploration of space for the implications of architectures on the Environmental Control and Life Support (ECLSS), Thermal Control (TCS), and Extravehicular Activity (EVA) Systems.

The use of an extended ventilation tube as a countermeasure for EVA-associated upper extremity medical issues

NASA Astrophysics Data System (ADS)

Jones, J. A.; Hoffman, R. B.; Buckland, D. A.; Harvey, C. M.; Bowen, C. K.; Hudy, C. E.; Strauss, S.; Novak, J.; Gernhardt, M. L.

Introduction: Onycholysis due to repetitive activity in the space suit glove during Neutral Buoyancy Laboratory (NBL) training and during spaceflight extravehicular activity (EVA) is a common observation. Moisture accumulates in gloves during EVA task performance and may contribute to the development of pain and damage to the fingernails experienced by many astronauts. The study evaluated the use of a long ventilation tube to determine if improved gas circulation into the hand area could reduce hand moisture and thereby decrease the associated symptoms. Methods: The current Extravehicular Mobility Unit (EMU) was configured with a ventilation tube that extended down a single arm of the crew member (E) and compared with the unventilated arm (C). Skin surface moisture was measured on both hands immediately after glove removal and a questionnaire administered to determine subjective measures. Astronauts ( n=6) were examined pre- and post-run. Results: There were consistent trends in the reduction of relative hydration ratios at dorsum ( C=3.34, E=2.11) and first ring finger joint ( C=2.46, E=1.96) when the ventilation tube was employed. Ventilation appeared more effective on the left versus the right hand, implying an interaction with hand anthropometry and glove fit. Symptom score was lower on the hand that had the long ventilation tube relative to the control hand in 2/6 EVA crew members. Conclusions: Increased ventilation to the hand was effective in reducing the risks of hand and nail discomfort symptoms from moderate to low in one-third of the subjects. Improved design in the ventilation capability of EVA spacesuits is expected to improve efficiency of air flow distribution.

Achieving environmental excellence through a multidisciplinary grassroots movement.

PubMed

Herechuk, Bryan; Gosse, Carolyn; Woods, John N

2010-01-01

St. Joseph's Healthcare Hamilton (SJHH) supports a grassroots green team, called Environmental Vision and Action (EVA). Since the creation of EVA, a healthy balance between corporate projects led by corporate leaders and grassroots initiatives led by informal leaders has resulted in many successful environmental initiatives. Over a relatively short period of time, environmental successes at SJHH have included waste diversion programs, energy efficiency and reduction initiatives, alternative commuting programs, green purchasing practices, clinical and pharmacy greening and increased staff engagement and awareness. Knowledge of social movements theory helped EVA leaders to understand the internal processes of a grassroots movement and helped to guide it. Social movements theory may also have broader applicability in health care by understanding the passionate engagement that people bring to a common cause and how to evolve sources of opposition into engines for positive change. After early successes, as the limitations of a grassroots movement began to surface, the EVA team revived the concept of evolving the grassroots green program into a corporate program for environmental stewardship. It is hard to quantify the importance of allowing our staff, physicians, volunteers and patients to engage in changes that they feel passionately about. However, at SJHH, the transformation of a group of people unsatisfied with the organization's environmental performance into an 'engine for change' has led to a rapid improvement in environmental stewardship at SJHH that is now regarded as a success.

Maturing Pump Technology for EVA Applications in a Collaborative Environment

NASA Technical Reports Server (NTRS)

Hodgson, Edward; Dionne, Steven; Gervais, Edward; Anchondo, Ian

2012-01-01

The transition from low earth orbit Extravehicular Activity (EVA) for construction and maintenance activities to planetary surface EVA on asteroids, moons, and, ultimately, Mars demands a new spacesuit system. NASA's development of that system has resulted in dramatically different pumping requirements from those in the current spacesuit system. Hamilton Sundstrand, Cascon, and NASA are collaborating to develop and mature a pump that will reliably meet those new requirements in space environments and within the design constraints imposed by spacesuit system integration. That collaboration, which began in the NASA purchase of a pump prototype for test evaluation, is now entering a new phase of development. A second generation pump reflecting the lessons learned in NASA's testing of the original prototype will be developed under Hamilton Sundstrand internal research funding and ultimately tested in an integrated Advanced Portable Life Support System (APLSS) in NASA laboratories at the Johnson Space Center. This partnership is providing benefit to both industry and NASA by supplying a custom component for EVA integrated testing at no cost to the government while providing test data for industry that would otherwise be difficult or impossible to duplicate in industry laboratories. This paper discusses the evolving collaborative process, component requirements and design development based on early NASA test experience, component stand alone test results, and near term plans for integrated testing at JSCs.

EVA Wiki - Transforming Knowledge Management for EVA Flight Controllers and Instructors

NASA Technical Reports Server (NTRS)

Johnston, Stephanie

2016-01-01

The EVA (Extravehicular Activity) Wiki was recently implemented as the primary knowledge database to retain critical knowledge and skills in the EVA Operations group at NASA's Johnson Space Center by ensuring that information is recorded in a common, searchable repository. Prior to the EVA Wiki, information required for EVA flight controllers and instructors was scattered across different sources, including multiple file share directories, SharePoint, individual computers, and paper archives. Many documents were outdated, and data was often difficult to find and distribute. In 2011, a team recognized that these knowledge management problems could be solved by creating an EVA Wiki using MediaWiki, a free and open-source software developed by the Wikimedia Foundation. The EVA Wiki developed into an EVA-specific Wikipedia on an internal NASA server. While the technical implementation of the wiki had many challenges, the one of the biggest hurdles came from a cultural shift. Like many enterprise organizations, the EVA Operations group was accustomed to hierarchical data structures and individually-owned documents. Instead of sorting files into various folders, the wiki searches content. Rather than having a single document owner, the wiki harmonized the efforts of many contributors and established an automated revision control system. As the group adapted to the wiki, the usefulness of this single portal for information became apparent. It transformed into a useful data mining tool for EVA flight controllers and instructors, and also for hundreds of other NASA and contract employees. Program managers, engineers, astronauts, flight directors, and flight controllers in differing disciplines now have an easier-to-use, searchable system to find EVA data. This paper presents the benefits the EVA Wiki has brought to NASA's EVA community, as well as the cultural challenges it had to overcome.

The Evolution of Extravehicular Activity Operations to Lunar Exploration Based on Operational Lessons Learned During 2009 NASA Desert RATS Field Testing

NASA Technical Reports Server (NTRS)

Bell, Ernest R., Jr.; Welsh, Daren; Coan, Dave; Johnson, Kieth; Ney, Zane; McDaniel, Randall; Looper, Chris; Guirgis, Peggy

2010-01-01

This paper will present options to evolutionary changes in several philosophical areas of extravehicular activity (EVA) operations. These areas will include single person verses team EVAs; various loss of communications scenarios (with Mission Control, between suited crew, suited crew to rover crew, and rover crew A to rover crew B); EVA termination and abort time requirements; incapacitated crew ingress time requirements; autonomous crew operations during loss of signal periods including crew decisions on EVA execution (including decision for single verses team EVA). Additionally, suggestions as to the evolution of the make-up of the EVA flight control team from the current standard will be presented. With respect to the flight control team, the major areas of EVA flight control, EVA Systems and EVA Tasks, will be reviewed, and suggested evolutions of each will be presented. Currently both areas receive real-time information, and provide immediate feedback during EVAs as well as spacesuit (extravehicular mobility unit - EMU) maintenance and servicing periods. With respect to the tasks being performed, either EMU servicing and maintenance, or the specific EVA tasks, daily revising of plans will need to be able to be smoothly implemented to account for unforeseen situations and findings. Many of the presented ideas are a result of lessons learned by the NASA Johnson Space Center Mission Operations Directorate operations team support during the 2009 NASA Desert Research and Technology Studies (Desert RATS). It is important that the philosophy of both EVA crew operations and flight control be examined now, so that, where required, adjustments can be made to a next generation EMU and EVA equipment that will complement the anticipated needs of both the EVA flight control team and the crews.

Advanced development of non-discoloring EVA-based PV encapsulants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holley, W.H.; Galica, J.P.; Argo, S.C.

1996-01-01

The purpose of this investigation was to better define the problem of field yellowing of EVA-based PV encapsulant, through laboratory study of probable chemical mechanisms and the development of stabilization strategies for protecting EVA from discoloration. EVA from fielded modules was analyzed for vinyl acetate content, unsaturation, and additive levels. These test results were then compared to results from Xenon Arc Weather-Ometer aged glass/EVA/glass laminates made in the laboratory. Variables evaluated in Weather-Ometer aged laminates included ``standard-cure`` A9918P EVA, ``fast-cure`` 15295P EVA, low iron glass superstrate containing cerium oxide, and systematic elimination or addition of specific additives. Six significant findingsmore » were revealed: 1) Improved ``standard-cure`` and ``fast-cure`` type EVA encapsulants, formulations X9903P and X15303P, respectively, showed little or no yellowing after extended Weather-Ometer exposure; 2) The use of {open_quote}{open_quote}fast-cure{close_quote}{close_quote} EVA reduced discoloration when compared with {open_quote}{open_quote}standard-cure{close_quote}{close_quote} A9918P EVA; 3) Glass superstrate containing cerium oxide resulted in a reduced rate of EVA discoloration; 4) {open_quote}{open_quote}Fast-cure{close_quote}{close_quote} EVA used with glass superstrate containing cerium oxide showed no visible yellowing after 32 weeks in the Weather-Ometer{emdash}a period estimated to be roughly equivalent to 20{endash}30 years of exposure in the Southwest; 5) Severely discolored EVA samples from the field showed no measurable loss of acetate group and little detectable unsaturation; and 6) EVA encapsulant with a Tefzel cover exhibited no yellowing after extended Weather-Ometer exposure. {copyright} {ital 1996 American Institute of Physics.}« less

Real-Time EVA Troubleshooting

NASA Technical Reports Server (NTRS)

Leestma, David

2013-01-01

David Leestma was EV-1 for the STS-41G extravehicular activity (EVA) with Kathy Sullivan (first American female spacewalker). They conducted an EVA to fully demonstrate the feasibility of refueling satellites from the Space Shuttle, and performed the first contingency EVA task involving the Ku-band antenna. STS-41G was the fourth Space Shuttle mission to perform an EVA, and Leestma related his experiences with training, the spacesuit, and EVA tasks that were conducted on October 11, 1984 during this mission.

EVA1A inhibits GBM cell proliferation by inducing autophagy and apoptosis.

PubMed

Shen, Xue; Kan, Shifeng; Liu, Zhen; Lu, Guang; Zhang, Xiaoyan; Chen, Yingyu; Bai, Yun

2017-03-01

Eva-1 homolog A (EVA1A) is a novel lysosome and endoplasmic reticulum-associated protein involved in autophagy and apoptosis. In this study, we constructed a recombinant adenovirus 5-EVA1A vector (Ad5-EVA1A) to overexpress EVA1A in glioblastoma (GBM) cell lines and evaluated its anti-tumor activities in vitro and in vivo. We found that overexpression of EVA1A in three GBM cell lines (U251, U87 and SHG44) resulted in a suppression of tumor cell growth via activation of autophagy and induction of cell apoptosis in a dose- and time-dependent manner. EVA1A-mediated autophagy was associated with inactivation of the mTOR/RPS6KB1 signaling pathway. Furthermore in vivo, overexpression of EVA1A successfully inhibited tumor growth in NOD/SCID mice. Our data suggest that EVA1A-induced autophagy and apoptosis play a role in suppressing the development of GBM and their up-regulation may be an effective method for treating this form of cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of Damp-Heat Resistant Self-Primed EVA and Non-EVA Encapsulant Formulations at NREL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F. J.; Jorgensen, G. J.

2005-11-01

Self-primed ethylene-vinyl acetate (EVA) and non-EVA (PMG) encapsulant formulations were developed that have greater resistance to damp heat exposure at 85 deg C and 85% relative humidity (RH) (in terms of adhesion strength to glass substrates) than a commonly used commercial EVA product. The self-primed EVA formulations were developed on the basis of high-performing glass priming formulations that have previously proven to significantly enhance the adhesion strength of unprimed and primed EVA films on glass substrates during damp heat exposure. The PMG encapsulant formulations were based on an ethylene-methylacrylate copolymer containing glycidyl methacrylate.

Effect of VA and MWNT contents on the rheological and physical properties of EVA

NASA Astrophysics Data System (ADS)

Kim, Jong-Ho; Lee, Seungwon; Kim, Byoung Chul; Shin, Bong-Seob; Jeon, Jong-Young; Chae, Dong Wook

2016-02-01

Ethylene vinyl acetate (EVA) copolymers with two different VA contents (15 and 33 wt.%, denoted by EVA15 and EVA33, respectively) were melt compounded with multi-walled carbon nanotubes (MWNTs) and the effect of VA and nanotube contents on the rheological, thermal and morphological properties was investigated. The addition of nanotubes into both EVAs increased the onset temperature of crystallization and broadened the peak, but further addition from 3 wt.% slightly decreased the temperature with increasing nanotube contents. In the wide angle X-ray diffraction patterns the peak of EVA15 was little affected by the presence of nanotubes but that of EVA33 slightly shifted to higher degree and became sharper with increasing nanotube contents. Dynamic viscosity (η') increased with nanotube contents giving abrupt increase at 2 wt.% nanotubes. Loss tangent decreased with increasing nanotube contents exhibiting the plateau-like behavior over most of the frequency range from 2 wt.% nanotubes. In the Casson plot, yield stress increased with nanotube content and its increasing extent was more notable for more VA content. In the Cole-Cole plot, the presence of nanotubes from 2 wt.% gave rise to the deviation from the single master curve by decreasing the slope. The deviated extent of EVA33 became more remarkable with increasing nanotube contents than that of EVA15. The stress-strain curve showed that more improved tensile modulus and yield stress were achieved by the introduction of MWNTs for EVA 33 than for EVA15. Tensile strength of EVA33 increased with increasing nanotube contents, while that of EVA15 decreased.

US EVA 16 EMU Prep

NASA Image and Video Library

2010-08-11

ISS024-E-011673 (11 Aug. 2010) --- NASA astronaut Tracy Caldwell Dyson, Expedition 24 flight engineer, attired in her Extravehicular Mobility Unit (EMU) spacesuit, is pictured in the Quest airlock of the International Space Station as the second of three planned spacewalks to remove and replace an ammonia pump module that failed July 31 draws to a close. NASA astronaut Shannon Walker and Russian cosmonaut Fyodor Yurchikhin, both flight engineers, assist Caldwell Dyson with the doffing of her spacesuit.

Cassidy, Barratt and Wakata in Airlock

NASA Image and Video Library

2009-07-27

ISS020-E-025693 (27 July 2009) --- Attired in his Extravehicular Mobility Unit (EMU) spacesuit, astronaut Christopher Cassidy, STS-127 mission specialist, is pictured in the Quest Airlock of the International Space Station as the mission's fifth and final session of extravehicular activity (EVA) draws to a close. Astronaut Michael Barratt, Expedition 20 flight engineer, photographs the EMU gloves worn by Cassidy while Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, mission specialist, assists with the doffing of the spacesuit.

Space shuttle EVA opportunities. [a technology assessment

NASA Technical Reports Server (NTRS)

Bland, D. A., Jr.

1976-01-01

A technology assessment is presented on space extravehicular activities (EVA) that will be possible when the space shuttle orbiter is completed and launched. The use of EVA in payload systems design is discussed. Also discussed is space crew training. The role of EVA in connection with the Large Space Telescope and Skylab are described. The value of EVA in constructing structures in space and orbital assembly is examined. Excellent color illustrations are provided which show the proposed EVA functions that were described.

[The present status and development of thermal control system of spacesuits for extravehicular activity].

PubMed

Zhao, C Y; Sun, J B; Yuan, X G

1999-04-01

With the extension of extravehicular activity (EVA) duration, the need for more effective thermal control of EVA spacesuits is required. The specific schemes investigated in heat sink system for EVA are discussed, including radiator, ice storage, metal hydride heat pump, phase-change storage/radiator and sublimator. The importance and requirements of automatic thermal control for EVA are also discussed. Existed automatic thermal control for EVA are reviewed. Prospects of further developments of thermal control of spacesuits for EVA are proposed.

Recycling WEEE: Polymer characterization and pyrolysis study for waste of crystalline silicon photovoltaic modules.

PubMed

Dias, Pablo; Javimczik, Selene; Benevit, Mariana; Veit, Hugo

2017-02-01

Photovoltaic (PV) modules contain both valuable and hazardous materials, which makes its recycling meaningful economically and environmentally. In general, the recycling of PV modules starts with the removal of the polymeric ethylene-vinyl acetate (EVA) resin using pyrolysis, which assists in the recovery of materials such as silicon, copper and silver. The pyrolysis implementation, however, needs improvement given its importance. In this study, the polymers in the PV modules were characterized by Fourier transform infrared spectroscopy (FTIR) and the removal of the EVA resin using pyrolysis has been studied and optimized. The results revealed that 30min pyrolysis at 500°C removes >99% of the polymers present in photovoltaic modules. Moreover, the behavior of different particle size milled modules during the pyrolysis process was evaluated. It is shown that polymeric materials tend to remain at a larger particle size and thus, this fraction has the greatest mass loss during pyrolysis. A thermo gravimetric analysis (TGA) performed in all polymeric matter revealed the optimum pyrolysis temperature is around 500°C. Temperatures above 500°C continue to degrade matter, but mass loss rate is 6.25 times smaller. This study demonstrates the use of pyrolysis can remove >99% of the polymeric matter from PV modules, which assists the recycling of this hazardous waste and avoids its disposal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Crew/Robot Coordinated Planetary EVA Operations at a Lunar Base Analog Site

NASA Technical Reports Server (NTRS)

Diftler, M. A.; Ambrose, R. O.; Bluethmann, W. J.; Delgado, F. J.; Herrera, E.; Kosmo, J. J.; Janoiko, B. A.; Wilcox, B. H.; Townsend, J. A.; Matthews, J. B.;

Heart Rhythm Monitoring in the Constellation Lunar and Launch/Landing EVA Suit: Recommendations from an Expert Panel

NASA Technical Reports Server (NTRS)

Scheuring, Richard A.; Hamilton, D.; Jones, J. A.; Alexander, D.

2008-01-01

Currently there are several physiological monitoring requirements for Extravehicular Activity (EVA) in the Human-Systems Interface Requirements (HSIR) document, including continuous heart rhythm monitoring. However, it is not known whether heart rhythm monitoring in the lunar surface space suit is a necessary capability for lunar surface operations or in launch/landing suit the event of a cabin depressurization enroute to or from the moon. Methods: Current US astronaut corps demographic information was provided to an expert panel of cardiovascular medicine experts, including specialists in electrophysiology, exercise physiology, interventional cardiology and arrhythmia. This information included averages for male/female age, body mass index (BMI), blood pressure, cholesterol, inflammatory markers, echocardiogram, ranges for coronary artery calcium (CAC) scores for long duration astronauts, and ranges for heart rate (HR) and metabolic (MET) rates obtained during microgravity and lunar EVA. Results: The panel determined that no uncontrolled hazard was likely to occur in the suit during lunar surface or contingency microgravity ops that would require ECG monitoring in the highly screened US astronaut population. However having the capability for rhythm monitoring inside the vehicle (IVA) was considered critical to manage an astronaut in distress. Discussion: Heart rate (HR) monitoring alone allows effective monitoring of astronaut health and function. Consequently, electrocardiographic (ECG) monitoring capability as a clinical tool is not essential in the lunar or launch/landing space suit. However, the panel considered that rhythm monitoring could be useful in certain clinical situations, it was not considered required for safe operations. Also, lunar vehicles should be required to have ECG monitoring capability with a minimum of 5-lead ECG (derived 12- lead) for IVA medical assessments.

Lithium Iron Phosphate Cell Performance Evaluations for Lunar Extravehicular Activities

NASA Technical Reports Server (NTRS)

Reid, Concha

2007-01-01

Lithium-ion battery cells are being evaluated for their ability to provide primary power and energy storage for NASA s future Exploration missions. These missions include the Orion Crew Exploration Vehicle, the Ares Crew Launch Vehicle Upper Stage, Extravehicular Activities (EVA, the advanced space suit), the Lunar Surface Ascent Module (LSAM), and the Lunar Precursor and Robotic Program (LPRP), among others. Each of these missions will have different battery requirements. Some missions may require high specific energy and high energy density, while others may require high specific power, wide operating temperature ranges, or a combination of several of these attributes. EVA is one type of mission that presents particular challenges for today s existing power sources. The Portable Life Support System (PLSS) for the advanced Lunar surface suit will be carried on an astronaut s back during eight hour long sorties, requiring a lightweight power source. Lunar sorties are also expected to occur during varying environmental conditions, requiring a power source that can operate over a wide range of temperatures. Concepts for Lunar EVAs include a primary power source for the PLSS that can recharge rapidly. A power source that can charge quickly could enable a lighter weight system that can be recharged while an astronaut is taking a short break. Preliminary results of Al23 Ml 26650 lithium iron phosphate cell performance evaluations for an advanced Lunar surface space suit application are discussed in this paper. These cells exhibit excellent recharge rate capability, however, their specific energy and energy density is lower than typical lithium-ion cell chemistries. The cells were evaluated for their ability to provide primary power in a lightweight battery system while operating at multiple temperatures.

Advanced EVA system design requirements study

NASA Technical Reports Server (NTRS)

Woods, T. G.

1988-01-01

The results are presented of a study to identify specific criteria regarding space station extravehicular activity system (EVAS) hardware requirements. Key EVA design issues include maintainability, technology readiness, LSS volume vs. EVA time available, suit pressure/cabin pressure relationship and productivity effects, crew autonomy, integration of EVA as a program resource, and standardization of task interfaces. A variety of DOD EVA systems issues were taken into consideration. Recommendations include: (1) crew limitations, not hardware limitations; (2) capability to perform all of 15 generic missions; (3) 90 days on-orbit maintainability with 50 percent duty cycle as minimum; and (4) use by payload sponsors of JSC document 10615A plus a Generic Tool Kit and Specialized Tool Kit description. EVA baseline design requirements and criteria, including requirements of various subsystems, are outlined. Space station/EVA system interface requirements and EVA accommodations are discussed in the areas of atmosphere composition and pressure, communications, data management, logistics, safe haven, SS exterior and interior requirements, and SS airlock.

EVA Swab Tool to Support Planetary Protection and Astrobiology Evaluations

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.; Hood, Drew; Walker, Mary; Venkateswaran, Kasthuri J.; Schuerger, Andrew C.

2018-01-01

When we send humans to search for life on other planets, we'll need to know what we brought with us versus what may already be there. To ensure our crewed systems meet planetary protection requirements-and to protect our science from human contamination-we'll need to assess whether microorganisms may be leaking or venting from our spacecraft. Microbial sample collection outside of a pressurized spacecraft is complicated by temperature extremes, low pressures that preclude the use of laboratory standard (wetted) swabs, and operation either in bulky spacesuits or with robotic assistance. A team at the National Aeronautics and Space Administration (NASA) recently developed a swab kit for use in collecting microbial samples from the external surfaces of crewed spacecraft, including spacesuits. The Extravehicular Activity (EVA) Swab Kit consists of a single swab tool handle and an eight-canister sample caddy. The design team minimized development cost by re-purposing a heritage Space Shuttle tile repair handle that was designed to quickly snap into different tool attachments by engaging a mating device in each end effector. This allowed the tool handle to snap onto a fresh swab end effector much like popular shaving razor handles can snap onto a disposable blade cartridge. To disengage the handle from a swab, the user performs two independent functions, which can be done with a single hand. This dual operation mitigates the risk that a swab will be inadvertently released and lost in microgravity. Each swab end effector is fitted with commercially available foam swab tips, vendor-certified to be sterile for Deoxyribonucleic Acid (DNA). A microbial filter installed in the bottom of each sample container allows the container to outgas and re-pressurize without introducing microbial contaminants to internal void spaces. Extensive ground testing, post-test handling, and sample analysis confirmed the design is able to maintain sterile conditions as the canister moves between various pressure environments. To further minimize cost, the design team acquired extensive ground test experience in a relevant flight environment by piggy-backing onto suited crew training runs. These training runs allowed the project to validate tool interfaces with pressurized EVA gloves and collect user feedback on the tool design and function, as well as characterize baseline microbial data for different types of spacesuits. In general, test subjects found the EVA Swab Kit relatively straightforward to operate, but identified a number of design improvements that will be incorporated into the final design. Although originally intended to help characterize human forward contaminants, this tool has other potential applications, such as for collecting and preserving space-exposed materials to support astrobiology experiments.

Suitport Feasibility: Development and Test of a Suitport and Space Suit for Human Pressurized Space Suit Donning Tests

NASA Technical Reports Server (NTRS)

Boyle, Robert M.; Mitchell, Kathryn; Allton, Charles; Ju, Hsing

2012-01-01

The suitport concept has been recently implemented as part of the small pressurized lunar rover (Currently the Space Exploration vehicle, or SEV) and the Multi-Mission Space Exploration Vehicle (MMSEV) concept demonstrator vehicle. Suitport replaces or augments the traditional airlock function of a spacecraft by providing a bulkhead opening, capture mechanism, and sealing system to allow ingress and egress of a space suit while the space suit remains outside of the pressurized volume of the spacecraft. This presents significant new opportunities to EVA exploration in both microgravity and surface environments. The suitport concept will enable three main improvements in EVA by providing reductions in: pre-EVA time from hours to less than thirty minutes; airlock consumables; contamination returned to the cabin with the EVA crewmember. To date, the first generation suitport has been tested with mockup suits on the rover cabins and pressurized on a bench top engineering unit. The work on the rover cabin has helped define the operational concepts and timelines, and has demonstrated the potential of suitport to save significant amounts of crew time before and after EVAs. The work with the engineering unit has successfully demonstrated the pressurizable seal concept including the ability to seal after the introduction and removal of contamination to the sealing surfaces. Using this experience, a second generation suitport was designed. This second generation suitport has been tested with a space suit prototype on the second generation MMSEV cabin, and testing is planned using the pressure differentials of the spacecraft. Pressurized testing will be performed using the JSC B32 Chamber B, a human rated vacuum chamber. This test will include human rated suitports, a suitport compatible prototype suit, and chamber modifications. This test will bring these three elements together in the first ever pressurized donning of a rear entry suit through a suitport. This paper presents the design of a human rated second generation suitport, the design of a suit capable of supporting pressurized human donning through a suitport, ambient pressure testing of the suit with the suitport, and modifications to the JSC human rated chamber B to accept a suitport. Design challenges and solutions, as well as compromises required to develop the system, are presented. Initial human testing results are presented.

EVA safety: Space suit system interoperability

NASA Technical Reports Server (NTRS)

Skoog, A. I.; McBarron, J. W.; Abramov, L. P.; Zvezda, A. O.

1995-01-01

The results and the recommendations of the International Academy of Astronautics extravehicular activities (IAA EVA) Committee work are presented. The IAA EVA protocols and operation were analyzed for harmonization procedures and for the standardization of safety critical and operationally important interfaces. The key role of EVA and how to improve the situation based on the identified EVA space suit system interoperability deficiencies were considered.

EVA Training and Development Facilities

NASA Technical Reports Server (NTRS)

Cupples, Scott

2016-01-01

Overview: Vast majority of US EVA (ExtraVehicular Activity) training and EVA hardware development occurs at JSC; EVA training facilities used to develop and refine procedures and improve skills; EVA hardware development facilities test hardware to evaluate performance and certify requirement compliance; Environmental chambers enable testing of hardware from as large as suits to as small as individual components in thermal vacuum conditions.

Improved Mineral Nutrition for Pear Shoot Cultures

USDA-ARS?s Scientific Manuscript database

The USDA-ARS National Clonal Germplasm Repository has over 200 pear accessions in culture, encompassing 18 species. Plant growth response on standard tissue culture medium varies widely due to the wide horticultural diversity of this collection. We used a systematic response-surface approach to eva...

Surface extra-vehicular activity emergency scenario management: Tools, procedures, and geologically related implications

NASA Astrophysics Data System (ADS)

Zea, Luis; Diaz, Alejandro R.; Shepherd, Charles K.; Kumar, Ranganathan

2010-07-01

Extra-vehicular activities (EVAs) are an essential part of human space exploration, but involve inherently dangerous procedures which can put crew safety at risk during a space mission. To help mitigate this risk, astronauts' training programs spend substantial attention on preparing for surface EVA emergency scenarios. With the help of two Mars Desert Research Station (MDRS) crews (61 and 65), wearing simulated spacesuits, the most important of these emergency scenarios were examined at three different types of locations that geologically and environmentally resemble lunar and Martian landscapes. These three platforms were analyzed geologically as well as topographically (utilizing a laser range finder with slope estimation capabilities and a slope determination software). Emergency scenarios were separated into four main groups: (1) suit issues, (2) general physiological, (3) attacks and (4) others. Specific tools and procedures were developed to address each scenario. The tools and processes were tested in the field under Mars-analog conditions with the suited subjects for feasibility and speed of execution.

An Integrated Extravehicular Activity Research Plan

NASA Technical Reports Server (NTRS)

Abercromby, Andrew F. J.; Ross, Amy J.; Cupples, J. Scott

2016-01-01

Multiple organizations within NASA and outside of NASA fund and participate in research related to extravehicular activity (EVA). In October 2015, representatives of the EVA Office, the Crew and Thermal Systems Division (CTSD), and the Human Research Program (HRP) at NASA Johnson Space Center agreed on a formal framework to improve multi-year coordination and collaboration in EVA research. At the core of the framework is an Integrated EVA Research Plan and a process by which it will be annually reviewed and updated. The over-arching objective of the collaborative framework is to conduct multi-disciplinary cost-effective research that will enable humans to perform EVAs safely, effectively, comfortably, and efficiently, as needed to enable and enhance human space exploration missions. Research activities must be defined, prioritized, planned and executed to comprehensively address the right questions, avoid duplication, leverage other complementary activities where possible, and ultimately provide actionable evidence-based results in time to inform subsequent tests, developments and/or research activities. Representation of all appropriate stakeholders in the definition, prioritization, planning and execution of research activities is essential to accomplishing the over-arching objective. A formal review of the Integrated EVA Research Plan will be conducted annually. External peer review of all HRP EVA research activities including compilation and review of published literature in the EVA Evidence Book is already performed annually. Coordination with stakeholders outside of the EVA Office, CTSD, and HRP is already in effect on a study-by-study basis; closer coordination on multi-year planning with other EVA stakeholders including academia is being actively pursued. Details of the current Integrated EVA Research Plan are presented including description of ongoing and planned research activities in the areas of: Benchmarking; Anthropometry and Suit Fit; Sensors; Human-Suit Modeling; Suit Trauma Monitoring and Countermeasures; EVA Workload and Duration Effects; Decompression Sickness Risk Mitigation; Deconditioned EVA Performance; and Exploration EVA Concept of Operations.

Integrated Extravehicular Activity Human Research Plan: 2017

NASA Technical Reports Server (NTRS)

Abercromby, Andrew

2017-01-01

Multiple organizations within NASA as well as industry and academia fund and participate in research related to extravehicular activity (EVA). In October 2015, representatives of the EVA Office, the Crew and Thermal Systems Division (CTSD), and the Human Research Program (HRP) at NASA Johnson Space Center agreed on a formal framework to improve multi-year coordination and collaboration in EVA research. At the core of the framework is an Integrated EVA Human Research Plan and a process by which it will be annually reviewed and updated. The over-arching objective of the collaborative framework is to conduct multi-disciplinary cost-effective research that will enable humans to perform EVAs safely, effectively, comfortably, and efficiently, as needed to enable and enhance human space exploration missions. Research activities must be defined, prioritized, planned and executed to comprehensively address the right questions, avoid duplication, leverage other complementary activities where possible, and ultimately provide actionable evidence-based results in time to inform subsequent tests, developments and/or research activities. Representation of all appropriate stakeholders in the definition, prioritization, planning and execution of research activities is essential to accomplishing the over-arching objective. A formal review of the Integrated EVA Human Research Plan will be conducted annually. Coordination with stakeholders outside of the EVA Office, CTSD, and HRP is already in effect on a study-by-study basis; closer coordination on multi-year planning with other EVA stakeholders including academia is being actively pursued. Details of the preliminary Integrated EVA Human Research Plan are presented including description of ongoing and planned research activities in the areas of: physiological and performance capabilities; suit design parameters; EVA human health and performance modeling; EVA tasks and concepts of operations; EVA informatics; human-suit sensors; suit sizing and fit; and EVA injury risk and mitigation. This paper represents the 2017 update to the Integrated EVA Human Research Plan.

Preparation, characterization and application of EVA film containing Eu3+ complex with 1-tridecanecarboxylic acid ligand

NASA Astrophysics Data System (ADS)

Dong, Jin; Lin, Baoping

2017-11-01

In this study, on the basis of complex Eu(DBM)3Phen which was widely applied in polymer matrices, quaternary complex Eu(DBM)2Phen(TA) was synthesized by the introduction of 1-tridecanecarboxylic acid (TA). XRD analyses show that Eu(DBM)2Phen(TA) inclines to amorphization compared with Eu(DBM)3Phen which is crystal. Ethylene-vinyl acetate (EVA) film doped with Eu(DBM)2Phen(TA) was prepared by casting method. SEM and AFM analyses show that the compatibility of Eu(DBM)2Phen(TA) with EVA is better than that of Eu(DBM)3Phen with EVA. Under the same addition amount of Eu3+ complexes, visible light transmittance of Eu(DBM)2Phen(TA)/EVA film is obviously greater than that of Eu(DBM)3Phen/EVA film, and the fluorescence intensity of Eu(DBM)2Phen(TA)/EVA film is only slightly lower than that of Eu(DBM)3Phen/EVA film. With the optimum addition amount of Eu3+ complexes, the energy conversion efficiency of the polycrystalline silicon solar cell coated with Eu(DBM)2Phen(TA)/EVA film is improved to 12.14%, and in comparison, that of the solar cell coated with Eu(DBM)3Phen/EVA film is only 11.98%. Hence Eu(DBM)2Phen(TA)/EVA film has a potential prospect as luminescent down-shifting material.

EVA Design, Verification, and On-Orbit Operations Support Using Worksite Analysis

NASA Technical Reports Server (NTRS)

Hagale, Thomas J.; Price, Larry R.

2000-01-01

The International Space Station (ISS) design is a very large and complex orbiting structure with thousands of Extravehicular Activity (EVA) worksites. These worksites are used to assemble and maintain the ISS. The challenge facing EVA designers was how to design, verify, and operationally support such a large number of worksites within cost and schedule. This has been solved through the practical use of computer aided design (CAD) graphical techniques that have been developed and used with a high degree of success over the past decade. The EVA design process allows analysts to work concurrently with hardware designers so that EVA equipment can be incorporated and structures configured to allow for EVA access and manipulation. Compliance with EVA requirements is strictly enforced during the design process. These techniques and procedures, coupled with neutral buoyancy underwater testing, have proven most valuable in the development, verification, and on-orbit support of planned or contingency EVA worksites.

Modified EVA Encapsulant Formulations for Low Temperature Processing: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei, Z.; Pern, F. J.; Glick, S. H.

2001-10-01

Presented at the 2001 NCPV Program Review Meeting: We have developed several new ethylene-vinyl acetate (EVA) formulations modified on the basis of NREL patented EVA formulations [1]. The new formulations can be cured to a desired gel content of {approx}80% in the ambient at temperatures 20-30 C lower than the typical conditions in vacuum (i.e. {approx}150 C). Glass/glass laminates showed transmittance spectra that are essentially the same as that of EVA 15295P in the visible and NIR regions but higher in the UV region. Results of fluorescence analysis of the ambient-processed new EVA formulations showed the concentrations of the curing-generatedmore » {alpha},{beta}-unsaturated carbonyl chromophores, which are responsible for the UV induced EVA discoloration and photodegradation, were considerably lower than that of EVA 15295P, therefore suggesting a better photochemical stability of new EVA formulations.« less

Space suit bioenergetics: framework and analysis of unsuited and suited activity.

PubMed

Carr, Christopher E; Newman, Dava J

2007-11-01

Metabolic costs limit the duration and intensity of extravehicular activity (EVA), an essential component of future human missions to the Moon and Mars. Energetics Framework: We present a framework for comparison of energetics data across and between studies. This framework, applied to locomotion, differentiates between muscle efficiency and energy recovery, two concepts often confused in the literature. The human run-walk transition in Earth gravity occurs at the point for which energy recovery is approximately the same for walking and running, suggesting a possible role for recovery in gait transitions. Muscular Energetics: Muscle physiology limits the overall efficiency by which chemical energy is converted through metabolism to useful work. Unsuited Locomotion: Walking and running use different methods of energy storage and release. These differences contribute to the relative changes in the metabolic cost of walking and running as gravity is varied, with the metabolic cost of locomoting at a given velocity changing in proportion to gravity for running and less than in proportion for walking. Space Suits: Major factors affecting the energetic cost of suited movement include suit pressurization, gravity, velocity, surface slope, and space suit configuration. Apollo lunar surface EVA traverse metabolic rates, while unexpectedly low, were higher than other activity categories. The Lunar Roving Vehicle facilitated even lower metabolic rates, thus longer duration EVAs. Muscles and tendons act like springs during running; similarly, longitudinal pressure forces in gas pressure space suits allow spring-like storage and release of energy when suits are self-supporting.

Constellation Space Suit System Development Status

NASA Technical Reports Server (NTRS)

Ross, Amy; Aitchison, Lindsay; Daniel, Brian

2007-01-01

The Constellation Program has initiated the first new flight suit development project since the Extravehicular Mobility Unit (EMU) was developed for the Space Shuttle Program in the 1970s. The Constellation suit system represents a significant challenge to designers in that the system is required to address all space suit functions needed through all missions and mission phases. This is in marked contrast to the EMU, which was designed specifically for micro-gravity space walks. The Constellation suit system must serve in all of the following scenarios: launch, entry and abort crew survival; micro-gravity extravehicular activity (EVA); and lunar (1/6th-gravity) surface EVA. This paper discusses technical efforts performed from May 2006 through February 2007 for the Constellation space suit system pressure garment.

Rock sample brought to earth from the Apollo 12 lunar landing mission

NASA Image and Video Library

1969-12-04

S69-60909 (November 1969) --- A close-up view of lunar sample 12,052 under observation in the Manned Spacecraft Center's Lunar Receiving Laboratory (LRL). Astronauts Charles Conrad Jr., and Alan L. Bean collected several rocks and samples of finer lunar matter during their Apollo 12 lunar landing mission extravehicular activity (EVA). This particular sample was picked up during the second space walk (EVA) on Nov. 20, 1969. It is a typically fine-grained crystalline rock with a concentration of holes on the left part of the exposed side. These holes are called vesicles and have been identified as gas bubbles formed during the crystallization of the rock. Several glass-lined pits can be seen on the surface of the rock.

LUNAR SITE MAP (APOLLO XV) - MSC

NASA Image and Video Library

1971-07-16

S71-40085 (July 1971) --- An enlarged Lunar Orbiter photograph of the Apollo 15 landing area in the Hadley-Apennine region on the nearside of the moon. The overlay indicates the location of the numerous informally-named surface features. These names will facilitate understanding the verbal descriptions from the astronauts during their lunar surface extravehicular activity (EVA). This is an August 1967, Lunar Orbiter V photograph of Site 26.1.

Photographic coverage of STS-112 during EVA 3 in VR Lab.

NASA Image and Video Library

2002-08-21

JSC2002-E-34625 (21 Aug. 2002) --- Astronaut Sandra H. Magnus (left), STS-112 mission specialist, uses the virtual reality lab at NASA?s Johnson Space Center (JSC) to train for her duties aboard the space shuttle Atlantis. This type of computer interface paired with virtual reality training hardware and software helps to prepare the entire team for dealing with ISS elements. Lead SSRMS instructor Elizabeth C. Bloomer assisted Magnus. Astronaut Ellen Ochoa (standing) looks on. Photo credit: NASA

Studies Relating to EVA

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session JA1, the discussion focuses on the following topics: The Staged Decompression to the Hypobaric Atmosphere as a Prophylactic Measure Against Decompression Sickness During Repetitive EVA; A New Preoxygenation Procedure for Extravehicular Activity (EVA); Metabolic Assessments During Extra-Vehicular Activity; Evaluation of Safety of Hypobaric Decompressions and EVA From Positions of Probabilistic Theory; Fatty Acid Composition of Plasma Lipids and Erythrocyte Membranes During Simulation of Extravehicular Activity; Biomedical Studies Relating to Decompression Stress with Simulated EVA, Overview; The Joint Angle and Muscle Signature (JAMS) System - Current Uses and Future Applications; and Experimental Investigation of Cooperative Human-Robotic Roles in an EVA Work Site.

Space Station Human Factors Research Review. Volume 1: EVA Research and Development

NASA Technical Reports Server (NTRS)

Cohen, Marc M. (Editor); Vykukal, H. C. (Editor)

1988-01-01

An overview is presented of extravehicular activity (EVA) research and development activities at Ames. The majority of the program was devoted to presentations by the three contractors working in parallel on the EVA System Phase A Study, focusing on Implications for Man-Systems Design. Overhead visuals are included for a mission results summary, space station EVA requirements and interface accommodations summary, human productivity study cross-task coordination, and advanced EVAS Phase A study implications for man-systems design. Articles are also included on subsea approach to work systems development and advanced EVA system design requirements.

The Use of Nanomaterials to Achieve NASA's Exploration Program Power Goals

NASA Technical Reports Server (NTRS)

Jeevarajan, J.

2009-01-01

This slide presentation reviews the power requirements for the space exploration and the lunar surface mobility programs. It includes information about the specifications for high energy batteries and the power requirements for lunar rovers, lunar outposts, lunar ascent module, and the lunar EVA suit.

Improved crystallinity and dynamic mechanical properties of reclaimed waste tire rubber/EVA blends under the influence of electron beam irradiation

NASA Astrophysics Data System (ADS)

Ramarad, Suganti; Ratnam, Chantara T.; Khalid, Mohammad; Chuah, Abdullah Luqman; Hanson, Svenja

2017-01-01

Dependence on automobiles has led to a huge amount of waste tires produced annually around the globe. In this study, the feasibility of recycling these waste tires by blending reclaimed waste tire rubber (RTR) with poly(ethylene-co-vinyl acetate) (EVA) and electron beam irradiation was studied. The RTR/EVA blends containing 100-0 wt% of RTR were prepared in the internal mixer followed by electron beam (EB) irradiation with doses ranging from 50 to 200 kGy. The processing torques, calorimetric and dynamic mechanical properties of the blends were studied. Blends were found to have lower processing torque indicating easier processability of RTR/EVA blends compared to EVA. RTR domains were found to be dispersed in EVA matrix, whereas, irradiation improved the dispersion of RTR into smaller domains in EVA matrix. Results showed the addition of EVA improves the efficiency of irradiation induced crosslink formation and dynamic mechanical properties of the blends at the expense of the calorimetric properties. Storage and loss modulus of 50 wt% RTR blend was higher than RTR and EVA, suggesting partial miscibility of the blend. Whereas, electron beam irradiation improved the calorimetric properties and dynamic mechanical properties of the blends through redistribution of RTR in smaller domain sizes within EVA.

NASA Research Announcement Phase 1 Report and Phase 2 Proposal for the Development of a Power Assisted Space Suit Glove Assembly

NASA Technical Reports Server (NTRS)

Cadogan, Dave; Lingo, Bob

1996-01-01

In July of 1996, ILC Dover was awarded Phase 1 of a contract for NASA to develop a prototype Power Assisted Space Suit glove to enhance the performance of astronauts during Extra-Vehicular Activity (EVA). This report summarizes the work performed to date on Phase 1, and details the work to be conducted on Phase 2 of the program. Phase 1 of the program consisted of research and review of related technical sources, concept brainstorming, baseline design development, modeling and analysis, component mock-up testing, and test data analysis. ILC worked in conjunction with the University of Maryland's Space Systems Laboratory (SSL) to develop the power assisted glove. Phase 2 activities will focus on the design maturation and the manufacture of a working prototype system. The prototype will be tested and evaluated in conjunction with existing space suit glove technology to determine the performance enhancement anticipated with the implementation of the power assisted joint technology in space suit gloves.

Effect of electron beam irradiation and microencapsulation on the flame retardancy of ethylene-vinyl acetate copolymer materials during hot water ageing test

NASA Astrophysics Data System (ADS)

Sheng, Haibo; Zhang, Yan; Wang, Bibo; Yu, Bin; Shi, Yongqian; Song, Lei; Kundu, Chanchal Kumar; Tao, Youji; Jie, Ganxin; Feng, Hao; Hu, Yuan

2017-04-01

Microencapsulated ammonium polyphosphate (MCAPP) in combination with polyester polyurethane (TPU) was used to flame retardant ethylene-vinyl acetate copolymer (EVA). The EVA composites with different irradiation doses were immersed in hot water (80 °C) to accelerate ageing process. The microencapsulation and irradiation dose ensured positive impacts on the properties of the EVA composites in terms of better dimensional stability and flame retardant performance. The microencapsulation of APP could lower its solubility in water and the higher irradiation dose led to the more MCAPP immobilized in three dimensional crosslinked structure of the EVA matrix which could jointly enhance the flame retardant and electrical insulation properties of the EVA composites. So, the EVA composites with 180 kGy irradiation dose exhibited better dimensional stability than the EVA composites with 120 kGy due to the higher crosslinking degree. Moreover, the higher irradiation dose lead to the more MCAPP immobilizated in crosslinked three-dimensional structure of EVA, enhancing the flame retardancy and electrical insulation properties of the EVA composites. After ageing test in hot water at 80 °C for 2 weeks, the EVA/TPU/MCAPP composite with 180 kGy could still maintain the UL-94 V-0 rating and the limiting oxygen index (LOI) value was as high as 30%. This investigation indicated the flame retardant EVA cable containing MCAPP could achieve stable properties and lower electrical fire hazard risk during long-term hot water ageing test.

Power assist EVA glove development

NASA Technical Reports Server (NTRS)

Main, John A.; Peterson, Steven W.; Strauss, Alvin M.

1992-01-01

Structural modeling of the EVA glove indicates that flexibility in the metacarpophalangeal (MCP) joint can be improved by selectively lowering the elasticity of the glove fabric. Two strategies are used to accomplish this. One method uses coil springs on the back of the glove to carry the tension in the glove skin due to pressurization. These springs carry the loads normally borne by the glove fabric, but are more easily deformed. An active system was also designed for the same purpose and uses gas filled bladders attached to the back of the EVA glove that change the dimensions of the back of the glove and allow the glove to bend at the MCP joint, thus providing greater flexibility at this joint. A threshold control scheme was devised to control the action of the joint actuators. Input to the controller was provided by thin resistive pressure sensors placed between the hand and the pressurized glove. The pressure sensors consist of a layer of polyester film that has a thin layer of ink screened on the surface. The resistivity of the ink is pressure dependent, so an extremely thin pressure sensor can be fabricated by covering the ink patch with another layer of polyester film and measuring the changing resistance of the ink with a bridge circuit. In order to sense the force between the hand and the glove at the MCP joint, a sensor was placed on the palmar face of the middle finger. The resultant signal was used by the controller to decide whether to fill or exhaust the bladder actuators on the back of the glove. The information from the sensor can also be used to evaluate the effectiveness of a given control scheme or glove design since the magnitude of the measured pressures gives some idea of the torque required to bend a glove finger at the MCP joint. Tests of this actuator, sensor, and control system were conducted in an 57.2 kPa glove box by performing a series of 90 degree finger bends with a glove without an MCP joint assembly, a glove with the coil spring assembly, and with the four fingered actuated glove. The tests of these three glove designs confirm the validity of the model.

XPS analysis of PE and EVA samples irradiated at different γ-doses

NASA Astrophysics Data System (ADS)

Dorey, Samuel; Gaston, Fanny; Marque, Sylvain R. A.; Bortolotti, Benjamin; Dupuy, Nathalie

2018-01-01

The principal plastic materials used for the fluid contact and storage in the biopharmaceutical industry are mainly made up of semi-crystalline polymers, polyolefins, PVC, Siloxane and PET. The polyethylene (PE) and the polypropylene (PP) are often used as fluid contact in multi-layer materials like films. As one sterilisation way of single-use plastic devices used in medical and pharmaceutical fields can take place via γ-irradiation, the effect of sterilization on plastics must be investigated. The irradiation process leads to the production of radicals, which can generate changes in the polymer structure and on the polymer surface. It is well known that the presence of oxygen with free radicals precede the generation of peroxide species so called ROS (reactive oxygen species) which are highly reactive. The purpose of this work is to investigate the γ-rays impact on the surface of PE (polyethylene) and EVA (polyethylene vinyl alcohol) based films when ionized at different doses. X-ray Photoelectron Spectroscopy (XPS) was applied to determine the surface compositions of the polymers to highlight the different chemical moieties generated during the γ-irradiation process and to monitor the potential presence of the ROS.

Construction concept for erecting an offset-fed antenna

NASA Technical Reports Server (NTRS)

Rhodes, M. D.

1984-01-01

A design concept for the construction of an offset-fed antenna is discussed. Antennas of this type are of interest for space applications because the configuration eliminates the effects of feed and feed-support blockage. The proposed construction concept is developed around the assembly of a stiff truss substructure by pressure-suited astronauts operating in extravehicular activity (EVA) assisted by a mobile platform that moves along the structure to position the astronauts at joint locations where they can latch members in place. Construction can be accomplished from the shuttle cargo bay in the course of a normal flight or from a space station platform. The concepts demonstrates the versatility of machine assisted manned assembly and is only one of many potential applications.

Astronaut Joseph Tanner is assisted into his EMU during training

NASA Image and Video Library

1994-08-01

S94-40048 (1 August 1994) --- Astronaut Joseph R. Tanner, mission specialist, is assisted by Boeing suit expert Steve Voyles as he prepares to be submerged in a 25-feet deep pool at the Johnson Space Center's (JSC) Weightless Environment Training Facility (WET-F). Though no extravehicular activity (EVA) is planned for the mission, at least two astronauts are trained to perform tasks that would require a space walk in the event of failure of remote systems. In November, Tanner will join four other NASA astronauts and a European mission specialist for a week and a half in space aboard the Space Shuttle Atlantis. The flight will support the Atmospheric Laboratory for Applications and Science (ATLAS-3) mission.

Simulation and preparation of surface EVA in reduced gravity at the Marseilles Bay subsea analogue sites

NASA Astrophysics Data System (ADS)

Weiss, P.; Gardette, B.; Chirié, B.; Collina-Girard, J.; Delauze, H. G.

2012-12-01

Extravehicular activity (EVA) of astronauts during space missions is simulated nowadays underwater in neutral buoyancy facilities. Certain aspects of weightlessness can be reproduced underwater by adding buoyancy to a diver-astronaut, therefore exposing the subject to the difficulties of working without gravity. Such tests were done at the COMEX' test pool in Marseilles in the 1980s to train for a French-Russian mission to the MIR station, for the development of the European HERMES shuttle and the COLUMBUS laboratory. However, space agencies are currently studying missions to other destinations than the International Space Station in orbit, such as the return to the Moon, NEO (near-Earth objects) or Mars. All these objects expose different gravities: Moon has one sixth of Earth's gravity, Mars has a third of Earth's gravity and asteroids have virtually no surface gravity; the astronaut "floats" above the ground. The preparation of such missions calls for a new concept in neutral buoyancy training, not on man-made structures, but on natural terrain, underwater, to simulate EVA operations such as sampling, locomotion or even anchoring in low gravity. Underwater sites can be used not only to simulate the reduced gravity that astronauts will experience during their field trips, also human factors like stress are more realistically reproduced in such environment. The Bay of Marseille hosts several underwater sites that can be used to simulate various geologic morphologies, such as sink-holes which can be used to simulate astronaut descends into craters, caves where explorations of lava tubes can be trained or monolithic rock structures that can be used to test anchoring devices (e.g., near Earth objects). Marseilles with its aerospace and maritime/offshore heritage hosts the necessary logistics and expertise that is needed to perform such simulations underwater in a safe manner (training of astronaut-divers in local test pools, research vessels, subsea robots and submarines). COMEX is currently preparing a space mission simulation in the Marseilles Bay (foreseen in June 2012), and the paper will give an overview of the different underwater analogue sites that are available to the scientific community for the simulation of surface EVA or the test of scientific instruments and devices.

Mars and Men

NASA Astrophysics Data System (ADS)

Muehlberger, W.

2001-01-01

Wherever mankind travels in space, people will always be preceded by unmanned probes that will provide the first bit of information. But there comes a time when we've learned all we can by unmanned vehicles. Man comes on the scene and makes the decisions about what is most valuable to us here, and that makes space into a new laboratory. Photography plays a vital role in all that John Glenn, in 'The View from Space'. Why do you take a photograph? We took a lot of documentation pictures because we were supposed to. But a lot of photographs were taken on instinct things you can't predict you're going to see or that are going to impress you. You say, 'Now I've got to take a picture of that" or "Look at the way that is positioned' or' Look at the way the sun is shining on that." Those 'stand-back' pictures were taken with aesthetics in mind, to capture and document the venture itself." Eugene Cernan in 'The View from Space'. The Apollo mode for a Science Support Room in Mission Control will not work for Mars. The time delay makes it nearly useless. Our team was available for instantaneous reaction and assistance to the crew on EVA. Therefore the Science Support Team has to be on Mars! The crew that went out the day before will do the supporting. They will hand off to each other for the next EVA. They will send a daily report back to Earth as to what was accomplished, problems that need resolution, supporting video, data, etc. etc. In Apollo, that was the role of my "Tiger Team," who sat in Gene Krantz' office watching and listening but having no role for directly helping the Back Room. They wrote a summary of the EVA, what was accomplished, what got omitted that was important to insert into the next EVA. It was distributed throughout Mission Control- especially to the Big Brass, Flight Director, and the CapCom.

Extravehicular Activity training and hardware design considerations

NASA Technical Reports Server (NTRS)

Thuot, Pierre J.; Harbaugh, Gregory J.

1993-01-01

Designing hardware that can be successfully operated by EVA astronauts for EVA tasks required to assemble and maintain Space Station Freedom requires a thorough understanding of human factors and of the capabilities and limitations of the space-suited astronaut, as well as of the effect of microgravity environment on the crew member's capabilities and on the overhead associated with EVA. This paper describes various training methods and facilities that are being designed for training EVA astronauts for Space Station assembly and maintenance, taking into account the above discussed factors. Particular attention is given to the user-friendly hardware design for EVA and to recent EVA flight experience.

Current status of EVA degradation in Si modules and interface stability in CdTe/CdS modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czanderna, A.W.

1994-06-30

The goals, objectives, background, technical approach, status, and accomplishments on the PV Module Reliability Research Task are summarized for FY 1993. The accomplishments are reported in two elements, ethylene vinyl acetate (EVA) degradation and stability in CdTe/CdS modules. The EVA results are presented under the headings modified EVA and potential EVA replacements, degradation mechanisms, efficiency losses from yellowed EVA, and equipment acquisitions. The results on CdTe/CdS modules are presented under subheadings of stability of the SnO[sub 2]/CdS interface and degradation at the CdTe/CdS interface.

An Experimental Investigation of Dextrous Robots Using EVA Tools and Interfaces

NASA Technical Reports Server (NTRS)

Ambrose, Robert; Culbert, Christopher; Rehnmark, Frederik

2001-01-01

This investigation of robot capabilities with extravehicular activity (EVA) equipment looks at how improvements in dexterity are enabling robots to perform tasks once thought to be beyond machines. The approach is qualitative, using the Robonaut system at the Johnson Space Center (JSC), performing task trials that offer a quick look at this system's high degree of dexterity and the demands of EVA. Specific EVA tools attempted include tether hooks, power torque tools, and rock scoops, as well as conventional tools like scissors, wire strippers, forceps, and wrenches. More complex EVA equipment was also studied, with more complete tasks that mix tools, EVA hand rails, tethers, tools boxes, PIP pins, and EVA electrical connectors. These task trials have been ongoing over an 18 month period, as the Robonaut system evolved to its current 43 degree of freedom (DOF) configuration, soon to expand to over 50. In each case, the number of teleoperators is reported, with rough numbers of attempts and their experience level, with a subjective difficulty rating assigned to each piece of EVA equipment and function. JSC' s Robonaut system was successful with all attempted EVA hardware, suggesting new options for human and robot teams working together in space.

Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT)

NASA Technical Reports Server (NTRS)

Brown, Cheryl B.; Conger, Bruce C.; Miranda, Bruno M.; Bue, Grant C.; Rouen, Michael N.

2007-01-01

An effort was initiated by NASA/JSC in 2001 to develop an Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT) for the sizing of Extravehicular Activity System (EVAS) architecture and studies. Its intent was to support space suit development efforts and to aid in conceptual designs for future human exploration missions. Its basis was the Life Support Options Performance Program (LSOPP), a spacesuit and portable life support system (PLSS) sizing program developed for NASA/JSC circa 1990. EVAS_SAT estimates the mass, power, and volume characteristics for user-defined EVAS architectures, including Suit Systems, Airlock Systems, Tools and Translation Aids, and Vehicle Support equipment. The tool has undergone annual changes and has been updated as new data have become available. Certain sizing algorithms have been developed based on industry standards, while others are based on the LSOPP sizing routines. The sizing algorithms used by EVAS_SAT are preliminary. Because EVAS_SAT was designed for use by members of the EVA community, subsystem familiarity on the part of the intended user group and in the analysis of results is assumed. The current EVAS_SAT is operated within Microsoft Excel 2003 using a Visual Basic interface system.

EVA: laparoscopic instrument tracking based on Endoscopic Video Analysis for psychomotor skills assessment.

PubMed

Oropesa, Ignacio; Sánchez-González, Patricia; Chmarra, Magdalena K; Lamata, Pablo; Fernández, Alvaro; Sánchez-Margallo, Juan A; Jansen, Frank Willem; Dankelman, Jenny; Sánchez-Margallo, Francisco M; Gómez, Enrique J

2013-03-01

The EVA (Endoscopic Video Analysis) tracking system is a new system for extracting motions of laparoscopic instruments based on nonobtrusive video tracking. The feasibility of using EVA in laparoscopic settings has been tested in a box trainer setup. EVA makes use of an algorithm that employs information of the laparoscopic instrument's shaft edges in the image, the instrument's insertion point, and the camera's optical center to track the three-dimensional position of the instrument tip. A validation study of EVA comprised a comparison of the measurements achieved with EVA and the TrEndo tracking system. To this end, 42 participants (16 novices, 22 residents, and 4 experts) were asked to perform a peg transfer task in a box trainer. Ten motion-based metrics were used to assess their performance. Construct validation of the EVA has been obtained for seven motion-based metrics. Concurrent validation revealed that there is a strong correlation between the results obtained by EVA and the TrEndo for metrics, such as path length (ρ = 0.97), average speed (ρ = 0.94), or economy of volume (ρ = 0.85), proving the viability of EVA. EVA has been successfully validated in a box trainer setup, showing the potential of endoscopic video analysis to assess laparoscopic psychomotor skills. The results encourage further implementation of video tracking in training setups and image-guided surgery.

Pulmonary gas exchange is not impaired 24 h after extravehicular activity.

PubMed

Prisk, G Kim; Fine, Janelle M; Cooper, Trevor K; West, John B

2005-12-01

Extravehicular activity (EVA) during spaceflight involves a significant decompression stress. Previous studies have shown an increase in the inhomogeneity of ventilation-perfusion ratio (VA/Q) after some underwater dives, presumably through the embolic effects of venous gas microemboli in the lung. Ground-based chamber studies simulating EVA have shown that venous gas microemboli occur in a large percentage of the subjects undergoing decompression, despite the use of prebreathe protocols to reduce dissolved N(2) in the tissues. We studied eight crewmembers (7 male, 1 female) of the International Space Station who performed 15 EVAs (initial cabin pressure 748 mmHg, final suit pressure either approximately 295 or approximately 220 mmHg depending on the suit used) and who followed the denitrogenation procedures approved for EVA from the International Space Station. The intrabreath VA/Q slope was calculated from the alveolar Po(2) and Pco(2) in a prolonged exhalation maneuver on the day after EVA and compared with measurements made in microgravity on days well separated from the EVA. There were no significant changes in intrabreath VA/Q slope as a result of EVA, although there was a slight increase in metabolic rate and ventilation (approximately 9%) on the day after EVA. Vital capacity and other measures of pulmonary function were largely unaltered by EVA. Because measurements could only be performed on the day after EVA because of logistical constraints, we were unable to determine an acute effect of EVA on VA/Q inequality. The results suggest that current denitrogenation protocols do not result in any major lasting alteration to gas exchange in the lung.

Mars Surface Tunnel Element Concept

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.; Jefferies, Sharon; Howe, A. Scott; Howard, Robert; Mary, Natalie; Watson, Judith; Lewis, Ruthan

2016-01-01

When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study

NASA Technical Reports Server (NTRS)

Blanco, Raul A.; Bowie, Jonathan T.; Watson, Richard D.; Sipila, Stephanie A.

2014-01-01

The Asteroid Redirect Crewed Mission (ARCM) requires a Launch/Entry/Abort (LEA) suit capability and short duration Extra Vehicular Activity (EVA) capability for Orion. The EVAs will involve a two-person crew for approximately four hours. Currently, two EVAs are planned with one contingency EVA in reserve. Providing this EVA capability is very challenging due to system level constraints and a new and unknown environment. The goal of the EVA architecture for ARCM is one that builds upon previously developed technologies and lessons learned, and that accomplishes the ARCM mission while providing a stepping stone to future missions and destinations. The primary system level constraints are to 1) minimize system mass and volume and 2) minimize the interfacing impacts to the baseline Orion design. In order to minimize the interfacing impacts and to not perturb the baseline Orion schedule, the concept of adding "kits" to the baseline system is proposed. These kits consist of: an EVA kit (converts LEA suit to EVA suit), EVA Servicing and Recharge Kit (provides suit consumables), the EVA Tools, Translation Aids & Sample Container Kit (the tools and mobility aids to complete the tasks), the EVA Communications Kit (interface between the EVA radio and the MPCV), and the Cabin Repress Kit (represses the MPCV between EVAs). This paper will focus on the trade space, analysis, and testing regarding the space suit (pressure garment and life support system). Historical approaches and lessons learned from all past EVA operations were researched. Previous and current, successfully operated EVA hardware and high technology readiness level (TRL) hardware were evaluated, and a trade study was conducted for all possible pressure garment and life support options. Testing and analysis was conducted and a recommended EVA system architecture was proposed. Pressure garment options that were considered for this mission include the currently in-use ISS EVA Mobility Unit (EMU), all variations of the Advanced Crew Escape Suit (ACES), and the Exploration Z-suit. For this mission, the pressure garment that was selected is the Modified ACES (MACES) with EVA enhancements. Life support options that were considered included short closed-loop umbilicals, long open-loop umbilicals, the currently in-use ISS EMU Portable Life Support System (PLSS), and the currently in development Exploration PLSS. For this mission, the life support option that was selected is the Exploration PLSS. The greatest risk in the proposed architecture is viewed to be the comfort and mobility of the baseline MACES and the delicate balance between adding more mobility features while not compromising landing safety. Feasibility testing was accomplished in low fidelity analogs and in the JSC Neutral Buoyancy Laboratory (NBL) to validate the concept before a final recommendation on the architecture was made. The proposed architecture was found to meet the mission constraints, but much more work is required to determine the details of the required suit upgrades, the integration with the PLSS, and the rest of the tools and equipment required to accomplish the mission. This work and further definition of the remaining kits will be conducted in government fiscal year 14.

Advanced EVA system design requirements study, executive summary

NASA Technical Reports Server (NTRS)

1986-01-01

Design requirements and criteria for the space station advanced Extravehicular Activity System (EVAS) including crew enclosures, portable life support systems, maneuvering propulsion systems, and related EVA support equipment were established. The EVA mission requirements, environments, and medical and physiological requirements, as well as operational, procedures and training issues were considered.

EVA design: lessons learned.

PubMed

Ross, J L

1994-01-01

Extravehicular Activities (EVAs) are very demanding and specialized space flight activities. There are many aspects to consider in the design of hardware, tools, and procedures to be used on an EVA mission. To help minimize costs and optimize the EVA productivity, experience shows that astronauts should become involved early in the design process.

Development of an EVA systems cost model. Volume 2: Shuttle orbiter crew and equipment translation concepts and EVA workstation concept development and integration

NASA Technical Reports Server (NTRS)

1975-01-01

EVA crewman/equipment translational concepts are developed for a shuttle orbiter payload application. Also considered are EVA workstation systems to meet orbiter and payload requirements for integration of workstations into candidate orbiter payload worksites.

Crew systems and architectural considerations for first lunar surface return missions

NASA Astrophysics Data System (ADS)

Winisdoerffer, F.; Ximenes, S.

1992-08-01

The design requirements for the habitability of the pressurized volumes of a typical first manned lander are presented. Attention is given to providing dual habitation/exploration services (EVA/IVA), supporting the separation of the surface/flight functions, allowing growth potential based on site characteristics, and in situ resources utilization. Lunar lander conceptual diagrams are provided for the basic system architecture, automatic cargo delivery, the piloted crew module, and the pressurized volumes.

The role of EVA on Space Shuttle. [experimental support and maintenance activities

NASA Technical Reports Server (NTRS)

Carson, M. A.

1974-01-01

The purpose of this paper is to present the history of Extravehicular Activity (EVA) through the Skylab Program and to outline the expected tasks and equipment capabilities projected for the Space Shuttle Program. Advantages offered by EVA as a tool to extend payload capabilities and effectiveness and economic advantages of using EVA will be explored. The presentation will conclude with some guidelines and recommendations for consideration by payload investigators in establishing concepts and designs utilizing EVA support.

Extravehicular Activity/Air Traffic Control (EVA/ATC) test report. [communication links to the astronaut

NASA Technical Reports Server (NTRS)

Tomaro, D. J.

1982-01-01

During extravehicular activity (EVA), communications between the EVA astronaut and the space shuttle orbiter are maintained by means of transceiver installed in the environmental support system backpack. Onboard the orbiter, a transceiver line replaceable unit and its associated equipment performs the task of providing a communications link to the astronaut in the extravehicular activity/air traffic control (EVA/ATC) mode. Results of the acceptance tests that performed on the system designed and fabricated for EVA/ATC testing are discussed.

Development and Test of Robotically Assisted Extravehicular Activity Gloves

NASA Technical Reports Server (NTRS)

Rogers, Jonathan M.; Peters, Benjamin J.; Laske, Evan A.; McBryan, Emily R.

2017-01-01

Over the past two years, the High Performance EVA Glove (HPEG) project under NASA's Space Technology Mission Directorate (STMD) funded an effort to develop an electromechanically-assisted space suit glove. The project was a collaboration between the Johnson Space Center's Software, Robotics, and Simulation Division and the Crew and Thermal Systems division. The project sought to combine finger actuator technology developed for Robonaut 2 with the softgoods from the ILC Phase VI EVA glove. The Space Suit RoboGlove (SSRG) uses a system of three linear actuators to pull synthetic tendons attached to the glove's fingers to augment flexion of the user's fingers. To detect the user's inputs, the system utilizes a combination of string potentiometers along the back of the fingers and force sensitive resistors integrated into the fingertips of the glove cover layer. This paper discusses the development process from initial concepts through two major phases of prototypes, and the results of initial human testing. Initial work on the project focused on creating a functioning proof of concept, designing the softgoods integration, and demonstrating augmented grip strength with the actuators. The second year of the project focused on upgrading the actuators, sensors, and software with the overall goal of creating a system that moves with the user's fingers in order to reduce fatigue associated with the operation of a pressurized glove system. This paper also discusses considerations for a flight system based on this prototype development and address where further work is required to mature the technology.

The SCRAM tool-kit

NASA Technical Reports Server (NTRS)

Tamir, David; Flanigan, Lee A.; Weeks, Jack L.; Siewert, Thomas A.; Kimbrough, Andrew G.; Mcclure, Sidney R.

1994-01-01

This paper proposes a new series of on-orbit capabilities to support the near-term Hubble Space Telescope, Extended Duration Orbiter, Long Duration Orbiter, Space Station Freedom, other orbital platforms, and even the future manned Lunar/Mars missions. These proposed capabilities form a toolkit termed Space Construction, Repair, and Maintenance (SCRAM). SCRAM addresses both intra-Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) needs. SCRAM provides a variety of tools which enable welding, brazing, cutting, coating, heating, and cleaning, as well as corresponding nondestructive examination. Near-term IVA-SCRAM applications include repair and modification to fluid lines, structure, and laboratory equipment inside a shirt-sleeve environment (i.e. inside Spacelab or Space Station). Near-term EVA-SCRAM applications include construction of fluid lines and structural members, repair of punctures by orbital debris, refurbishment of surfaces eroded by contaminants. The SCRAM tool-kit also promises future EVA applications involving mass production tasks automated by robotics and artificial intelligence, for construction of large truss, aerobrake, and nuclear reactor shadow shields structures. The leading candidate tool processes for SCRAM, currently undergoing research and development, include Electron Beam, Gas Tungsten Arc, Plasma Arc, and Laser Beam. A series of strategic space flight experiments would make SCRAM available to help conquer the space frontier.

Effect of TiO2-Crystal Forms on the Photo-Degradation of EVA/PLA Blend Under Accelerated Weather Testing

NASA Astrophysics Data System (ADS)

Van Cong, Do; Trang, Nguyen Thi Thu; Giang, Nguyen Vu; Lam, Tran Dai; Hoang, Thai

2016-05-01

Photo-degradation of poly (ethylene-co-vinyl acetate) (EVA)/poly (lactic acid) (PLA) blend and EVA/PLA/TiO2 nanocomposites was carried out under accelerated weather testing conditions by alternating cycles of ultraviolet (UV) light and moisture at controlled and elevated temperatures. The characters, properties, and morphology of these materials before and after accelerated weather testing were determined by Fourier transform infrared spectroscopy, colour changes, viscosity, tensile test, thermogravimetric analysis, and field emission scanning electron microscopy. The increases in the content of oxygen-containing groups, colour changes; the decreases in viscosity, tensile properties, and thermal stability of these materials after accelerated weather testing are the evidence for the photo-degradation of the blend and nanocomposites. After accelerated weather testing, the appearance of many micro-holes and micro-pores on the surface of the collected samples was observed. The photo-degradation degree of the nanocomposites depended on the TiO2-crystal form. Rutile TiO2 do not enhance the degradation, but anatase and mixed crystals TiO2 nanoparticles promoted the degradation of the nanocomposites. Particularly, the mixed crystals TiO2 nanoparticles showed the highest photo-catalytic activity of the nanocomposites.

US space flight experience. Physical exertion and metabolic demand of extravehicular activity: Past, present, and future

NASA Technical Reports Server (NTRS)

Moore, Thomas P.

1989-01-01

A review of physical exertion and metabolic demands of extravehicular activity (EVA) on U.S. astronauts is given. Information is given on EVA during Gemini, Apollo and Skylab missions. It is noted that nominal EVA's should not be overstressful from a cardiovascular standpoint; that manual-intensive EVA's such as are planned for the construction phase of the Space Station can and will be demanding from a muscular standpoint, primarily for the upper extremities; that off-nominal unplanned EVA's can be physically demanding both from an endurance and from a muscular standpoint; and that crewmembers should be physically prepared and capable of performing these EVA's at any time during the mission.

Calculating and Mitigating the Risk of a Cut Glove to a Space Walking Astronaut

NASA Technical Reports Server (NTRS)

Castillo, Theresa; Haught, Megan

2013-01-01

One of the high risk operations on the International Space Station (ISS) is conducting a space walk, or an Extra Vehicular Activity (EVA). Threats to the space walking crew include airlock failures, space suit failures, and strikes from micro ]meteoroids and orbital debris (MM/OD). There are risks of becoming untethered from the space station, being pinched between the robotic arm and a piece of equipment, tearing your suit on a sharp edge, and other human errors that can be catastrophic. For decades NASA identified and tried to control sharp edges on external structure and equipment by design; however a new and unexpected source of sharp edges has since become apparent. Until recently, one of the underappreciated environmental risks was damage to EVA gloves during a spacewalk. The ISS has some elements which have been flying in the environment of space for over 14 years. It has and continues to be bombarded with MM/OD strikes that have created small, sharp craters all over the structure, including the dedicated EVA handrails and surrounding structure. These craters are capable of cutting through several layers of the EVA gloves. Starting in 2006, five EVA crewmembers reported cuts in their gloves so large they rendered the gloves unusable and in some cases cut the spacewalk short for the safety of the crew. This new hazard took engineers and managers by surprise. NASA has set out to mitigate this risk to safety and operations by redesigning the spacesuit gloves to be more resilient and designing a clamp to isolate MM/OD strikes on handrails, and is considering the necessity of an additional tool to repair strikes on non ]handrail surfaces (such as a file). This paper will address how the ISS Risk Team quantified an estimate of the MM/OD damage to the ISS, and the resulting likelihood of sustaining a cut glove in order to measure the effectiveness of the solutions being investigated to mitigate this risk to the mission and crew.

Benzo[a]pyrene bioavailability from pristine soil and contaminated sediment assessed using two in vitro models.

PubMed

Vasiluk, Luba; Pinto, Linda J; Walji, Zahra A; Tsang, Wing Shan; Gobas, Frank A P C; Eickhoff, Curtis; Moore, Margo M

2007-03-01

A major route of exposure to hydrophobic organic contaminants (HOCs), such as benzo[a]pyrene (BaP), is ingestion. Matrix-bound HOCs may become bioavailable after mobilization by the gastrointestinal fluids followed by sorption to the intestinal epithelium. The purpose of this research was to measure the bioavailability of [14C]-BaP bound to pristine soils or field-contaminated sediment using an in vitro model of gastrointestinal digestion followed by sorption to human enterocytes (Caco-2 cells) or to a surrogate membrane, ethylene vinyl acetate (EVA) thin film. Although Caco-2 cells had a twofold higher lipid-normalized fugacity capacity than EVA, [14C]-BaP uptake by Caco-2 lipids and EVA thin film demonstrated a linear relationship within the range of BaP concentrations tested. These results suggest that EVA thin film is a good membrane surrogate for passive uptake of BaP. The in vitro system provided enough sensitivity to detect matrix effects on bioavailability; after 5 h, significantly lower concentrations of [14C]-BaP were sorbed into Caco-2 cells from soil containing a higher percentage of organic matter compared to soil with a lower percentage of organic matter. The [14C]-BaP desorption rate from Caco-2 lipids consistently was twofold higher than from EVA thin film for all matrices tested. The more rapid kinetics observed with Caco-2 cells probably were due to the greater surface area available for absorption/desorption in the cells. After 5 h, the uptake of BaP into Caco-2 lipid was similar in live and metabolically inert Caco-2 cells, suggesting that the primary route of BaP uptake is by passive diffusion. Moreover, the driving force for uptake is the fugacity gradient that exists between the gastrointestinal fluid and the membrane.

The combination effects of licl and the active leflunomide metabolite, A771726, on viral-induced interleukin 6 production and EV-A71 replication.

PubMed

Hung, Hui-Chen; Shih, Shin-Ru; Chang, Teng-Yuan; Fang, Ming-Yu; Hsu, John T-A

2014-01-01

Enterovirus 71 (EV-A71) is a neurotropic virus that can cause severe complications involving the central nervous system. No effective antiviral therapeutics are available for treating EV-A71 infection and drug discovery efforts are rarely focused to target this disease. Thus, the main goal of this study was to discover existing drugs with novel indications that may effectively inhibit EV-A71 replication and the inflammatory cytokines elevation. In this study, we showed that LiCl, a GSK3β inhibitor, effectively suppressed EV-A71 replication, apoptosis and inflammatory cytokines production (Interleukin 6, Interleukin-1β) in infected cells. Furthermore, LiCl and an immunomodular agent were shown to strongly synergize with each other in suppressing EV-A71 replication. The results highlighted potential new treatment regimens in suppressing sequelae caused by EV-A71 replication.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.; Czanderna, A.W.

The stabilization effects of various superstrate materials against UV-induced EVA discoloration and the effect of photocurrent enhancement by white light-reflecting substrates are summarized. Based on the results, some alternative PV module encapsulation schemes are proposed for improved module performance, where the current or modified formulations of EVA encapsulants still can be used so that the typical processing tools and conditions need not to be changed significantly. The schemes are designed in an attempt to eliminate or minimize the EVA yellow-browning and to increase the module power output. Four key experimental results from the studies of EVA discoloration and encapsulation aremore » to employ: (1) UV-absorbing (filtering) glasses as superstrates to protect EVA from UV-induced discoloration, (2) gas-permeable polymer films as superstrates and/or substrates to prevent EVA yellowing by permitting photobleaching reactions, (3) modified EVA formulations, and (4) internal reflection of the light by white substrates. {copyright} {ital 1996 American Institute of Physics.}« less

Extravehicular activities limitations study. Volume 2: Establishment of physiological and performance criteria for EVA gloves

NASA Technical Reports Server (NTRS)

Ohara, John M.; Briganti, Michael; Cleland, John; Winfield, Dan

1988-01-01

One of the major probelms faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human hand capabilities. This report describes the development of a standardized set of tests designed to assess EVA-gloved hand capabilities in six measurement domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based on an assessment of general human hand functioning and EVA task requirements several tests within each measurement domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand as a baseline and the EVA glove at operating pressure. A test program was conducted to evaluate the tests using a representative EVA glove. Eleven test subjects participated in a repeated-measures design. The report presents the results of the tests in each capability domain.

Does hard insertion and space improve shock absorption ability of mouthguard?

PubMed

Takeda, Tomotaka; Ishigami, Keiichi; Handa, Jun; Naitoh, Kaoru; Kurokawa, Katsuhide; Shibusawa, Mami; Nakajima, Kazunori; Kawamura, Shintaro

2006-04-01

Mouthguards are expected to reduce sports-related orofacial injuries. Numerous studies have been conduced to improve the shock absorption ability of mouthguards using air cells, sorbothane, metal wire, or hard material insertion. Most of these were shown to be effective; however, the result of each study has not been applied to clinical use. The aim of this study was to develop mouthguards that have sufficient prevention ability and ease of clinical application with focus on a hard insertion and space. Ethylene vinyl acetate (EVA) mouthguard blank used was Drufosoft and the acrylic resin was Biolon (Dreve-Dentamid GMBH, Unna, Germany). Three types of mouthguard samples tested were constructed by means of a Dreve Drufomat (Type SO, Dreve-Dentamid) air pressure machine: the first was a conventional laminated type of EVA mouthguard material; the second was a three layer type with acrylic resin inner layer (hard-insertion); the third was the same as the second but with space that does not come into contact with tooth surfaces (hard + space). As a control, without any mouthguard condition (NOMG) was measured. A pendulum type impact testing machine with interchangeable impact object (steel ball and baseball) and dental study model (D17FE-NC.7PS, Nissin, Tokyo, Japan) with the strain gages (KFG-1-120-D171-11N30C2: Kyowa, Tokyo, Japan) applied to teeth and the accelerometer to the dentition (AS-A YG-2768 100G, Kyowa) were used to measure transmitted forces. Statistical analysis (anova, P < 0.01) showed significant differences among four conditions of NOMG and three different mouthguards in both objects and sensor. About acceleration: in a steel ball which was a harder impact object, shock absorption ability of about 40% was shown with conventional EVA and hard-insertion and about 50% with hard + space. In a baseball that was softer compared with steel ball, a decrease rate is smaller, reduction (EVA = approximately 4%, hard-insertion = approximately 12%, hard + space = approximately 25%) was admitted in the similar order. A significant difference was found with all the combinations except for between EVA and hard-insertion with steel ball (Tukey test). About distortion: both buccal and lingual, distortions had become small in order of EVA, hard-insertion, and hard + space, too. The decrease rate is larger than acceleration, EVA = approximately 47%, hard-insertion = 80% or more, and hard +space = approximately 98%, in steel ball. EVA = approximately 30%, hard-insertion = approximately 75%, and hard + space = approximately 98% in baseball. And a significant difference was found with all the combinations (Tukey test). Especially, hard + space has decreased the distortion of teeth up to several percentages. Acceleration of the maxilla and distortions of the tooth became significantly smaller when wearing any type of mouthguard, in both impact objects. But the effect of mouthguard was clearer in the distortion of the tooth and with steel ball. Considering the differences of mouthguards, the hard-insertion and the hard + space had significantly greater buffer capacity than conventional EVA. Furthermore, hard + space shows quite high shock absorption ability in the tooth distortion. Namely, hard + space has decreased the distortion of teeth up to several percentages in both impact objects.

View of the orange soil which Apollo 17 crewmen found at Station 4 during EVA

NASA Image and Video Library

1972-12-12

AS17-137-20989 (12 Dec. 1972) --- A close-up view of the much-publicized orange soil which the Apollo 17 crewmen found at Station 4 (Shorty Crater) during the second Apollo 17 extravehicular activity (EVA) at the Taurus-Littrow landing site. The orange soil was first spotted by scientist-astronaut Harrison H. Schmitt. While astronauts Schmitt and Eugene A. Cernan descended in the Lunar Module (LM) "Challenger" to explore the lunar surface, astronaut Ronald E. Evans remained with the Apollo 17 Command and Service Modules (CSM) in lunar orbit. The orange soil was never seen by the crewmen of the other lunar landing missions - Apollo 11 (Sea of Tranquility); Apollo 12 (Ocean of Storms); Apollo 14 (Fra Mauro); Apollo 15 (Hadley-Apennines); and Apollo 16 (Descartes).

Preliminary analysis of the implications of natural radiations on geostationary operations

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Denn, F. M.

1976-01-01

The natural radiations present at geostationary orbit are discussed. Low-level galactic cosmic rays are important for careers spending a year or more at geostationary altitude. Trapped radiation will on occasion require interruption of extravehicular activity (EVA). The spacesuit shield requirements are strongly affected by the number of interruptions allowed. EVA cannot proceed during a large solar event and maximum allowable doses are exceeded in a few hours unless a heavily shielded area is provided. A shelter of 10 g/sq cm with personal shielding for the eyes and testes would contain exposure to within the presently accepted exposure constraints. Since radiation levels can increase unexpectedly to serious levels, an onboard radiation monitoring system with rate and integration capabilities is required for both surface-dose and depth-dose monitoring.

Lunar Roving Vehicle photographed against lunar background during EVA

NASA Image and Video Library

1971-08-01

AS15-88-11901 (31 July-2 Aug. 1971) --- The Lunar Roving Vehicle (LRV) is photographed alone against the desolate lunar background during the third Apollo 15 lunar surface extravehicular activity (EVA) at the Hadley-Apennine landing site. This view is looking north. The west edge of Mount Hadley is at the upper right edge of the picture. Mount Hadley rises approximately 4,500 meters (about 4,765 feet) above the plain. The most distant lunar feature visible is approximately 25 kilometers (about 15.5 statute miles) away. While astronauts David R. Scott, commander; and James B. Irwin, lunar module pilot, descended in the Lunar Module (LM) "Falcon" to explore the moon, astronaut Alfred M. Worden, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit.

Close-up of lunar roving vehicle at Apollo 17 Taurus-Littrow landing site

NASA Image and Video Library

1972-12-12

AS17-137-20979 (12 Dec. 1972) --- A close-up view of the lunar roving vehicle (LRV) at the Taurus-Littrow landing site photographed during Apollo 17 lunar surface extravehicular activity. Note the makeshift repair arrangement on the right rear fender of the LRV. During EVA-1 a hammer got underneath the fender and a part of it was knocked off. Astronauts Eugene A. Cernan and Harrison H. Schmitt were reporting a problem with lunar dust because of the damage fender. Following a suggestion from astronaut John W. Young in the Mission Control Center at Houston the crewmen repaired the fender early in EVA-2 using lunar maps and clamps from the optical alignment telescope lamp. Schmitt is seated in the rover. Cernan took this picture.

Advanced EVA system design requirements study

NASA Technical Reports Server (NTRS)

1986-01-01

Design requirements and criteria for the Space Station Advanced Extravehicular Activity System (EVAS) including crew enclosures, portable life support systems, maneuvering propulsion systems, and related extravehicular activity (EVA) support equipment were defined and established. The EVA mission requirements, environments, and medical and physiological requirements, as well as opertional, procedures, and training issues were considered.

U.S. Exploration EVA: ConOps, Interfaces and Test Objectives for Airlocks

NASA Technical Reports Server (NTRS)

Buffington, J.

2017-01-01

NASA is moving forward on defining the xEVA System Architecture and its implications to the spacecraft that host exploration EVA systems. This presentation provides an overview of the latest information for NASA's Concept of Operations (ConOps), Interfaces and corresponding Test Objectives for Airlocks hosting the xEVA System.

2014 Decompression Sickness/Extravehicular Activity Risks Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan

2015-01-01

The 2014 Decompression Sickness (DCS)/Extravehicular Activity (EVA) Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on November 4 - 5, 2014. The SRP reviewed the updated Evidence Reports for The Risk of Decompression Sickness (from here on referred to as the 2014 DCS Evidence Report) and the Risk of Injury and Compromised Performance due to EVA Operations (from here on referred to as the 2014 EVA Evidence Report), as well as the Research Plans for these Risks. The SRP appreciated the time and effort that the DCS and EVA disciplines put into their review documents and presentations. The SRP felt that the 2014 DCS Evidence Report and the 2014 EVA Evidence Reports were very thorough and addressed the majority of the known DCS and EVA issues. The researchers at NASA Johnson Space Center (JSC) have the knowledge base to deal with the DCS and EVA issues. Overall, the SRP thinks the DCS and EVA research teams have compiled excellent reports which address the majority of the literature and background information.

Role of EVA viscoelastic properties in the protective performance of a sport shoe: computational studies.

PubMed

Even-Tzur, Nurit; Weisz, Ety; Hirsch-Falk, Yifat; Gefen, Amit

2006-01-01

Modern sport shoes are designed to attenuate mechanical stress waves, mainly through deformation of the viscoelastic midsole which is typically made of ethylene vinyl acetate (EVA) foam. Shock absorption is obtained by flow of air through interconnected air cells in the EVA during shoe deformation under body-weight. However, when the shoe is overused and air cells collapse or thickness of the EVA is reduced, shock absorption capacity may be affected, and this may contribute to running injuries. Using lumped system and finite element models, we studied heel pad stresses and strains during heel-strike in running, considering the viscoelastic constitutive behavior of both the heel pad and EVA midsole. In particular, we simulated wear cases of the EVA, manifested in the modeling by reduced foam thickness, increased elastic stiffness, and shorter stress relaxation with respect to new shoe conditions. Simulations showed that heel pad stresses and strains were sensitive to viscous damping of the EVA. Wear of the EVA consistently increased heel pad stresses, and reduced EVA thickness was the most influential factor, e.g., for a 50% reduction in thickness, peak heel pad stress increased by 19%. We conclude that modeling of the heel-shoe interaction should consider the viscoelastic properties of the tissue and shoe components, and the age of the studied shoe.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Eisgruber, I.L.; Micheels, R.H.

The effects of ethylene-vinyl acetate (EVA) discoloration due to accelerated field or laboratory exposure on the encapsulated silicon (Si) solar cells or EVA/glass laminates were characterized quantitatively by using non-invasive, non-destructive ultraviolet-visible (UV-vis) spectrophotometry, spectrocolorimetry, spectrofluorometry, scanning laser OBIC (optical beam induced current) spectroscopy, and current-voltage (I-V) and quantum efficiency (QE) measurements. The results show that the yellowness index (YI) measured directly over the AR-coated solar cells under the glass superstrate increased from the range of {minus}80 to {minus}90 to the range of {minus}20 to 15 as the EVA changed from clear to brown. The ratio of two fluorescence emissionmore » peak areas generally increased from 1.45 to 5.69 as browning increased, but dropped to 4.21 on a darker EVA. For a solar cell with brown EVA in the central region, small-area grating QE measurements and scanning laser OBIC analysis between the brown and clear EVA regions showed that the quantum efficiency loss at 633 nm was 42%--48% of the loss at 488 nm, due to a reduced decrease of transmittance in browned EVA at the longer wavelengths. The portion of the solar cell under the browned EVA showed a decrease of {approximately}36% in efficiency, as compared to the cell efficiency under clear EVA. Transmittance loss at 633 nm was 38% of the loss at 488 nm for a light yellow-brown EVA/glass laminate that showed a small increase of 10 in the yellowness index.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Eisgruber, I.L.; Micheels, R.H.

The effects of ethylene-vinyl acetate (EVA) discoloration due to accelerated field or laboratory exposure on the encapsulated silicon (Si) solar cells or EVA/glass laminates were characterized quantitatively by using non-invasive, non-destructive ultraviolet-visible (UV-vis) spectrophotometry, spectrocolorimetry, spectrofluorometry, scanning laser OBIC (optical beam induced current) spectroscopy, and current-voltage (I-V) and quantum efficiency (QE) measurements. The results show that the yellowness index (YI) measured directly over the AR-coated solar cells under the glass superstrate increased from the range of -80 to -90 to the range of -20 to 15 as the EVA changed from clear to brown. The ratio of two fluorescence emissionmore » peak areas generally increased from 1.45 to 5.69 as browning increased, but dropped to 4.21 on a darker EVA. For a solar cell with brown EVA in the central region, small-area grating QE measurements and scanning laser OBIC analysis between the brown and clear EVA regions showed that the quantum efficiency loss at 633 nm was 42%-48% of the loss at 488 nm, due to a reduced decrease of transmittance in browned EVA at the longer wavelengths. The portion of the solar cell under the browned EVA showed a decrease of {approximately}36% in efficiency, as compared to the cell efficiency under clear EVA. Transmittance loss at 633 nm was 38% of the loss at 488 nm for a light yellow-brown EVA/glass laminate that showed a small increase of 10 in the yellowness index.« less

Clinically isolated enterovirus A71 subgenogroup C4 strain with lethal pathogenicity in 14-day-old mice and the application as an EV-A71 mouse infection model.

PubMed

Xu, Yi; Ma, Shuzhi; Zhu, Limeng; Huang, Zhiqiu; Chen, Liyun; Xu, Yuhua; Yin, Haibin; Peng, Tao; Wang, Yi

2017-01-01

The Enterovirus A71 (EV-A71) subgenogroup C4 is prevalent in China. EV-A71 causes hand, foot and mouth disease (HFMD) in children and may lead to severe neurological diseases. The development of antiviral and protective vaccines against EV-A71 is significantly hindered by the lack of suitable animal models to recapitulate human neurological symptoms. In this study, GZ-CII, a highly virulent EV-A71 subgenogroup C4 strain, was isolated from hospitalized children with HFMD. Intraperitoneal infections of GZ-CII resulted in progressive neurological disease in mice as old as 14 days. Administration of an inactivated EV-A71 vaccine or an anti-EV-A71 immune serum protected the mice against the GZ-CII infection. This demonstrated that a mouse model with EV-A71 GZ-CII could be used to evaluate potential vaccine candidates and therapeutics for subgenogroup C4. Comparing the genome sequence of GZ-CII with that of the avirulent EV-A71 subgenogroup C4 strain revealed unique mutations in GZ-CII. When mutation VP2-K149I was introduced into the nonpathogenic EV-A71 subgenogroup C4 strain, the variant similar to GZ-CII significantly increased viral replication and virulence in mice. These results indicated that the VP2-K149I mutation played an important role in enhancing the virulence of the EV-A71 subgenogroup C4 strain in mice, and that mice infected with the GZ-CII strain are a promising model for evaluating vaccines and therapeutics against the EV-A71 subgenogroup C4. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced Lithium-Ion Cell Development for NASA's Constellation Missions

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Miller, Thomas B.; Manzo, Michelle A.; Mercer, Carolyn R.

2008-01-01

The Energy Storage Project of NASA s Exploration Technology Development Program is developing advanced lithium-ion batteries to meet the requirements for specific Constellation missions. NASA GRC, in conjunction with JPL and JSC, is leading efforts to develop High Energy and Ultra High Energy cells for three primary Constellation customers: Altair, Extravehicular Activities (EVA), and Lunar Surface Systems. The objective of the High Energy cell development is to enable a battery system that can operationally deliver approximately 150 Wh/kg for 2000 cycles. The Ultra High Energy cell development will enable a battery system that can operationally deliver 220 Wh/kg for 200 cycles. To accomplish these goals, cathode, electrolyte, separator, and safety components are being developed for High Energy Cells. The Ultra High Energy cell development adds lithium alloy anodes to the component development portfolio to enable much higher cell-level specific energy. The Ultra High Energy cell development is targeted for the ascent stage of Altair, which is the Lunar Lander, and for power for the Portable Life support System of the EVA Lunar spacesuit. For these missions, mass is highly critical, but only a limited number of cycles are required. The High Energy cell development is primarily targeted for Mobility Systems (rovers) for Lunar Surface Systems, however, due to the high risk nature of the Ultra High Energy cell development, the High Energy cell will also serve as a backup technology for Altair and EVA. This paper will discuss mission requirements and the goals of the material, component, and cell development efforts in further detail.

Cluster-based exposure variation analysis

PubMed Central

2013-01-01

Background Static posture, repetitive movements and lack of physical variation are known risk factors for work-related musculoskeletal disorders, and thus needs to be properly assessed in occupational studies. The aims of this study were (i) to investigate the effectiveness of a conventional exposure variation analysis (EVA) in discriminating exposure time lines and (ii) to compare it with a new cluster-based method for analysis of exposure variation. Methods For this purpose, we simulated a repeated cyclic exposure varying within each cycle between “low” and “high” exposure levels in a “near” or “far” range, and with “low” or “high” velocities (exposure change rates). The duration of each cycle was also manipulated by selecting a “small” or “large” standard deviation of the cycle time. Theses parameters reflected three dimensions of exposure variation, i.e. range, frequency and temporal similarity. Each simulation trace included two realizations of 100 concatenated cycles with either low (ρ = 0.1), medium (ρ = 0.5) or high (ρ = 0.9) correlation between the realizations. These traces were analyzed by conventional EVA, and a novel cluster-based EVA (C-EVA). Principal component analysis (PCA) was applied on the marginal distributions of 1) the EVA of each of the realizations (univariate approach), 2) a combination of the EVA of both realizations (multivariate approach) and 3) C-EVA. The least number of principal components describing more than 90% of variability in each case was selected and the projection of marginal distributions along the selected principal component was calculated. A linear classifier was then applied to these projections to discriminate between the simulated exposure patterns, and the accuracy of classified realizations was determined. Results C-EVA classified exposures more correctly than univariate and multivariate EVA approaches; classification accuracy was 49%, 47% and 52% for EVA (univariate and multivariate), and C-EVA, respectively (p < 0.001). All three methods performed poorly in discriminating exposure patterns differing with respect to the variability in cycle time duration. Conclusion While C-EVA had a higher accuracy than conventional EVA, both failed to detect differences in temporal similarity. The data-driven optimality of data reduction and the capability of handling multiple exposure time lines in a single analysis are the advantages of the C-EVA. PMID:23557439

Bilateral Sequential Cochlear Implantation in Patients With Enlarged Vestibular Aqueduct (EVA) Syndrome.

PubMed

Manzoor, Nauman F; Wick, Cameron C; Wahba, Marian; Gupta, Amit; Piper, Robin; Murray, Gail S; Otteson, Todd; Megerian, Cliff A; Semaan, Maroun T

2016-02-01

To analyze audiometric outcomes after bilateral cochlear implantation in patients with isolated enlarged vestibular aqueduct (EVA) syndrome and associated incomplete partition (IP) malformations. Secondary objective was to analyze rate of cerebrospinal fluid (CSF) gusher in patients with IP-EVA spectrum deformities and compare this with the existing literature. Retrospective chart review. Thirty-two patients with EVA syndrome who received unilateral or bilateral cochlear implants between June 1999 and January 2014 were identified in the University Hospitals Case Medical Center cochlear implant database. Isolated EVA (IEVA) and Incomplete Partition Type II (IP-II) malformations were identified by reviewing high-resolution computed tomography (HRCT) imaging. Demographic information, age at implantation, surgical details, postimplantation audiometric data including speech reception thresholds (SRT), word, and sentence scores were reviewed and analyzed. Intra- and postoperative complications were analyzed as well and compared with the literature. Seventeen patients (32 implanted ears) had pediatric cochlear implantation for EVA-associated hearing loss. Data from 16 controls (32 implanted ears) were used to compare audiometric and speech outcomes of EVA cohort. Mean age at implantation was 6.8 years for EVA cohort and 6.0 years for controls. There was no statistically significant difference in long-term postoperative SRT, monaurally aided word scores, and binaurally tested word scores between pediatric EVA group and controls. The EVA patients had a long-term mean sentence score of 85.92%. A subset of EVA patients implanted at mean age of 3.18 years (n = 15 ears) had similar audiometric outcomes to another control group with Connexin 26 mutations (n = 20 ears) implanted at a similar age. Further subset analysis revealed no significant differences in age at implantation, SRT, and word scores in patients with IEVA and IP-II malformation. There was no significant association between size of vestibular aqueduct and age at implantation. There was no CSF gusher or other intra- or postoperative complications reported in our series. Bilateral sequential cochlear implantation can be performed safely in patients with EVA. Audiometric outcomes are excellent and comparable to pediatric cochlear implant patients with no malformations. CSF gusher rates can be minimized by trans-round window approach. Further long-term studies are needed to identify differences within IP-EVA spectrum deformities, audiometric outcomes, and proportions of EVA patients who will need cochlear implantation for hearing rehabilitation.

Thermal analysis and evolution of shape loss phenomena during polymer burnout in powder metal processing

NASA Astrophysics Data System (ADS)

Enneti, Ravi Kumar

2005-07-01

Powder metallurgy technology involves manufacturing of net shape or near net shape components starting from metal powders. Polymers are used to provide lubrication during shaping and handling strength to the shaped component. After shaping, the polymers are removed from the shaped components by providing thermal energy to burnout the polymers. Polymer burnout is one of the most critical step in powder metal processing. Improper design of the polymer burnout cycle will result in formation of defects, shape loss, or carbon contamination of the components. The effect of metal particles on polymer burnout and shape loss were addressed in the present research. The study addressing the effect of metal powders on polymer burnout was based on the hypothesis that metal powders act to catalyze polymer burnout. Thermogravimetric analysis (TGA) on pure polymer, ethylene vinyl acetate (EVA), and on admixed powders of 316L stainless steel and 1 wt. % EVA were carried out to verify the hypothesis. The effect of metal powders additions was studied by monitoring the onset temperature for polymer degradation and the temperature at which maximum rate of weight loss occurred from the TGA data. The catalytic behavior of the powders was verified by varying the particle size and shape of the 316L stainless powder. The addition of metal particles lowered the polymer burnout temperatures. The onset temperature for burnout was found to be sensitive to the surface area of the metal particle as well as the polymer distribution. Powders with low surface area and uniform distribution of polymer showed a lower burnout temperature. The evolution of shape loss during polymer burnout was based on the hypothesis that shape loss occurs during the softening of the polymer and depends on the sequence of chemical bonding in the polymer during burnout. In situ observation of shape loss was carried out on thin beams compacted from admixed powders of 316L stainless steel and 1 wt. % ethylene vinyl acetate (EVA). The results showed that shape loss primarily occurs by viscous creep during the softening of the polymer. At the onset of burnout of EVA, a recovery in shape loss was observed. The recovery occurred primarily during the first stage burnout of EVA and was attributed to the formation of polyethylene co-polyacetylene which forms with a carbon double bond. The in situ strength was also found to increase during the formation of polyethylene co-polyacetylene. No recovery of shape loss was observed during burnout of polymers (polyethylene and polypropylene) which convert to yield hydrocarbons without forming carbon double bonds. (Abstract shortened by UMI.)

EVA console personnel during STS-61 simulations

NASA Image and Video Library

1993-09-01

Susan P. Rainwater monitors an extravehicular activity (EVA) simulation from the EVA console at JSC's Mission Control Center (MCC) during joint integrated simulations for the STS-61 mission. Astronauts assigned to extravehicular activity (EVA) tasks with the Hubble Space Telescope (HST) were simultaneously rehearsing in a neutral buoyancy tank at the Marshall Space Flight Center (MSFC) in Alabama.

ChEVAS: Combining Suprarenal EVAS with Chimney Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torella, Francesco, E-mail: f.torella@liverpool.ac.uk; Chan, Tze Y., E-mail: tze.chan@rlbuht.nhs.uk; Shaikh, Usman, E-mail: usman.shaikh@rlbuht.nhs.uk

2015-10-15

Endovascular sealing with the Nellix{sup ®} endoprosthesis (EVAS) is a new technique to treat infrarenal abdominal aortic aneurysms. We describe the use of endovascular sealing in conjunction with chimney stents for the renal arteries (chEVAS) in two patients, one with a refractory type Ia endoleak and an expanding aneurysm, and one with a large juxtarenal aneurysm unsuitable for fenestrated endovascular repair (EVAR). Both aneurysms were successfully excluded. Our report confirms the utility of chEVAS in challenging cases, where suprarenal seal is necessary. We suggest that, due to lack of knowledge on its durability, chEVAS should only been considered when moremore » conventional treatment modalities (open repair and fenestrated EVAR) are deemed difficult or unfeasible.« less

NASA Glenn Research Center Battery Activities Overview

NASA Technical Reports Server (NTRS)

Manzo, Michelle A.

2009-01-01

This paper will provide an overview of the planned energy storage systems for the Orion Spacecraft and the Aries rockets that will be used in the return journey to the Moon and GRC's involvement in their development. Technology development goals and approaches to provide batteries and fuel cells for the Altair Lunar Lander, the new space suit under development for extravehicular activities (EVA) on the Lunar surface, and the Lunar Surface Systems operations will also be discussed.

Astronaut John Young leaps from lunar surface as he salutes U.S. flag

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, leaps from the lunar surface as he salutes the U.S. flag during the first Apollo 16 extravehicular activity (EVA-1) on the Moon, as seen in this reproduction taken from a color transmission made by the color TV camera mounted on the Lunar Roving Vehicle. Astronaut Charles M. Duke Jr., lunar module pilot, is standing in the background.

Effect of PEG6000 on the in vitro and in vivo transdermal permeation of ondansetron hydrochloride from EVA1802 membranes.

PubMed

Krishnaiah, Yellela S R; Rama, Bukka; Raghumurthy, Vanambattina; Ramanamurthy, Kolapalli V; Satyanarayana, Vemulapalli

2009-01-01

The objective was to evaluate ethylene vinyl acetate (EVA) copolymer membranes with vinyl acetate content of 18% w/w (EVA1802) for transdermal delivery of ondansetron hydrochloride. The EVA1802 membranes containing selected concentrations (0, 5, 10 and 15% w/w) of PEG6000 were prepared, and subjected to in vitro permeation studies from a nerodilol-based drug reservoir. Flux of ondansetron from EVA1802 membranes without PEG6000 was 64.1 +/- 0.6 microg/cm(2.)h, and with 10%w/w of PEG6000 (EVA1802-PEG6000-10) it increased to 194.9 +/- 4.6 microg/cm(2.)h. However, with 15%w/w of PEG6000, EVA1802 membranes produced a burst release of drug which in turn decreased drug flux. The EVA1802-PEG6000-10 membrane was coated with an adhesive emulsion, applied to rat epidermis and subjected to in vitro permeation studies against controls. Flux of ondansetron from transdermal patch across rat epidermis was 111.7 +/- 1.3 microg/cm(2.)h, which is about 1.3 times the required flux. A TTS was fabricated using adhesive-coated EVA1802-PEG6000-10 membrane and other TTS components, and subjected to in vivo delivery in human volunteers against a control. It was concluded from the comparative pharmacokinetic study that TTS of ondansetron, prepared with EVA1802-PEG6000-10 membrane, provided average steady-state plasma concentration on par with multiple-dosed oral tablets, but with a low percent of peak-to-trough fluctuation.

Self-Control and Emotional and Verbal Aggression in Dating Relationships: A Dyadic Understanding.

PubMed

Baker, Elizabeth A; Klipfel, Katherine M; van Dulmen, Manfred H M

2016-08-01

Guided by the dynamic developmental systems perspective, this study extends past research by examining the association between self-control and emotional and verbal aggression (EVA) using a dyadic multi-method design. Guided by empirical research and the dynamic developmental systems perspective, we hypothesized that (a) there would be a negative association between one's own self-control and one's own perpetration of EVA and (b) there would also be a negative association between one's partner's self-control and one's own perpetration of EVA. One hundred twenty heterosexual dating couples (ages 18-25 years) provided data on self-control (Grasmick et al.'s Low Self-Control Scale; reverse scored for ease of interpretation), self-reported perpetration of EVA (Emotional and Verbal Abuse subscale of the Conflict in Adolescent Dating Relationships Inventory), and observationally assessed perpetration of EVA. Data were analyzed using path analyses within the Actor-Partner Interdependence Model (APIM) framework. Consistent with previous findings, we found that self-control was negatively associated with the perpetration of EVA. Furthermore, we found partner effects, such that female-but not male-self-control predicted partner-observed perpetration of EVA. These findings highlight the importance of examining risk factors for EVA of both partners. Our findings also suggest that the association between self-control and EVA is partially a function of whether EVA is assessed through self-report or observational methodology. This highlights the need to conduct multi-method assessments in future research. As discussed in the article, our findings have implications for theories on intimate partner violence, study designs, and couple interventions.

Eva1 Maintains the Stem-like Character of Glioblastoma-Initiating Cells by Activating the Noncanonical NF-κB Signaling Pathway.

PubMed

Ohtsu, Naoki; Nakatani, Yuka; Yamashita, Daisuke; Ohue, Shiro; Ohnishi, Takanori; Kondo, Toru

2016-01-01

Glioblastoma (GBM)-initiating cells (GIC) are a tumorigenic subpopulation that are resistant to radio- and chemotherapies and are the source of disease recurrence. Therefore, the identification and characterization of GIC-specific factors is critical toward the generation of effective GBM therapeutics. In this study, we investigated the role of epithelial V-like antigen 1 (Eva1, also known as myelin protein zero-like 2) in stemness and GBM tumorigenesis. Eva1 was prominently expressed in GICs in vitro and in stem cell marker (Sox2, CD15, CD49f)-expressing cells derived from human GBM tissues. Eva1 knockdown in GICs reduced their self-renewal and tumor-forming capabilities, whereas Eva1 overexpression enhanced these properties. Eva1 deficiency was also associated with decreased expression of stemness-related genes, indicating a requirement for Eva1 in maintaining GIC pluripotency. We further demonstrate that Eva1 induced GIC proliferation through the activation of the RelB-dependent noncanonical NF-κB pathway by recruiting TRAF2 to the cytoplasmic tail. Taken together, our findings highlight Eva1 as a novel regulator of GIC function and also provide new mechanistic insight into the role of noncanonical NF-κB activation in GIC, thus offering multiple potential therapeutic targets for preclinical investigation in GBM. ©2015 American Association for Cancer Research.

A human factors analysis of EVA time requirements

NASA Technical Reports Server (NTRS)

Pate, D. W.

1996-01-01

Human Factors Engineering (HFE), also known as Ergonomics, is a discipline whose goal is to engineer a safer, more efficient interface between humans and machines. HFE makes use of a wide range of tools and techniques to fulfill this goal. One of these tools is known as motion and time study, a technique used to develop time standards for given tasks. A human factors motion and time study was initiated with the goal of developing a database of EVA task times and a method of utilizing the database to predict how long an ExtraVehicular Activity (EVA) should take. Initial development relied on the EVA activities performed during the STS-61 mission (Hubble repair). The first step of the analysis was to become familiar with EVAs and with the previous studies and documents produced on EVAs. After reviewing these documents, an initial set of task primitives and task time modifiers was developed. Videotaped footage of STS-61 EVAs were analyzed using these primitives and task time modifiers. Data for two entire EVA missions and portions of several others, each with two EVA astronauts, was collected for analysis. Feedback from the analysis of the data will be used to further refine the primitives and task time modifiers used. Analysis of variance techniques for categorical data will be used to determine which factors may, individually or by interactions, effect the primitive times and how much of an effect they have.

Applications of EVA guidelines and design criteria. Volume 3: EVA systems cost model formating

NASA Technical Reports Server (NTRS)

Brown, N. E.

1973-01-01

The development of a model for estimating the impact of manned EVA costs on future payloads is discussed. Basic information on the EV crewman requirements, equipment, physical and operational characteristics, and vehicle interfaces is provided. The cost model is being designed to allow system designers to quantify the impact of EVA on vehicle and payload systems.

Study to evaluate the effect of EVA on payload systems. Volume 1: Executive summary. [project planning of space missions employing extravehicular activity as a means of cost reduction

NASA Technical Reports Server (NTRS)

Patrick, J. W.; Kraly, E. F.

1975-01-01

Programmatic benefits to payloads are examined which can result from the routine use of extravehicular activity (EVA) during space missions. Design and operations costs were compared for 13 representative baseline payloads to the costs of those payloads adapted for EVA operations. The EVA-oriented concepts developed in the study were derived from these baseline concepts and maintained mission and program objectives as well as basic configurations. This permitted isolation of cost saving factors associated specifically with incorporation of EVA in a variety of payload designs and operations. The study results were extrapolated to a total of 74 payload programs. Using appropriate complexity and learning factors, net EVA savings were extrapolated to over $551M for NASA and U.S. civil payloads for routine operations. Adding DOD and ESRO payloads increases the net estimated savings of $776M. Planned maintenance by EVA indicated an estimated $168M savings due to elimination of automated service equipment. Contingency problems of payloads were also analyzed to establish expected failure rates for shuttle payloads. The failure information resulted in an estimated potential for EVA savings of $1.9 B.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holley, W.H. Jr.; Agro, S.C.; Galica, J.P.

The problem of browning in a number of EVA encapsulated flat plate photovoltaic modules has led to the questioning of EVA as a suitable material for such applications. By isolating the variables that could possibly lead to EVA browning, such as module construction, types of glass superstrates, additives, and processing conditions, the authors have been able to determine those significant specific variables that seem to have the most influence on discoloration.When standard-cure EVA-based laminates were exposed to accelerated UV aging, measurable yellowing of those laminates was evident after only one to two weeks exposure, and visual discoloration was observed aftermore » four to six weeks. Some samples yellowed quickly and some not at all, and there were significant differences in the rates of discoloration between standard-cure and fast-cure EVA. This paper looks at the results of these studies, especially focusing on the effect of additives in the EVA on the rate of yellowing, and discusses how preliminary results can be used to reformulate EVA encapsulants.« less

STS-87 crew participates in Crew Equipment Interface Test

NASA Technical Reports Server (NTRS)

1997-01-01

Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center are STS-87 crew members, assisted by Glenda Laws, extravehicular activity (EVA) coordinator, Johnson Space Center. Standing behind Laws are Takao Doi, Ph.D., of the National Space Development Agency of Japan, and Winston Scott, both mission specialists on STS-87. The STS-87 mission will be the fourth United States Microgravity Payload and flight of the Spartan-201 deployable satellite. During the mission, scheduled for a Nov. 19 liftoff from KSC, Dr. Doi and Scott will both perform spacewalks.

STS-132 crew during their MSS/SIMP EVA3 OPS 4 training

NASA Image and Video Library

2010-01-28

JSC2010-E-014957 (28 Jan. 2010) --- NASA astronaut Michael Good, STS-132 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. David Homan assisted Good.

KSC-97PC1512

NASA Image and Video Library

1997-10-02

Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center are STS-87 crew members, assisted by Glenda Laws, extravehicular activity (EVA) coordinator, Johnson Space Center. Standing behind Laws are Takao Doi, Ph.D., of the National Space Development Agency of Japan, and Winston Scott, both mission specialists on STS-87. The STS-87 mission will be the fourth United States Microgravity Payload and flight of the Spartan-201 deployable satellite. During the mission, scheduled for a Nov. 19 liftoff from KSC, Dr. Doi and Scott will both perform spacewalks

EVA 4 - Massimino with EMS on RMS arm

NASA Image and Video Library

2002-03-07

STS109-323-035 (7 March 2002) --- Astronaut Michael J. Massimino, on the shuttle’s robotic arm, prepares to install the Electronic Support Module (ESM) in the aft shroud of the Hubble Space Telescope (HST), with the assistance of astronaut James H. Newman (out of frame). The module will support a new experimental cooling system to be installed during the next day's fifth and final scheduled spacewalk of the mission. That cooling system is designed to bring the telescope's Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) back to life.

RoboGlove: Initial Work Toward a Robotically Assisted EVA Glove

NASA Technical Reports Server (NTRS)

Rogers, Jonathan

2015-01-01

The RoboGlove is a device designed to provide additional grip strength or endurance for a user. In applying this Robonaut 2 spinoff technology to the Phase VI Space Suit glove, the project is using robotic tendons and actuators to regain some of the hand performance that is lost when wearing a pressurized glove. An array of sensors embedded into the finger softgoods provides input to the control system which retracts the tendons, helping to close the user's hand. While active, this system provides augmentation, but is nonintrusive to glove usage when disabled.

EVA 4 activity on Flight Day 7 to service the Hubble Space Telescope

NASA Image and Video Library

1997-02-17

S82-E-5606 (17 Feb. 1997) --- Astronaut Gregory J. Harbaugh at work on Hubble Space Telescope (HST), with the assistance of astronaut Joseph R. Tanner (out of frame) on Remote Manipulator System (RMS). After replacing the HST's Solar Array Drive Electronics (SADE), Harbaugh and Tanner replaced the Magnetic Sensing System (MSS) protective lids with new, permanent covers; and they installed pre-cut insulation pieces to correct tears in the HST's protective covering caused by temperature changes in space. This view was taken with an Electronic Still Camera (ESC).

International Space Station (ISS)

NASA Image and Video Library

2007-08-15

As the construction continued on the International Space Station (ISS), STS-118 astronaut and mission specialist Rick Mastracchio was anchored on the foot restraint of the Canadarm2 as he participated in the third session of Extra Vehicular Activity (EVA) for the mission. Assisting Mastracchio was Expedition 15 flight engineer Clay Anderson (out of frame). During the 5 hour, 28 minute space walk, the two relocated the S-band Antenna Sub-Assembly from the Port 6 (P6) truss to the Port 1 (P1) truss, installed a new transponder on P1 and retrieved the P6 transponder.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Lik Fai, E-mail: rickieclf@yahoo.com.hk; Cheung, Kwok Fai; Chan, Kwong Man

Nellix Endovascular Aneurysm Sealing (EVAS) system is a new concept and technology of abdominal aortic aneurysm (AAA) repair. Elective EVAS using Nellix device was performed for a 83-year-old man with AAA. 2-month post-EVAS CTA surveillance demonstrated mild enlargement of aneurysmal sac and separation of the EndoBags, but without detectable endoleak. The patient developed sudden AAA rupture with retroperitoneal hematoma at about 4 months after EVAS. We postulated that early enlargement of aneurysmal sac and separation of EndoBags of Nellix devices after EVAS, even without detectable endoleak, might indicate significant aneurysmal wall weakening with increased risk of later AAA rupture. To themore » best of the authors’ knowledge, this was the first reported case of aortic rupture after EVAS without detectable endoleak during and after the procedure.« less

Energy Expenditure During Extravehicular Activity Through Apollo

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and crewmembers (CMs) ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVA, and provides a historical look at energy expenditure during EVA through the Apollo program.

EVA - Don't Leave Earth Without It

NASA Technical Reports Server (NTRS)

Cupples, J. Scott; Smith, Stephen A.

2011-01-01

Modern manned space programs come in two categories: those that need Extravehicular Activity (EVA) and those that will need EVA. This paper discusses major milestones in the Shuttle Program where EVA was used to save payloads, enhance on-orbit capabilities, and build structures in order to ensure success of National Aeronautics and Space Administration (NASA) missions. In conjunction, the Extravehicular Mobility Unit s (EMU) design, and hence, its capabilities evolved as its mission evolved. It is the intent that lessons can be drawn from these case studies so that EVA compatibility is designed into future vehicles and payloads.

EVA Metro Sedan electric-propulsion system: test and evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reimers, E.

1979-09-01

The procedure and results of the performance evaluation of the EVA Metro Sedan (car No. 1) variable speed dc chopper motor drive and its three speed automatic transmission are presented. The propulsion system for a battery powered vehicle manufactured by Electric Vehicle Associates, Valley View, Ohio, was removed from the vehicle, mounted on the programmable electric dynamometer test facility and evaluated with the aid of a hp 3052A Data Acquisition System. Performance data for the automatic transmission, the solid state dc motor speed controller, and the dc motor in the continuous and pulsating dc power mode, as derived on themore » dynamometer test facility, as well as the entire propulsion system are given. This concept and the system's components were evaluated in terms of commercial applicability, maintainability, and energy utility to establish a design base for the further development of this system or similar propulsion drives. The propulsion system of the EVA Metro Sedan is powered by sixteen 6-volt traction batteries, Type EV 106 (Exide Battery Mfg. Co.). A thyristor controlled cable form Pulsomatic Mark 10 controller, actuated by a foot throttle, controls the voltage applied to a dc series field motor, rated at 10 hp at 3800 rpm (Baldor Electric Co.). Gear speed reduction to the wheel is accomplished by the original equipment three speed automatic transmission with torque converter (Renault 12 Sedan). The brake consists of a power-assisted, hydraulic braking system with front wheel disk and rear drum. An ability to recuperate electric energy with subsequent storage in the battery power supply is not provided.« less

Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients

PubMed Central

Aw-Yong, Kam Leng; Sam, I-Ching; Koh, Mia Tuang

2016-01-01

Enterovirus A71 (EV-A71) is one of the main causative agents of hand, foot and mouth disease (HFMD). Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4), and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142–156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41–55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates. PMID:27806091

SLC26A4 mutation testing for hearing loss associated with enlargement of the vestibular aqueduct

PubMed Central

Ito, Taku; Muskett, Julie; Chattaraj, Parna; Choi, Byung Yoon; Lee, Kyu Yup; Zalewski, Christopher K; King, Kelly A; Li, Xiangming; Wangemann, Philine; Shawker, Thomas; Brewer, Carmen C; Alper, Seth L; Griffith, Andrew J

2014-01-01

Pendred syndrome (PS) is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct (EVA), and mutations of the SLC26A4 gene. However, not all EVA patients have PS or SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in ¼ of North American or European EVA populations, one mutant allele is detected in another ¼ of patient populations, and no mutations are detected in the other ½. The presence of two mutant alleles of SLC26A4 is associated with abnormal iodide organification, increased thyroid gland volume, increased severity of hearing loss, and bilateral EVA. The presence of a single mutant allele of SLC26A4 is associated with normal iodide organification, normal thyroid gland volume, less severe hearing loss and either bilateral or unilateral EVA. When other underlying correlations are accounted for, the presence of a cochlear malformation or the size of EVA does not have an effect on hearing thresholds. This is consistent with observations of an Slc26a4 mutant mouse model of EVA in which hearing loss is independent of endolymphatic hydrops or inner ear malformations. Segregation analyses of EVA in families suggest that the patients carrying one mutant allele of SLC26A4 have a second, undetected mutant allele of SLC26A4, and the probability of a sibling having EVA is consistent with its segregation as an autosomal recessive trait. Patients without any mutations are an etiologically heterogeneous group in which siblings have a lower probability of having EVA. SLC26A4 mutation testing can provide prognostic information to guide clinical surveillance and management, as well as the probability of EVA affecting a sibling. PMID:25960948

The economic value added (EVA) resulting from medical care of functional amblyopia, strabismus, (pathologies of binocular vision) and asthma.

PubMed

Beauchamp, Cynthia L; Felius, Joost; Beauchamp, George R

2010-01-01

Value analysis in health care calculates the economic value added (EVA) that results from improvements in health and health care. Our purpose was to develop an EVA model and to apply the model to typical and hypothetical (instantaneous and perfect) cures for amblyopia, surgical strabismus and asthma, as another, but non-ophthalmological disease standard for comparison, in the United States. The model is based on changes in utility and longevity, the associated incremental costs, and an estimate of the value of life. Univariate sensitivity analyses were performed to arrive at a plausible range of outcomes. For the United States, the EVA for current practice amblyopia care is 12.9B dollars (billion) per year, corresponding to a return on investment (ROI) of 10.4% per yr. With substantial increases in investment aimed at maximal improvement ("perfect cure"), the EVA is 32.7B per yr, with ROI of 5.3% per yr. The EVA for typical surgical strabismus care is 10.3B per yr. A perfect cure may yield EVA of 9.6B per yr. The EVA for asthma is 1317B per yr (ROI 20.4% per yr.., while a perfect cure may yield EVA of 110 B per yr. Sensitivity analysis demonstrated the relatively large effects of incidence, utility, and longevity, while incremental costs have a relatively minor effect on the EVA. The economic value added by improvements in patient-centered outcomes is very large. Failing to make the necessary investments in research, prevention, detection, prompt treatment and rehabilitation of these diseases, at virtually any conceivable cost, appears economically, medically, morally and ethically deficient and consequently wasteful at very least economically for our society.

Evaluation of Visual Acuity Measurements after Autorefraction versus Manual Refraction in Eyes with and without Diabetic Macular Edema

PubMed Central

Sun, Jennifer K.; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W.; Andreoli, Christopher M.; Edwards, Paul A.; Glassman, Adam R.; Pavlica, Michael R.

2012-01-01

Objective To compare visual acuity (VA) scores after autorefraction versus research protocol manual refraction in eyes of patients with diabetes and a wide range of VA. Methods Electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) VA Test© letter score (EVA) was measured after autorefraction (AR-EVA) and after Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction (MR-EVA). Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA utilizing an identical manual refraction (MR-EVAsupl) was performed to determine test-retest variability. Results In 878 eyes of 456 study participants, median MR-EVA was 74 (Snellen equivalent approximately 20/32). Spherical equivalent was often similar for manual and autorefraction (median difference: 0.00, 5th and 95th percentiles −1.75 to +1.13 Diopters). However, on average, MR-EVA results were slightly better than AR-EVA results across the entire VA range. Furthermore, variability between AR-EVA and MR-EVA was substantially greater than the test-retest variability of MR-EVA (P<0.001). Variability of differences was highly dependent on autorefractor model. Conclusions Across a wide range of VA at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models comparing most favorably to manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA. PMID:22159173

Neutral buoyancy test evaluation of hardware and extravehicular activity procedures for on-orbit assembly of a 14 meter precision reflector

NASA Technical Reports Server (NTRS)

Heard, Walter L., Jr.; Lake, Mark S.

1993-01-01

A procedure that enables astronauts in extravehicular activity (EVA) to perform efficient on-orbit assembly of large paraboloidal precision reflectors is presented. The procedure and associated hardware are verified in simulated Og (neutral buoyancy) assembly tests of a 14 m diameter precision reflector mockup. The test article represents a precision reflector having a reflective surface which is segmented into 37 individual panels. The panels are supported on a doubly curved tetrahedral truss consisting of 315 struts. The entire truss and seven reflector panels were assembled in three hours and seven minutes by two pressure-suited test subjects. The average time to attach a panel was two minutes and three seconds. These efficient assembly times were achieved because all hardware and assembly procedures were designed to be compatible with EVA assembly capabilities.

Enlarged Vestibular Aqueducts and Childhood Hearing Loss

MedlinePlus

... EVA. However, this is a rare event in commercial aircraft with pressurized cabins. If you have EVA, ... EVA, will benefit from learning other forms of communication, such as sign language or cued speech, or ...

Equine viral arteritis in breeding and sport horses in central Spain.

PubMed

Cruz-Lopez, Fatima; Newton, Richard; Sanchez-Rodriguez, Ana; Ireland, Joanne; Mughini-Gras, Lapo; Moreno, Miguel A; Fores, Paloma

2017-12-01

Equine viral arteritis (EVA) may have a high economic impact on breeding stud farms due to the occurrence of EVA-associated abortion outbreaks and the ability of the virus to persist in carrier stallions. While the consequences of EVA in premises with sport horses are usually less severe, the first confirmed outbreak of EVA in Spain occurred in a riding club in Barcelona, but no data on the seroprevalence of EVA in sport horses have been reported in Spain. Given the importance of both Spanish Purebred (SP) breeding horses and sport horses for Spain's equine industry, the aim of this study was to determine and compare the seroprevalence of EVA in these two horse populations in central Spain. Serum samples from 155 SP breeding horses residing in 16 stud farms and 105 sport horses of different breeds housed in 12 riding clubs, collected between September 2011 and November 2013, were tested using a commercial EVA antibody ELISA test with a 100% sensitivity, and confirmed by seroneutralisation (SN) test. EVA seroprevalence in SP breeding horses was higher 21.1% (95% CI 15.3-26.8%) than that in sport horses (6.7%, 95% CI 1.89-11.45%). However, the primary use (breeding vs. sport) was not significantly associated with seropositivity to Equine Arteritis Virus (EAV), suggesting that different management factors do not affect EVA circulation in these two horse populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics of vestibular evoked myogenic potentials in children with enlarged vestibular aqueduct.

PubMed

Zhou, Guangwei; Gopen, Quinton

2011-01-01

To explore the characteristics of vestibular evoked myogenic potential (VEMP) in children with enlarged vestibular aqueduct (EVA) and to determine the diagnostic value of VEMP testing for this particular inner ear structural anomaly. Retrospective cohort study in a pediatric tertiary care facility. A total of 25 pediatric cases (37 ears) of EVA were identified with complete records, including otologic evaluation, CT scan of the temporal bone, and audiologic assessment. Results of audiometry, tympanometry, and VEMP testing were analyzed. Hearing loss was found in 97% (36/37) of the ears with EVA. Airbone gaps (conductive components) were found in all hearing losses with normal middle ear pressure and mobility. Abnormally low threshold VEMP responses were found in 92% (34/37) of the ears with EVA. VEMP responses were absent unilaterally in three EVA patients who had vestibular complaints. No clear correlation was found between the size of EVA and the audiologic findings. The presence of airbone gaps in children with EVA was found without apparent middle ear pathology. Characteristics of VEMP in EVA were lower thresholds and higher amplitudes despite of the presence of airbone gaps. The abnormally low threshold VEMP responses suggested a "third" window effect in the pathologic condition of EVA. Unilateral absence of VEMP may implicate peripheral vestibular impairment. The findings from our study are helpful in clinical evaluation of young children who usually give limited and ambiguous input regarding their hearing and vestibular problems.

Collaborative Human Engineering Work in Space Exploration Extravehicular Activities (EVA)

NASA Technical Reports Server (NTRS)

DeSantis, Lena; Whitmore, Mihriban

2007-01-01

A viewgraph presentation on extravehicular activities in space exploration in collaboration with other NASA centers, industries, and universities is shown. The topics include: 1) Concept of Operations for Future EVA activities; 2) Desert Research and Technology Studies (RATS); 3) Advanced EVA Walkback Test; 4) Walkback Subjective Results; 5) Integrated Suit Test 1; 6) Portable Life Support Subsystem (PLSS); 7) Flex PLSS Design Process; and 8) EVA Information System; 9)

Advanced extravehicular activity systems requirements definition study. Phase 2: Extravehicular activity at a lunar base

NASA Technical Reports Server (NTRS)

Neal, Valerie; Shields, Nicholas, Jr.; Carr, Gerald P.; Pogue, William; Schmitt, Harrison H.; Schulze, Arthur E.

1988-01-01

The focus is on Extravehicular Activity (EVA) systems requirements definition for an advanced space mission: remote-from-main base EVA on the Moon. The lunar environment, biomedical considerations, appropriate hardware design criteria, hardware and interface requirements, and key technical issues for advanced lunar EVA were examined. Six remote EVA scenarios (three nominal operations and three contingency situations) were developed in considerable detail.

Climbing the Extravehicular Activity (EVA) Wall - Safely

NASA Technical Reports Server (NTRS)

Fuentes, Jose; Greene, Stacie

2010-01-01

The success of the EVA team, that includes the EVA project office, Crew Office, Mission Operations, Engineering and Safety, is assured by the full integration of all necessary disciplines. Safety participation in all activities from hardware development concepts, certification and crew training, provides for a strong partnership within the team. Early involvement of Safety on the EVA team has mitigated risk and produced a high degree of mission success.

Decision rules for spaceborne operations planning

NASA Technical Reports Server (NTRS)

Smith, Jeffrey H.

1992-01-01

Recent study of Space Station Freedom requirements for extravehicular activity (EVA) to perform external maintenance tasks emphasize an oversubscription of resources for performing on-orbit tasks. Extravehicular robotics (EVR) and cooperative EVA combined with EVR (using crew and robots synergistically to perform tasks) have been suggested as a part of the solution to reduce EVA. The question remains however, 'Under what conditions is it cost-effective to use the EVA and/or EVR resource.' The answer to such a question also has implications for the Space Station Freedom and its external maintenance as well as the Space Exploration Initiative (SEI) where the issue of work-system allocation is magnified by the long distances and scope of EVA work. This paper describes a simple technique of interest to operational planners and robot technology planners for determining in an economic context whether to use EVA alone, EVR alone, or Cooperative EVA. It is also shown that given: (1) the task times for these alternatives; and (2) the marginal costs of EVA, EVR, and IVA, the appropriate work system for performing the task can be identified. The paper illustrates how the work system choice is based on the ratio of costs. An example using Space Station Freedom data is presented to illustrate the trade-offs among alternative work-systems.

Study of space shuttle EVA/IVA support requirements. Volume 2: EVA/IVA tasks, guidelines, and constraints definition

NASA Technical Reports Server (NTRS)

Webbon, B. W.; Copeland, R. J.; Wood, P. W., Jr.; Cox, R. L.

1973-01-01

The guidelines for EVA and IVA tasks to be performed on the space shuttle are defined. In deriving tasks, guidelines, and constraints, payloads were first identified from the mission model. Payload requirements, together with man and manipulator capabilities, vehicle characteristics and operation, and safety considerations led to a definition of candidate tasks. Guidelines and constraints were also established from these considerations. Scenarios were established, and screening criteria, such as commonality of EVA and IVA activities, were applied to derive representative planned and unplanned tasks. The whole spectrum of credible contingency situations with a potential requirement for EVA/IVA was analyzed.

Energy Expenditure During Extravehicular Activity Through Apollo

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2012-01-01

Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and, as a result, crew members ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVAs, and provides a historical look at energy expenditure during EVAs through the Apollo Program.

Morphological and Mechanical Properties of Polypropylene[PP]/Poly(Ethylene Vinyl Acetate)[EVA] Blends. I. Homopolymer PP/Eva Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramirez-Vargas, E.

2000-10-01

Morphological and mechanical properties of polypropylene [PP]/poly(ethylene vinyl acetate) [EVA] blends have been studied. Infrared results using thin films first indicated a transition toward compatibility between both components at concentrations above 40% EVA. The transition was verified with different experimental techniques and it was associated to morphological changes and mechanical properties. The PP/EVA blends were mechanically evaluated in terms of impact and tensile strength to determine the influence of blending on the performance properties of these materials. Agreement was found between the transition and the enhancement of both elongation at break and impact strength.

Suited crewmember productivity.

PubMed

Barer, A S; Filipenkov, S N

1994-01-01

Analysis of the extravehicular activity (EVA) sortie experience gained in the former Soviet Union and physiologic hygienic aspect of space suit design and development shows that crewmember productivity is related to the following main factors: -space suit microclimate (gas composition, pressure and temperature); -limitation of motion activity and perception, imposed by the space suit; -good crewmember training in the ground training program; -level of crewmember general physical performance capabilities in connection with mission duration and intervals between sorties; -individual EVA experience (with accumulation) at which workmanship improves, while metabolism, physical and emotional stress decreases; -concrete EVA duration and work rate; -EVA bioengineering, including selection of tools, work station, EVA technology and mechanization.

Apollo 11 Facts Project [EVA Training/Washington, D. C. Tour

NASA Technical Reports Server (NTRS)

1994-01-01

Footage shows the crew of Apollo 11, Commander Neil Armstrong, Lunar Module Pilot Edwin Aldrin Jr., and Command Module Pilot Michael Collins, during various pre-mission activities. They are seen training for the extravehicular activity on the surface of the Moon, giving speeches in front of the White House, and during a parade in Houston.

Moments applied in the manual assembly of space structures - Ease biomechanics results from STS-61B. [Experimental Assembly of Structures in EVA

NASA Technical Reports Server (NTRS)

Cousins, D.; Akin, D. L.

1989-01-01

Measurements of the level and pattern of moments applied in the manual assembly of a space structure were made in extravehicular activity (EVA) and neutral buoyancy simulation (NBS). The Experimental Assembly of Structures in EVA program included the repeated assembly of a 3.6 m tetrahedral truss structure in EVA on STS-61B after extensive neutral buoyancy crew training. The flight and training structures were of equivalent mass and geometry to allow a direct correlation between EVA and NBS performance. A stereo photographic motion camera system was used to reconstruct in three dimensions rotational movements of structural beams during assembly. Moments applied in these manual handling tasks were calculated on the basis of the reconstructed movements taking into account effects of inertia, drag and virtual mass. Applied moments of 2.0 Nm were typical for beam rotations in EVA. Corresponding applied moments in NBS were typically up to five times greater. Moments were applied as impulses separated by several seconds of coasting in both EVA and NBS. Decelerating impulses were only infrequently observed in NBS.

Extravehicular activity space suit interoperability.

PubMed

Skoog, A I; McBarron JW 2nd; Severin, G I

1995-10-01

The European Agency (ESA) and the Russian Space Agency (RKA) are jointly developing a new space suit system for improved extravehicular activity (EVA) capabilities in support of the MIR Space Station Programme, the EVA Suit 2000. Recent national policy agreements between the U.S. and Russia on planned cooperations in manned space also include joint extravehicular activity (EVA). With an increased number of space suit systems and a higher operational frequency towards the end of this century an improved interoperability for both routine and emergency operations is of eminent importance. It is thus timely to report the current status of ongoing work on international EVA interoperability being conducted by the Committee on EVA Protocols and Operations of the International Academy of Astronauts initiated in 1991. This paper summarises the current EVA interoperability issues to be harmonised and presents quantified vehicle interface requirements for the current U.S. Shuttle EMU and Russian MIR Orlan DMA and the new European/Russian EVA Suit 2000 extravehicular systems. Major critical/incompatible interfaces for suits/mother-craft of different combinations are discussed, and recommendations for standardisations given.

ISS Charging Hazards and Low Earth Orbit Space Weather Effects

NASA Technical Reports Server (NTRS)

Minow, Joseph; Parker, L.; Coffey, V.; Wright K.; Koontz, S.; Edwards, D.

2008-01-01

Current collection by high voltage solar arrays on the International Space Station (ISS) drives the vehicle to negative floating potentials in the low Earth orbit daytime plasma environment. Pre-flight predictions of ISS floating potentials Phi greater than |-100 V| suggested a risk for degradation of dielectric thermal control coatings on surfaces in the U.S. sector due to arcing and an electrical shock hazard to astronauts during extravehicular activity (EVA). However, hazard studies conducted by the ISS program have demonstrated that the thermal control material degradation risk is effectively mitigated during the lifetime of the ISS vehicle by a sufficiently large ion collection area present on the vehicle to balance current collection by the solar arrays. To date, crew risk during EVA has been mitigated by operating one of two plasma contactors during EVA to control the vehicle potential within Phi less than or equal to |-40 V| with a backup process requiring reorientation of the solar arrays into a configuration which places the current collection surfaces into wake. This operation minimizes current collection by the solar arrays should the plasma contactors fail. This paper presents an analysis of F-region electron density and temperature variations at low and midlatitudes generated by space weather events to determine what range of conditions represent charging threats to ISS. We first use historical ionospheric plasma measurements from spacecraft operating at altitudes relevant to the 51.6 degree inclination ISS orbit to provide an extensive database of F-region plasma conditions over a variety of solar cycle conditions. Then, the statistical results from the historical data are compared to more recent in-situ measurements from the Floating Potential Measurement Unit (FPMU) operating on ISS in a campaign mode since its installation in August, 2006.

European Space Agency (ESA) Mission Specialist Nicollier trains in JSC's WETF

NASA Technical Reports Server (NTRS)

1987-01-01

European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier (left) is briefed by Randall S. McDaniel on Space Shuttle extravehicular activity (EVA) tools and equipment prior to donning an extravehicular mobility unit and participating in an underwater EVA simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Nicollier is holding the EMU mini workstation. Other equipment on the table includes EVA tool caddies and EVA crewmember safety tethers.

Generic extravehicular (EVA) and telerobot task primitives for analysis, design, and integration. Version 1.0: Reference compilation for the EVA and telerobotics communities

NASA Technical Reports Server (NTRS)

Smith, Jeffrey H.; Drews, Michael

1990-01-01

The results are described of an effort to establish commonality and standardization of generic crew extravehicular (crew-EVA) and telerobotic task analysis primitives used for the study of spaceborne operations. Although direct crew-EVA plans are the most visible output of spaceborne operations, significant ongoing efforts by a wide variety of projects and organizations also require tools for estimation of crew-EVA and telerobotic times. Task analysis tools provide estimates for input to technical and cost tradeoff studies. A workshop was convened to identify the issues and needs to establish a common language and syntax for task analysis primitives. In addition, the importance of such a syntax was shown to have precedence over the level to which such a syntax is applied. The syntax, lists of crew-EVA and telerobotic primitives, and the data base in diskette form are presented.

Early Enlargement of Aneurysmal Sac and Separation of EndoBags of Nellix Endovascular Aneurysm Sealing System as Signs of Increased Risk of Later Aneurysm Rupture.

PubMed

Cheng, Lik Fai; Cheung, Kwok Fai; Chan, Kwong Man; Ma, Johnny Ka Fai; Luk, Wing Hang; Chan, Micah Chi King; Ng, Carol Wing Kei; Mahboobani, Neeraj Ramesh; Ng, Wai Kin; Wong, Ting

2016-11-01

Nellix Endovascular Aneurysm Sealing (EVAS) system is a new concept and technology of abdominal aortic aneurysm (AAA) repair. Elective EVAS using Nellix device was performed for a 83-year-old man with AAA. 2-month post-EVAS CTA surveillance demonstrated mild enlargement of aneurysmal sac and separation of the EndoBags, but without detectable endoleak. The patient developed sudden AAA rupture with retroperitoneal hematoma at about 4 months after EVAS. We postulated that early enlargement of aneurysmal sac and separation of EndoBags of Nellix devices after EVAS, even without detectable endoleak, might indicate significant aneurysmal wall weakening with increased risk of later AAA rupture. To the best of the authors' knowledge, this was the first reported case of aortic rupture after EVAS without detectable endoleak during and after the procedure.

Suitport Feasibility - Human Pressurized Space Suit Donning Tests with the Marman Clamp and Pneumatic Flipper Suitport Concepts

NASA Technical Reports Server (NTRS)

Boyle, Robert M.; Rodriggs, Liana; Allton, Charles; Jennings, Mallory; Aitchision, Lindsay

2013-01-01

The suitport concept has been recently implemented as part of the small pressurized lunar rover (Currently the Space Exploration vehicle, or SEV) and the Multi-Mission Space Exploration Vehicle (MMSEV) concept demonstrator vehicle. Suitport replaces or augments the traditional airlock function of a spacecraft by providing a bulkhead opening, capture mechanism, and sealing system to allow ingress and egress of a space suit while the space suit remains outside of the pressurized volume of the spacecraft. This presents significant new opportunities to EVA exploration in both microgravity and surface environments. The suitport concept will enable three main improvements in EVA by providing reductions in: pre-EVA time from hours to less than thirty minutes; airlock consumables; contamination returned to the cabin with the EVA crewmember. Two second generation suitports were designed and tested. The previously reported second generation Marman Clamp suitport and a newer concept, the Pneumatic Flipper Suitport. These second generation suitports demonstrated human donning and doffing of the Z1 spacesuit with an 8.3 psi pressure differential across the spacesuit. Testing was performed using the JSC B32 Chamber B, a human rated vacuum chamber. The test included human rated suitports, the suitport compatible prototype suit, and chamber modifications. This test brought these three elements together in the first ever pressurized donning of a rear entry suit through a suitport. This paper presents the results of the testing, including unexpected difficulties with doffing, and engineering solutions implemented to ease the difficulties. A review of suitport functions, including a discussion of the need to doff a pressurized suit in earth gravity, is included. Recommendations for future design and testing are documented.

Suitport Feasibility - Human Pressurized Space Suit Donning Tests with the Marmon Clamp and Pneumatic Flipper Suitport Concepts

NASA Technical Reports Server (NTRS)

Boyle, Robert M.; Rodriggs, Liana; Alton, Charles; Jennings, Mallory; Aitchison, Lindsay

2012-01-01

The suitport concept has been recently implemented as part of the small pressurized lunar rover (Currently the Space Exploration vehicle, or SEV) and the Multi-Mission Space Exploration Vehicle (MMSEV) concept demonstrator vehicle. Suitport replaces or augments the traditional airlock function of a spacecraft by providing a bulkhead opening, capture mechanism, and sealing system to allow ingress and egress of a space suit while the space suit remains outside of the pressurized volume of the spacecraft. This presents significant new opportunities to EVA exploration in both microgravity and surface environments. The suitport concept will enable three main improvements in EVA by providing reductions in: pre-EVA time from hours to less than thirty minutes; airlock consumables; contamination returned to the cabin with the EVA crewmember. Two second generation suitports were designed and tested. The previously reported second generation Marman Clamp suitport and a newer concept, the Pneumatic Flipper Suitport. These second generation suitports demonstrated human donning and doffing of the Z1 spacesuit with an 8.3 psi pressure differential across the spacesuit. Testing was performed using the JSC B32 Chamber B, a human rated vacuum chamber. The test included human rated suitports, the suitport compatible prototype suit, and chamber modifications. This test brought these three elements together in the first ever pressurized donning of a rear entry suit through a suitport. This paper presents the results of the testing, including unexpected difficulties with doffing, and engineering solutions implemented to ease the difficulties. A review of suitport functions, including a discussion of the need to doff a pressurized suit in earth gravity, is included. Recommendations for future design and testing are documented.

Astronaut EVA exposure estimates from CAD model spacesuit geometry.

PubMed

De Angelis, Giovanni; Anderson, Brooke M; Atwell, William; Nealy, John E; Qualls, Garry D; Wilson, John W

2004-03-01

Ongoing assembly and maintenance activities at the International Space Station (ISS) require much more extravehicular activity (EVA) than did the earlier U.S. Space Shuttle missions. It is thus desirable to determine and analyze, and possibly foresee, as accurately as possible what radiation exposures crew members involved in EVAs will experience in order to minimize risks and to establish exposure limits that must not to be exceeded. A detailed CAD model of the U.S. Space Shuttle EVA Spacesuit, developed at NASA Langley Research Center (LaRC), is used to represent the directional shielding of an astronaut; it has detailed helmet and backpack structures, hard upper torso, and multilayer space suit fabric material. The NASA Computerized Anatomical Male and Female (CAM and CAF) models are used in conjunction with the space suit CAD model for dose evaluation within the human body. The particle environments are taken from the orbit-averaged NASA AP8 and AE8 models at solar cycle maxima and minima. The transport of energetic particles through space suit materials and body tissue is calculated by using the NASA LaRC HZETRN code for hadrons and a recently developed deterministic transport code, ELTRN, for electrons. The doses within the CAM and CAF models are determined from energy deposition at given target points along 968 directional rays convergent on the points and are evaluated for several points on the skin and within the body. Dosimetric quantities include contributions from primary protons, light ions, and electrons, as well as from secondary brehmsstrahlung and target fragments. Directional dose patterns are displayed as rays and on spherical surfaces by the use of a color relative intensity representation.

Dust control research for SEI. [Space Exploration Initiative

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Harris, Jeffrey R.

1992-01-01

A study, at NASA Johnson Space Center, of dust control requirements for surface habitats has focused on identification of the dust problem, identifying dust control techniques and dust control technology areas requiring research development. This research was performed for the Surface Habitats and Construction (SHAC) technology area. Dust control consists of two problems: (1) how to keep it out of the habitat; and (2) once the habitat or airlock is contaminated with dust, how to collect it. This paper describes the dust environment, the Apollo experience and dust control methods used, future EVA operational considerations, and dust control concepts for surface habitats.

A generic assay for whole-genome amplification and deep sequencing of enterovirus A71

PubMed Central

Tan, Le Van; Tuyen, Nguyen Thi Kim; Thanh, Tran Tan; Ngan, Tran Thuy; Van, Hoang Minh Tu; Sabanathan, Saraswathy; Van, Tran Thi My; Thanh, Le Thi My; Nguyet, Lam Anh; Geoghegan, Jemma L.; Ong, Kien Chai; Perera, David; Hang, Vu Thi Ty; Ny, Nguyen Thi Han; Anh, Nguyen To; Ha, Do Quang; Qui, Phan Tu; Viet, Do Chau; Tuan, Ha Manh; Wong, Kum Thong; Holmes, Edward C.; Chau, Nguyen Van Vinh; Thwaites, Guy; van Doorn, H. Rogier

2015-01-01

Enterovirus A71 (EV-A71) has emerged as the most important cause of large outbreaks of severe and sometimes fatal hand, foot and mouth disease (HFMD) across the Asia-Pacific region. EV-A71 outbreaks have been associated with (sub)genogroup switches, sometimes accompanied by recombination events. Understanding EV-A71 population dynamics is therefore essential for understanding this emerging infection, and may provide pivotal information for vaccine development. Despite the public health burden of EV-A71, relatively few EV-A71 complete-genome sequences are available for analysis and from limited geographical localities. The availability of an efficient procedure for whole-genome sequencing would stimulate effort to generate more viral sequence data. Herein, we report for the first time the development of a next-generation sequencing based protocol for whole-genome sequencing of EV-A71 directly from clinical specimens. We were able to sequence viruses of subgenogroup C4 and B5, while RNA from culture materials of diverse EV-A71 subgenogroups belonging to both genogroup B and C was successfully amplified. The nature of intra-host genetic diversity was explored in 22 clinical samples, revealing 107 positions carrying minor variants (ranging from 0 to 15 variants per sample). Our analysis of EV-A71 strains sampled in 2013 showed that they all belonged to subgenogroup B5, representing the first report of this subgenogroup in Vietnam. In conclusion, we have successfully developed a high-throughput next-generation sequencing-based assay for whole-genome sequencing of EV-A71 from clinical samples. PMID:25704598

Suited crewmember productivity

NASA Astrophysics Data System (ADS)

Barer, A. S.; Filipenkov, S. N.

Analysis of the extravehicular activity (EVA) sortie experience gained in the former Soviet Union and physiologic hygienic aspect of space suit design and development shows that crewmember productivity is related to the following main factors: —space suit microclimate (gas composition, pressure and temperature); —limitation of motion activity and perception, imposed by the space suit; —good crewmember training in the ground training program; —level of crewmember general physical performance capabilities in connection with mission duration and intervals between sorties; —individual EVA experience (with accumulation) at which workmanship improves, while metabolism, physical and emotional stress decreases; —concrete EVA duration and work rate; —EVA bioengineering, including selection of tools, work station, EVA technology and mechanization.

Minerva: An Integrated Geospatial/Temporal Toolset for Real-time Science Decision Making and Data Collection

NASA Astrophysics Data System (ADS)

Lees, D. S.; Cohen, T.; Deans, M. C.; Lim, D. S. S.; Marquez, J.; Heldmann, J. L.; Hoffman, J.; Norheim, J.; Vadhavk, N.

2016-12-01

Minerva integrates three capabilities that are critical to the success of NASA analogs. It combines NASA's Exploration Ground Data Systems (xGDS) and Playbook software, and MIT's Surface Exploration Traverse Analysis and Navigation Tool (SEXTANT). Together, they help to plan, optimize, and monitor traverses; schedule and track activity; assist with science decision-making and document sample and data collection. Pre-mission, Minerva supports planning with a priori map data (e.g., UAV and satellite imagery) and activity scheduling. During missions, xGDS records and broadcasts live data to a distributed team who take geolocated notes and catalogue samples. Playbook provides live schedule updates and multi-media chat. Post-mission, xGDS supports data search and visualization for replanning and analysis. NASA's BASALT (Biologic Analog Science Associated with Lava Terrains) and FINESSE (Field Investigations to Enable Solar System Science and Exploration) projects use Minerva to conduct field science under simulated Mars mission conditions including 5 and 15 minute one-way communication delays. During the recent BASALT-FINESSE mission, two field scientists (EVA team) executed traverses across volcanic terrain to characterize and sample basalts. They wore backpacks with communications and imaging capabilities, and carried field portable spectrometers. The Science Team was 40 km away in a simulated mission control center. The Science Team monitored imaging (video and still), spectral, voice, location and physiological data from the EVA team via the network from the field, under communication delays. Minerva provided the Science Team with a unified context of operations at the field site, so they could make meaningful remote contributions to the collection of 10's of geotagged samples. Minerva's mission architecture will be presented with technical details and capabilities. Through the development, testing and application of Minerva, we are defining requirements for the design of future capabilities to support human and human-robotic missions to deep space and Mars.

Information requirements and methodology for development of an EVA crewmember's heads up display

NASA Astrophysics Data System (ADS)

Petrek, J. S.

This paper presents a systematic approach for developing a Heads Up Display (HUD) to be used within the helmet of the Extra Vehicular Activity (EVA) crewmember. The information displayed on the EVA HUD will be analogous to EVA Flight Data File (FDF) information, which is an integral part of NASA's current Space Transportation System. Another objective is to determine information requirements and media techniques ultimately leading to the helmet-mounted HUD presentation technique.

Extravehicular Crewman Work System (ECWS) study program: Prebreathe elimination study

NASA Technical Reports Server (NTRS)

Wilde, R. L.

1981-01-01

The study examined impacts of changing Orbiter cabin pressure and EMU EVA pressure to eliminate pure O2 prebreathing prior to EVA. The investigation defines circumscribing physiological boundaries and identifies changes required within Orbiter to reduce cabin pressure. The study also identifies payload impacts, payload flight assignment constraints, and impacts upon EMU resulting from raising EVA pressure. The study presents the trade-off which optimizes the choice of reduced cabin pressure and increased EVA pressure.

The main results of EVA medical support on the Mir Space Station

NASA Astrophysics Data System (ADS)

Katuntsev, V. P.; Osipov, Yu. Yu.; Barer, A. S.; Gnoevaya, N. K.; Tarasenkov, G. G.

2004-04-01

The aim of this paper is to review the main results of medical support of 78 two-person extravehicular activities (EVAs) which have been conducted in the Mir Space Program. Thirty-six male crewmembers participated in these EVAs. Maximum length of a space walk was equal to 7 h 14 min. The total duration of all space walks reached 717.1 man-hours. The maximum frequency of EVA's execution was 10 per year. Most of the EVAs (67) have been performed at mission elapsed time ranging from 31 to 180 days. The oxygen atmosphere of the Orlan space suit with a pressure of 40 kPa in combination with the normobaric cabin environment and a short (30 min) oxygen prebreathe protocol have minimized the risk of decompression sickness (DCS). There has been no incidence of DCS during performed EVAs. At the peak activity, metabolic rates and heart rates increased up to 9.9- 13 kcal/ min and 150- 174 min-1, respectively. The medical problems have centred on feeling of moderate overcooling during a rest period in a shadow after the high physical loads, episodes with tachycardia accompanied by cardiac rhythm disorders at the moments of emotional stress, pains in the muscles and general fatigue after the end of a hard EVA. All of the EVAs have been completed safely.

A clinically authentic mouse model of enterovirus 71 (EV-A71)-induced neurogenic pulmonary oedema.

PubMed

Victorio, Carla Bianca Luena; Xu, Yishi; Ng, Qimei; Chua, Beng Hooi; Alonso, Sylvie; Chow, Vincent T K; Chua, Kaw Bing

2016-06-30

Enterovirus 71 (EV-A71) is a neurotropic virus that sporadically causes fatal neurologic illness among infected children. Animal models of EV-A71 infection exist, but they do not recapitulate in animals the spectrum of disease and pathology observed in fatal human cases. Specifically, neurogenic pulmonary oedema (NPE)-the main cause of EV-A71 infection-related mortality-is not observed in any of these models. This limits their utility in understanding viral pathogenesis of neurologic infections. We report the development of a mouse model of EV-A71 infection displaying NPE in severely affected animals. We inoculated one-week-old BALB/c mice with an adapted EV-A71 strain and identified clinical signs consistent with observations in human cases and other animal models. We also observed respiratory distress in some mice. At necropsy, we found their lungs to be heavier and incompletely collapsed compared to other mice. Serum levels of catecholamines and histopathology of lung and brain tissues of these mice strongly indicated onset of NPE. The localization of virally-induced brain lesions also suggested a potential pathogenic mechanism for EV-A71-induced NPE. This novel mouse model of virally-induced NPE represents a valuable resource for studying viral mechanisms of neuro-pathogenesis and pre-clinical testing of potential therapeutics and prophylactics against EV-A71-related neurologic complications.

The main results of EVA medical support on the Mir Space Station.

PubMed

Katuntsev, V P; Osipov, Yu Yu; Barer, A S; Gnoevaya, N K; Tarasenkov, G G

2004-04-01

The aim of this paper is to review the main results of medical support of 78 two-person extravehicular activities (EVAs) which have been conducted in the Mir Space Program. Thirty-six male crewmembers participated in these EVAs. Maximum length of a space walk was equal to 7 h 14 min. The total duration of all space walks reached 717.1 man-hours. The maximum frequency of EVA's execution was 10 per year. Most of the EVAs (67) have been performed at mission elapsed time ranging from 31 to 180 days. The oxygen atmosphere of the Orlan space suit with a pressure of 40 kPa in combination with the normobaric cabin environment and a short (30 min) oxygen prebreathe protocol have minimized the risk of decompression sickness (DCS). There has been no incidence of DCS during performed EVAs. At the peak activity, metabolic rates and heart rates increased up to 9.9-13 kcal/min and 150-174 min-1, respectively. The medical problems have centred on feeling of moderate overcooling during a rest period in a shadow after the high physical loads, episodes with tachycardia accompanied by cardiac rhythm disorders at the moments of emotional stress, pains in the muscles and general fatigue after the end of a hard EVA. All of the EVAs have been completed safely. c2003 Elsevier Ltd. All rights reserved.

NEEMO 15: Evaluation of Human Exploration Systems for Near-Earth Asteroids

NASA Technical Reports Server (NTRS)

Chappell, Steven P.; Gernhardt, Michael L.

2011-01-01

The NASA Extreme Environment Mission Operations (NEEMO) 15 mission was focused on near-Earth Asteroid (NEA) exploration techniques evaluation. It began with a University of Delaware autonomous underwater vehicle (AUV) systematically mapping the coral reef for hundreds of meters surrounding the Aquarius habitat. This activity is akin to the type of "far field survey" approach that may be used by a robotic precursor in advance of a human mission to a NEA. Data from the far-field survey were then examined by the NEEMO science team and follow-up exploration traverses were planned, which used Deepworker single-person submersibles. Science traverses at NEEMO 15 were planned according to a prioritized list of scientific objectives developed by the science team based on review and discussion of previous related marine science research including previous marine science saturation missions conducted at the Aquarius habitat. AUV data was used to select several areas of scientific interest. The Deepworker science traverses were then executed at these areas of interest during 4 days of the NEEMO 15 mission and provided higher resolution data such as coral species distribution and mortality. These traverses are analogous to the "near field survey" approach that is expected to be performed by a multi mission space exploration vehicle (MMSEV) during a human mission to a NEA before conducting extravehicular activities (EVA)s. In addition to the science objectives that were pursued, the NEEMO 15 science traverses provided an opportunity to test newly developed software and techniques. Sample collection and instrument deployment on the NEA surface by EVA crew would follow the "near field survey" in a human NEA mission. Sample collection was not necessary for the purposes of the NEEMO science objectives; however, the engineering and operations objectives during NEEMO 15 were to evaluate different combinations of vehicles, crewmembers, tools, and equipment that could be used to perform these tasks on a NEA. Specifically, the productivity and acceptability of simulated NEA exploration activities were systematically quantified and compared when operating with different combinations of crew sizes and exploration systems including MMSEVs, EVA jet packs, and EVA translation devices.

Payload bay activity during second EVA of STS-72 mission

NASA Image and Video Library

1996-01-16

STS072-393-008 (17 Jan. 1996) --- Astronaut Leroy Chiao gives a thumbs up signal, marking the success of his second extravehicular activity (EVA) in three days. Chiao was joined by astronaut Winston E. Scott on this EVA.

Shkaplerov works with EVA Hardware in the SM

NASA Image and Video Library

2012-02-03

ISS030-E-061158 (3 Feb. 2012) --- Russian cosmonaut Oleg Kononenko, Expedition 30 flight engineer, works with extravehicular activity (EVA) hardware in the Zvezda Service Module of the International Space Station in preparation for an EVA scheduled for Feb. 16, 2012.

Shkaplerov works with EVA Hardware in the SM

NASA Image and Video Library

2012-02-03

ISS030-E-061157 (3 Feb. 2012) --- Russian cosmonaut Anton Shkaplerov, Expedition 30 flight engineer, works with extravehicular activity (EVA) hardware in the Zvezda Service Module of the International Space Station in preparation for an EVA scheduled for Feb. 16, 2012.

Mapping Enterovirus A71 Antigenic Determinants from Viral Evolution.

PubMed

Huang, Sheng-Wen; Tai, Ching-Hui; Fonville, Judith M; Lin, Chin-Hui; Wang, Shih-Min; Liu, Ching-Chung; Su, Ih-Jen; Smith, Derek J; Wang, Jen-Ren

2015-11-01

Human enterovirus A71 (EV-A71) belongs to the Enterovirus A species in the Picornaviridae family. Several vaccines against EV-A71, a disease causing severe neurological complications or even death, are currently under development and being tested in clinical trials, and preventative vaccination programs are expected to start soon. To characterize the potential for antigenic change of EV-A71, we compared the sequences of two antigenically diverse genotype B4 and B5 strains of EV-A71 and identified substitutions at residues 98, 145, and 164 in the VP1 capsid protein as antigenic determinants. To examine the effects of these three substitutions on antigenicity, we constructed a series of recombinant viruses containing different mutation combinations at these three residues with a reverse genetics system and then investigated the molecular basis of antigenic changes with antigenic cartography. We found that a novel EV-A71 mutant, containing lysine, glutamine, and glutamic acid at the respective residues 98, 145, and 164 in the VP1 capsid protein, exhibited neutralization reduction against patients' antisera and substantially increased virus binding ability to human cells. These observations indicated that this low-neutralization-reactive EV-A71 VP1-98K/145Q/164E mutant potentially increases viral binding ability and that surveillance studies should look out for these mutants, which could compromise vaccine efficacy. Emerging and reemerging EV-A71 viruses can cause severe neurological etiology, primarily affecting children, especially around Asia-Pacific countries. We identified a set of mutations in EV-A71 that both reduced neutralization activity against humoral immunity in antisera of patients and healthy adults and greatly increased the viral binding ability to cells. These findings provide important insights for EV-A71 antigenic determinants and emphasize the importance of continuous surveillance, especially after EV-A71 vaccination programs begin. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mapping Enterovirus A71 Antigenic Determinants from Viral Evolution

PubMed Central

Huang, Sheng-Wen; Tai, Ching-Hui; Fonville, Judith M.; Lin, Chin-Hui; Wang, Shih-Min; Liu, Ching-Chung; Su, Ih-Jen

2015-01-01

ABSTRACT Human enterovirus A71 (EV-A71) belongs to the Enterovirus A species in the Picornaviridae family. Several vaccines against EV-A71, a disease causing severe neurological complications or even death, are currently under development and being tested in clinical trials, and preventative vaccination programs are expected to start soon. To characterize the potential for antigenic change of EV-A71, we compared the sequences of two antigenically diverse genotype B4 and B5 strains of EV-A71 and identified substitutions at residues 98, 145, and 164 in the VP1 capsid protein as antigenic determinants. To examine the effects of these three substitutions on antigenicity, we constructed a series of recombinant viruses containing different mutation combinations at these three residues with a reverse genetics system and then investigated the molecular basis of antigenic changes with antigenic cartography. We found that a novel EV-A71 mutant, containing lysine, glutamine, and glutamic acid at the respective residues 98, 145, and 164 in the VP1 capsid protein, exhibited neutralization reduction against patients' antisera and substantially increased virus binding ability to human cells. These observations indicated that this low-neutralization-reactive EV-A71 VP1-98K/145Q/164E mutant potentially increases viral binding ability and that surveillance studies should look out for these mutants, which could compromise vaccine efficacy. IMPORTANCE Emerging and reemerging EV-A71 viruses can cause severe neurological etiology, primarily affecting children, especially around Asia-Pacific countries. We identified a set of mutations in EV-A71 that both reduced neutralization activity against humoral immunity in antisera of patients and healthy adults and greatly increased the viral binding ability to cells. These findings provide important insights for EV-A71 antigenic determinants and emphasize the importance of continuous surveillance, especially after EV-A71 vaccination programs begin. PMID:26339057

Evaluation of visual acuity measurements after autorefraction vs manual refraction in eyes with and without diabetic macular edema.

PubMed

Sun, Jennifer K; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W; Andreoli, Christopher M; Edwards, Paul A; Glassman, Adam R; Pavlica, Michael R

2012-04-01

To compare visual acuity (VA) scores after autorefraction vs manual refraction in eyes of patients with diabetes mellitus and a wide range of VAs. The letter score from the Electronic Visual Acuity (EVA) test from the electronic Early Treatment Diabetic Retinopathy Study was measured after autorefraction (AR-EVA score) and after manual refraction (MR-EVA score), which is the research protocol of the Diabetic Retinopathy Clinical Research Network. Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA test using an identical supplemental manual refraction (MR-EVAsuppl score) was performed to determine test-retest variability. In 878 eyes of 456 study participants, the median MR-EVA score was 74 (Snellen equivalent, approximately 20/32). The spherical equivalent was often similar for manual refraction and autorefraction (median difference, 0.00; 5th-95th percentile range, -1.75 to 1.13 diopters). However, on average, the MR-EVA scores were slightly better than the AR-EVA scores, across the entire VA range. Furthermore, the variability between the AR-EVA scores and the MR-EVA scores was substantially greater than the test-retest variability of the MR-EVA scores (P < .001). The variability of differences was highly dependent on the autorefractor model. Across a wide range of VAs at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models that compare most favorably with manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that, with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA.

An Alternative Approach to Human Servicing of Crewed Earth Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Mularski, John R.; Alpert, Brian K.

2017-01-01

As crewed spacecraft have grown larger and more complex, they have come to rely on spacewalks, or Extravehicular Activities (EVA), for mission success and crew safety. Typically, these spacecraft maintain all of the hardware and trained personnel needed to perform an EVA on-board at all times. Maintaining this capability requires volume and up-mass for storage of EVA hardware, crew time for ground and on-orbit training, and on-orbit maintenance of EVA hardware. This paper proposes an alternative methodology, utilizing launch on-need hardware and crew to provide EVA capability for space stations in Earth orbit after assembly complete, in the same way that one would call a repairman to fix something at their home. This approach would reduce ground training requirements, save Intravehicular Activity (IVA) crew time in the form of EVA hardware maintenance and on-orbit training, and lead to more efficient EVAs because they would be performed by specialists with detailed knowledge and training stemming from their direct involvement in the development of the EVA. The on-orbit crew would then be available to focus on the immediate response to the failure as well as the day-to-day operations of the spacecraft and payloads. This paper will look at how current unplanned EVAs are conducted, including the time required for preparation, and offer alternatives for future spacecraft. As this methodology relies on the on-time and on-need launch of spacecraft, any space station that utilized this approach would need a robust transportation system including more than one launch vehicle capable of carrying crew. In addition, the fault tolerance of the space station would be an important consideration in how much time was available for EVA preparation after the failure. Each future program would have to weigh the risk of on-time launch against the increase in available crew time for the main objective of the spacecraft.

Cyclical Patterns of Hand, Foot and Mouth Disease Caused by Enterovirus A71 in Malaysia

PubMed Central

NikNadia, NMN; Sam, I-Ching; Rampal, Sanjay; WanNorAmalina, WMZ; NurAtifah, Ghazali; Verasahib, Khebir; Ong, Chia Ching; MohdAdib, MohdAidinniza; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71) is an important emerging pathogen causing large epidemics of hand, foot and mouth disease (HFMD) in children. In Malaysia, since the first EV-A71 epidemic in 1997, recurrent cyclical epidemics have occurred every 2–3 years for reasons that remain unclear. We hypothesize that this cyclical pattern is due to changes in population immunity in children (measured as seroprevalence). Neutralizing antibody titers against EV-A71 were measured in 2,141 residual serum samples collected from children ≤12 years old between 1995 and 2012 to determine the seroprevalence of EV-A71. Reported national HFMD incidence was highest in children <2 years, and decreased with age; in support of this, EV-A71 seroprevalence was significantly associated with age, indicating greater susceptibility in younger children. EV-A71 epidemics are also characterized by peaks of increased genetic diversity, often with genotype changes. Cross-sectional time series analysis was used to model the association between EV-A71 epidemic periods and EV-A71 seroprevalence adjusting for age and climatic variables (temperature, rainfall, rain days and ultraviolet radiance). A 10% increase in absolute monthly EV-A71 seroprevalence was associated with a 45% higher odds of an epidemic (adjusted odds ratio, aOR1.45; 95% CI 1.24–1.69; P<0.001). Every 10% decrease in seroprevalence between preceding and current months was associated with a 16% higher odds of an epidemic (aOR = 1.16; CI 1.01–1.34 P<0.034). In summary, the 2–3 year cyclical pattern of EV-A71 epidemics in Malaysia is mainly due to the fall of population immunity accompanying the accumulation of susceptible children between epidemics. This study will impact the future planning, timing and target populations for vaccine programs. PMID:27010319

An Alternative Approach to Human Servicing of Manned Earth Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Mularski, John; Alpert, Brian

2011-01-01

As manned spacecraft have grown larger and more complex, they have come to rely on spacewalks or Extravehicular Activities (EVA) for both mission success and crew safety. Typically these spacecraft maintain all of the hardware and trained personnel needed to perform an EVA on-board at all times. Maintaining this capability requires volume and up-mass for storage of EVA hardware, crew time for ground and on-orbit training, and on-orbit maintenance of EVA hardware . This paper proposes an alternative methodology to utilize launch-on-need hardware and crew to provide EVA capability for space stations in Earth orbit after assembly complete, in the same way that most people would call a repairman to fix something at their home. This approach would not only reduce ground training requirements and save Intravehicular Activity (IVA) crew time in the form of EVA hardware maintenance and on-orbit training, but would also lead to more efficient EVAs because they would be performed by specialists with detailed knowledge and training stemming from their direct involvement in the development of the EVA. The on-orbit crew would then be available to focus on the immediate response to the failure as well as the day-to-day operations of the spacecraft and payloads. This paper will look at how current ISS unplanned EVAs are conducted, including the time required for preparation, and offer alternatives for future spacecraft utilizing lessons learned from ISS. As this methodology relies entirely on the on-time and on-need launch of spacecraft, any space station that utilized this approach would need a robust transportation system including more than one launch vehicle capable of carrying crew. In addition the fault tolerance of the space station would be an important consideration in how much time was available for EVA preparation after the failure. Each future program would have to weigh the risk of on-time launch against the increase in available crew time for the main objective of the spacecraft.

EVA Performance Prediction

NASA Technical Reports Server (NTRS)

Peacock, Brian; Maida, James; Rajulu, Sudhakar

2004-01-01

Astronaut physical performance capabilities in micro gravity EV A or on planetary surfaces when encumbered by a life support suit and debilitated by a long exposure to micro gravity will be less than unencumbered pre flight capabilities. The big question addressed by human factors engineers is: what can the astronaut be expected to do on EVA or when we arrive at a planetary surface? A second question is: what aids to performance will be needed to enhance the human physical capability? These questions are important for a number of reasons. First it is necessary to carry out accurate planning of human physical demands to ensure that time and energy critical tasks can be carried out with confidence. Second it is important that the crew members (and their ground or planetary base monitors) have a realistic picture of their own capabilities, as excessive fatigue can lead to catastrophic failure. Third it is important to design appropriate equipment to enhance human sensory capabilities, locomotion, materials handling and manipulation. The evidence from physiological research points to musculoskeletal, cardiovascular and neurovestibular degradation during long duration exposure to micro gravity . The evidence from the biomechanics laboratory (and the Neutral Buoyancy Laboratory) points to a reduction in range of motion, strength and stamina when encumbered by a pressurized suit. The evidence from a long history of EVAs is that crewmembers are indeed restricted in their physical capabilities. There is a wealth of evidence in the literature on the causes and effects of degraded human performance in the laboratory, in sports and athletics, in industry and in other physically demanding jobs. One approach to this challenge is through biomechanical and performance modeling. Such models must be based on thorough task analysis, reliable human performance data from controlled studies, and functional extrapolations validated in analog contexts. The task analyses currently carried out for EVA activities are based more on extensive domain experience than any formal analytic structure. Conversely, physical task analysis for industrial and structured evidence from training and EV A contexts. Again on earth there is considerable evidence of human performance degradation due to encumbrance and fatigue. These industrial models generally take the form of a discounting equation. The development of performance estimates for space operations, such as timeline predictions for EVA is generally based on specific input from training activity, for example in the NBL or KC135. uniformed services tasks on earth are much more formalized. Human performance data in the space context has two sources: first there is the micro analysis of performance in structured tasks by the space physiology community and second there is the less structured evidence from training and EV A contexts.

EVA Health and Human Performance Benchmarking Study

NASA Technical Reports Server (NTRS)

Abercromby, A. F.; Norcross, J.; Jarvis, S. L.

2016-01-01

Multiple HRP Risks and Gaps require detailed characterization of human health and performance during exploration extravehicular activity (EVA) tasks; however, a rigorous and comprehensive methodology for characterizing and comparing the health and human performance implications of current and future EVA spacesuit designs does not exist. This study will identify and implement functional tasks and metrics, both objective and subjective, that are relevant to health and human performance, such as metabolic expenditure, suit fit, discomfort, suited postural stability, cognitive performance, and potentially biochemical responses for humans working inside different EVA suits doing functional tasks under the appropriate simulated reduced gravity environments. This study will provide health and human performance benchmark data for humans working in current EVA suits (EMU, Mark III, and Z2) as well as shirtsleeves using a standard set of tasks and metrics with quantified reliability. Results and methodologies developed during this test will provide benchmark data against which future EVA suits, and different suit configurations (eg, varied pressure, mass, CG) may be reliably compared in subsequent tests. Results will also inform fitness for duty standards as well as design requirements and operations concepts for future EVA suits and other exploration systems.

Astronaut John Young at LRV prior to deployment of ALSEP during first EVA

NASA Image and Video Library

1972-04-21

AS16-116-18578 (21 April 1972) --- Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, works at the Lunar Roving Vehicle (LRV) just prior to deployment of the Apollo Lunar Surface Experiments Package (ALSEP) during the first extravehicular activity (EVA) on April 21, 1972. Note the Ultraviolet (UV) Camera/Spectrometer to the right of the Lunar Module (LM) ladder. Also, note the pile of protective/thermal foil under the U.S. flag on the LM which the astronauts pulled away to get to the Modular Equipment Storage Assembly (MESA) bay. While astronauts Young and Charles M. Duke Jr., lunar module pilot; descended in the Apollo 16 LM "Orion" to explore the Descartes highlands landing site on the moon, astronaut Thomas K. Mattingly II, command module pilot, remained with the Command and Service Modules (CSM) "Casper" in lunar orbit.

Astronaut Ronald Evans photographed during transearth coast EVA

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Ronald E. Evans is photographed performing extravehicular activity (EVA) during the Apollo 17 spacecraft's transearth coast. During his EVA Command Module pilot Evans retrieved film cassettes from the Lunar Sounder, Mapping Camera, and Panoramic Camera. The total time for the transearth EVA was one hour seven minutes 19 seconds, starting at ground elapsed time of 257:25 (2:28 p.m.) amd ending at ground elapsed time of 258:42 (3:35 p.m.) on Sunday, December 17, 1972.

Spaceborne construction and operations planning - Decision rules for selecting EVA, telerobot, and combined work-systems

NASA Technical Reports Server (NTRS)

Smith, Jeffrey H.

1992-01-01

An approach is presented for selecting an appropriate work-system for performing construction and operations tasks by humans and telerobots. The decision to use extravehicular activity (EVA) performed by astronauts, extravehicular robotics (EVR), or a combination of EVA and EVR is determined by the ratio of the marginal costs of EVA, EVR, and IVA. The approach proposed here is useful for examining cost trade-offs between tasks and performing trade studies of task improvement techniques (human or telerobotic).

The development of a test methodology for the evaluation of EVA gloves

NASA Technical Reports Server (NTRS)

O'Hara, John M.; Cleland, John; Winfield, Dan

1988-01-01

This paper describes the development of a standardized set of tests designed to assess EVA-gloved hand capabilities in six measurement domains: range of motion, strength, tactile perception, dexterity, fatigue, and comfort. Based upon an assessment of general human-hand functioning and EVA task requirements, several tests within each measurement domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand as a baseline and the EVA glove at operating pressure.

Helms during EVA on the ISS

NASA Image and Video Library

2001-04-06

STS102-325-023 (11 March 2001) --- Astronaut Susan J. Helms completes a scheduled space walk task on the International Space Station (ISS). This extravehicular activity (EVA), on which Helms was joined by astronaut James S. Voss (out of frame), was the first of two scheduled STS-102 EVA sessions. The pair, destined to become members of the Expedition Two crew aboard the station later in the mission, rode aboard Discovery into orbit and at the time of this EVA were still regarded as STS-102 mission specialists.

Enterovirus A71 DNA-Launched Infectious Clone as a Robust Reverse Genetic Tool

PubMed Central

Tan, Chee Wah; Tee, Han Kang; Lee, Michelle Hui Pheng; Sam, I-Ching; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71) causes major outbreaks of hand, foot and mouth disease, and is occasionally associated with neurological complications and death in children. Reverse genetics is widely used in the field of virology for functional study of viral genes. For EV-A71, such tools are limited to clones that are transcriptionally controlled by T7/SP6 bacteriophage promoter. This is often time-consuming and expensive. Here, we describe the development of infectious plasmid DNA-based EV-A71 clones, for which EV-A71 genome expression is under transcriptional control by the CMV-intermediate early promoter and SV40 transcriptional-termination signal. Transfection of this EV-A71 infectious DNA produces good virus yield similar to in vitro-transcribed EV-A71 infectious RNA, 6.4 and 5.8 log10PFU/ml, respectively. Infectious plasmid with enhanced green fluorescence protein and Nano luciferase reporter genes also produced good virus titers, with 4.3 and 5.0 log10 PFU/ml, respectively. Another infectious plasmid with both CMV and T7 promoters was also developed for easy manipulation of in vitro transcription or direct plasmid transfection. Transfection with either dual-promoter infectious plasmid DNA or infectious RNA derived from this dual-promoter clone produced infectious viral particles. Incorporation of hepatitis delta virus ribozyme, which yields precise 3’ ends of the DNA-launched EV-A71 genomic transcripts, increased infectious viral production. In contrast, the incorporation of hammerhead ribozyme in the DNA-launched EV-A71 resulted in lower virus yield, but improved the virus titers for T7 promoter-derived infectious RNA. This study describes rapid and robust reverse genetic tools for EV-A71. PMID:27617744

Metabolic assessments during extra-vehicular activity.

PubMed

Osipov YuYu; Spichkov, A N; Filipenkov, S N

1998-01-01

Extra-vehicular activity (EVA) has a significant role during extended space flights. It demonstrates that humans can survive and perform useful work outside the Orbital Space Stations (OSS) while wearing protective space suits (SS). When the International Space Station 'Alpha' (ISSA) is fully operational, EVA assembly, installation, maintenance and repair operations will become an everyday repetitive work activity in space. It needs new ergonomic evaluation of the work/rest schedule for an increasing of the labor amount per EVA hour. The metabolism assessment is a helpful method to control the productivity of the EVA astronaut and to optimize the work/rest regime. Three following methods were used in Russia to estimate real-time metabolic rates during EVA: 1. Oxygen consumption, computed from the pressure drop in a high pressure bottle per unit time (with actual thermodynamic oxygen properties under high pressure and oxygen leakage taken into account). 2. Carbon dioxide production, computed from CO2 concentration at the contaminant control cartridge and gas flow rate in the life support subsystem closed loop (nominal mode) or gas leakage in the SS open loop (emergency mode). 3. Heat removal, computed from the difference between the temperatures of coolant water or gas and its flow rate in a unit of time (with assumed humidity and wet oxygen state taken into account). Comparison of heat removal values with metabolic rates enables us to determine the thermal balance during an operative medical control of EVA at "Salyut-6", "Salyut-7" and "Mir" OSS. Complex analysis of metabolism, body temperature and heat rate supports a differential diagnosis between emotional and thermal components of stress during EVA. It gives a prognosis of human homeostasis during EVA. Available information has been acquired into an EVA data base which is an effective tool for ergonomical optimization.

Metabolic assessments during extra-vehicular activity

NASA Astrophysics Data System (ADS)

Osipov, Yu. Yu.; Spichkov, A. N.; Filipenkov, S. N.

Extra-vehicular activity (EVA) has a significant role during extended space flights. It demonstrates that humans can survive and perform useful work outside the Orbital Space Stations (OSS) while wearing protective space suits (SS). When the International Space Station 'Alpha'(ISSA) is fully operational, EVA assembly, installation, maintenance and repair operations will become an everyday repetitive work activity in space. It needs new ergonomic evaluation of the work/rest schedule for an increasing of the labor amount per EVA hour. The metabolism assessment is a helpful method to control the productivity of the EVA astronaut and to optimize the work/rest regime. Three following methods were used in Russia to estimate real-time metabolic rates during EVA: 1. Oxygen consumption, computed from the pressure drop in a high pressure bottle per unit time (with actual thermodynamic oxygen properties under high pressure and oxygen leakage taken into account). 2. Carbon dioxide production, computed from CO 2 concentration at the contaminant control cartridge and gas flow rate in the life support subsystem closed loop (nominal mode) or gas leakage in the SS open loop (emergency mode). 3. Heat removal, computed from the difference between the temperatures of coolant water or gas and its flow rate in a unit of time (with assumed humidity and wet oxygen state taken into account). Comparison of heat removal values with metabolic rates enables us to determine the thermal balance during an operative medical control of EVA at "Salyut-6", "Salyut-7" and "Mir" OSS. Complex analysis of metabolism, body temperature and heat rate supports a differential diagnosis between emotional and thermal components of stress during EVA. It gives a prognosis of human homeostasis during EVA. Available information has been acquired into an EVA data base which is an effective tool for ergonomical optimization.

New monitoring by thermogravimetry for radiation degradation of EVA

NASA Astrophysics Data System (ADS)

Boguski, J.; Przybytniak, G.; Łyczko, K.

2014-07-01

The radiation ageing of ethylene vinyl-acetate copolymer (EVA) as the jacket of cable applied in nuclear power plant was carried out by gamma rays irradiation, and the degradation was monitored by a thermo-gravimetric analysis (TGA). The EVA decomposition rate in air by the isothermal at 400 °C decreased with increase of dose and also with decrease of the dose rate. The behavior of EVA jacket of cable indicated that the decomposition rate at 400 °C was reduced with increase of oxidation. The elongation at break by tensile test for the radiation aged EVA was closely related to the decomposition rate at 400 °C; therefore, the TGA might be applied for a diagnostic technique of the cable degradation.

Extravehicular Activity (EVA) 101: Constellation EVA Systems

NASA Technical Reports Server (NTRS)

Jordan, Nicole C.

2007-01-01

A viewgraph presentation on Extravehicular Activity (EVA) Systems is shown. The topics include: 1) Why do we need space suits? 2) Protection From the Environment; 3) Primary Life Support System (PLSS); 4) Thermal Control; 5) Communications; 6) Helmet and Extravehicular Visor Assy; 7) Hard Upper Torso (HUT) and Arm Assy; 8) Display and Controls Module (DCM); 9) Gloves; 10) Lower Torso Assembly (LTA); 11) What Size Do You Need?; 12) Boot and Sizing Insert; 13) Boot Heel Clip and Foot Restraint; 14) Advanced and Crew Escape Suit; 15) Nominal & Off-Nominal Landing; 16) Gemini Program (mid-1960s); 17) Apollo EVA on Service Module; 18) A Bold Vision for Space Exploration, Authorized by Congress; 19) EVA System Missions; 20) Configurations; 21) Reduced Gravity Program; and 22) Other Opportunities.

Study of space shuttle EVA/IVA support requirements. Volume 4: Requirements study for space shuttle mobility aids

NASA Technical Reports Server (NTRS)

Wood, P. W., Jr.

1973-01-01

The requirements for mobility aids and restraint devices for use by personnel of the space shuttle were investigated. The devices considered were as follows: (1) translational devices to assist crewmen in moving from place to place and in moving equipment, (2) restraint devices for crewman at the worksite to prevent undesired induced motion between the crewman and the worksite, and (3) other necessary worksite provisions. Existing devices in each category are reviewed and new concepts are generated as required. Diagrams and line drawings of items of equipment are provided.

Fusing human and machine skills for remote robotic operations

NASA Technical Reports Server (NTRS)

Schenker, Paul S.; Kim, Won S.; Venema, Steven C.; Bejczy, Antal K.

1991-01-01

The question of how computer assists can improve teleoperator trajectory tracking during both free and force-constrained motions is addressed. Computer graphics techniques which enable the human operator to both visualize and predict detailed 3D trajectories in real-time are reported. Man-machine interactive control procedures for better management of manipulator contact forces and positioning are also described. It is found that collectively, these novel advanced teleoperations techniques both enhance system performance and significantly reduce control problems long associated with teleoperations under time delay. Ongoing robotic simulations of the 1984 space shuttle Solar Maximum EVA Repair Mission are briefly described.

KSC-97PC1515

NASA Image and Video Library

1997-10-02

Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center are STS-87 crew members, assisted by Glenda Laws, extravehicular activity (EVA) coordinator, Johnson Space Center, at left. Next to Laws is Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, who is looking on as Mission Specialist Winston Scott gets a hands-on look at some of the equipment. The STS-87 mission will be the fourth United States Microgravity Payload and flight of the Spartan-201 deployable satellite. During the mission, scheduled for a Nov. 19 liftoff from KSC, Dr. Doi and Scott will both perform spacewalks

ASTRONAUT CRIPPEN, ROBERT L. - PILOT - STS-1 - TRAINING - JSC

NASA Image and Video Library

1978-03-22

S79-25007 (13 Dec. 1978) --- Astronaut Robert L. Crippen, pilot for the first space shuttle orbital flight test (STS-1), is assisted by technicians prior to entering a water immersion facility (WIF) during a training session. The zero-gravity familiarization took place in the Johnson Space Center?s training and test center (Building 260). The WIF afford one of two ways to simulate the feeling of weightlessness experienced during space extravehicular activity (EVA), the other being inside aircraft flying a parabolic curve. Crippen will be joined by astronaut John W. Young for the STS-1 flight. Photo credit: NASA

Robinson in Destiny laboratory module wearing yellow hard hat

NASA Image and Video Library

2005-07-29

S114-E-5591 (29 July 2005) --- Less than 24 hours away from performing a space walk, when he will be exchanging this gag hardhat for the helmet portion of an extravehicular mobility unit (EMU) space suit, astronaut Stephen K. Robinson shares some light humor with his spacewalking colleague, Japanese Aerospace Agency astronaut Soichi Noguchi, out of frame. Before the EVA is scheduled to begin, however, those two will assist in moving supplies from Raffaello. Today marks the second day of joint activities between the astronauts of Discovery and the crewmembers of the International Space Station onboard the orbital outpost.

Spacsuit donning and doffing in zero-g training for Story Musgrave STS-6

NASA Image and Video Library

1982-07-14

S82-33603 (November 1982) --- Astronaut F. Story Musgrave, STS-6 mission specialist, is assisted in a suit donning and doffing exercise in the weightlessness provided by a KC-135 ?zero-gravity? aircraft. Dr. Musgrave and the next mission?s other mission specialist, astronaut Donald H. Peterson, participated in the donning and doffing as a simulation for their preparations aboard the Challenger when they are called upon to perform an extravehicular activity (EVA) which was postponed from NASA?s first operational STS flight earlier this month. The suit is called an Extravehicular Mobility Unit (EMU). Photo credit: NASA

STS-116/ISS 12A.1 flight controllers on console during EVA #4

NASA Image and Video Library

2006-12-18

JSC2006-E-54436 (18 Dec. 2006) --- ISS lead flight director John Curry (right) and astronaut Stephen K. Robinson, at the CAPCOM console, represent part of the busy ground support effort for the add-on spacewalk by the STS-116 crew. Astronaut Joseph R. Tanner, who like Robinson is a veteran of multiple space walks, assisted with CAPCOM duties. While flight controllers in this space station flight control room were busy supporting the spacewalk, so were their counterparts in the space shuttle flight control room, not far away in the Johnson Space Center's Mission Control Center.

STS-48 MS Buchli dons EMU with technicians' assistance prior to JSC WETF dive

NASA Technical Reports Server (NTRS)

1991-01-01

STS-48 Mission Specialist (MS) James F. Buchli, wearing an extravehicular mobility unit (EMU) and communications carrier assembly (CCA), smiles as he listens to a technician's instructions prior to an underwater extravehicular activity (EMU) session in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Buchli is fully suited with the exception of his helmet as he stands on the WETF platform. He will be lowered into the WETF's 25-foot deep pool and once underwater he will practice contingency EVA operations for his upcoming mission aboard Discovery, Orbiter Vehicle (OV) 103.

International Space Station (ISS)

NASA Image and Video Library

2007-11-03

Astronaut Doug Wheelock, STS-120 mission specialist, participated in the mission's fourth session of extravehicular activity (EVA) while Space Shuttle Discovery was docked with the International Space Station (ISS). During the 7-hour and 19-minute space walk, astronaut Scott Parazynski (out of frame), mission specialist, cut a snagged wire and installed homemade stabilizers designed to strengthen the structure and stability of the damaged P6 4B solar array wing. Wheelock assisted from the truss by keeping an eye on the distance between Parazynski and the array. Once the repair was complete, flight controllers on the ground successfully completed the deployment of the array.

Underwater EVA training in the WETF with astronaut Robert L. Stewart

NASA Technical Reports Server (NTRS)

1983-01-01

Underwater extravehicular activity (EVA) training in the weightless environment training facility (WETF) with astronaut Robert L. Stewart. Stewart is simulating a planned EVA using the mobile foot restraint device and a one-G version of the Canadian-built remote manipulator system.

A human factors evaluation of Extravehicular Activity gloves

NASA Technical Reports Server (NTRS)

O'Hara, John M.; Briganti, Michael; Cleland, John; Winfield, Dan

1989-01-01

One of the major problems faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human-hand capabilities. NASA has sponsored a program to develop a standardized set of tests designed to assess EVA-gloved hand capabilities in six performance domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based upon an assessment of general human-hand functioning and EVA task requirements, several tests within each performance domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand, an EVA glove without pressure, an EVA glove at operation pressure. Thus, the differential effect on performance of the glove with and without pressure was tested. Bare hand performance was used to 'calibrate' the effects. Ten subjects participated in the test setup as a repeated-measures experimental design. The paper will report the results of the test program.

Enhancing enterovirus A71 vaccine production yield by microcarrier profusion bioreactor culture.

PubMed

Liu, Chia-Chyi; Wu, Suh-Chin; Wu, Shang-Rung; Lin, Hsiao-Yu; Guo, Meng-Shin; Yung-Chih Hu, Alan; Chow, Yen-Hung; Chiang, Jen-Ron; Shieh, Dar-Bin; Chong, Pele

2018-05-24

Hand, foot and mouth diseases (HFMD) are mainly caused by Enterovirus A71 (EV-A71) infections. Clinical trials in Asia conducted with formalin-inactivated EV-A71 vaccine candidates produced from serum-free Vero cell culture using either roller bottle or cell factory technology, are found to be safe and highly efficacious. To increase vaccine yields and reduce the production costs, the bioprocess improvement for EV-A71 vaccine manufacturing is currently being investigated. The parameters that could affect and enhance the production yields of EV-A71 virus growth in the microcarrier bioreactor were investigated. The medium replacement culture strategy included a multi-harvested semi-batch process and perfusion technology and was found to increase the production yields more than 7-14 folds. Based on the western blot and cryo-EM analyses of the EV-A71 virus particles produced from either the multi-harvested semi-batch (MHSBC) or perfusion cultures were found to be similar to those virus particles obtained from the single batch culture. Mouse immunogenicity studies indicate that the EV-A71 vaccine candidates produced from the perfusion culture have similar potency to those obtained from single batch bioprocess. The physical structures of the EV-A71 particles revealed by the cryo-EM analysis were found to be spherical capsid particles. These results provide feasible technical bioprocesses for increasing virus yields and the scale up of EV-A71 vaccine manufacturing using the bioreactor cell culture methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Risk Factors for Enterovirus A71 Seropositivity in Rural Indigenous Populations in West Malaysia.

PubMed

NikNadia, Nmn; Sam, I-Ching; Khaidir, Nasibah; Ngui, Romano; Lim, Yvonne A L; Goh, Xiang Ting; Choy, Seow Huey; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71), which is transmitted by the fecal-oral route, causes hand, foot and mouth disease and, rarely, severe neurological complications. In Malaysia, the indigenous rural community (Orang Asli) has a high prevalence of parasitic diseases due to poor sanitation, water supply and hygiene practices. This cross-sectional study compared the seroepidemiology of EV-A71 among rural Orang Asli and urban Kuala Lumpur populations in West Malaysia, and determined the risk factors associated with EV-A71 seropositivity in rural Orang Asli. Seropositive rates were determined by neutralization assay. EV-A71 seropositivity was strongly associated with increasing age in both populations. Rural Orang Asli children ≤12 years had significantly higher EV-A71 seropositivity rates than urban Kuala Lumpur children (95.5% vs 57.6%, P < 0.001), and also higher rates in the age groups of 1-3, 4-6 and 7-12 years. Multivariate analysis confirmed that age ≤12 years (adjusted OR 8.1, 95% CI 3.2-20.7, P < 0.001) and using untreated water (adjusted OR 6.2, 95% CI 2.3-16.6, P < 0.001) were independently associated with EV-A71 seropositivity in the Orang Asli population. Supply of clean drinking water may reduce the risk of EV-A71 infection. With significantly higher EV-A71 seropositive rates, younger rural children should be a priority target for future vaccination programs in Malaysia.

Epidemiology of hand, foot and mouth disease in China, 2008 to 2015 prior to the introduction of EV-A71 vaccine.

PubMed

Yang, Bingyi; Liu, Fengfeng; Liao, Qiaohong; Wu, Peng; Chang, Zhaorui; Huang, Jiao; Long, Lu; Luo, Li; Li, Yu; Leung, Gabriel M; Cowling, Benjamin J; Yu, Hongjie

2017-12-01

Hand, foot and mouth disease (HFMD) is usually caused by several serotypes from human enterovirus A species, including enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). Two inactivated monovalent EV-A71 vaccines have been recently licensed in China and monovalent CV-A16 vaccine and bivalent EV-A71 and CV-A16 vaccine are under development. Using notifications from the national surveillance system, we describe the epidemiology and dynamics of HFMD in the country, before the introduction of EV-A71 vaccination, from 2008 through 2015. Laboratory-identified serotype categories, i.e. CV-A16, EV-A71 and other enteroviruses, circulated annually. EV-A71 remained the most virulent serotype and was the major serotype for fatal cases (range: 88.5-95.4%) and severe cases (range: 50.7-82.3%) across years. Except for 2013 and 2015, when other enteroviruses were more frequently found in mild HFMD (48.8% and 52.5%), EV-A71 was more frequently detected from mild cases in the rest of the years covered by the study (range: 39.4-52.6%). The incidence rates and severity risks of HFMD associated with all serotype categories were the highest for children aged 1 year and younger, and decreased with increasing age. This study provides baseline epidemiology for evaluation of vaccine impact and potential serotype replacement.

Risk Factors for Enterovirus A71 Seropositivity in Rural Indigenous Populations in West Malaysia

PubMed Central

NikNadia, NMN; Sam, I-Ching; Khaidir, Nasibah; Ngui, Romano; Lim, Yvonne A. L.; Goh, Xiang Ting; Choy, Seow Huey; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71), which is transmitted by the fecal-oral route, causes hand, foot and mouth disease and, rarely, severe neurological complications. In Malaysia, the indigenous rural community (Orang Asli) has a high prevalence of parasitic diseases due to poor sanitation, water supply and hygiene practices. This cross-sectional study compared the seroepidemiology of EV-A71 among rural Orang Asli and urban Kuala Lumpur populations in West Malaysia, and determined the risk factors associated with EV-A71 seropositivity in rural Orang Asli. Seropositive rates were determined by neutralization assay. EV-A71 seropositivity was strongly associated with increasing age in both populations. Rural Orang Asli children ≤12 years had significantly higher EV-A71 seropositivity rates than urban Kuala Lumpur children (95.5% vs 57.6%, P < 0.001), and also higher rates in the age groups of 1–3, 4–6 and 7–12 years. Multivariate analysis confirmed that age ≤12 years (adjusted OR 8.1, 95% CI 3.2–20.7, P < 0.001) and using untreated water (adjusted OR 6.2, 95% CI 2.3–16.6, P < 0.001) were independently associated with EV-A71 seropositivity in the Orang Asli population. Supply of clean drinking water may reduce the risk of EV-A71 infection. With significantly higher EV-A71 seropositive rates, younger rural children should be a priority target for future vaccination programs in Malaysia. PMID:26866912

Heart Rhythm Monitoring in the Constellation Lunar and Launch/Landing EVA Suit: Recommendations from an Expert Panel

NASA Technical Reports Server (NTRS)

Scheuring, Richard A.; Hamilton, Doug; Jones, Jeffrey A.; Alexander, David

2009-01-01

There are currently several physiological monitoring requirements for EVA in the Human-Systems Interface Requirements (HSIR) document. There are questions as to whether the capability to monitor heart rhythm in the lunar surface space suit is a necessary capability for lunar surface operations. Similarly, there are questions as to whether the capability to monitor heart rhythm during a cabin depressurization scenario in the launch/landing space suit is necessary. This presentation seeks to inform space medicine personnel of recommendations made by an expert panel of cardiovascular medicine specialists regarding in-suit ECG heart rhythm monitoring requirements during lunar surface operations. After a review of demographic information and clinical cases and panel discussion, the panel recommended that ECG monitoring capability as a clinical tool was not essential in the lunar space suit; ECG monitoring was not essential in the launch/landing space suit for contingency scenarios; the current hear rate monitoring capability requirement for both launch/landing and lunar space suits should be maintained; lunar vehicles should be required to have ECG monitoring capability with a minimum of 5-lead ECG for IVA medical assessments; and, exercise stress testing for astronaut selection and retention should be changed from the current 85% maximum heart rate limit to maximal, exhaustive 'symptom-limited' testing to maximize diagnostic utility as a screening tool for evaluating the functional capacity of astronauts and their cardiovascular health.

Decoding static and dynamic arm and hand gestures from the JPL BioSleeve

NASA Astrophysics Data System (ADS)

Wolf, M. T.; Assad, C.; Stoica, A.; You, Kisung; Jethani, H.; Vernacchia, M. T.; Fromm, J.; Iwashita, Y.

This paper presents methods for inferring arm and hand gestures from forearm surface electromyography (EMG) sensors and an inertial measurement unit (IMU). These sensors, together with their electronics, are packaged in an easily donned device, termed the BioSleeve, worn on the forearm. The gestures decoded from BioSleeve signals can provide natural user interface commands to computers and robots, without encumbering the users hands and without problems that hinder camera-based systems. Potential aerospace applications for this technology include gesture-based crew-autonomy interfaces, high degree of freedom robot teleoperation, and astronauts' control of power-assisted gloves during extra-vehicular activity (EVA). We have developed techniques to interpret both static (stationary) and dynamic (time-varying) gestures from the BioSleeve signals, enabling a diverse and adaptable command library. For static gestures, we achieved over 96% accuracy on 17 gestures and nearly 100% accuracy on 11 gestures, based solely on EMG signals. Nine dynamic gestures were decoded with an accuracy of 99%. This combination of wearableEMGand IMU hardware and accurate algorithms for decoding both static and dynamic gestures thus shows promise for natural user interface applications.

Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system

NASA Astrophysics Data System (ADS)

Massina, Christopher James

The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity radiator architecture is considered to be at a technology readiness level of 3/4, indicating that analytical proof-of-concept and component level validation in a laboratory environment have been completed. While this is not a numeric increase from previous investigations, these contributions are a significant iteration within those levels. These results improve the understanding of the capabilities provided by the full suit, variable emissivity architecture.

Battery and Fuel Cell Development for NASA's Exploration Missions

NASA Technical Reports Server (NTRS)

Manzo, Michelle A.; Reid, Concha M.

2009-01-01

NASA's return to the moon will require advanced battery, fuel cell and regenerative fuel cell energy storage systems. This paper will provide an overview of the planned energy storage systems for the Orion Spacecraft and the Aries rockets that will be used in the return journey to the Moon. Technology development goals and approaches to provide batteries and fuel cells for the Altair Lunar Lander, the new space suit under development for extravehicular activities (EVA) on the Lunar surface, and the Lunar Surface Systems operations will also be discussed.

Close-up view of astronauts foot and footprint in lunar soil

NASA Image and Video Library

1969-07-20

AS11-40-5880 (20 July 1969) --- A close-up view of an astronaut's boot and bootprint in the lunar soil, photographed with a 70mm lunar surface camera during the Apollo 11 lunar surface extravehicular activity (EVA). While astronauts Neil A. Armstrong, commander, and Edwin A. Aldrin Jr., lunar module pilot, descended in the Lunar Module (LM) "Eagle" to explore the Sea of Tranquility region of the moon, astronaut Michael Collins, command module pilot, remained with the Command and Service Modules (CSM)" Columbia" in lunar orbit.

Apollo 12 Mission image - View of lunar surface mound

NASA Image and Video Library

1969-11-19

AS12-46-6795 (19-20 Nov. 1969) --- A view of the lunar surface in the vicinity of the Apollo 12 lunar landing site, photographed during the extravehicular activity (EVA) of astronauts Charles Conrad Jr., commander, and Alan L. Bean, lunar module pilot. Conrad and Bean encountered the odd, anthill-shaped mound during their lunar traverse. The two descended in the Apollo 12 Lunar Module (LM) to explore the moon, while astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit.

Astronaut John Young leaps from lunar surface to salute flag

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, leaps from the lunar surface as he salutes the U.S. Flag at the Descartes landing site during the first Apollo 16 extravehicular activity (EVA-1). Astronaut Charles M. Duke Jr., lunar module pilot, took this picture. The Lunar Module (LM) 'Orion' is on the left. The Lunar Roving Vehicle is parked beside the LM. The object behind Young in the shade of the LM is the Far Ultraviolet Camera/Spectrograph. Stone Mountain dominates the background in this lunar scene.

Astronaut David Scott practicing for Gemini 8 EVA

NASA Image and Video Library

1966-02-01

S66-19284 (1 Feb. 1966) --- Astronaut David R. Scott practicing for Gemini-8 extravehicular activity (EVA) in building 4 of the Manned Spacecraft Center on the air bearing floor. He is wearing the Hand-Held Maneuvering Unit which he will use during the EVA. Photo credit: NASA

Mission control activity during STS-61 EVA

NASA Image and Video Library

1993-12-07

Flight controller Susan P. Rainwater observes as two astronauts work through a lengthy period of extravehicular activity (EVA) in the cargo bay of the Earth-looking Space Shuttle Endeavour. Rainwater's EVA console was one of Mission Control's busiest during this eleven-day Hubble Space Telescope (HST) servicing mission in Earth orbit.

"Astronaut STS-123 EVA 1, NBL Training"

NASA Image and Video Library

2007-04-18

• Event (Mission for flight / Class for training): STS-118 (13A.1) • Title: STS-118 EVA 1 NBL • Date: 4-18-07 • Location: NBL • Key words: 118, 13A.1, S5, NBL • Description: NBL underwater photos of STS-118 EVA 1 S5 install.

76 FR 30143 - Proposed Agency Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... soon as possible. ADDRESSES: Written comments may be sent to: Eva Auman, GC-63; Department of Energy;1000 Independence Ave, SW.; Washington, DC 20585; Fax: 202-586-7373; E-mail: eva[email protected] . FOR... instrument and instructions should be directed to Eva Auman, GC-63; Department of Energy; 1000 Independence...

STS-49 MS Akers in OV-105's payload bay during ASEM procedures

NASA Image and Video Library

1992-05-14

STS049-77-023 (14 May 1992) --- Astronaut Thomas D. Akers joins three struts together, as fourth period of extravehicular activity (EVA) proceeds in the Space Shuttle Endeavour's cargo bay. The purpose of the final EVA on this nine-day mission was the evaluation of Assembly of Station by EVA Methods (ASEM). The scene was recorded on 70mm film by a fellow crew member in the Space Shuttle's cabin. Astronaut Kathryn C. Thornton (out of frame) joined Akers on the 7 1/2 hour EVA.

Astronaut Ronald Evans photographed during transearth coast EVA

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Ronald E. Evans is photographed performing extravehicular activity (EVA) during the Apollo 17 spacecraft's transearth coast. During his EVA Command Module pilot Evans retrieved film cassettes from the Lunar Sounder, Mapping Camera, and Panoramic Camera. The cylindrical object at Evans left side is the mapping camera cassette. The total time for the transearth EVA was one hour seven minutes 19 seconds, starting at ground elapsed time of 257:25 (2:28 p.m.) amd ending at ground elapsed time of 258:42 (3:35 p.m.) on Sunday, December 17, 1972.

Dynamics, control and sensor issues pertinent to robotic hands for the EVA retriever system

NASA Technical Reports Server (NTRS)

Mclauchlan, Robert A.

1987-01-01

Basic dynamics, sensor, control, and related artificial intelligence issues pertinent to smart robotic hands for the Extra Vehicular Activity (EVA) Retriever system are summarized and discussed. These smart hands are to be used as end effectors on arms attached to manned maneuvering units (MMU). The Retriever robotic systems comprised of MMU, arm and smart hands, are being developed to aid crewmen in the performance of routine EVA tasks including tool and object retrieval. The ultimate goal is to enhance the effectiveness of EVA crewmen.

Man in space.

PubMed

Solovjev, V A

1987-09-01

Today, more than 20 years after the first in the world man's space walk, soviet cosmonautics gained large experience of extravehicular activity (EVA). Space suits of high reliability, onboard facilities for passing through the airlock, sets of special tools and technological rigging, as well as procedures for carrying out various EVA's were developed. In the course of the Salyut-7 space station orbital operation the EVA's have become regular. The author of the report as the participant of the EVA's considers the main steps of man activities in space and analyzes specific problems arised in performing such activities.

Astronaut Jack Lousma seen outside Skylab space station during EVA

NASA Image and Video Library

1973-08-06

S73-31976 (5 Aug. 1973) --- Astronaut Jack R. Lousma, Skylab 3 pilot, is seen outside the Skylab space station in Earth orbit during the Aug. 5, 1973 Skylab 3 extravehicular activity (EVA) in this photographic reproduction taken from a television transmission made by a color TV camera aboard the space station. Scientist-astronaut Owen K. Garriott, Skylab 3 science pilot, participated in the EVA with Lousma. During the EVA the two crewmen deployed the twin pole solar shield to help shade the Orbital Workshop. Photo credit: NASA

ESEM analysis of polymeric film in EVA-modified cement paste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, D.A.; Monteiro, P.J.M.

2005-10-01

Portland cement pastes modified by 20% weight (polymer/cement ratio) of poly(ethylene-co-vinyl acetate) (EVA) were prepared, cured, and immersed in water for 11 days. The effects of water saturation and drying on the EVA polymeric film formed in cement pastes were observed using environmental scanning electron microscopy (ESEM). This technique allowed the imaging of the EVA film even in saturated samples. The decrease of the relative humidity inside the ESEM chamber did not cause any visual modification of the polymeric film during its drying.

EVA Suit Microbial Leakage Investigation Project

NASA Technical Reports Server (NTRS)

Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

2016-01-01

The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

Preparation, Characterization and Thermo-Chromic Properties of EVA/VO2 Laminate Films for Smart Window Applications and Energy Efficiency in Building

PubMed Central

Srirodpai, Onruthai; Wootthikanokkhan, Jatuphorn; Nawalertpanya, Saiwan; Yuwawech, Kitti; Meeyoo, Vissanu

2017-01-01

Thermochromic films based on vanadium dioxide (VO2)/ethylene vinyl acetate copolymer (EVA) composite were developed. The monoclinic VO2 particles was firstly prepared via hydrothermal and calcination processes. The effects of hydrothermal time and tungsten doping agent on crystal structure and morphology of the calcined metal oxides were reported. After that, 1 wt % of the prepared VO2 powder was mixed with EVA compound, using two different mixing processes. It was found that mechanical properties of the EVA/VO2 films prepared by the melt process were superior to those of which prepared by the solution process. On the other hand, percentage visible light transmittance of the solution casted EVA/VO2 film was greater than that of the melt processed composite film. This was related to the different gel content of EVA rubber and state of dispersion and distribution of VO2 within the polymer matrix phase. Thermochromic behaviors and heat reflectance of the EVA/VO2 film were also verified. In overall, this study demonstrated that it was possible to develop a thermochromic film using the polymer composite approach. In this regard, the mixing condition was found to be one of the most important factors affecting morphology and thermo-mechanical properties of the films. PMID:28772413

EVA-1 functions as an UNC-40 Co-receptor to enhance attraction to the MADD-4 guidance cue in Caenorhabditis elegans.

PubMed

Chan, Kevin Ka Ming; Seetharaman, Ashwin; Bagg, Rachel; Selman, Guillermo; Zhang, Yuqian; Kim, Joowan; Roy, Peter J

2014-08-01

We recently discovered a secreted and diffusible midline cue called MADD-4 (an ADAMTSL) that guides migrations along the dorsoventral axis of the nematode Caenorhabditis elegans. We showed that the transmembrane receptor, UNC-40 (DCC), whose canonical ligand is the UNC-6 (netrin) guidance cue, is required for extension towards MADD-4. Here, we demonstrate that MADD-4 interacts with an EVA-1/UNC-40 co-receptor complex to attract cell extensions. EVA-1 is a conserved transmembrane protein with predicted galactose-binding lectin domains. EVA-1 functions in the same pathway as MADD-4, physically interacts with both MADD-4 and UNC-40, and enhances UNC-40's sensitivity to the MADD-4 cue. This enhancement is especially important in the presence of UNC-6. In EVA-1's absence, UNC-6 interferes with UNC-40's responsiveness to MADD-4; in UNC-6's absence, UNC-40's responsiveness to MADD-4 is less dependent on EVA-1. By enabling UNC-40 to respond to MADD-4 in the presence of UNC-6, EVA-1 may increase the precision by which UNC-40-directed processes can reach their MADD-4-expressing targets within a field of the UNC-6 guidance cue.

EVA-1 Functions as an UNC-40 Co-receptor to Enhance Attraction to the MADD-4 Guidance Cue in Caenorhabditis elegans

PubMed Central

Bagg, Rachel; Selman, Guillermo; Zhang, Yuqian; Kim, Joowan; Roy, Peter J.

2014-01-01

We recently discovered a secreted and diffusible midline cue called MADD-4 (an ADAMTSL) that guides migrations along the dorsoventral axis of the nematode Caenorhabditis elegans. We showed that the transmembrane receptor, UNC-40 (DCC), whose canonical ligand is the UNC-6 (netrin) guidance cue, is required for extension towards MADD-4. Here, we demonstrate that MADD-4 interacts with an EVA-1/UNC-40 co-receptor complex to attract cell extensions. EVA-1 is a conserved transmembrane protein with predicted galactose-binding lectin domains. EVA-1 functions in the same pathway as MADD-4, physically interacts with both MADD-4 and UNC-40, and enhances UNC-40's sensitivity to the MADD-4 cue. This enhancement is especially important in the presence of UNC-6. In EVA-1's absence, UNC-6 interferes with UNC-40's responsiveness to MADD-4; in UNC-6's absence, UNC-40's responsiveness to MADD-4 is less dependent on EVA-1. By enabling UNC-40 to respond to MADD-4 in the presence of UNC-6, EVA-1 may increase the precision by which UNC-40-directed processes can reach their MADD-4-expressing targets within a field of the UNC-6 guidance cue. PMID:25122090

Preparation, Characterization and Thermo-Chromic Properties of EVA/VO₂ Laminate Films for Smart Window Applications and Energy Efficiency in Building.

PubMed

Srirodpai, Onruthai; Wootthikanokkhan, Jatuphorn; Nawalertpanya, Saiwan; Yuwawech, Kitti; Meeyoo, Vissanu

2017-01-11

Thermochromic films based on vanadium dioxide (VO₂)/ethylene vinyl acetate copolymer (EVA) composite were developed. The monoclinic VO₂ particles was firstly prepared via hydrothermal and calcination processes. The effects of hydrothermal time and tungsten doping agent on crystal structure and morphology of the calcined metal oxides were reported. After that, 1 wt % of the prepared VO₂ powder was mixed with EVA compound, using two different mixing processes. It was found that mechanical properties of the EVA/VO₂ films prepared by the melt process were superior to those of which prepared by the solution process. On the other hand, percentage visible light transmittance of the solution casted EVA/VO₂ film was greater than that of the melt processed composite film. This was related to the different gel content of EVA rubber and state of dispersion and distribution of VO₂ within the polymer matrix phase. Thermochromic behaviors and heat reflectance of the EVA/VO₂ film were also verified. In overall, this study demonstrated that it was possible to develop a thermochromic film using the polymer composite approach. In this regard, the mixing condition was found to be one of the most important factors affecting morphology and thermo-mechanical properties of the films.

Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination

PubMed Central

Takahashi, Saki; Liao, Qiaohong; Van Boeckel, Thomas P.; Xing, Weijia; Sun, Junling; Hsiao, Victor Y.; Metcalf, C. Jessica E.; Chang, Zhaorui; Liu, Fengfeng; Zhang, Jing; Wu, Joseph T.; Cowling, Benjamin J.; Leung, Gabriel M.; Farrar, Jeremy J.; van Doorn, H. Rogier; Grenfell, Bryan T.; Yu, Hongjie

2016-01-01

Background Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. Methods and Findings Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible–infected–recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R 0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71-vaccination period remained either comparable to or only slightly increased from levels prior to vaccination. The duration and strength of cross-protection following infection with EV-A71 or CV-A16 was estimated to be 9.95 wk (95% confidence interval [CI]: 3.31, 23.40) in 68% of the population (95% CI: 37%, 96%). Our predictions are limited by the necessarily short and under-sampled time series and the possible circulation of unidentified serotypes, but, nonetheless, sensitivity analyses indicate that our results are robust in predicting that the vaccine should drastically reduce incidence of EV-A71 without a substantial competitive release of CV-A16. Conclusions The ability of our models to capture the observed epidemic cycles suggests that herd immunity is driving the epidemic dynamics caused by the multiple serotypes of enterovirus. Our results predict that the EV-A71 and CV-A16 serotypes provide a temporary immunizing effect against each other. Achieving high coverage rates of EV-A71 vaccination would be necessary to eliminate the ongoing transmission of EV-A71, but serotype replacement by CV-A16 following EV-A71 vaccination is likely to be transient and minor compared to the corresponding reduction in the burden of EV-A71-associated HFMD. Therefore, a mass EV-A71 vaccination program of infants and young children should provide significant benefits in terms of a reduction in overall HFMD burden. PMID:26882540

Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination.

PubMed

Takahashi, Saki; Liao, Qiaohong; Van Boeckel, Thomas P; Xing, Weijia; Sun, Junling; Hsiao, Victor Y; Metcalf, C Jessica E; Chang, Zhaorui; Liu, Fengfeng; Zhang, Jing; Wu, Joseph T; Cowling, Benjamin J; Leung, Gabriel M; Farrar, Jeremy J; van Doorn, H Rogier; Grenfell, Bryan T; Yu, Hongjie

2016-02-01

Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71-vaccination period remained either comparable to or only slightly increased from levels prior to vaccination. The duration and strength of cross-protection following infection with EV-A71 or CV-A16 was estimated to be 9.95 wk (95% confidence interval [CI]: 3.31, 23.40) in 68% of the population (95% CI: 37%, 96%). Our predictions are limited by the necessarily short and under-sampled time series and the possible circulation of unidentified serotypes, but, nonetheless, sensitivity analyses indicate that our results are robust in predicting that the vaccine should drastically reduce incidence of EV-A71 without a substantial competitive release of CV-A16. The ability of our models to capture the observed epidemic cycles suggests that herd immunity is driving the epidemic dynamics caused by the multiple serotypes of enterovirus. Our results predict that the EV-A71 and CV-A16 serotypes provide a temporary immunizing effect against each other. Achieving high coverage rates of EV-A71 vaccination would be necessary to eliminate the ongoing transmission of EV-A71, but serotype replacement by CV-A16 following EV-A71 vaccination is likely to be transient and minor compared to the corresponding reduction in the burden of EV-A71-associated HFMD. Therefore, a mass EV-A71 vaccination program of infants and young children should provide significant benefits in terms of a reduction in overall HFMD burden.

The Walkback Test: A Study to Evaluate Suit and Life Support System Performance Requirements for a 10 Kilometer Traverse in a Planetary Suit

NASA Technical Reports Server (NTRS)

Vos, Jessica R.; Gernhardt, Michael L.; Lee, Lesley

2007-01-01

As planetary suit and planetary life support systems develop, specific design inputs for each system relate to a presently unanswered question concerning operational concepts: What distance can be considered a safe walking distance for a suited EVA crew member exploring the surface of the Moon to "walk-back" to the habitat in the event of a rover breakdown, taking into consideration the planned EVA tasks as well as the possible traverse back to the habitat? It has been assumed, based on Apollo program experience, that 10 kilometers (6.2 mi) will be the maximum EVA excursion distance from the lander or habitat to ensure the crew member s safe return to the habitat in the event of a rover failure. To investigate the feasibility of performing a suited 10 km Walkback, NASA-JSC assembled a multi-disciplinary team to design and implement the Lunar Walkback Test . The test was designed not only to determine the feasibility of a 10 km excursion, but also to collect human performance, biomedical, and biomechanical data relevant to optimizing space suit design and life support system sizing. These data will also be used to develop follow-on studies to understand interrelationships of such key parameters as suit mass, inertia, suit pressure, and center of gravity (CG), and the respective influences of each on human performance.

Human and Robotic Exploration Missions to Phobos Prior to Crewed Mars Surface Missions

NASA Technical Reports Server (NTRS)

Gernhardt, Michael L.; Chappell, Steven P.; Bekdash, Omar S.; Abercromby, Andrew F.

2016-01-01

Phobos is a scientifically significant destination that would facilitate the development and operation of the human Mars transportation infrastructure, unmanned cargo delivery systems and other Mars surface systems. In addition to developing systems relevant to Mars surface missions, Phobos offers engineering, operational, and public engagement opportunities that could enhance subsequent Mars surface operations. These opportunities include the use of low latency teleoperations to control Mars surface assets associated with exploration science, human landing-site selection and infrastructure development which may include in situ resource utilization (ISRU) to provide liquid oxygen for the Mars Ascent Vehicle (MAV). A human mission to Mars' moons would be preceded by a cargo predeploy of a surface habitat and a pressurized excursion vehicle (PEV) to Mars orbit. Once in Mars orbit, the habitat and PEV would spiral to Phobos using solar electric propulsion based systems, with the habitat descending to the surface and the PEV remaining in orbit. When a crewed mission is launched to Phobos, it would include the remaining systems to support the crew during the Earth-Mars transit and to reach Phobos after insertion in to Mars orbit. The crew would taxi from Mars orbit to Phobos to join with the predeployed systems in a spacecraft that is based on a MAV, dock with and transfer to the PEV in Phobos orbit, and descend in the PEV to the surface habitat. A static Phobos surface habitat was chosen as a baseline architecture, in combination with the PEV that was used to descend from orbit as the main exploration vehicle. The habitat would, however, have limited capability to relocate on the surface to shorten excursion distances required by the PEV during exploration and to provide rescue capability should the PEV become disabled. To supplement exploration capabilities of the PEV, the surface habitat would utilize deployable EVA support structures that allow astronauts to work from portable foot restraints or body restrain tethers in the vicinity of the habitat. Prototype structures were tested as part of NEEMO 20. PEVs would contain closed loop guidance and provide life support and consumables for two crew for 2 weeks plus reserves. The PEV has a cabin that uses the exploration atmosphere of 8.2 psi with 34% oxygen, enabling use of suit ports for rapid EVA with minimal oxygen prebreathe as well as dust control by keeping the suits outside the pressurized volume. When equipped with outriggers and control moment gyros, the PEV enables EVA tasks of up to 8 pounds of force application without the need to anchor. Tasks with higher force requirements can be performed with PEV propulsion providing the necessary thrust to react forces. Exploration of Phobos builds heavily from the developments of the cis-lunar proving ground, and significantly reduces Mars surface risk by facilitating the development and testing of habitats, MAVs, and pressurized rover cabins that are all Mars surface forward. A robotic precursor mission to Phobos and Deimos is also under consideration and would need to launch in 2022 to support a 2031 human Phobos mission.

Coronal CT scan measurements and hearing evolution in enlarged vestibular aqueduct syndrome.

PubMed

Saliba, Issam; Gingras-Charland, Marie-Eve; St-Cyr, Karine; Décarie, Jean-Claude

2012-04-01

To assess the correlation between the enlarged vestibular aqueduct (EVA) diameter and (1) the hearing loss level (mild, moderate, severe and profound and (2) the hearing evolution. The secondary objective was to obtain measurement limits on the coronal plane of the temporal bone CT scan for the diagnosis of EVA. Retrospective study in a tertiary pediatric center. Mastoid CT scans were reviewed to measure the VA diameter at its midpoint and operculum on axial and coronal planes in a pathologic and normal population. We used their serial audiograms to assess the evolution of hearing. 101 EVA was identified out of 1812 temporal bones CT scan from our radiologic database in 8 years. Bone conduction was stable after a mean follow-up of 40.9 ± 32.9 months. PTA has been the most affected in time by the EVA (p=0.006). No correlation was identified between impedancemetry and the diameter of the EVA. On the diagnostic audiogram, 61% of hearing loss were in the mild and moderate hearing levels; at the end of the follow-up 64% of hearing loss are still in the mild and moderate hearing levels. The cut-off values for the coronal midpoint and operculum planes on the CT scan to diagnose an EVA are 2.4 mm and 4.34 mm respectively. Conductive or mixed hearing loss might be the first manifestation of EVA. Coronal CT scan cuts can provide additional information to evaluate EVA especially when axial cuts are not conclusive. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A Human Factors Analysis of EVA Time Requirements

NASA Technical Reports Server (NTRS)

Pate, Dennis W.

1997-01-01

Human Factors Engineering (HFE) is a discipline whose goal is to engineer a safer, more efficient interface between humans and machines. HFE makes use of a wide range of tools and techniques to fulfill this goal. One of these tools is known as motion and time study, a technique used to develop time standards for given tasks. During the summer of 1995, a human factors motion and time study was initiated with the goals of developing a database of EVA task times and developing a method of utilizing the database to predict how long an EVA should take. Initial development relied on the EVA activities performed during the STS-61 (Hubble) mission. The first step of the study was to become familiar with EVA's, the previous task-time studies, and documents produced on EVA's. After reviewing these documents, an initial set of task primitives and task-time modifiers was developed. Data was collected from videotaped footage of two entire STS-61 EVA missions and portions of several others, each with two EVA astronauts. Feedback from the analysis of the data was used to further refine the primitives and modifiers used. The project was continued during the summer of 1996, during which data on human errors was also collected and analyzed. Additional data from the STS-71 mission was also collected. Analysis of variance techniques for categorical data was used to determine which factors may affect the primitive times and how much of an effect they have. Probability distributions for the various task were also generated. Further analysis of the modifiers and interactions is planned.

The MADD-3 LAMMER Kinase Interacts with a p38 MAP Kinase Pathway to Regulate the Display of the EVA-1 Guidance Receptor in Caenorhabditis elegans.

PubMed

D'Souza, Serena A; Rajendran, Luckshika; Bagg, Rachel; Barbier, Louis; van Pel, Derek M; Moshiri, Houtan; Roy, Peter J

2016-04-01

The proper display of transmembrane receptors on the leading edge of migrating cells and cell extensions is essential for their response to guidance cues. We previously discovered that MADD-4, which is an ADAMTSL secreted by motor neurons in Caenorhabditis elegans, interacts with an UNC-40/EVA-1 co-receptor complex on muscles to attract plasma membrane extensions called muscle arms. In nematodes, the muscle arm termini harbor the post-synaptic elements of the neuromuscular junction. Through a forward genetic screen for mutants with disrupted muscle arm extension, we discovered that a LAMMER kinase, which we call MADD-3, is required for the proper display of the EVA-1 receptor on the muscle's plasma membrane. Without MADD-3, EVA-1 levels decrease concomitantly with a reduction of the late-endosomal marker RAB-7. Through a genetic suppressor screen, we found that the levels of EVA-1 and RAB-7 can be restored in madd-3 mutants by eliminating the function of a p38 MAP kinase pathway. We also found that EVA-1 and RAB-7 will accumulate in madd-3 mutants upon disrupting CUP-5, which is a mucolipin ortholog required for proper lysosome function. Together, our data suggests that the MADD-3 LAMMER kinase antagonizes the p38-mediated endosomal trafficking of EVA-1 to the lysosome. In this way, MADD-3 ensures that sufficient levels of EVA-1 are present to guide muscle arm extension towards the source of the MADD-4 guidance cue.

The MADD-3 LAMMER Kinase Interacts with a p38 MAP Kinase Pathway to Regulate the Display of the EVA-1 Guidance Receptor in Caenorhabditis elegans

PubMed Central

D’Souza, Serena A.; Rajendran, Luckshika; Bagg, Rachel; van Pel, Derek M.; Moshiri, Houtan; Roy, Peter J.

2016-01-01

The proper display of transmembrane receptors on the leading edge of migrating cells and cell extensions is essential for their response to guidance cues. We previously discovered that MADD-4, which is an ADAMTSL secreted by motor neurons in Caenorhabditis elegans, interacts with an UNC-40/EVA-1 co-receptor complex on muscles to attract plasma membrane extensions called muscle arms. In nematodes, the muscle arm termini harbor the post-synaptic elements of the neuromuscular junction. Through a forward genetic screen for mutants with disrupted muscle arm extension, we discovered that a LAMMER kinase, which we call MADD-3, is required for the proper display of the EVA-1 receptor on the muscle’s plasma membrane. Without MADD-3, EVA-1 levels decrease concomitantly with a reduction of the late-endosomal marker RAB-7. Through a genetic suppressor screen, we found that the levels of EVA-1 and RAB-7 can be restored in madd-3 mutants by eliminating the function of a p38 MAP kinase pathway. We also found that EVA-1 and RAB-7 will accumulate in madd-3 mutants upon disrupting CUP-5, which is a mucolipin ortholog required for proper lysosome function. Together, our data suggests that the MADD-3 LAMMER kinase antagonizes the p38-mediated endosomal trafficking of EVA-1 to the lysosome. In this way, MADD-3 ensures that sufficient levels of EVA-1 are present to guide muscle arm extension towards the source of the MADD-4 guidance cue. PMID:27123983

Astronauts James Lovell uses scoop from ALHT during simulation

NASA Image and Video Library

1969-12-01

S70-20272 (December 1969) --- Astronaut James A. Lovell Jr., commander of the upcoming Apollo 13 lunar landing mission, uses a scoop from the Apollo Lunar Hand Tools (ALHT) during a simulated lunar surface traverse at the Kapoho, Hawaii training site. While at the Hawaii training sites, Lovell and Haise are participating in thorough rehearsals of their extravehicular activity (EVA). Photo credit: NASA

On the moon with Apollo 15: A guidebook to Hadley Rille and the Apennine Mountains

NASA Technical Reports Server (NTRS)

Simmons, G.

1971-01-01

Information is given in simple terms of the Apollo 15 lunar exploration and scientific equipment, to be used in conjunction with other material shown over commercial TV. The EVAs of the astronauts on the surface are divided into experiments and traverses. The landing site and experimental equipment are described, and life sketches are given of the crew.

An Alternative Approach to Human Servicing of Crewed Earth Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Mularski, John R.; Alpert, Brian K.

2017-01-01

As crewed spacecraft have grown larger and more complex, they have come to rely on spacewalks, or Extravehicular Activities (EVA), for assembly and to assure mission success. Typically, these spacecraft maintain all of the hardware and trained personnel needed to perform an EVA on-board at all times. Maintaining this capability requires up-mass, volume for storage of EVA hardware, crew time for ground and on-orbit training, and on-orbit maintenance of EVA hardware. This paper proposes an alternative methodology, utilizing either launch-on-need hardware and crew or regularly scheduled missions to provide EVA capability for space stations in low Earth orbit after assembly complete. Much the same way that one would call a repairman to fix something at their home these EVAs are dedicated to maintenance and upgrades of the orbiting station. For crew safety contingencies it is assumed the station would be designed such the crew could either solve those issues from inside the spacecraft or use the docked Earth to Orbit vehicles as a return lifeboat, in the same manner as the International Space Station (ISS) which does not rely on EVA for crew safety related contingencies. This approach would reduce ground training requirements for long duration crews, save Intravehicular Activity (IVA) crew time in the form of EVA hardware maintenance and on-orbit training, and lead to more efficient EVAs because they would be performed by specialists with detailed knowledge and training stemming from their direct involvement in the development of the EVA. The on-orbit crew would then be available to focus on the immediate response to any failures such as IVA systems reconfiguration or jumper installation as well as the day-to-day operations of the spacecraft and payloads. This paper will look at how current unplanned EVAs are conducted on ISS, including the time required for preparation, and offer an alternative for future spacecraft. As this methodology relies on the on-time and on-need launch of spacecraft, any space station that utilized this approach would need a robust transportation system, possibly including more than one launch vehicle capable of carrying crew. In addition, the fault tolerance of the future space station would be an important consideration in how much time was available for EVA preparation after the failure. Ideally the fault tolerance of the station would allow for the maintenance tasks to be grouped such that they could be handled by regularly scheduled maintenance visits and not contingency launches. Each future program would have to weigh the risk of on-time launch against the increase in available crew time for the main objective of the spacecraft. This is only one of several ideas that could be used to reduce or eliminate a station's reliance on rapid turnaround EVAs using on-board crew. Others could include having shirt-sleeve access to critical systems or utilizing low pressure temporarily pressurized equipment bays.

EVA 4 - Massimino during EVA

NASA Image and Video Library

2002-03-07

STS109-323-013 (7 March 2002) --- Astronaut Michael J. Massimino moves about in the cargo bay of the Space Shuttle Columbia while performing work on the Hubble Space Telescope (HST), partially visible behind him. Astronauts Massimino and James H. Newman (out of frame), mission specialists, were participating in the fourth STS-109 space walk (EVA-4).

Extravehicular activity training and hardware design consideration

NASA Technical Reports Server (NTRS)

Thuot, P. J.; Harbaugh, G. J.

1995-01-01

Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented.

Biosensors for EVA: Muscle Oxygen and pH During Walking, Running and Simulated Reduced Gravity

NASA Technical Reports Server (NTRS)

Lee, S. M. C.; Ellerby, G.; Scott, P.; Stroud, L.; Norcross, J.; Pesholov, B.; Zou, F.; Gernhardt, M.; Soller, B.

2009-01-01

During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO2 on the leg during cycling. Our NSBRI-funded project is looking to extend this methodology to examine activities which more appropriately represent EVA activities, such as walking and running and to better understand factors that determine the metabolic cost of exercise in both normal and lunar gravity. Our 4 year project specifically addresses risk: ExMC 4.18: Lack of adequate biomedical monitoring capability for Constellation EVA Suits and EPSP risk: Risk of compromised EVA performance and crew health due to inadequate EVA suit systems.

Wax inhibitor based on ethylene vinyl acetate with methyl methacrylate and diethanolamine for crude oil pipeline

NASA Astrophysics Data System (ADS)

Anisuzzaman, S. M.; Abang, S.; Bono, A.; Krishnaiah, D.; Karali, R.; Safuan, M. K.

2017-06-01

Wax precipitation and deposition is one of the most significant flow assurance challenges in the production system of the crude oil. Wax inhibitors are developed as a preventive strategy to avoid an absolute wax deposition. Wax inhibitors are polymers which can be known as pour point depressants as they impede the wax crystals formation, growth, and deposition. In this study three formulations of wax inhibitors were prepared, ethylene vinyl acetate, ethylene vinyl acetate co-methyl methacrylate (EVA co-MMA) and ethylene vinyl acetate co-diethanolamine (EVA co-DEA) and the comparison of their efficiencies in terms of cloud point¸ pour point, performance inhibition efficiency (%PIE) and viscosity were evaluated. The cloud point and pour point for both EVA and EVA co-MMA were similar, 15°C and 10-5°C, respectively. Whereas, the cloud point and pour point for EVA co-DEA were better, 10°C and 10-5°C respectively. In conclusion, EVA co-DEA had shown the best % PIE (28.42%) which indicates highest percentage reduction of wax deposit as compared to the other two inhibitors.

Extravehicular activity training and hardware design consideration.

PubMed

Thuot, P J; Harbaugh, G J

1995-07-01

Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented.

Development of a Modified Vacuum Cleaner for Lunar Surface Systems

NASA Technical Reports Server (NTRS)

Toon, Katherine P.; Lee, Steve A.; Edgerly, Rachel D.

2009-01-01

The National Aeronautics and Space Administration (NASA) mission to expand space exploration will return humans to the Moon with the goal of maintaining a long-term presence. One challenge that NASA will face returning to the Moon is managing the lunar regolith found on the Moon's surface, which will collect on extravehicular activity (EVA) suits and other equipment. Based on the Apollo experience, the issues astronauts encountered with lunar regolith included eye/lung irritation, and various hardware failures (seals, screw threads, electrical connectors and fabric contamination), which were all related to inadequate lunar regolith mitigation. A vacuum cleaner capable of detaching, transferring, and efficiently capturing lunar regolith has been proposed as a method to mitigate the lunar regolith problem in the habitable environment on lunar surface. In order to develop this vacuum, a modified "off-the-shelf" vacuum cleaner has been used to determine detachment efficiency, vacuum requirements, and optimal cleaning techniques to ensure efficient dust removal in habitable lunar surfaces, EVA spacesuits, and air exchange volume. During the initial development of the Lunar Surface System vacuum cleaner, systematic testing was performed with varying flow rates on multiple surfaces (fabrics and metallics), atmospheric (14.7 psia) and reduced pressures (10.2 and 8.3 psia), different vacuum tool attachments, and several vacuum cleaning techniques to determine the performance requirements for the vacuum cleaner. The data recorded during testing was evaluated by calculating percent removal, relative to the retained simulant on the tested surface. In addition, Scanning Electron Microscopy (SEM) imaging was used to determine particle size distribution retained on the surface. The scope of this paper is to explain the initial phase of vacuum cleaner development, including historical Apollo mission data, current state-of-the-art vacuum cleaner technology, and vacuum cleaner testing that has focused on detachment capabilities varying pressure environments.

Development of a Modified Vacuum Cleaner for Lunar Surface Systems

NASA Technical Reports Server (NTRS)

Toon, Katherine P.; Lee, Steve A.; Edgerly, Rachel D.

2010-01-01

The National Aeronautics and Space Administration (NASA) mission to expand space exploration will return humans to the Moon with the goal of maintaining a long-term presence. One challenge that NASA will face returning to the Moon is managing the lunar regolith found on the Moon's surface, which will collect on extravehicular activity (EVA) suits and other equipment. Based on the Apollo experience, the issues astronauts encountered with lunar regolith included eye/lung irritation, and various hardware failures (seals, screw threads, electrical connectors and fabric contamination), which were all related to inadequate lunar regolith mitigation. A vacuum cleaner capable of detaching, transferring, and efficiently capturing lunar regolith has been proposed as a method to mitigate the lunar regolith problem in the habitable environment on lunar surface. In order to develop this vacuum, a modified "off-the-shelf' vacuum cleaner will be used to determine detachment efficiency, vacuum requirements, and optimal cleaning techniques to ensure efficient dust removal in habitable lunar surfaces, EVA spacesuits, and air exchange volume. During the initial development of the Lunar Surface System vacuum cleaner, systematic testing was performed with varying flow rates on multiple surfaces (fabrics and metallics), atmospheric (14.7 psia) and reduced pressures (10.2 and 8.3 psia), different vacuum tool attachments, and several vacuum cleaning techniques in order to determine the performance requirements for the vacuum cleaner. The data recorded during testing was evaluated by calculating particulate removal, relative to the retained simulant on the tested surface. In addition, optical microscopy was used to determine particle size distribution retained on the surface. The scope of this paper is to explain the initial phase of vacuum cleaner development, including historical Apollo mission data, current state-of-the-art vacuum cleaner technology, and vacuum cleaner testing that has focused on detachment capabilities at varying pressure environments.

Enhancing the thermal conductivity of ethylene-vinyl acetate (EVA) in a photovoltaic thermal collector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allan, J., E-mail: james.p.allan14@gmail.com; ChapmanBDSP, Saffron House, 6-10 Kirby Street, London, EC1N 8EQ; Pinder, H.

2016-03-15

Samples of Ethylene-Vinyl Acetate (EVA) were doped with particles of Boron Nitride (BN) in concentrations ranging from 0-60% w/w. Thermal conductivity was measured using a Differential Scanning Calorimetery (DSC) technique. The thermal conductivity of parent EVA was increased from 0.24 W/m ⋅ K to 0.80 W/m ⋅ K for the 60% w/w sample. Two PV laminates were made; one using the parent EVA the other using EVA doped with 50% BN. When exposed to a one directional heat flux the doped laminate was, on average, 6% cooler than the standard laminate. A finite difference model had good agreement with experimentalmore » results and showed that the use of 60% BN composite achieved a PV performance increase of 0.3% compared to the standard laminate.« less

The Potential of Wearable Sensor Technology for EVA Glove Ergonomic Evaluation

NASA Technical Reports Server (NTRS)

Reid, Christopher R.; McFarland, Shane M.; Norcross, Jason R.; Rajulu, Sudhakar

2014-01-01

Injuries to the hands are common among astronauts who train for extravehicular activity (EVA). Many of these injuries refer to the gloves worn during EVA as the root cause. While pressurized, the bladder and outer material of these gloves restrict movement and create pressure points while performing tasks, sometimes resulting in pain, muscle fatigue, abrasions, and occasionally a more severe injury, onycholysis (fingernail delamination). The most common injury causes are glove contact (pressure point/rubbing), ill-fitting gloves, and/or performing EVA tasks in pressurized gloves. A brief review of the Lifetime Surveillance of Astronaut Health's injury database reveals over 57% of the total injuries to the upper extremities during EVA training occurred either to the metacarpophalangeal (MCP) joint, fingernail, or the fingertip. Twenty-five of these injuries resulted in a diagnosis of onycholysis.

The Potential of Wearable Sensor Technology for EVA Glove Ergonomic Evaluation

NASA Technical Reports Server (NTRS)

Reid, Christopher R.; McFarland, Shane; Norcross, Jason R.; Rajulu, Sudhakar

2014-01-01

Injuries to the hands are common among astronauts who train for extravehicular activity (EVA). Many of these injuries refer to the gloves worn during EVA as the root cause. While pressurized, the bladder and outer material of these gloves restrict movement and create pressure points while performing tasks, sometimes resulting in pain, muscle fatigue, abrasions, and occasionally a more severe injury, onycholysis (fingernail delamination). The most common injury causes are glove contact (pressure point/rubbing), ill-fitting gloves, and/or performing EVA tasks in pressurized gloves. A brief review of the Lifetime Surveillance of Astronaut Health's injury database reveals over 57% of the total injuries to the upper extremities during EVA training occurred either to the metacarpophalangeal (MCP) joint, fingernail, or the fingertip. Twenty-five of these injuries resulted in a diagnosis of onycholysis

Plasma Hazards and Acceptance for International Space Station Extravehicular Activities

NASA Astrophysics Data System (ADS)

Patton, Thomas

2010-09-01

Extravehicular activity(EVA) is accepted by NASA and other space faring agencies as a necessary risk in order to build and maintain a safe and efficient laboratory in space. EVAs are used for standard construction and as contingency operations to repair critical equipment for vehicle sustainability and safety of the entire crew in the habitable volume. There are many hazards that are assessed for even the most mundane EVA for astronauts, and the vast majority of these are adequately controlled per the rules of the International Space Station Program. The need for EVA repair and construction has driven acceptance of a possible catastrophic hazard to the EVA crewmember which cannot currently be controlled adequately. That hazard is electrical shock from the very environment in which they work. This paper describes the environment, causes and contributors to the shock of EVA crewmembers attributed to the ionospheric plasma environment in low Earth orbit. It will detail the hazard history, and acceptance process for the risk associated with these hazards that give assurance to a safe EVA. In addition to the hazard acceptance process this paper will explore other factors that go into the decision to accept a risk including criticality of task, hardware design and capability, and the probability of hazard occurrence. Also included will be the required interaction between organizations at NASA(EVA Office, Environments, Engineering, Mission Operations, Safety) in order to build and eventually gain adequate acceptance rationale for a hazard of this kind. During the course of the discussion, all current methods of mitigating the hazard will be identified. This paper will capture the history of the plasma hazard analysis and processes used by the International Space Station Program to formally assess and qualify the risk. The paper will discuss steps that have been taken to identify and perform required analysis of the floating potential shock hazard from the ISS environment which eventually led to its status as an accepted risk for ISS EVAs.

Overview of EVA PRA for TPS Repair for Hubble Space Telescope Servicing Mission

NASA Technical Reports Server (NTRS)

Bigler, Mark; Duncan, Gary; Roeschel, Eduardo; Canga, Michael

2010-01-01

Following the Columbia accident in 2003, NASA developed techniques to repair the Thermal Protection System (TPS) in the event of damage to the TPS as one of several actions to reduce the risk to future flights from ascent debris, micro-meteoroid and/or orbital debris (MMOD). Other actions to help reduce the risk include improved inspection techniques, reduced shedding of debris from the External Tank and ability to rescue the crew with a launch on need vehicle. For the Hubble Space Telescope (HST) Servicing Mission the crew rescue capability was limited by the inability to safe haven on the International Space Station (ISS), resulting in a greater reliance on the repair capability. Therefore it was desirable to have an idea of the risk associated with conducting a repair, where the repair would have to be conducted using an Extra-Vehicular Activity (EVA). Previously, focused analyses had been conducted to quantify the risk associated with certain aspects of an EVA, for example the EVA Mobility Unit (EMU) or Space Suit; however, the analyses were somewhat limited in scope. A complete integrated model of an EVA which could quantify the risk associated with all of the major components of an EVA had never been done before. It was desired to have a complete integrated model to be able to assess the risks associated with an EVA to support the Space Shuttle Program (SSP) in making risk informed decisions. In the case of the HST Servicing Mission, this model was developed to assess specifically the risks associated with performing a TPS repair EVA. This paper provides an overview of the model that was developed to support the HST mission in the event of TPS damage. The HST Servicing Mission was successfully completed on May 24th 2009 with no critical TPS damage; therefore the model was not required for real-time mission support. However, it laid the foundation upon which future EVA quantitative risk assessments could be based.

Extravehicular Activity Testing in Analog Environments: Evaluating the Effects of Center of Gravity and Environment on Human Performance

NASA Technical Reports Server (NTRS)

Chappell, Steve P.; Gernhardt, Michael L.

2009-01-01

Center of gravity (CG) is likely to be an important variable in astronaut performance during partial gravity extravehicular activity (EVA). The Apollo Lunar EVA experience revealed challenges with suit stability and control. The EVA Physiology, Systems and Performance Project (EPSP) in conjunction with the Constellation EVA Systems Project Office have developed plans to systematically understand the role of suit weight, CG and suit pressure on astronaut performance in partial gravity environments. This presentation based upon CG studies seeks to understand the impact of varied CG on human performance in lunar gravity.

EVA manipulation and assembly of space structure columns

NASA Technical Reports Server (NTRS)

Loughead, T. E.; Pruett, E. C.

1980-01-01

Assembly techniques and hardware configurations used in assembly of the basic tetrahedral cell by A7LB pressure-suited subjects in a neutral bouyancy simulator were studied. Eleven subjects participated in assembly procedures which investigated two types of structural members and two configurations of attachment hardware. The assembly was accomplished through extra-vehicular activity (EVA) only, EVA with simulated manned maneuvering unit (MMU), and EVA with simulated MMU and simulated remote manipulator system (RMS). Assembly times as low as 10.20 minutes per tetrahedron were achieved. Task element data, as well as assembly procedures, are included.

Extravehicular Space Suit Bearing Technology Development Research

NASA Astrophysics Data System (ADS)

Pang, Yan; Liu, Xiangyang; Guanghui, Xie

2017-03-01

Pressure bearing has been acting an important role in the EVA (extravehicular activity) suit as a main mobility component. EVA suit bearing has its unique traits on the material, dustproof design, seal, interface, lubrication, load and performance. This paper states the peculiarity and development of the pressure bearing on the construction design element, load and failure mode, and performance and test from the point view of structure design. The status and effect of EVA suit pressure bearing is introduced in the paper. This analysis method can provide reference value for our country’s EVA suit pressure bearing design and development.

[Radiation effect on cosmonauts during extravehicular activities in 2008-2009].

PubMed

Mitrikas, V G

2010-01-01

The geometrical model of suited cosmonaut's phantom was used in mathematical modeling of EVAs performed by cosmonauts with consideration of changes in the ISS Russian segment configuration during 2008-2009 and the dependence of space radiation absorbed dose on EVA scene. Influence of spatial position of cosmonaut on absorbed dose value was evaluated with the EVA dosimeter model reproducing the actually determined weight and dimension. Calculated absorbed dose values are in good agreement with experimental data. Absorbed doses imparted to body organs (skin, lens, hemopoietic system, gastrointestinal tract, central nervous system, gonads) were determined for specific EVA events.

Vascular Aging: Lessons From Pediatric Hypertension.

PubMed

Litwin, Mieczyslaw; Feber, Janusz; Ruzicka, Marcel

2016-05-01

Hypertension (HTN) in children is associated with early vascular aging (EVA) and underlying immunologic-metabolic abnormalities and accelerated biological maturation. Morphologic and functional vascular changes underlying EVA and HTN in children resemble those seen in the elderly including but not limited to an increase in intima-media thickness (IMT) and arterial stiffness and endothelial dysfunction. Although progeria syndrome leading to EVA and the development of clinically manifested cardiovascular (CV) disease in the second decade of life is a rare hereditary disorder, primary HTN, which is also associated with EVA, is much more common (reported in up to 10% in adolescents). EVA associated with HTN in children leads to the premature development of target organ injury in childhood and CV events in early adulthood. Limited evidence from prospective observational studies in children and adolescents indicates that early lifestyle measures (low salt/low sugar intake and exercise) or pharmacologic treatment of HTN, or both, partially reverses morphologic and functional changes underlying EVA such as an increase in carotid IMT and pulse wave velocity, a decrease in flow-mediated dilation of the brachial artery, and an increase in oxidative stress and visceral fat. Future mechanistic and therapeutic clinical trials are desirable to assess the mechanisms and treatment strategies of EVA in the context of HTN in children and their effect on CV events in early adulthood. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Genetic Characterization of Enterovirus A71 Circulating in Africa.

PubMed

Fernandez-Garcia, Maria Dolores; Volle, Romain; Joffret, Marie-Line; Sadeuh-Mba, Serge Alain; Gouandjika-Vasilache, Ionela; Kebe, Ousmane; Wiley, Michael R; Majumdar, Manasi; Simon-Loriere, Etienne; Sakuntabhai, Anavaj; Palacios, Gustavo; Martin, Javier; Delpeyroux, Francis; Ndiaye, Kader; Bessaud, Maël

2018-04-01

We analyzed whole-genome sequences of 8 enterovirus A71 isolates (EV-A71). We confirm the circulation of genogroup C and the new genogroup E in West Africa. Our analysis demonstrates wide geographic circulation and describes genetic exchanges between EV-A71 and autochthonous EV-A that might contribute to the emergence of pathogenic lineages.

Genetic Characterization of Enterovirus A71 Circulating in Africa

PubMed Central

Volle, Romain; Joffret, Marie-Line; Sadeuh-Mba, Serge Alain; Gouandjika-Vasilache, Ionela; Kebe, Ousmane; Wiley, Michael R.; Majumdar, Manasi; Simon-Loriere, Etienne; Sakuntabhai, Anavaj; Palacios, Gustavo; Martin, Javier; Delpeyroux, Francis; Ndiaye, Kader; Bessaud, Maël

2018-01-01

We analyzed whole-genome sequences of 8 enterovirus A71 isolates (EV-A71). We confirm the circulation of genogroup C and the new genogroup E in West Africa. Our analysis demonstrates wide geographic circulation and describes genetic exchanges between EV-A71 and autochthonous EV-A that might contribute to the emergence of pathogenic lineages. PMID:29553325

Compiling a Comprehensive EVA Training Dataset for NASA Astronauts

NASA Technical Reports Server (NTRS)

Laughlin, M. S.; Murry, J. D.; Lee, L. R.; Wear, M. L.; Van Baalen, M.

2016-01-01

Training for a spacewalk or extravehicular activity (EVA) is considered hazardous duty for NASA astronauts. This activity places astronauts at risk for decompression sickness as well as various musculoskeletal disorders from working in the spacesuit. As a result, the operational and research communities over the years have requested access to EVA training data to supplement their studies.

Activity during first EVA of STS-72 mission

NASA Image and Video Library

1996-01-15

STS072-305-034 (15 Jan. 1996) --- Astronaut Daniel T. Barry, mission specialist, works in the cargo bay of the Space Shuttle Endeavour during the first of two extravehicular activities (EVA). Barry was joined by astronaut Leroy Chiao for the EVA. The two joined four other NASA astronauts for a week and a half aboard Endeavour.

Evaluation of cardiac rhythm disturbances during extravehicular activity.

PubMed

Rossum, A C; Wood, M L; Bishop, S L; Deblock, H; Charles, J B

1997-04-15

This study represents the first systematic evaluation of dysrhythmias before, during, and after spaceflight including extravehicular activity (EVA). The data, based on 7 Shuttle crew members, revealed a nonsignificant decrease in ventricular and supraventricular ectopy during EVA, suggesting that the incidence of dysrhythmias is no greater during EVA than with any other phase of a mission or preflight.

Space Shuttle Projects

NASA Image and Video Library

1994-09-16

Astronaut Mark Lee floats freely as he tests the new backpack called the Simplified Aid for EVA Rescue (SAFER) system. SAFER is designed for use in the event a crew member becomes untethered while conducting an EVA. The STS-64 mission marked the first untethered U.S. EVA in 10 years, and was launched on September 9, 1994, aboard the Space Shuttle Orbiter Discovery.

Compiling a Comprehensive EVA Training Dataset for NASA Astronauts

NASA Technical Reports Server (NTRS)

Laughlin, M. S.; Murray, J. D.; Lee, L. R.; Wear, M. L.; Van Baalen, M.

2016-01-01

Training for a spacewalk or extravehicular activity (EVA) is considered a hazardous duty for NASA astronauts. This places astronauts at risk for decompression sickness as well as various musculoskeletal disorders from working in the spacesuit. As a result, the operational and research communities over the years have requested access to EVA training data to supplement their studies. The purpose of this paper is to document the comprehensive EVA training data set that was compiled from multiple sources by the Lifetime Surveillance of Astronaut Health (LSAH) epidemiologists to investigate musculoskeletal injuries. The EVA training dataset does not contain any medical data, rather it only documents when EVA training was performed, by whom and other details about the session. The first activities practicing EVA maneuvers in water were performed at the Neutral Buoyancy Simulator (NBS) at the Marshall Spaceflight Center in Huntsville, Alabama. This facility opened in 1967 and was used for EVA training until the early Space Shuttle program days. Although several photographs show astronauts performing EVA training in the NBS, records detailing who performed the training and the frequency of training are unavailable. Paper training records were stored within the NBS after it was designated as a National Historic Landmark in 1985 and closed in 1997, but significant resources would be needed to identify and secure these records, and at this time LSAH has not pursued acquisition of these early training records. Training in the NBS decreased when the Johnson Space Center in Houston, Texas, opened the Weightless Environment Training Facility (WETF) in 1980. Early training records from the WETF consist of 11 hand-written dive logbooks compiled by individual workers that were digitized at the request of LSAH. The WETF was integral in the training for Space Shuttle EVAs until its closure in 1998. The Neutral Buoyancy Laboratory (NBL) at the Sonny Carter Training Facility near JSC opened in March 1997 and is the current site for US EVA training. Other space agencies also have used water to simulate weightlessness and train for EVAs. Russia has a training facility similar to the NBL named the Hydro Lab. The Hydro Lab began operations at the Gagarin Cosmonaut Training Center (GCTC) in 1980 and has been used extensively to the present. Although a majority of training in the Hydro Lab uses the Russian Orlan suit, a small number of sessions have been conducted using a NASA suit. The Japanese Weightlessness Environment Test System (WETS) went into service at the Tsukuba Space Center in 1997 but was closed in 2011 due to extensive earthquake damage. Several sessions were performed using a NASA suit, but these sessions were short and considered "development" runs. LSAH has assembled records from the WETF, NBL and Hydro Lab. Recording of the EVA training data has changed considerably from 1967 to present. The goal of early record keeping was to track use of hardware components, and the person involved was treated as a suited operator, not as a focus of interest. Records from the past two decades are fairly precise with the person, date, suit type and size noted. On occasion the length of the session was listed, but this data is not included on all records. Records were merged from data sources and extensive cleaning of the records was required since the multiple sources frequently overlapped and duplicated records. To date the LSAH EVA training dataset includes over 12,500 EVA training sessions performed by NASA astronauts since 1981. The following variables are included for most records: Name, Sex, Event date, Event name, HUT type, HUT size, Facility, and Estimated run time. For a smaller subset of records, the following variables are available: Actual run time, Time inverted, and the suit components Waist bearing type, Shoulder harness, Shoulder pads, and Teflon inserts. The LSAH dataset is currently the most complete resource for data regarding EVA training sessions performed by NASA astronauts. However, it is not 100 percent complete since the WETS (Japan) and NBS (Marshall) training facility data were not included. This dataset has been compiled by LSAH to study the relationship of EVA training to musculoskeletal injuries but has many other non-medical applications. This dataset can be provided to other groups in order to respond to program and research questions with appropriate board approvals.

Exploratory Visual Analysis of Statistical Results from Microarray Experiments Comparing High and Low Grade Glioma

PubMed Central

Reif, David M.; Israel, Mark A.; Moore, Jason H.

2007-01-01

The biological interpretation of gene expression microarray results is a daunting challenge. For complex diseases such as cancer, wherein the body of published research is extensive, the incorporation of expert knowledge provides a useful analytical framework. We have previously developed the Exploratory Visual Analysis (EVA) software for exploring data analysis results in the context of annotation information about each gene, as well as biologically relevant groups of genes. We present EVA as a flexible combination of statistics and biological annotation that provides a straightforward visual interface for the interpretation of microarray analyses of gene expression in the most commonly occuring class of brain tumors, glioma. We demonstrate the utility of EVA for the biological interpretation of statistical results by analyzing publicly available gene expression profiles of two important glial tumors. The results of a statistical comparison between 21 malignant, high-grade glioblastoma multiforme (GBM) tumors and 19 indolent, low-grade pilocytic astrocytomas were analyzed using EVA. By using EVA to examine the results of a relatively simple statistical analysis, we were able to identify tumor class-specific gene expression patterns having both statistical and biological significance. Our interactive analysis highlighted the potential importance of genes involved in cell cycle progression, proliferation, signaling, adhesion, migration, motility, and structure, as well as candidate gene loci on a region of Chromosome 7 that has been implicated in glioma. Because EVA does not require statistical or computational expertise and has the flexibility to accommodate any type of statistical analysis, we anticipate EVA will prove a useful addition to the repertoire of computational methods used for microarray data analysis. EVA is available at no charge to academic users and can be found at http://www.epistasis.org. PMID:19390666

Frequency of early vascular aging and associated risk factors among an adult population in Latin America: the OPTIMO study.

PubMed

Botto, Fernando; Obregon, Sebastian; Rubinstein, Fernando; Scuteri, Angelo; Nilsson, Peter M; Kotliar, Carol

2018-03-01

The main objective was to estimate the frequency of early vascular aging (EVA) in a sample of subjects from Latin America, with emphasis in young adults. We included 1416 subjects from 12 countries in Latin America who provided information about lifestyle, cardiovascular risk factors (CVRF), and anthropometrics. We measured pulse wave velocity (PWV) as a marker of arterial stiffness, and blood pressure (BP) using an oscillometric device (Mobil-O-Graph). To determine the frequency of EVA, we used multiple linear regression to estimate each subject's PWV expected for his/her age and systolic BP, and compared with observed values to obtain standardized residuals (z-scores). We defined EVA when z-score was ≥1.96. Finally, a multivariable logistic regression analysis was performed to determine baseline characteristics associated with EVA. Mean age was 49.9 ± 15.5 years, male gender was 50.3%. Mean PWV was 7.52 m/s (SD 1.97), mean systolic BP was 125.3 mmHg (SD 16.7) and mean diastolic BP was 78.9 mmHg (SD 12.2). The frequency of EVA was 5.7% in the total population, 9.8% in adults of 40 years or less and 18.7% in those 30 years or less. In these young adults, multiple logistic regression analyses demonstrated that dyslipidemia and hypertension showed an independent association with EVA, and smoking a borderline association (p  =  0.07). In conclusion, the frequency of EVA in a sample from Latin America was around 6%, with higher rates in young adults. These results would support the search of CVRF and EVA during early adulthood.

Minimizing EVA Airlock Time and Depress Gas Losses

NASA Technical Reports Server (NTRS)

Trevino, Luis A.; Lafuse, Sharon A.

2008-01-01

This paper describes the need and solution for minimizing EVA airlock time and depress gas losses using a new method that minimizes EVA out-the-door time for a suited astronaut and reclaims most of the airlock depress gas. This method consists of one or more related concepts that use an evacuated reservoir tank to store and reclaim the airlock depress gas. The evacuated tank can be an inflatable tank, a spent fuel tank from a lunar lander descent stage, or a backup airlock. During EVA airlock operations, the airlock and reservoir would be equalized at some low pressure, and through proper selection of reservoir size, most of the depress gas would be stored in the reservoir for later reclamation. The benefit of this method is directly applicable to long duration lunar and Mars missions that require multiple EVA missions (up to 100, two-person lunar EVAs) and conservation of consumables, including depress pump power and depress gas. The current ISS airlock gas reclamation method requires approximately 45 minutes of the astronaut s time in the airlock and 1 KW in electrical power. The proposed method would decrease the astronaut s time in the airlock because the depress gas is being temporarily stored in a reservoir tank for later recovery. Once the EVA crew is conducting the EVA, the volume in the reservoir would be pumped back to the cabin at a slow rate. Various trades were conducted to optimize this method, which include time to equalize the airlock with the evacuated reservoir versus reservoir size, pump power to reclaim depress gas versus time allotted, inflatable reservoir pros and cons (weight, volume, complexity), and feasibility of spent lunar nitrogen and oxygen tanks as reservoirs.

Near Real Time Tools for ISS Plasma Science and Engineering Applications

NASA Astrophysics Data System (ADS)

Minow, J. I.; Willis, E. M.; Parker, L. N.; Shim, J.; Kuznetsova, M. M.; Pulkkinen, A. A.

2013-12-01

The International Space Station (ISS) program utilizes a plasma environment forecast for estimating electrical charging hazards for crews during extravehicular activity (EVA). The process uses ionospheric electron density and temperature measurements from the ISS Floating Potential Measurement Unit (FPMU) instrument suite with the assumption that the plasma conditions will remain constant for one to fourteen days with a low probability for a space weather event which would significantly change the environment before an EVA. FPMU data is typically not available during EVA's, therefore, the most recent FPMU data available for characterizing the state of the ionosphere during EVA is typically a day or two before the start of an EVA or after the EVA has been completed. In addition to EVA support, information on ionospheric plasma densities is often needed for support of ISS science payloads and anomaly investigations during periods when the FPMU is not operating. This presentation describes the application of space weather tools developed by MSFC using data from near real time satellite radio occultation and ground based ionosonde measurements of ionospheric electron density and a first principle ionosphere model providing electron density and temperature run in a real time mode by GSFC. These applications are used to characterize the space environment during EVA periods when FPMU data is not available, monitor for large charges in ionosphere density that could render the ionosphere forecast and plasma hazard assessment invalid, and validate the assumption of 'persistence of conditions' used in deriving the hazard forecast. In addition, the tools are used to provide space environment input to science payloads on ISS and anomaly investigations during periods the FPMU is not operating.

A rapidly equilibrating, thin film, passive water sampler for organic contaminants; characterization and field testing.

PubMed

St George, Tiffany; Vlahos, Penny; Harner, Tom; Helm, Paul; Wilford, Bryony

2011-02-01

Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log K(EVA-W) partition coefficients correlate well (r(2) = 0.87) with Log K(OW) values for selected pesticides and polychlorinated biphenyls (PCBs) where Log K(EVA-W) = 1.04 Log K(OW) + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter. Published by Elsevier Ltd.

Information Flow Model of Human Extravehicular Activity Operations

NASA Technical Reports Server (NTRS)

Miller, Matthew J.; McGuire, Kerry M.; Feigh, Karen M.

2014-01-01

Future human spaceflight missions will face the complex challenge of performing human extravehicular activity (EVA) beyond the low Earth orbit (LEO) environment. Astronauts will become increasingly isolated from Earth-based mission support and thus will rely heavily on their own decision-making capabilities and onboard tools to accomplish proposed EVA mission objectives. To better address time delay communication issues, EVA characters, e.g. flight controllers, astronauts, etc., and their respective work practices and roles need to be better characterized and understood. This paper presents the results of a study examining the EVA work domain and the personnel that operate within it. The goal is to characterize current and historical roles of ground support, intravehicular (IV) crew and EV crew, their communication patterns and information needs. This work provides a description of EVA operations and identifies issues to be used as a basis for future investigation.

The micro conical system: Lessons learned from a successful EVA/robot-compatible mechanism

NASA Technical Reports Server (NTRS)

Gittleman, Mark; Johnston, Alistair

1996-01-01

The Micro Conical System (MCS) is a three-part, multi-purpose mechanical interface system used for acquiring and manipulating masses on-orbit by either extravehicular activity (EVA) or telerobotic means. The three components of the system are the micro conical fitting (MCF), the EVA micro tool (EMCT), and the Robot Micro Conical Tool (RMCT). The MCS was developed and refined over a four-year period. This period culminated with the delivery of 358 Class 1 and Class 2 micro conical fittings for the International Space Station and with its first use in space to handle a 1272 kg (2800 lbm) Spartan satellite (11000 times greater than the MCF mass) during an EVA aboard STS-63 in February, 1995. The micro conical system is the first successful EVA/robot-compatible mechanism to be demonstrated in the external environment aboard the U.S. Space Shuttle.

Human Space Exploration and Radiation Exposure from EVA: 1981-2011

NASA Astrophysics Data System (ADS)

Way, A. R.; Saganti, S. P.; Erickson, G. M.; Saganti, P. B.

2011-12-01

There are several risks for any human space exploration endeavor. One such inevitable risk is exposure to the space radiation environment of which extra vehicular activity (EVA) demands more challenges due to limited amount of protection from space suit shielding. We recently compiled all EVA data comprising low-earth orbit (LEO) from Space Shuttle (STS) flights, International Space Station (ISS) expeditions, and Shuttle-Mir missions. Assessment of such radiation risk is very important, particularly for the anticipated long-term, deep-space human explorations in the near future. We present our assessment of anticipated radiation exposure and space radiation dose contribution to each crew member from a listing of 350 different EVA events resulting in more than 1000+ hrs of total EVA time. As of July 12, 2011, 197 astronauts have made spacewalks (out of 520 people who have gone into Earth orbit). Only 11 women have been on spacewalks.

A simulation system for Space Station extravehicular activity

NASA Technical Reports Server (NTRS)

Marmolejo, Jose A.; Shepherd, Chip

1993-01-01

America's next major step into space will be the construction of a permanently manned Space Station which is currently under development and scheduled for full operation in the mid-1990's. Most of the construction of the Space Station will be performed over several flights by suited crew members during an extravehicular activity (EVA) from the Space Shuttle. Once fully operational, EVA's will be performed from the Space Station on a routine basis to provide, among other services, maintenance and repair operations of satellites currently in Earth orbit. Both voice recognition and helmet-mounted display technologies can improve the productivity of workers in space by potentially reducing the time, risk, and cost involved in performing EVA. NASA has recognized this potential and is currently developing a voice-controlled information system for Space Station EVA. Two bench-model helmet-mounted displays and an EVA simulation program have been developed to demonstrate the functionality and practicality of the system.

Mechanical behaviour study on SBR/EVA composite for FDM feedstock fabrication

NASA Astrophysics Data System (ADS)

Raveverma, P.; Ibrahim, M.; Sa'ude, N.; Yarwindran, M.; Nasharuddin, M.

2017-04-01

This paper presents the research development of a new SBR/EVA composite flexible feedstock material by the injection moulding machine. The material consists of poly (ethylene-co-vinyl acetate) in styrene butadiene rubber cross-linked by Dicumyl Peroxide. In this study, the mechanical behaviour of injection moulded SBR/EVA composite with different blend ratio investigated experimentally. The formulations of blend ratio with several combinations of a new SBR/EVA flexible feedstock was done by volume percentage (vol. %). Based on the result obtained from the mechanical testing done which is tensile and hardness the composite of SBR/EVA has the high potency to be fabricated as the flexible filament feedstock. The ratio of 80:20 which as an average hardness and tensile strength proved to be the suitable choice to be fabricated as the flexible filament feedstock. The study has reached its goals on the fabricating and testing a new PMC which is flexible.

STS-57 MS2 Sherlock dons EMU upper torso with technicians' help at JSC's WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-57 Mission Specialist 2 (MS2) Nancy J. Sherlock, wearing the liquid cooling and ventilation garment (LCVG) and an extravehicular mobility unit (EMU) lower torso, squats under the EMU upper torso and prepares to raise her arms into the sleeves. Technicians stand on either side of Sherlock and are ready to assist her in donning the upper torso. When fully suited the platform Sherlock is on will be lowered into the 25 foot deep pool located in JSC's Weightless Environment Training Facility (WETF) Bldg 29. During the underwater simulation, Sherlock will practice extravehicular activity (EVA) procedures.

Astronaut Carl Walz during EVA in Discovery's payload bay

NASA Technical Reports Server (NTRS)

1993-01-01

Astronaut Carl E. Walz reaches for equipment from the provisional stowage assembly (PSA) in Discvoery's cargo bay during a lengthy period of extravehicular activity (EVA). The hatch to Discovery's airlock is open nearby. Sun glare is evident above the orbiter. The picture was taken with a 35mm camera by astronaut James H. Newman, who shared EVA duties with Walz.