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At least 235 records · Page 13

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NASA NTRS2014

Shoulder Injury Incidence Rates in NASA Astronauts

Evaluation of the astronaut shoulder injury rates began with an operational concern at the Neutral Buoyancy Laboratory (NBL) during Extravehicular Activity (EVA) training. An astronaut suffered a shoulder injury during an NBL training run and commented that it was possibly due to a hardware issue. During the subsequent investigation, questions arose regarding the rate of shoulder injuries in recent years and over the entire history of the astronaut corps.

Laughlin, Mitzi S.↗

NASA NTRSDate not supplied

Development of Lunar EVA Fitness for Duty Standards for Aerobic Capacity and Muscle Strength

Current aerobic Fitness Standards for NASA astronauts are based on peak aerobic capacity (i.e. VO2peak (ml/kg/min))and are related to aerobic metabolic requirements for Extravehicular Activity (EVA) in microgravity and in 1 g operational environments. Standards for muscle strength need to be developed. Fitness for Duty Standards for partial gravity EVA (e.g. 1/6 g EVA on the Lunar surface) are not developed in terms of aerobic fitness and muscle strength. Defining thresholds for aerobic fitness and muscle strength will help to provide guidance in determining recommendations for optimal fitness necessary for partial g EVA success.

D Frisco↗

NASA NTRS1988

A simulation system for Space Station extravehicular activity

A simulation program has been developed which addresses the human factors required to provide a crewmember with productive information during Space Station EVA. The operation of the voice recognition and control system and helmet-mounted projection display in the Space Station Extravehicular Mobility Unit (EMU) is reviewed. The features of the simulation program are discussed, including logic flow, information types, and the man-machine interface techniques used in the simulation program, voice recognizer, and helmet-mounted display.

Marmolejo, Jose A.↗

NASA NTRSDate not supplied

Uncrewed Lunar Surface Operations and Support Activities

A sustained human presence on the surface of the Moon and future missions to Mars require increased independence from surface crews and Earth-based mission control to operate efficiently, safely, and reliably. The number of astronauts and the availability of the surface crew to perform tasks will be limited, and extravehicular activities are burdensome and time-consuming. A balance of crewed and uncrewed surface operations will maximize crew exploration time by reducing their time dedicated to routine maintenance and support tasks. Certain sustaining activities that consume valuable crew time and preparation tasks such as staging and prepositioning equipment and materials can be performed without the crew, either before their arrival on the lunar surface or after their departure, thus improving task efficiency and mission effectiveness. This paper will define uncrewed operations and support activities and examine the functions, features, and capabilities that support sustained human and robotic surface operations. It will also discuss the extreme environmental challenges and the complexities associated with the development and operation of autonomous systems, as well as some suggested methods, techniques, and tools to overcome these challenges.

Lunar↗

NASA NTRS1992

Meeting human needs

Manned space flight can be viewed as an interaction of three general elements: the human crewmember, spacecraft systems, and the environment. While the human crewmember is a crucial element in the system, certain physiological, psychological, environ- mental and spacecraft systems factors can compromise human performance in space. These factors include atmospheric pressure, physiology, uncertainties associated with space radiation, the potential for exposure to toxic materials in the closed environment, and spacecraft habitability. Health protection in space, for current and future missions, relies on a philosophy of risk reduction, which in the space program is achieved in four ways-through health maintenance, health care, design criteria, an selection and training. Emphasis is place upon prevention, through selection criteria and careful screening. Spacecraft health care systems must be absolutely reliable, and they will be automated and computerized to the maximum extent possible, but still designed with the human crewmember's capabilities in mind. The autonomy and technological sophistication of future missions will require a greater emphasis on high-level interaction between the human operator and automated systems, with effective allocation of tasks between humans and machines. Performance in space will include complex tasks during extravehicular activity (EVA) and on planetary surfaces, and knowledge of crewmembers' capability and limitations during such operations will be critical to mission success. Psychological support will become increasingly important on space missions, as crews spend long periods in remote and potentially hazardous environments. The success of future missions will depend on both individual psychological health and group cohesion and productivity, particularly as crew profiles become more heterogeneous. Thus, further human factors are needed in the area of small-group dynamics and performance.

Nicogossian, Arnauld E.↗

NASA NTRS1993

Extravehicular Activity training and hardware design considerations

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.

Thuot, Pierre J.↗

NASA NTRS2000

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

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.

Hagale, Thomas J.↗

NASA NTRS1987

Robot hands and extravehicular activity

Extravehicular activity (EVA) is crucial to the success of both current and future space operations. As space operations have evolved in complexity so has the demand placed on the EVA crewman. In addition, some NASA requirements for human capabilities at remote or hazardous sites were identified. One of the keys to performing useful EVA tasks is the ability to manipulate objects accurately, quickly and without early or excessive fatigue. The current suit employs a glove which enables the crewman to perform grasping tasks, use tools, turn switches, and perform other tasks for short periods of time. However, the glove's bulk and resistance to motion ultimately causes fatigue. Due to this limitation it may not be possible to meet the productivity requirements that will be placed on the EVA crewman of the future with the current or developmental Extravehicular Mobility Unit (EMU) hardware. In addition, this hardware will not meet the requirements for remote or hazardous operations. In an effort to develop ways for improving crew productivity, a contract was awarded to develop a prototype anthromorphic robotic hand (ARH) for use with an extravehicular space suit. The first step in this program was to perform a a design study which investigated the basic technology required for the development of an ARH to enhance crew performance and productivity. The design study phase of the contract and some additional development work is summarized.

Marcus, Beth↗

NASA NTRSDate not supplied

Training Artemis Astronauts to Explore the Moon

To prepare for human exploration of the Moon in the mid-2020s, NASA is developing a program to provide geoscience and planetary science classroom training and geologic eld training to astronauts and other mission personnel. The Artemis geoscience training plan builds on a long legacy: NASA has trained astronauts in geology, planetary science, and geological eld work for more than 50 years. From ~1965-1972, the geology focus for astronauts included orbital Earth observations during the early NASA missions, but the endgame was preparation for the Apollo missions to the Lunar surface [see Phinney (2015), NASA-SP-2015-626; Lofgren et al.(2011);Schmitt, et al. (2011); and El Baz (2011), all from GSA SP483]. From the mid 1970s through2017, the primary purpose for geoscience training was to prepare astronauts to observe theEarth and document a wide variety of Earth processes from orbital platforms (Skylab, SpaceShuttle and International Space Station). Astronaut observations of Earth from the InternationalSpace Station remain an important activity today, but the prospect of exploration of the lunar surface through the Artemis Program lends additional purpose to the geoscience content and eld experiences that we provide the astronauts. We recently completed the geology and eld training with Astronaut Class 22 and are now planning both focused eld exercises and simulations for future Artemis crews, as well as the accompanying classroom lessons on lunar and planetary sciences. The training we offer extends beyond the astronaut office – we partner across operational and engineering organizations at NASA and provide eld work exercises and opportunities to personnel in the Flight Operations Directorate (responsible for the overall training and certification), as well as the exploration Extravehicular Activity Oce (developing spacewalk suits and tools). These partnerships contribute to building a common language and sense of purpose, and also help to ensure that NASA’s geoscience training and science operations are fully integrated with the teams and systems responsible for getting the next generation of astronauts to the surface of the Moon.

Artemis↗

NASA NTRS2019

Psychophysiological Monitoring of Aerospace Crew State

As next-generation space exploration missions necessitate increasingly autonomous systems, there is a critical need to better detect and anticipate crewmember interactions with these systems. The success of present and future autonomous technology in exploration spaceflight is ultimately dependent upon safe and efficient interaction with the human operator. Optimal interaction is particularly important for surface missions during highly coordinated extravehicular activity (EVA), which consists of high physical and cognitive demands with limited ground support. Crew functional state may be affected by a number of variables including workload, stress, and motivation. Real-time assessments of crew state that do not require a crewmember’s time and attention to complete will be especially important to assess operational performance and behavioral health during flight. In response to the need for objective, passive assessment of crew state, the aim of this work is to develop an accurate and precise prediction model of human functional state for surface EVA using multi-modal psychophysiological sensing. The psychophysiological monitoring approach relies on extracting a set of features from physiological signals and using these features to classify an operator’s cognitive state. This work aims to compile a non-invasive sensor suite to collect physiological data in real-time. Training data during cognitive and more complex functional tasks will be used to develop a classifier to discriminate high and low cognitive workload crew states. The classifier will then be tested in an operationally relevant EVA simulation to predict cognitive workload over time. Once a crew state is determined, further research into specific countermeasures, such as decision support systems, would be necessary to optimize the automation and improve crew state and operational performance.

Wusk, Grace C.↗

NASA NTRS2001

Absorbed Dose Determination Using Experimental and Analytical Predictions of X-Ray Spectra

Electron beam welding in a vacuum is a technology that NASA is investigating as a joining technique for manufacture of space structures. This investigation characterizes the x-ray environment due to operation of an in-vacuum electron beam welding tool and provides recommendations for adequate shielding for astronauts performing the in-vacuum electron beam welding. NASA, in a joint venture with the Russian Space Agency, was scheduled to perform a series of welding in space experiments on board the U.S. Space Shuttle. This series of experiments was named the international space welding experiment (ISWE). The hardware associated with the ISWE was leased to NASA by the Paton Welding Institute (PWI) in Ukraine for ground-based welding experiments in preparation for flight. Two ground tests were scheduled, using the ISWE electron beam welding tool, to characterize the radiation exposure to an astronaut during the operation of the ISWE. These radiation exposure tests used thermoluminescence dosimeters (TLD's) shielded with material currently used by astronauts during extravehicular activities to measure the radiation dose. The TLD's were exposed to x-ray radiation generated by operation of the ISWE in-vacuum electron beam welding tool. This investigation was the first known application of TLD's to measure absorbed dose from x rays of energy less than 10 keV. The ISWE hardware was returned to Ukraine before the issue of adequate shielding for the astronauts was completely verified. Therefore, alternate experimental and analytical methods were developed to measure and predict the x-ray spectral and intensity distribution generated by ISWE electron beam impact with metal. These x-ray spectra were normalized to an equivalent ISWE exposure, then used to calculate the absorbed radiation dose to astronauts. These absorbed dose values were compared to TLD measurements obtained during actual operation of the ISWE in-vacuum electron beam welding tool. The calculated absorbed dose values were found to be in agreement with the measured TLD values.

Edwards, D. L.↗

NASA NTRS1977

Automatic control of human thermal comfort with a liquid-cooled garment

Water cooling in a liquid-cooled garment is used to maintain the thermal comfort of crewmembers during extravehicular activity. The feasibility of a simple control that will operate automatically to maintain the thermal comfort is established. Data on three test subjects are included to support the conclusion that heat balance can be maintained well within allowable medical limits. The controller concept was also successfully demonstrated for ground-based applications and shows potential for any tasks involving the use of liquid-cooled garments.

Kuznetz, L. H.↗

NASA NTRS1992

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

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).

Smith, Jeffrey H.↗

NASA NTRS1993

Hypobaric decompression prebreathe requirements and breathing environment

To reduce incidence of decompression sickness (DCS), prebreathing 100 percent oxygen to denitrogenate is required prior to hypobaric decompressions from a sea level pressure breathing environment to pressures lower than 350 mm Hg (20,000 ft; 6.8 psia). The tissue ratio (TR) of such exposures equals or exceeds 1.7; TR being the tissue nitrogen pressure prior to decompression divided by the total pressure after decompression (((0.781)(14.697))/6.758). Designing pressure suits capable of greater pressure differentials, lower TR's, and procedures which limit the potential for DCS occurrence would enhance operational efficiency. The current 10.2 psia stage decompression prior to extravehicular activity (EVA) from the Shuttle in the 100 percent oxygen, 4.3 psia suit, results in a TR of 1.65 and has proven to be relatively free of DCS. Our recent study of zero-prebreathe decompressions to 6.8 psia breathing 100 percent oxygen (TR = 1.66) also resulted in no DCS (N = 10). The level of severe, Spencer Grades 3 or 4, venous gas emboli (VGE) increased from 0 percent at 9.5 psia to 40 percent at 6.8 psia yielding a Probit curve of VGE risk for the 51 male subjects who participated in these recent studies. Earlier, analogous decompressions using a 50 percent oxygen, 50 percent nitrogen breathing mixture resulted in one case of DCS and significantly higher levels of severe VGE, e.g., at 7.8 psia, the mixed gas breathing environment resulted in a 56 percent incidence of severe VGE versus 10 percent with use of 100 percent oxygen. The report of this study recommended use of 100 percent oxygen during zero-prebreathe exposure to 6.8 psia if such a suit could be developed. For future, long-term missions, we suggest study of the effects of decompression over several days to a breathing environment of 150 mmHg O2 and approximately 52 mmHg He as a means of eliminating DCS and VGE hazards during subsequent excursions. Once physiologically adapted to a 4 psia vehicle, base, or space station segment, crew members could use greatly simplified EVA suits with greater mobility and no prebreathe requirement.

Webb, James T.↗

NASA NTRS2005

STS-114: Discovery Question & Answer with Joint Crew on ISS

STS-114 Commander Eileen Collins, Pilot James Kelly, Mission Specialists Souichi Noguchi, Stephen Robinson, Charles Camarda, Andrew Thomas, Wendy Lawrence, and Expedition 11 Commander Sergei Krikalev and Flight Engineer John Phillips answers questions from United States, Japanese and Russian News media in the Destiny laboratory of the International Space Station. Risk, safety, extravehicular activities, spacewalks, re-entry, gap fillers, tiles, flight operations, flight crew activities, team work, and life in space are topics covered with the News media.

Source record↗

NASA NTRS2010

Design and Testing of the Primary and Secondary Oxygen Regulators for the Flexible Portable Life Support System (FlexPLSS)

The next generation space suit requires additional capabilities for controlling and adjusting internal pressure compared to that of historical designs. Although the general configuration of the oxygen systems for the next generation space suit is similar or derived from the Apollo and Shuttle Extravehicular Mobility Unit (EMU) with Primary closed loop life support operation and Secondary sourced open loop life support operations, nearly everything else has evolved with new available technologies. For the case of the primary and secondary regulators, the design has gone away from purely mechanical systems actuated with pull-cords or "bicycle cables" to electro-mechanical hybrids that provide the best of both worlds with respect to power draw, reliability, and versatility. This paper discusses the development and testing of a Secondary Oxygen Regulator bench-top prototype along with comparisons of operation with the various prototypes for the Primary Oxygen Regulator.

Campbell, Colin↗

NASA NTRS2011

Spacesuit Portable Life Support System Breadboard (PLSS 1.0) Development and Test Results

A multi-year effort has been carried out at NASA-JSC to develop an advanced Extravehicular Activity (EVA) PLSS design intended to further the current state of the art by increasing operational flexibility, reducing consumables, and increasing robustness. Previous efforts have focused on modeling and analyzing the advanced PLSS architecture, as well as developing key enabling technologies. Like the current International Space Station (ISS) Extravehicular Mobility Unit (EMU) PLSS, the advanced PLSS comprises of three subsystems required to sustain the crew during EVA including the Thermal, Ventilation, and Oxygen Subsystems. This multi-year effort has culminated in the construction and operation of PLSS 1.0, a test rig that simulates full functionality of the advanced PLSS design. PLSS 1.0 integrates commercial off the shelf hardware with prototype technology development components, including the primary and secondary oxygen regulators, ventilation loop fan, Rapid Cycle Amine (RCA) swingbed, and Spacesuit Water Membrane Evaporator (SWME). Testing accumulated 239 hours over 45 days, while executing 172 test points. Specific PLSS 1.0 test objectives assessed during this testing include: confirming key individual components perform in a system level test as they have performed during component level testing; identifying unexpected system-level interactions; operating PLSS 1.0 in nominal steady-state EVA modes to baseline subsystem performance with respect to metabolic rate, ventilation loop pressure and flow rate, and environmental conditions; simulating nominal transient EVA operational scenarios; simulating contingency EVA operational scenarios; and further evaluating individual technology development components. Successful testing of the PLSS 1.0 provided a large database of test results that characterize system level and component performance. With the exception of several minor anomalies, the PLSS 1.0 test rig performed as expected; furthermore, many system responses trended in accordance with pre-test predictions.

Vogel, Matt R.↗

NASA NTRSDate not supplied

Characterizing the Risk: Review of Sensorimotor Evidence and Research Roadmap

BACKGROUND: NASA’s Artemis program will take astronauts back to the lunar surface for the first time in almost 50 years. Despite the successes of the previous Apollo program, the Artemis missions will differ in duration, vehicle characteristics, and landing tasks that may exacerbate the risks to crew health/safety and mission objectives. NASA’s Human Research Program identifies the risk of altered sensorimotor/vestibular function impacting critical mission tasks as one of the top priority risks to lunar exploration missions. This session will review the existing evidence and remaining gaps in knowledge for the sensorimotor risk. DESCRIPTION: Alterations in sensorimotor processing during spaceflight can lead to motion sickness, spatial disorientation, and decrements in postural control, locomotion, and fine motor control during and following gravity-transitions. The risk of impairment is greatest during and soon after gravity-transitions, when performance decrements may have high operational impacts (e.g., manual landings, immediate egress following landing, and early extravehicular activities (EVAs)). Recent studies have specifically improved the risk characterization of changes in perception, motion sickness, postural and locomotor control, manual control, and fine-motor coordination. However, given the difficulty in obtaining measurements during and soon after gravity-transitions, evidence for initial decrements immediately following gravity-transitions remains limited. The most significant gaps in the risk include manual control ability around gravity-transitions, the incidence and severity of motion sickness during landings, and the ability to perform egress/EVAs soon after gravity-transition. To address these gaps, current research roadmaps leverage both spaceflight studies and ground-based analogs for risk characterization and countermeasure development/validation. DISCUSSION: This panel will further describe the current sensorimotor research strategies with an emphasis on the operational scenarios of manual control, crew egress, and EVA. The goal of this research is to accommodate the needs of the crew and facilitate human capabilities to ensure lunar mission success. This work will prepare NASA for successful Artemis missions and enable the next giant leap, the exploration of Mars.

Timothy Ryan Macaulay↗