Integrated Extravehicular Activity 

Human Research Plan: 2017

NASA Point of Contact: Andrew F. J. Abercromby, Ph.D.

andrew.abercromby@nasa.gov

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. 

Acronyms

ABF = Anthropometry and Biomechanics Facility

AES = Advanced Exploration Systems

CTSD = Crew and Thermal Systems Division

EMC = Evolvable Mars Campaign

EVA = Extravehicular Activity

HHP = Human Health and Performance

HITL = Human-In-The-Loop

HRP = Human Research Program

HUT = Hard Upper Torso

ISS = International Space Station

LCVG = Liquid Cooling and Ventilation Garment

LSAH = Longitudinal Survey of Astronaut Health

MDV = Mars Descent Vehicle
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NASA = National Aeronautics and Space Administration

NEEMO = NASA Extreme Environment Mission Operations

NBL = Neutral Buoyancy Laboratory

PRR = Path to Risk Reduction

PXS = Prototype Exploration Suit

SMT = System Maturation Team

I. Introduction

ASA’s 2014 Strategic Plan1identifies that “Our long-term goal is to send humans to Mars. Over the next two 

decades, we will develop and demonstrate the technologies and capabilities needed to send humans to explore 

the red planet and safely return them to Earth.” Current spacesuits and EVA concepts of operations used on the 

International Space Station or used previously during the Apollo missions to the Moon are inadequate to support even

the shortest possible Mars exploration missions. Many questions must be answered with respect to the ability of EVA 

systems and crewmembers to function safely, reliably, and effectively for missions lasting a year or longer in what 

will be the most hostile and challenging environment ever explored by humans. A variety of intermediate missions 

and destinations will precede humans setting foot on Mars, beginning with testing of exploration systems on the 

International Space Station (ISS), currently in low-earth orbit, followed by missions incrementally further from Earth. 

NASA is studying a variety of pathways to Mars that include design reference missions to cis-lunar space, asteroids, 

Mars orbit, and the moons of Mars2, 3, while the technology developments that are expected to enhance and enable 

such missions are tracked, prioritized, and published in NASA’s Space Technology Roadmap4. Meanwhile, NASA’s 

Human Research Program focuses on identifying, researching, and mitigating risks to astronauts’ health and 

performance during exploration missions. 

The primary purpose of the Integrated EVA Human Research Plan presented here is to improve multi-year 

coordination and collaboration among three of the primary participants in EVA research at NASA’s Johnson Space 

Center; specifically, the EVA Office, the Crew and Thermal Systems Division (CTSD), and the Human Research 

Program (HRP). While these organizations work together successfully on EVA research projects on an almost 

continual basis, it was recognized that the multi-year planning and coordination of research activities could be 

improved. To this end, a formal framework of collaboration was established. 

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, 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.

Multiple organizations within NASA and outside of NASA have been successfully conducting EVA research and 

development efforts since the 1960s. The Integrated EVA Human Research Plan currently reflects only a small subset 

of all stakeholders in the field of EVA and was intended primarily as an internal NASA creation; however, the 

preliminary version of the plan is presented here in recognition of the importance of coordination and collaboration 

with the broader NASA community and beyond. Furthermore, this plan is not intended to be exhaustive but rather 

aims to identify the Human-In-The-Loop (HITL) research tasks that will require more coordination in terms of 

personnel, budgets, facilities, and test hardware as well as tasks that may provide for opportunistic add-on objectives. 

It is important to understand that, other than the studies that are already in progress, the other research tasks 

described in this plan are only proposed, and have not yet been formally reviewed or approved by the prospective 

funding organizations. This review and funding process differs among organizations; this plan is intended to assist 

with coordination of those decisions among the respective funding organizations. 

The identification and organization of EVA research priorities is described in Section II, the technical content of 

the plan is described in Section III, and the process by which the plan will be maintained is explained in Section IV. 

II. Identifying and Organizing EVA Research Priorities

A. EVA System Maturation Team (SMT) Gaps

Following the creation of NASA’s Space Technology Roadmaps4, the EVA Office and CTSD led the development 

of an EVA System Maturation Team (SMT) Gap List, the purpose of which was to identify EVA-relevant technology 

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research and development priorities in more detail than is included in the Space Technology Roadmaps. The EVA 

SMT Gap List is used by the EVA Office and CTSD in identifying and prioritizing EVA research activities. A subset of SMT gaps most directly relevant to the human-suit interactions that are the focus of this plan is included as an 

appendix to this paper. 

B. Human Research Program (HRP) EVA Risk and Gaps

HRP uses a well-defined and documented process for the formal identification, prioritization, researching, and 

mitigation of risks to astronauts. The gaps in knowledge or countermeasure technology necessary to mitigate each risk 

are also identified. All HRP-funded research activities must directly target one or more formally identified gaps. The 

Risk of Injury and Compromised Performance Due to EVA Operations and seven corresponding gaps are currently 

being tracked by HRP (Table 1). An additional gap, EVA 7B, identified during the development of this integrated 

plan, has been proposed to HRP: How does EVA suit sizing and fit affect crew health, performance, and injury risk? 

Table 1. Current and proposed (*) Human Research Program EVA Gaps5.

HRP Gap ID Description

EVA 6: What crew physiological & performance capabilities1are required for EVA operations2in 

exploration environments3?

EVA 7: How do EVA suit system design parameters4affect crew health and performance in exploration 

environments3?

*EVA 7B: How does EVA suit sizing and fit affect crew health, performance, and injury risk? [Note that 

this has not yet been approved as a new EVA Gap]

EVA 8: What are the physiological inputs and outputs associated with EVA operations2in exploration 

environments3?

EVA 9: What is the effect on crew performance & health of variations in EVA task design and operations 

concepts for exploration environments3?

EVA 10: Can knowledge and use of real-time physiological and system parameters during EVA 

operations2improve crew health and performance? 

EVA 11: How do EVA operations2in exploration environments3increase the risk of crew injury and how 

can the risk be mitigated?

EVA 14: What other EVA-related risks, developments and technologies exist that may affect EVA 

research?

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e.g. anthropometry, aerobic fitness, muscle strength & power; 2acceptable functional performance of expected nominal and 

contingency suited tasks; 3i.e. Moon, NEA, Mars, L2 and other deep space microgravity locations; 4(e.g. center of gravity, mass, 

pressure, mobility, joint characteristics, suit fit; includes suit, portable life support system, and other enabling equipment). Note: 

Numbering of HRP EVA Gaps is not sequential due, in part, to previous recategorization of decompression sickness gaps into a 

separate HRP risk (Risk of Decompression Sickness).

EVA is recognized as a distinct discipline by HRP. The HRP EVA Discipline is responsible for coordinating a 

“Path to Risk Reduction (PRR)”5, which is a multi-year test plan that aims to close or mitigate the EVA-related risks 

and gaps to acceptable levels in time to enable human exploration missions. The HRP EVA Discipline also maintains 

an “EVA Evidence Report”

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, a publicly available document in which literature relevant to the EVA risks is reviewed 

and continually updated as more research studies are performed. All aspects of the HRP EVA risks, gaps, schedules, 

and evidence reports are reviewed annually by an external (non-NASA) review panel of experts. Additionally, 

proposals are submitted and externally peer-reviewed for all HRP-funded EVA studies. Studies are open to 

competition by industry and academia (i.e. non-NASA organizations) except where studies can only be performed 

using facilities, hardware and expertise available within NASA. Full details can be found on the publicly accessible 

HRP website, humanresearchroadmap.nasa.gov. 

In the process of developing the Integrated EVA Human Research Plan described here, the HRP EVA aspects 

were reviewed and revised in collaboration between the HRP EVA Discipline, EVA Office, and CTSD. The tasks 

planned for addressing the Risk of Decompression Sickness and the Risk of Hypobaric Hypoxia are not presented here; 

however, those tasks are also being coordinated with the EVA Office and CTSD. 

Note that the numbering shown in Table 1 is not sequential due, in part, to restructuring the original gaps and the 

recategorization of decompression sickness and hypobaric hypoxia gaps into separate HRP risks (Risk of 

Decompression Sickness and Risk of Hypobaric Hypoxia). Gap EVA 14 is being proposed for closure as a consequence 

of this Integrated EVA Human Research Plan. The gap was intended to address the possibility of failure to adequately 
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coordinate and communicate among the EVA research community, which is specifically what this plan is intended to 

avoid. 

C. EVA Development Milestones 

There is currently no over-arching program defining the schedule by which exploration EVA capabilities must be 

developed. For the purposes of this plan, notional steps required to enable Mars surface exploration missions in the 

2030s are used as a basis for phasing and prioritization of EVA HITL research efforts. The notional EVA milestones, 

shown in Figure 1, assume that a next generation (NextGen, in this paper) spacesuit will be developed for microgravity 

operation on ISS with the goal of extensibility supporting exploration upgrades at a later date. Figure 1 also indicates 

specific products (and their respective HRP and SMT Gaps, in italics) that are expected to result from the Integrated 

EVA Human Research Plan and their relation to the notional EVA development schedule.

It should be noted that the extent to which aspects of the microgravity-focused NextGen suit will be extensible to 

planetary exploration is not yet understood. Additionally, the milestones in Figure 1 are provided as an example and 

will be updated with formal milestones once those milestones are defined by NASA. The phasing and products of the 

planned research tasks will also be revised at that time. 

Figure 1. Notional EVA development milestones used for phasing and prioritization of EVA research by fiscal 

year (FY).

D. Organization of the Integrated EVA Human Research Plan

The HRP EVA Evidence Report6explains that review of the EVA Risk within the EVA research community and 

the NASA Human Systems Risk Board resulted in identification of 24 separate factors that contribute to the risk of 

injury and compromised performance due to EVA operations. These factors are separated into the interacting domains 

of Human, Suit, and Operations and are further grouped into categories of suit habitability, in-suit physical 

environment, EVA factors, crewmember physical state, and crewmember psychological state. The 3 domains, 5 

categories, and 24 factors are shown in the EVA Risk Master Logic Diagram (Figure 2) and are described in the 

Evidence Report along with the an overview of the available evidence for each identified factor. The mapping of the 

HRP EVA Gaps (Table 1) to the contributing factors identified in Figure 2 is included in Appendix A of the HRP 

EVA Evidence Report6. 
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Figure 2. HRP EVA Risk Master Logic Diagram6.

Figure 3. Organization of the Integrated EVA Human Research Plan.
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By comparison, the EVA SMT Gaps are categorized primarily by different EVA systems such as Exploration EVA 

Avionics, Exploration EVA Tools, etc. Specific gaps are then identified within each system-level category. The 

different approaches reflect the different perspectives of the corresponding organizations and result in partial but not 

complete overlap between EVA SMT and HRP EVA Gaps. 

For the purposes of organizing the Integrated EVA Human Research Plan, proposed tasks are grouped by 

functional areas that approximately map to the HRP EVA Gaps, as shown in Figure 3. All tasks are mapped to at least 

one HRP EVA Gap and/or an EVA SMT Gap and are briefly described in the following section. The intent of this 

document is to summarize the integrated plan rather than to provide significant detail on any specific study. 

III. The Baseline Integrated EVA Human Research Plan

The tasks are not described in the chronological order in which they are expected to be performed. Instead, tasks 

are grouped into categories corresponding approximately to the HRP EVA Gaps that each would be primarily intended 

to address as summarized in Figure 3. The content is structured around the HRP EVA Gaps due to the human-centered 

focus of the plan; however, the relationship of the plan content to EVA SMT Gaps is also described, where applicable. 

The proposed sequencing of activities within the plan is shown in Figure 4. 

Figure 4. Proposed phasing of tasks in Integrated EVA Human Research Plan.

A. Physiological and Performance Capabilities

Tasks in this section are relevant primarily to HRP EVA Gap 6: What crew physiological & performance 

capabilities are required for EVA operations in exploration environments?
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1. Impaired EVA Performance 

Physiological adaptation to the microgravity environment during transit to Mars is likely to result in reduced 

functional capacity after landing on Mars’ surface. While muscular and aerobic capacity may be preserved through 

inflight countermeasures, returning long-duration ISS crewmembers demonstrate significant decrements in functional 

performance upon return to a gravity environment due to neurovestibular / sensorimotor adaptation to microgravity 

that can take days or weeks from which to recover. The implications of such performance decrements are significant 

since they may require that the Mars Descent Vehicle (MDV) be capable of supporting astronauts for up to two weeks 

on Mars’ surface to allow astronauts to rehabilitate before performing EVAs to egress the MDV and ingress a surface 

habitat or pressurized rover.

The purpose of the Impaired EVA Performance studies is to characterize suited health and performance outcomes 

in crewmembers as a function of vestibular / sensorimotor dysfunction during and after gravitational transitions, which 

will inform questions such as how long crew must remain in the MDV before they can go EVA after landing on Mars; 

which EVA tasks can be performed; and whether systems or operations can be modified to enable earlier post-landing 

EVA. The study is expected to consist of two parts.

The first study will be an unsuited ground study that begins with development of the method to simulate postflight 

vestibular disturbances using galvanic vestibular stimulation (GVS). This investigation will entail calibrating GVS 

intensity to match post-flight performance decrements and recovery profiles measured on functional task test and field 

test studies. The calibrated GVS will then be used on suited test subjects to assess suited functional performance 

outcomes for simulated vestibular disturbances in crewmembers during simulated planetary EVA. Functional 

performance outcomes will be based on the HHP Benchmarking methodology, but may be adapted to focus on the 

“First EVA on Mars” scenario. 

The second part of the study will also involve measurement of functional EVA performance using the same 

simulated planetary EVA tasks and spacesuits; but instead of experiencing simulated vestibular disturbances, test 

subjects will be returning long-duration ISS crewmembers.

2. Fitness for Mission Tasks Exercise Studies

Two studies are currently funded by HRP to use unsuited 1-g testing of physically demanding critical misison 

tasks to establish aerobic and muscular fitness for duty standards. Three of the four tasks are EVA tasks and one of 

those tasks involves the rescue of an incapacitated EVA crewmember. The details of the EVA tasks that are to be 

simulated, and particularly the incapacitated crewmember rescue task, are not yet well defined and will be informed 

by the EVA Tasks and ConOps studies (Section III.D). 

3. Aerobic and Muscle Fitness for Duty Standards - Suited Validation Study

Following completion of the 1-g Fitness for Mission Tasks Exercise Studies, aerobic and muscular fitness for duty 

standards will be recommended. These standards will also be informed by suited human performance results from the 

EVA Human Health and Performance (HHP) Benchmarking 1 study. However, validation of these standards will 

require a suited evaluation in which subjects both above and below the proposed fitness for duty standards will attempt 

to complete a set of functional EVA tasks in simulated Martian gravity. The tasks used will be based on the EVA 

Tasks and ConOps studies (Section III.D).

B. Suit Design Parameters

Tasks in this section are relevant primarily to the EVA SMT Pressure Garment System (PGS) Gap and the HRP 

EVA Gap 7: How do EVA suit system design parameters affect crew health and performance in exploration 

environments? These studies are also a primary source of data for the EVA HHP Model associated with EVA Gap 8:

What are the physiological inputs and outputs associated with EVA operations in exploration environments?

1. Review and Archiving of Unpublished EVA Test Data 

Human testing of EVA suits and suit prototypes has been ongoing for decades with many results published in 

conference papers, NASA technical reports, and peer-reviewed journal papers. However, results of many tests are not 

published or archived in a way that is readily searchable or accessible by anybody other than the person or people 

directly responsible for conducting the study. In many cases, the fact that the studies have even occurred is often 

known only by a small number of people, and many of the generation of scientists and engineers responsible for EVA 

testing in the 1960s and 1970s are now at or approaching retirement age. The purpose of this task is to update the HRP 

EVA Evidence Report and EVA Engineering archives with relevant findings from unpublished research studies that 

will be identified primarily through discussions and interviews with engineers in EVA Engineering and the EVA 

Office at JSC. 
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2. EVA Human Health and Performance (HHP) Benchmarking 1: EMU, Mark III

Suit performance is understood qualitatively from observation and subjective feedback and decades of effort has 

been spent attempting to quantify space suited performance with some methodologies resulting in more information

than others. However, a rigorous and comprehensive characterization of the HHP implications of current and future 

EVA spacesuit designs does not yet exist. Standard methods for quantification of specific aspects of suited 

performance, such as metabolic expenditure or kinematic measures, serve as tools in understanding and describing 

desired suited performance. Specifically, tools are helpful in providing insight into the performance of full-suit 

mobility architectures and of individual components, with the goal of aiding selection for specific missions and 

motions. It is important in the development of these quantitative metrics that they be robust for comparisons across 

suit operators and that a thorough understanding exists of how the measures are affected by the selected task 

parameters. Consideration must also be given to the sensitivity and specificity of a selected measure when used for 

predicting an outcome. In this manner, the quantitative metrics will enable inferences to be made across multiple gap 

areas. In addition to informing suit design, standard methods are also necessary for many other tasks described in this 

plan, including the rigorous assessment of the effects of sensorimotor impairement, suit fit, aerobic fitness, strength, 

fatigue, and inspired Carbon Dioxide (CO2) on suited human performance. Many of these features are coupled, for 

example the suit fit may affect how an operator’s underlying strength can be applied to enable performance of a 

specific operational task. With the data from the Benchmarking study, these interactions can be examined and new 

quantitative measures assessed and validated.

The aim of the EVA HHP Benchmarking study, initiated in 2016, is to identify a standard set of tasks and metrics 

with known margins of error, to facilitate meaningful assessment and comparison of suit configurations and test 

conditions in current and future studies7. Through collaboration with the EVA community, the study will identify and 

develop a methodology to reliably characterize HHP metrics for individuals working inside EVA suits under realistic 

microgravity and planetary spaceflight conditions. In addition to a Subjective Suit Fit assessment methodology that 

will be developed and implemented as a part of this study, pilot data aimed at objective quantification of suit fit will 

also be collected (Section F.2). Testing will involve a combination of static offloading and dynamic offloading using 

the Active Response Gravity Offload Simulator (ARGOS)

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. The HHP benchmarking methodology will be used to 

characterize and compare existing spacesuits (Figure 5) and test subjects will also complete tasks unsuited to provide 

a comparative baseline.

Figure 5. The EMU (left) and Mark III spacesuits planned for evaluation using the EVA HHP Benchmarking 

methodology. 
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3. Z-2 Neutral Buoyancy Laboratory (NBL) Mobility Testing and Worksite Assessments

NASA’s EVA Engineering program is currently developing a new generation of ‘Z-series’ planetary EVA suits to 

test technologies for future EVAs, with the newest of these being the Z-2. These prototype suits will be assessed in a 

series of HITL evaluations over the next several years beginning with NBL testing with a particular focus on lowerbody mobility requirements for the NextGen suit as well as analysis and HITL evaluation of ISS EVA worksite access. 

The integrated data collection efforts supporting the NBL ergonomic and metabolic assessments, described in 

Section H.4, are being leveraged to enable support for Z-2 NBL testing. The Anthropometry and Biomechanics 

Facility (ABF) is working with CTSD personnel to apply computational photogrammetry techniques, along with 

commercial-off-the-shelf hardware approved by the NBL, to collect reach envelope data underwater. The reach 

envelope data will be collected on the EMU, the Z-2, and the Z-2 configured with an EMU lower torso assembly 

(LTA) and a 3-D reach volume will be statistically approximated for each suit configuration. This evaluation will 

allow performance differences to be assessed across the different suit architectures, in a microgravity analog that 

allows full body reach motions that could not easily be replicated outside of the NBL. Metabolic rate data will also be 

collected by the EVA Physiology Laboratory to provide another method of assessment and comparison of human 

performance under each of the test conditions. 

The extent to which the Z-2 suit will be incorporated into HRP-funded studies will depend, in part, on the 

availability of the hardware; Z-2 NBL testing is planned during the first two quarters of FY17. The HRP-funded EVA 

HHP Benchmarking 1 Study is expected to use the EMU and Mark III spacesuits during FY17. Future testing of Z-2 

and the Prototype Exploration Suit (PXS) hardware on ARGOS using the HHP benchmarking methodology is 

proposed as part of a Z-2 / PXS Hybrid study, described next. 

4. EVA HHP Benchmarking 2: Suit Design Parameters

The Z-2 and PXS suits (Figure 6) are designed for different EVA environments. The Z-2 spacesuit prototype includes 

a lower-torso assembly (LTA) designed for planetary ambulation. The PXS uses an LTA designed to meet

microgravity EVA requirements. However, the Z-2 and PXS suits share several common interfaces that may allow 

for certain components of PXS and Z-2 suits to be combined into hybrid configurations. This capability, combined 

with the HHP benchmarking methodology would provide for the opportunity to systematically vary suit design 

features and rigorously assess their respective contributions to human health and performance outcomes. The aim of 

the second EVA HHP Benchmarking study is to use the benchmarking methodology to characterize and compare 

human health and performance outcomes for different suit configurations with the purpose of informing specification 

and design of the NextGen suit. The specific suit configurations to be tested will be discussed and agreed upon with 

Co-Investigators from CTSD and the EVA Office. As with the first HHP Benchmarking study, this second study is 

expected to complement ISS-funded hardware evaluations that are already planned for the prototype hardware. 
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5. NextGen Hardware Testing; EVA HHP Benchmarking 3 and 4

The results of the HHP Benchmarking studies will be used to inform the design and build of the NextGen suit. The 

aim of the HHP Benchmarking 3 and 4 studies will be to use the established HHP benchmarking methodology to 

characterize the human health and performance outcomes of human subjects using the NextGen suit for microgravity 

operations and planetary operations, respectively. Data will be compared with data collected from the EMU and other 

suits during the preceding HHP benchmarking evaluations. It is expected that this study will be performed in 

conjunction with ISS-funded HITL evaluations of the NextGen suit hardware. 

6. Suit Pressure Study

The pressure at which EVA suits operate affects the resistance experienced by crewmembers at individual joints, 

which can affect the health and performance outcomes for those crewmembers. Lower suit pressure reduces suit joint 

torques but also increases the risk of decompression sickness. The purpose of this study is to use the EVA HHP 

Benchmarking methodology to quantify and compare health and human performance outcomes for human subjects 

operating in the spacesuit at a range of pressures from 26.2 kPa (3.8 psia) to 56.5 kPa (8.2 psia). The duration of testing 

will be adequate to identify fatigue effects. It is not expected that these data will affect suit design, because it is 

currently assumed that the pressure garment system (PGS) for exploration missions will be capable of operating at up 

to 56.5 kPa (8.2 psia); however, results of this study are expected to inform the selection of suit operating pressure(s) 

used during EVAs, which is a trade between decompression stress at lower suit pressures and increased joint resistance 

and fatigue at higher pressures. Findings of acceptable health and performance outcomes during extended operations 

at higher suit pressures could lead to the development of shorter prebreathe protocols, if EVAs are to be performed at 

higher suit pressures, and could even preclude the need for developing habitation and life support systems capable of 

operating at the Exploration Atmosphere 9. 

7. High Performance EVA Glove (HPEG) Prototype Evaluations

The design and fit of EVA gloves affects performance of tasks requiring manual dexterity and gripping and also 

affects the risk of fingernail delamination and other hand and finger trauma. Almost all EVA suits and EVA gloves 

are designed with a common glove attachment mechanism, meaning that most EVA gloves are interchangeable among 

different suits. Thus, the benchmarking of EVA gloves will be considered separately from the benchmarking of EVA 

Figure 6. The PXS (left) and Z-2 (right) spacesuits proposed for evaluation during the EVA HHP 

Benchmarking 2 Study.
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suits, although testing will preferably be performed by subjects wearing a pressurized suit as opposed to a glove box. 

It is understood, however, that logistics may sometimes preclude the availability of suits for use in these evaluations, 

especially in cases where glove sizes are being built for subjects who may fall on the extreme ends of the suit sizing 

spectrum. The purpose of the HPEG evaluations is to identify and use a standard set of tasks and metrics, with known 

margins of error, to facilitate meaningful assessment and comparison of human health and performance when using 

different EVA glove designs and configurations. FY17 evaluations are expected to include assessment of prototype 

gloves in the B34 glove box, and may also include use of the ABF sensor glove in NBL and/or glove box settings for 

assessment of stresses and strains as well as heat and humidity seen at the hands during EVA glove use. This task is 

relevant to the Gloves I and Gloves II EVA SMT Gaps. 

8. Carbon Dioxide Washout; Inspired Carbon Dioxide Requirement

Exposure to excessive levels of CO2 can lead to hypercapnia, with consequences including reduced cognitive 

performance, fatigue, dizziness, reduced visual acuity, headache, panic and ultimately convulsions, unconsciousness, 

or death 10-12. Adequate elimination of CO2 produced by respiration is therefore an essential requirement for 

spacesuits. The elimination of exhaled CO2 from the spacesuit helmet is commonly referred to as washout and the 

effectiveness with which washout occurs is affected by many factors related to the design and operation of the 

spacesuit hardware as well as the characteristics and activities of the person inside the spacesuit. 

The importance and challenge of accurately measuring CO2 washout is not unique to spacesuits; a variety of 

methods have been developed and used to measure CO2 washout in respiratory protective equipment (RPE) for use in 

industries such as diving, firefighting and aviation. Previous studies conducted at the Johnson Space Center (JSC) 

have compared different sampling methodologies but have not yet enabled definition of a standardized test procedure 

13-15. The results of these previous studies in combination with unpublished laboratory testing indicates that the 

accuracy and reliability of inspired CO2 measurements inside spacesuits depends on many variables related to the 

measurement equipment setup, the analysis methods used, as well as the human subjects themselves. 

The over-arching objective of this task is to thoroughly review existing test methodologies and test data in 

conjunction with systematic quantification of potential sources of measurement error to inform the definition of a 

standard procedure for the measurement of inspired CO2 in spacesuits. Determination of a standard methodology for 

quantification of inspired CO2 inside spacesuits as well as definition of an evidence-based standard for acceptable 

levels of inspired CO2 is relevant to HRP EVA Gap 7 as well as the EVA SMT Ventilation Gap. 

Testing in FY17 will consist of a thorough review of existing methodologies for CO2 washout measurement 

followed by unmanned laboratory testing using calibration gas, unsuited human testing, and suited human testing 

using the EMU. Results will characterize sources of variability associated with measurement equipment and methods 

as well as intra-subject and inter-subject variability associated with HITL testing of CO2 washout. The EMU data will 

also provide a reference of current CO2 washout capability using the newly established standard testing methodology. 

The next step of this work will be to establish an evidence-based standard for inspired CO2 during EVA. This will 

begin with an exhaustive literature search and, if necessary, unsuited testing using an environmental chamber to 

evaluate functional impairment due to CO2. Finally, CO2-related performance decrements in suited subjects will be 

quantified using neurocognitive assessment and functional performance tasks from the HHP Benchmarking protocol. 

9. Mass Sensitivity Study 

The purpose of this study is to use the HHP Benchmarking methodology and the ARGOS test environment to 

evaluate the sensitivity of human health and performance measures to changes in simulated suit mass, center of gravity 

(CG), and gravity level. The range of masses and CGs evaluated will be based on the likely range of achievable masses 

and CGs anticipated for the NextGen planetary suit. Results of this study are expected to inform suit mass and primary 

life support system trades. For example, results may show that mass reductions beyond a threshold value yield 

negligible changes in human health and performance outcomes or that increases above a threshold value result in 

significant increases in workload and consumables usage. In addition, results could show that overall suited mass may 

affect performance in Mars gravity but that CG affects performance more in lower gravity. For these reasons, results 

will also directly inform the design of the Fitness for Duty Validation, EVA Workload and Duration, and Impaired 

EVA studies. 

C. EVA Human Health and Performance Model

The EVA HHP Model is expected to address HRP EVA Gap 8: What are the physiological inputs and outputs 

associated with EVA operations in exploration environments? Specifically, the purpose of this task is to develop a 

parametric model for providing time-varying estimates of EVA translation distances, joint cycles, ground reaction 

force dose, decompression stress, workload, fatigue, and metabolic rates when given model inputs including suit mass, 
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gravity level, and task type. Additional metrics determined through the Benchmarking study may also prove valuable 

in this parametric model as surrogates for values that can not be directly estimated or measured, and data from the 

EVA Workload and Duration Study (Section D.2) may also be used to incorporate fatigue-related effects. Model 

outputs will inform fitness for duty standards, exercise prescriptions, prebreathe validation protocols, suit lifecycle 

information for certification profiles, EVA consumables sizing, and may also inform exploration concepts of 

operations, task design, and eventual exploration EVA planning. 

The model will use a combination of data from analog field tests and pressurized suit testing. The model will begin 

with existing datasets from testing of the Mark III suit and will be incrementally updated and validated through 

prediction and incorporation of additional physiological datasets as they become available. Studies associated with 

HRP EVA Gaps 6, 7, and 9 will provide the primary sources of empirical data, but the EVA Biomechanical model 

may also eventually be capable of enhancing the predictive capacity of the EVA HHP Model.

D. EVA Tasks and Concepts of Operations 

Tasks in this section are relevant primarily to HRP EVA Gap 9: What is the effect on crew performance and health 

of variations in EVA task design and operations concepts for exploration environments?

1. Human Health and Performance EVA Tasks and ConOps

The EVA research tasks described in this plan require definition of the assumed EVA tasks and ConOps during 

future mission architectures and, in some cases, results of these research tasks will, in turn, inform changes or add 

detail to those tasks, ConOps and even to overall mission architectures. This activity will serve as a focusing element 

to develop and maintain a single set of consistent assumptions with respect to EVA tasks and ConOps as they pertain 

to HHP. 

While EVA ConOps documents are maintained for design reference missions by the EVA Office, in some cases 

they do not include the necessary detail to inform the design of HHP studies or they lack detail on expected human 

constraints and considerations that may affect architectural decisions. Through close coordination with the EVA 

Office, existing ConOps documents will be supplemented with relevant HHP data and assumptions, including 

information such as estimated metabolic rates, ground reaction forces, task types and frequencies, and decompression 

profiles. The EVA HHP Model is expected to serve as the source of data in many cases. Through coordination with 

the Exploration EVA Working Group, this document will be developed and then periodically reviewed and updated 

based on results of research studies, architectural trade studies, and changes to design reference missions. A similar 

document was developed for lunar surface operations during the Constellation Program 16. 

In addition to the documentation and assimilation of existing data sets made available from other studies, this study 

will use existing studies such as Biologic Analog Science Associated with Lava Terrains (BASALT), funded by the 

Science Mission Directorate (SMD), and possibly other SMD-funded analog studies, to collect task characterization 

data. At a minimum, data is expected to include the types, durations, and frequencies of tasks, distances and terrains 

traversed, and may also include perceived exertion, heart rate, joint kinematics, and even metabolic rate data, if 

possible. Although SMD-funded studies are unsuited and in 1-g, they represent real geological and biological 

exploration operations and therefore are reasonable approximations of what might be attempted during planetary 

EVAs as well as a physiological baseline against which to compare predicted planetary EVA workload. Data from 1-

g unsuited exploration environments and data from suited, reduced gravity tests such as the benchmarking studies will 

then be combined within the EVA HHP Model. These data are also synergistic with the EVA Biomechanical model 

(Section H.1) and can be used to computationally assess performance decrements for specific ConOps profiles. 

2. EVA Workload and Duration Study

The human health and performance implications of current architectural assumptions of up to 24 hours EVA per 

person per week for long duration planetary missions have not been evaluated and may not be credible. The purpose 

of the EVA Workload and Duration Study will be to characterize suited health and performance outcomes as a function 

of EVA duration and frequency, up to 24 hours of EVA in a week. 

It is anticipated that multiple test subjects will perform up to 3 x 8 hour simulated planetary EVAs on ARGOS or 

NBL in a week. The circuit components of the HHP benchmarking methodology will be employed to periodically 

measure performance during the simulated EVAs. Criteria will be defined and assessed for ending EVAs given 

specific degrees of decrement in physical and/or cognitive performance. Additional measures of physical and 

neurocognitive fatigue resulting from EVA performance may also be incorporated based on the NBL Ergonomic 

Assessments and Metabolic Rates task (Section H.4). The types, frequencies, and durations of tasks performed during 

the EVA simulations will be based on the HHP EVA Tasks and ConOps as well as results of the HHP Benchmarking 

studies. The simulated suit mass will be informed by the Mass Sensitivity Study (Section B.9). 
13

Opportunities to incorporate this study within end-to-end mission simulations such as HERA will be investigated

since the pre- and post-EVA workload associated with maintenance and preparation of EVA hardware should also be 

considered. For best engineering data, this investigation would be performed with a high fidelity system requiring 

realistic maintenance to assess the success of efforts to ease and limit required maintenance.

3. Incapacitated Crewmember Rescue

The Incapacitated Crewmember Rescue EVA SMT Gap specifically identifies the need to develop methodology for 

transfer/transport of an incapacitated crewmember at each destination and how to transfer him/her onto the 

ingress/egress hardware or through side hatch, and doff suit. As described previously, the Fitness for Mission Tasks 

studies also plan to use this task in determining fitness for duty standards. While previous studies have been 

conducted17, 18, the limited fidelity and scope of those studies have precluded the establishment of a baseline protocol 

for this important contingency EVA task. The purpose of this study is to design, build, and test high-fidelity concepts 

for incapacitated EVA crewmember rescue. Test environments may include NASA Extreme Environment Mission 

Operations (NEEMO)

17

, NBL, and/or ARGOS as well as 1-g testing. Results are expected to directly inform design 

features required to facilitate EVA rescue. 

E. EVA Informatics

The tasks described in this section are relevant to HRP EVA Gap 10: Can knowledge and use of real-time 

physiological and system parameters during EVA operations improve crew health and performance? In addition, 

these tasks are relevant to several EVA SMT Gaps: Biomedical Sensors; Displays and Controls; and Information 

Systems.

1. EVA Biomedical Monitoring Requirements Definition

This task will involve coordination between the HRP EVA Discipline, Exploration Medical Capabilities (ExMC), 

Medical Operations, EVA Office, CTSD, Crew Office, and other stakeholders to seek consensus on the EVA 

biomedical monitoring requirements and operations concepts for exploration missions. Beginning with requirements 

and rationale developed during the Constellation Program, the multi-disciplinary team will consider which data are 

minimally necessary as well as whether data should be self-monitored, monitored by an IV crewmember, monitored 

by the ground, and/or monitored by an algorithm. This assessment will be achieved through one or more workshops 

involving all stakeholders and will conclude with updates to NASA Standard 3001 NASA Space Flight HumanSystem Standard and, depending on the recommended approach, may also include functional requirements for 

biomedical monitoring hardware, software, and operations. More specific knowledge gaps and associated tests may 

be identified if existing literature and experience are found to be inadequate to make specific recommendations. 

2. EVA Informatics Interfaces

A human interface is required to navigate the non-critical informatics system, while not interfering with critical 

display information. This technology would be required for full evaluation of the informatics system, since it is an 

integrated package with a menu-driven system that must be designed with the particular interface in mind. For 

example, a voice navigated menu would look different than a gesture driven system. This proposed task will develop

and evaluate information systems and interfaces for processing, displaying, and interacting with physiological and 

system parameters during EVAs. These systems may be multi-modal in terms of input by and output to the operator.

Evaluations should consider the operational use cases of the interfaces, which present physical and cognitive loads to 

the user, potentially interfering with system operation. Considerations in development should be made to minimize 

interference in operating the EVA informatics and controlling external systems or vehicles such that ConOps are not 

hindered. The task is proposed as a collaboration with EVA Engineering, HRP EVA discipline, HRP Space Human 

Factors and Habitability element, and ExMC. 

It is proposed that a packaged prototype of the interface system be designed and fabricated for integration into the 

Portable Life Support System (PLSS) prototype for evaluation. Prototype systems may be evaluated during suited test 

opportunities such as the EVA Workload and Duration study (D.2) to determine the acceptability of user interfaces as 

well as the utility of the physiological and system data in improving crew health and/or performance. Dedicated testing 

may be necessary to provide controlled comparisons in which case those tests will be designed to use other tests in 

the Integrated EVA Human Research Plan as the control condition. 

Opportunities for unsuited assessment of EVA Informatics in operational field (i.e., non-laboratory) environments

such as the BASALT project will also be sought. Indeed, a central component of the BASALT project is the 

development and assessment of exploration information system capabilities and EVA operations concepts. The impact 

on EVA efficiency of the quality of navigational data and the way in which the data is displayed is the subject of the 
14

SEXTANT project, which is currently being funded by BASALT. SEXTANT provides tools for pre-EVA path 

planning and also gives astronauts the ability to replan traverses in real time. In the future, this work will investigate 

the utility of a “heads-up display” during EVA traverses. Previous work performed by the Space Human Factors and 

Habitability element in collaboration with engineers at NASA Glenn Research Center as well as HRP-funded work 

on a bioadvisory algorithm, and BASALT-funded work on exploration information systems will be leveraged.

F. Human-Suit Sensors

The tasks described in this section are all relevant to the EVA SMT Pressure Garment System Gap. Additionally, 

the Objective Suit Fit Sensors task will be relevant to the Suit Sizing & Fit Gap that will be proposed to HRP as a new 

EVA Gap, while the Human-Suit Interaction Sensors will be relevant to EVA Gap 11: How do EVA operations in 

exploration environments increase the risk of crew injury and how can the risk be mitigated? The proposed phasing 

of studies is shown in Figure 4. 

1. Human-Suit Interaction Sensors Assessment 

Understanding the interaction between the human and the spacesuit is necessary for both identifying and improving

the interrelated determinants of suit fit, suited performance, and suit injury risk. Much of what is known today comes 

from valuable subjective data provided by test subjects and crewmembers and incorporating sensor technology to 

measure human-suit interactions (i.e., forces, pressures, and human/suit kinematics) could provide a valuable objective 

complement to the subjective data19. In particular, ergonomic suit design could be informed by improved 

understanding of where the human drives the suit, the contact forces required to drive the suit, and the resulting forces 

and pressures experienced by the human. However, many technical challenges remain, including the possibility that 

sensors inside the suit will themselves affect fit, discomfort, and injury risk, and the ability of the crewmember to 

perform EVA tasks, all of which could confound the primary test objectives. 

The objective of this task is to identify technologies and methods that provide valid and reliable quantification of 

human-suit interactions that can be related to specific locations on the human and the suit. This includes generating 

an understanding of the sensitivity of the measures to detect relevant effects and the specificity of the measures to 

direct to the relevant cause in the context of general suit use. Considerations will be given to a minimum set of ConOps 

that must be considered when evaluating human-suit interaction. If a valid and reliable approach is identified, it will 

be incorporated into the Suit Sizing and Fit Study to measure human-suit interactions as a function of suit fit and tasks 

and to identify and mitigate potential mechanisms of suit trauma and injury. The approach will also be used in the 

assessment of Second Generation Suit Trauma Countermeasures. 

2. Objective Suit Fit 

A separate but related task will aim to complement subjective ratings of suit fit with objective measures of critical 

suit fit dimensions. The objective suit fit task is a counterpart to the subjective suit fit methodology that is being 

developed under the HHP Benchmarking Study and it is possible that elements of both objective and subjective suit 

fit assessment methodologies could be utilized during future studies. While the Human-Suit Interaction Sensors will 

quantify forces, pressures and kinematics between the human and suit, this task will attempt to quantify offsets 

between the human and the suit in critical dimensions; for example, offsets between joint centers. If successful, the 

Objective Suit Fit methodology will be employed, along with the subjective suit fit methodology, during the Suit 

Sizing and Fit Study (Section G.3) during which the statistical reliability of objective and subjective suit fit measures

may be calculated and compared. Depending on the overhead and efficacy of the Objective Suit Fit methodology, it 

may also be used routinely during suit fit checks for objective verification of acceptable fit. Alternatively, if the 

comparison of objective and subjective suit fit assessment methods during the Suit Sizing and Fit Study shows close 

agreement between methods, then the simpler subjective approach may be adequate in most cases. Any approach to 

assessment of suit fit must allow for the possibility that multiple acceptable suit sizing approaches may exist for 

subjects. 

3. Manloads Testing

The forces exerted by the human into the axial restraint system of the suit are referred to as manloads20 and must 

be measured so that appropriate conservatism is incorporated into the suit structure design, ensuring that the suit 

cannot be damaged by the movement of the human. The manloads input to suit structure is suit design dependent and, 

as such, the test set up is specific to the suit load path and suit hardware being evaluated. Measured manloads are also 

dependent on suit sizing and fit; in most cases, a subject wearing a tighter fitting suit (fingertip-to-fingertip, heel-toshoulder, crotch-to shoulder) will induce greater manloads than a subject wearing a loosely fitting suit. 
15

The manloads associated with the Z-2 suit mobility architecture will be measured during this study using on-suit 

axial sensors. Options for combining aspects of manloads testing with the Suit Sizing & Fit Study will be investigated,

potentially providing the opportunity to characterize manloads for a range of suit sizes and fits in multiple test subjects.

G. EVA Suit Sizing & Fit

Tasks in this section are relevant to the EVA SMT Pressure Garment System Gap and also HRP EVA Gap 7: How 

do EVA suit system design parameters affect crew health and performance in exploration environments? However, 

while suit fit is a function of suit system design, fit is also dependent on how the suit is sized as well as the 

anthropometry of the human. And while there exists universal recognition of the importance of suit fit, there is 

currently no established method for fit quantification or definition of acceptable suit fit. As such, a new EVA Gap is 

proposed: How does EVA suit sizing and fit affect crew health, performance, and injury risk? 

1. “Proteus” Suit Sizing and Fit Model

A simulation of suit-human interaction can help improve suit designs by developing optimized hardware solutions 

for human performance and anthropometric accommodation. The end product of the multi-year tasks described in the 

Suit Sizing and Fit section will be a predictive model that, given inputs of an individual’s anthropometric dimensions 

and a spacesuit’s geometry and adjustability features, will provide a quantitative estimate of suit fit for that individual 

in each of the critical dimensions, as well as recommended suit sizing parameters.This requires developing the criteria 

for permissible interaction forces as a function of location, as well as permissible misalignments between the human 

joint and suit. For the critical dimensions, ranges within which fit has been shown to be associated with decreased 

performance or increased injury risk will be provided based on the Suit Sizing and Fit Studies (G.1), as well as 

modeling efforts (H.1). Predictions of suit fit changes in critical dimensions due to in-flight anthropometry changes 

will also be provided. In addition to individual predictions of suit fit, the model will enable population analysis, 

providing estimates of the proportion of the general population or the astronaut population that would be 

accommodated with acceptable suit fit by different suit design and sizing strategies. Within this analysis, different 

relative proportions will be considered. The model will be developed and validated using data from Suit Sizing and 

Fit studies in combination with customized digital manikins and computer models of EVA suits (Figure 7), described 

later in this section.

The focus of FY17 work on the Proteus Suit Sizing and Fit model will be integration of a parametric human model 

with existing suit CAD models. This will improve upon the current human model by adding greater fidelity to the 

body shape represented for each individual that is modeled. The clearance and contact volume will be quantifiably 

identified and analyzed between the suit and body surface models. Time permitting, additional work will be done on 

adding adjustability to existing suit components to allow for design change comparisons.

Validation of predicted changes due to in-flight anthropometry changes may be possible once the NextGen suit is 

flown on ISS, although subjective rather than objective in-flight suit fit assessments may be required. The Suit Sizing 

and Fit Model development is expected to be complementary to the aforementioned EVA HHP Model and, 

particularly, the EVA Biomechanical Model, as described in the Injury Risk and Mitigation section. 

2. Customized Digital Manikins; Statistical Body Shape Modeling

Customized Computer-Aided Design (CAD) models of human body shape (manikins) are a critical component of 

the Proteus Suit Sizing and Fit Model as well as the EVA Biomechanical Model. However, current modeling tools 

use generic “average” or “boundary” manikins rather than representing the actual anthropometry of individual 

Figure 7. Screenshots taken from prototype version of the future Proteus Suit Sizing and Fit Model. 
16

astronauts or test subjects. This task will develop a more flexible capacity for CAD manikins to represent a specific 

person’s body shape and anthropometry measurements. Scanned body shapes from the Astronaut Anthropometry 

Database will be transformed into geometry data in standard format and dimensions. The standardized body shape 

data will be summarized by a vector of principal components, which can quantitatively characterize and categorize a 

person’s body shape. Computational mapping between the principal components and CAD manikin geometry will 

then be defined, enabling reconstruction of CAD manikins from the anthropometry of individuals in the Astronaut 

Anthropometry Database. A statistical model will be also developed to reconstruct a CAD manikin for an arbitrary set 

of anthropometry parameters, which can fill in the gaps in the Anthropometry Database. Further the model can 

generate body shapes by cross-mixing, combining and permuting the characteristics of multiple individual 

crewmembers, which will help to simulate and investigate “what-if” scenarios.

3. EVA Suit Sizing and Fit Studies

It is understood that the sizing of certain critical dimensions of EVA suits relative to critical anthropometric 

dimensions of the human inside the suit will affect the fit of that human in that suit. During development of the Space 

Suit Assembly Enhancements, crewmembers reported sensitivities to changes in arm length of 6 mm (1/4 inch); 

changes in sizing smaller than that were not discernable by the crew. Suit fit sensitivity is also likely to differ between 

microgravity and planetary EVA environments. However, the sensitivity of suit fit with respect to suited health and 

performance outcomes has not been systematically characterized for microgravity or planetary environments. This 

data is necessary to inform the degree of customization that must be provided by spacesuits, including spares, to ensure 

that inadequate suit fit will not affect human health and performance outcomes, including accommodation for the 

potential impact of in-flight anthropometric changes. Suit fit sensitivity characterization will also enable definition of 

test subject selection criteria to mitigate suit fit as a potentially confounding factor in EVA research studies for which 

a very limited degree of suit sizing is typically available. An accurate model may also reduce the fit check iterations 

necessary to obtain an acceptable suit fit.

This study will use the benchmarking methodology and a repeated-measures study design with varied suit sizing. 

The same test subjects will perform the same benchmarking tasks in the same suit, but with the variable that the suit 

will be sized differently on each occasion, with sizing being initially based on predictions from the Suit Sizing and Fit 

Model. Suit fit will be assessed for the suit’s critical suit fit dimensions (e.g., heel-to-shoulder, crotch-to-shoulder, 

etc.) using the Objective Suit Fit methodology and subjective suit fit ratings, while performance decrements will be 

assessed using the benchmarking methodology. Data will be used to validate the Suit Sizing and Fit Model and will 

enable definition of the range of values for critical suit fit dimensions that provide acceptable suited health and 

performance outcomes. All primary testing is expected to occur in 1-g and ARGOS with a subset of validation data 

points collected during NBL and parabolic flight testing, if available. 

Human-Suit Interaction Sensors as well as manloads sensors will also be incorporated into testing, if practical, 

which would enable characterization of the relationship between suit fit, performance, injury/trauma risk, and 

manloads. Initial pilot testing using the MIII suit are being performed at JSC in collaboration with the Massachusetts 

Institute of Technology. In this evaluation, a decomposition of loads is examined to assess the self-supported load of 

the suit transferred to the ground, the load transferred to the human through the designed straps, and the load 

transferred through other interaction locations. This evaluation examines four levels of indexing to inform on the 

differences in load transfer and measures of performance.

Up to three Suit Sizing and Fit studies are proposed. The first would use the existing EMU, which would ensure 

that the Proteus Suit Sizing Model and the Objective Suit Fit methods have been developed to enable prediction and 

quantification of suit fit for test subjects. Results are expected to precede the NextGen suit Critical Design Review by 

1-2 years. A second study will be conducted following delivery of the NextGen suit, results of which are expected to 

inform the quantities and sizes of suit components and spares necessary to support ISS and future exploration missions. 

The second study will also evaluate suit sizing and fit sensitivity for a prototype planetary suit configuration and is 

expected to be followed by a third study after delivery of the NextGen-2 planetary suit. 

4. In-Flight Anthropometry Changes

Changes in anthropometry occur during spaceflight due to fluid shifts, spinal elongation, and changes in body 

composition. These changes are known to affect suit fit, and on-orbit fit checks are required prior to EVAs on ISS to

ensure acceptable fit. Ensuring acceptable suit fit during all phases of exploration missions requires that 

anthropometric variability be predicted and accommodated within the suit design and sizing strategy. 

A study titled Body Measures is currently underway onboard ISS, and will continue in FY17, that measures inflight changes in anthropometry using measurements of critical suit sizing parameters. In-flight physical changes due 

to neutral body postures (NBP) and the associated spinal elongation effect on NBP during extended exposure to 
17

microgravity are also being quantified. The study involves collecting anthropometric data using standard equipment 

(anthropometer, tape measure, weight scale), video imaging (digital still photographs and video), and a 3d whole body 

scanner to measure changes in body shape, size and posture during space flight.

Pre-flight, in-flight, and post-flight anthropometry data from the Body Measures study will be incorporated into 

the Proteus Suit Sizing and Fit Model. Although no data exists for anthropometric changes in lunar or Martian gravity, 

it is expected that earth gravity and microgravity represent the two bounding cases. 

5. Astronaut and Test Subject Anthropometry; Scanner Validation

As the Consolidated Center for Astronaut Anthropometric Data, the ABF is solely responsible for extracting all 

vital and critical anthropometric measurements that are necessary for vehicle, suit, Soyuz, Extravehicular Mobility 

Unit (EMU), glove design, verification purposes, and other analyses and data requests. The data collected allows the 

ABF to obtain and maintain an anthropometric database that can be used for population analyses, univariate and 

multivariate analyses, volumetric data analyses, and, when requested, in releasing data as per the guidelines set forth 

in the ABF CPHS Master Protocol.

A 3dMD scanner system based on photogrammetry is an alternative to the current laser scanner(s) used by the 

ABF, and is anticipated to expedite the collection and post-processing of anthropometric data from test subjects and 

astronauts. Prior to implementation, the 3dMD system must be certified for use. This task consists of comparing scans 

in the 3dMD and Human Solutions laser scanners, and ensuring that the system preserves the level of accuracy of the 

current hardware, while streamlining data collection and processing. A new protocol and procedure(s) will be 

developed to perform data collection and data extraction of anthropometric measurements using the 3dMD system. 

H. Injury Risk & Mitigation

Tasks in this section are relevant primarily to the EVA SMT Pressure Garment System Gap and the HRP EVA 

Gap 11: How do EVA operations in exploration environments increase the risk of crew injury and how can the risk 

be mitigated?

1. EVA Biomechanical Model

The EVA Biomechanical Model will combine suit geometry and customized anthropometric manikins from the 

Suit Sizing and Fit Model, while also incorporating musculoskeletal modeling and finite element modeling (FEM) to 

predict human-suit interaction forces, pressure distributions, manloads, bearing loading, and crewmember injury risk 

for different combinations of subjects, tasks, suit designs, and suit sizes. Extending the manikins used for Suit Sizing 

and Fit with dynamic properties (i.e., bearing resistance torques, inertias) enables a dynamic motion analysis, 

permitting an understanding of the added torques (e.g. due to bearing design 21) and a decomposition of the overall 

joint torques to quantify the effect of design decisions22 . Converting the solid model to finite element model permits 

estimating the location and magnitude of the interaction forces. These interaction forces can then be input into a 

musculoskeletal model to estimate joint torques, muscle activation, and metabolic expenditure. Initially, the model is 

expected to assist with identification and mitigation of injury mechanisms for the EMU, including development of the 

Second Generation Suit Trauma Countermeasures; application will also extend to informing development and 

operation of the NextGen suit. For example, the effects of bearing torques versus inertial torques due to lower-body 

kinematics may be estimated, optimized, and fed back into suit design22. In this manner, the EVA Biomechanical 

model can leverage the kinematic trajectories of the human from the ConOps study (Section D.1) to determine the 

effect on human performance in a way that is not possible experimentally, extending what is understand about the 

human-suit system. These models can be validated with data collected through human studies with select suit designs, 

such as from the Benchmarking studies. Once validated, these models could be embedded within an optimization 

framework to determine specific design parameters. 

This study will seek to leverage and complement ongoing work at JSC and in academia and will use data collected 

during the Human-Suit Interaction Sensors Assessment study (Section F.1) to validate model predictions. Once 

available, the comprehensive human-suit interaction data set from the Suit Sizing and Fit study (Section G.3) will be 

used to validate the biomechanical model for the NextGen suit. 

2. EVA Suit Occupational Surveillance

A critical element in future EVA risk and injury mitigation efforts is the systematic collection and archiving of 

suit occupational surveillance data. Specifically, data regarding the suit used, how it was sized, assessment of suit fit, 

tasks performed, the person using the suit, any existing health conditions, and any discomfort, trauma, or injuries that 

result from suit exposure. This data has been collected with varying levels of consistency in prior years. Previous data 

mining efforts have provided valuable insights23, 24, but have been limited by inconsistent and incomplete datasets. A 
18

task is currently underway to implement a standard tracking questionnaire, database, and process for the systematic 

collection of this data for all EVA suit exposures including testing, training, and flight EVAs. 

The data collected will be continually analyzed and used to identify potential injury mechanisms and predictors of 

negative health consequences. Over time, the data will also be used to assess the efficacy of countermeasures as they 

are implemented in the form of modifications to hardware, training, and/or operations. 

3. Historical EVA Health Data Mining

An ongoing study has been using existing data on EVA-related injuries and suit trauma from the Longitudinal 

Survey of Astronaut Health (LSAH) and combining that data with anthropometry, shoulder anatomy, strength, and 

range of motion data, where available. The focus of the study to date has been limited to predictors of EMU shoulder 

injury, but the scope is planned to increase to look at a broader dataset. This study in FY17 will expand upon the 

previous anthropometric evaluation with the goal of comparing the anthropometry results and additional information 

from LSAH, such as suit experience at time of injury, type of injury, suit sizing, and task being performed when injury 

occurred. The ABF will look at the human factor characteristics of the injury, anthropometry, volumetric factors, 

shoulder anatomy, strength, range of motion, and suit experience to determine whether risk factors for injury can be 

identified that may indicate increased likelihood of shoulder injury during EVA training and operations.

4. NBL Ergonomic Assessments and Metabolic Rates

To prepare for mission operations, astronauts perform a significant 

amount of training in the NBL while wearing the EMU. Previous 

investigations have correlated EMU operations and astronaut 

injury, but the relationship between injury risk and the types and 

durations of work being performed during EVA training is not well 

understood. 

Ergonomists began conducting subjective assessments of 

ergonomic risk factors during a limited number of NBL training 

runs during 2015-16 including analyses on ergonomic risk 

exposures to crewmembers and job analyses of time spent 

performing various common tasks. Ergonomic assessments will 

continue in 2017 and are expected to additionally include 

quantitative metrics of crew performance including pre- and postNBL run measures of mobility, strength, and rate of perceived 

exertion. If feasible, in-water assessment of functional strength and 

other measures will also be performed (Figure 8). Metabolic rate 

data is also routinely collected during NBL training runs as a requirement for EVA medical monitoring, and this data 

will be combined with the other ergonomic assessment data to further understanding of crew exertion during common 

training operations. 

Results are expected to lead to recommendations for reducing crew injury risk. Additional resources may also be 

directed towards ergonomic training for NBL Divers and Crewmembers to aid in identification of activities with an 

increased potential for injury risk.

5. Planetary EVA Injury Mechanisms

Although there is some familiarity with the type of injuries that occur during microgravity EVA, there is limited 

knowledge of how operation in a planetary suit may expose a crewmember to injury risk. The Planetary EVA Injury 

Mechanisms task will attempt to anticipate the types of injuries that may result from planetary EVA through a 

combination of occupational surveillance data mining, ergonomic assessments, and predictions from the EVA 

Biomechanical Model (Section H.1). In support of this over-arching task, the Lumbar Kinematics task during FY17 

will attempt to develop a method for collecting lumbar kinematic data using a matrix of fabric strain sensors and a 

series of retro-reflective markers attached to the lumbar region of the back in various configurations. Subjects will 

perform prescribed movements (lumbar flexion, lumbar extension, right and left lateral flexion, right and left rotation). 

The kinematic measurements from the fabric strain sensors will be cross validated with a reference motion capture 

system. The analysis will be focused in particular on the complex motion types using multiple lumbar joints.

6. Second-Generation Suit Trauma Countermeasures 

HRP solicited for proposals to develop and a test a second generation suit trauma countermeasure in a 2015 Human 

Exploration Research Opportunities (HERO) announcement (NNJ15ZSA001N-FLAGSHIP). It is expected that the 

Figure 8. Example of in-water assessment of 

functional strength at the NBL. 
19

work will be performed by a research team from the Univerity of Colorado – Boulder and the Massachussets Institute 

of Technology during FY2017 and FY2018. The task will involve the design, build, and test of a garment that is 

intended to improve health and comfort outcomes for EVA crewmembers during training and flight without 

unacceptable decreases in functional performance. The content of the project has the potential to leverage and 

complement multiple other studies described in this plan. 

IV. Maintaining and Executing the Plan

The Integrated EVA Human Research Plan presented here is intended as a tool to facilitate collaboration and 

coordination on human-in-the-loop EVA research. Representation of all appropriate stakeholders in the definition, 

prioritization, planning and execution of research activities is essential to accomplishing the over-arching objective. 

Coordination with stakeholders outside of the EVA Office, CTSD, and HRP is already in effect on a study-by-study 

basis; however, closer coordination on multi-year planning with other EVA stakeholders, including academia, is being 

actively pursued.

Given the dynamic nature of NASA organizations, budgets, and priorities, it is understood that this plan must be 

continually reviewed and revised in order to remain useful. As specified in the formal framework of collaboration that 

led to creation of this plan, representatives of the EVA Office, HRP EVA Discipline, and CTSD will review the plan 

on an annual basis and make updates as necessary. The plan will also directly inform budget planning and prioritization 

for the respective organizations. It is intended that updates to the plan be made publicly available each year, either 

through publication on a NASA website and/or through publication and presentation at a national or international 

conference. 

External peer-review panels will continue to review and provide input to the multi-year plan for HRP-funded EVA 

research (the “Path to Risk Reduction”), and detailed proposals associated with each individual HRP-funded study 

described in the plan will also be submitted and subjected to external peer-review. Studies that require the unique 

facilities and expertise available at NASA JSC, as determined by HRP management, will be performed as directed 

studies, meaning that they will be led from JSC but will still allow for external collaborators and will still be subject 

to external peer review prior. All other HRP-funded studies will be competed through research announcements. 

As studies are performed, updates will be made to the EVA Evidence Report, results will be presented to NASA’s 

Human Systems Risk Board (HSRB), EVA Configuration Control Board, and to external standing review panels

(SRPs) during regularly scheduled reviews. Updates will be made to the EVA risk classification via the HSRB where 

results are determined to have reduced or closed knowledge gaps.

Appendix

SMT Gap 

Name

Description

Pressure 

Garment

System (PGS)

Need new lightweight pressure garment for walking and other exploration tasks. Need new pressure 

garment to accommodate full 5th to 95th percentile anthropometric range while having adequate 

space for inherently required services (PPRV, Purge Valve, DCU mounting, Umbilical Attachment, 

etc.). Need new pressure garment which is designed to latest understanding of crew injury data 

(glove and shoulder are greatest concerns). Need new pressure garment which is compatible with 

frequent ingress/egress method (i.e., pressurized donning and 8 psi compatible, e.g., suit port). 

Need new pressure garment which is cut and puncture resistant and/or which can self-heal after 

sustaining damage. Need a pressure garment which is designed to function in the relevant 

environments (gravity, dust, radiation, thermal, plasma, etc.). Need durable pressure garment to 

meet DRM EVA models. Need durable boot design which can accommodate dust and integrates 

ankle/hip bearings to accommodate walking. Frequently solutions for one gap tend to negatively 

impact other areas.

Ventilation Need an improved helmet vent inlet that washes CO2 from the oral/nasal area of the suited astronaut, 

resulting in possible reduction to fan speed and reduced power which would result in mass savings 

and/or longer duration EVAs.

Anthropometry 

– Minimum 

suit size

Need a suit that accommodates fifth percentile crewmember dimensions (minimum) and still 

accommodates all system required services (purge valve, umbilical services, display/control unit, 

positive pressure relief valve, etc.). 
20

Gloves I Need improved moisture removal from glove region to improve comfort and reduce finger & hand 

trauma. 

Need Cut and puncture resistant gloves. Abrasion resistant surfaces need longer life cycle than 

current. Glove is susceptible to cuts, need restraint and bladder materials which can self-heal after 

being cut or punctured. 

Need hand heating that covers a more appropriate region of the hand (current heaters are fingertip 

only). Need glove with more thermal protection for wider range thermal environment at each 

destination without compromising mobility.

Gloves II Need glove design that minimizes impact on hand strength and mobility (phase VI glove reduces 

both by 75%). Need improved glove fit and design to increase flexibility of the metacarpal joint. 

Loss of mobility is measured by glove sweep volume. Need glove design for fine motor tasks. 

Hydration Need a reusable drink bag that is not susceptible to biological build-up and that requires limited 

maintenance between EVA uses, to decrease the amount of logistics during long duration missions.

Biomedical 

Sensors

Need a radiation hardened, wearable biomedical system that does not require the crew to shave or 

crew time to don. 

Displays & 

Controls; 

Information 

Systems

Need a radiation tolerant graphical display that is compatible with the suit (either 100% O2

compatible and inside the PGS –OR- compatible with the helmet & visors). 

Need to develop an informatics storage/processor system to provide the information to the display. 

Desire a hands-free user input device to control the informatics system. This device could consist 

of a speech recognition system with a minimum of 95% accurate word identification.

Integration: Need to integrate all of the above into a system.

Incapacitated 

Crewmember 

Rescue

Integration, Need to develop methodology for transfer/transport of an incapacitated crewmember 

at each destination and how to transfer crewmember onto the ingress/egress hardware, or through 

side hatch, and doff suit. 

Knowledge: Rescue protocol has not been identified for each destination. Determine how to 

address rescue of incapacitated crewmember on single person EVA scenarios. How does a 5th

percentile strength crewmember rescue a 95th percentile mass crewmember?

Suit Sizing Knowledge: Need program and mission definition to determine PGS sizing strategy (ISS style suit 

resizing vs custom suit for each CM). 

References

1NASA Strategic Plan 2014. 2014, National Aeronautics & Space Administration, Office of the Administrator: 

http://science.nasa.gov/media/medialibrary/2014/04/18/FY2014_NASA_StrategicPlan_508c.pdf.

2Craig, D.A., N.B. Herrmann, and P.A. Troutman. The Evolvable Mars Campaign - study status. in Aerospace Conference, 

2015 IEEE. 2015.

3Abercromby, A.F., et al., Human Exploration of Phobos, in IEEE Aerospace Conference. 2015: Big Sky, MT.

42015 NASA Technology Roadmaps. 2015 [cited 2016 February 15]; Available from: 

http://www.nasa.gov/offices/oct/home/roadmaps/index.html.

5Human Research Program EVA Risk: Path to Risk Reduction. 2015 [cited 2016 February 18]; Available from: 

http://humanresearchroadmap/schedules/?i=84.

6Chappell, S.P., et al., Risk of Injury and Compromised Performance Due to EVA Operations. Human Research Program 

Evidence Report, 2015.

7Abercromby, A.F.J., J.R. Norcross, and S.L. Jarvis, EVA Human Health and Performance Benchmarking Study, in Human 

Research Program Investigators' Workshop. 2016: Galveston Island Convention Center.

8Valle, P., et al., Active Response Gravity Offload System, in NASA Tech Brief MSC-24815-1/24-1. 2011.

9Abercromby, A.F.J., J. Conkin, and M.L. Gernhardt, Modeling a fifteen-minute extravehicular activity prebreathe protocol 

using NASA's exploration atmosphere (56.5 kPa / 34% O2). Acta Astronautica, 2015(0).

10Law, J., S. Watkins, and D. Alexander, In-flight carbon dioxide exposures and related symptoms: association, susceptibility, 

and operational implications. NASA Technical Paper, 2010. 216126.

11Glatte Jr, H., G. Motsay, and B. Welch, CARBON DIOXIDE TOLERANCE STUDIES. 1967.

12Lambertsen, C., Carbon dioxide tolerance and toxicity. 1971, PENNSYLVANIA UNIV PHILADELPHIA SCHOOL OF 

MEDICINE.

13Korona, F.A., et al., Carbon Dioxide Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit.

2014.

14Mitchell, K. and J. Norcross. CO2 washout testing of the REI and EM-ACES space suits. in 42nd International Conference 

on Environmental Systems, San Diego, CA. 2012.

15Meginnis, I.M., et al., Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit.

2016.
21

16Chappell, S.P., et al., Life Sciences Implications of Lunar Surface Operations. NASA Technical Report, 2010. NASA/TM2010-216138.

17Chappell, S.P., A.F. Abercromby, and M.L. Gernhardt, NEEMO 14: Evaluation of Human Performance for Rover, Cargo 

Lander, Crew Lander, and Exploration Tasks in Simulated Partial Gravity. NASA Technical Report, 2011. NASA/TP-2011-

216152 

18Chappell, S., et al., Access Systems for Partial Gravity Exploration & Rescue: Results from Prototype Testing in an Analog 

Environment. 2007, SAE Technical Paper.

19Anderson, A., et al. In-suit sensor systems for characterizing human-space suit interaction. 2014. 44th International 

Conference on Environmental Systems.

20Pantaleano, M.J. and D.F. Lacey, Satellite Handling Loads on the Shuttle Extravehicular Mobility Unit (EMU) Spacesuit: An 

Examination of the Loads Imparted to the Suit as a Result of Handling Massive Objects in EVA. 1992, SAE Technical Paper.

21Cullinane, C., Rhodes, R., Stirling, L. A Pilot Study Evaluation of Mobility and Agility During Locomotion in the Mark III 

Space Suit Assembly. . Aerospace Medicine and Human Performance, 2017. Accepted.

22Cullinane, C., Rhodes, R., and Stirling, L. Implementation of a Mark III Computational Model to Decompose Hip Joint 

Torques. in Annual Meeting of the Aerospace Medical Association. 2017. Denver, CO.

23Strauss, S., R.L. Krog, and A.H. Feiveson, Extravehicular mobility unit training and astronaut injuries. Aviation, space, and 

environmental medicine, 2005. 76(5): p. 469-474.

24Anderson, A.P., D.J. Newman, and R.E. Welsch, Statistical evaluation of causal factors associated with astronaut shoulder 

injury in space suits. Aerospace medicine and human performance, 2015. 86(7): p. 606-613.