Att J-02 xEVAS System Requirements Document.pdf

National Aeronautics and Space Administration

ATTACHMENT J-02

XEVAS SYSTEM REQUIREMENT DOCUMENT (SRD)

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TABLE OF CONTENTS

SECTION PAGE

1.0 INTRODUCTION

1.1 Purpose

1.2 Scope

1.3 EVA Services Overview

1.4 Change Authority/Responsibility

1.5 System Interface Diagram

1.5.1 ISS Interfaces

1.5.2 Artemis Interfaces

2.0 DOCUMENTS

2.1 Applicable Documents

2.2 Reference Documents

3.0 XEVAS SYSTEM REQUIREMENTS

3.1 General Mission

3.1.1 ISS EVA Capability (RQMT-001)

3.1.2 Lunar EVA Capability (RQMT-003)

3.1.3 EVA Rate (RQMT-004)

3.1.4 EVA Availability (RQMT-005)

3.1.5 Spacecraft Independent Operation (RQMT-006)

3.1.6 Operation with Spacecraft Utilities and Consumable Resources (RQMT-081)

3.1.7 ISS Task Capability (RQMT-007)

3.1.8 Lunar Task Capability (RQMT-008)

3.1.9 Crew Time Allocation (RQMT-009)

3.2 Environments

3.2.1 Destination Environments (RQMT-013)

3.2.2 Lunar Surface Dust Mitigation (RQMT-014)

3.2.3 Lunar Dust Contamination (RQMT-082)

3.2.4 Micro Meteoroids and Orbital Debris Probability of No Penetration (RQMT-015)

3.2.5 Lunar Surface Permanently Shadowed Region (PSR) Minimum Exposure Time (RQMT-083)

3.2.6 Quiescent Stowage (RQMT-084)

3.3 Performance

3.3.1 Suit Habitability (RQMT-016)

3.3.2 Spacesuit Inspired Partial Pressure of Carbon Dioxide (RQMT-085)

3.3.3 Internal Suit Surface Temperatures (RQMT-086)

3.3.4 Trace Contaminants (RQMT-087)

3.3.5 Sound Pressure Level Limits for Continuous Noise (RQMT-088)

3.3.6 Noise Limit for Personal Communication Devices (RQMT-089)

3.3.7 O2 Partial Pressure Range for Crew Exposure (RQMT-090)

3.3.8 Metabolic Rate (RQMT-017)

3.3.9 Suit Accommodation of Metabolic Loads (RQMT-091)

3.3.10 Indicate Pressure (RQMT-018)

3.3.11 Impact Performance – Microgravity (RQMT-020)

3.3.12 Impact Performance – Partial Gravity (RQMT-021)

3.3.13 Visual Capabilities (RQMT-022)

3.3.14 Protection from Ultraviolet and Infrared (RQMT-023)

3.3.15 Ability to Work in Suits (RQMT-024)

3.3.16 ISS Suit Mobility (RQMT-025)

3.3.17 Anthropometry (RQMT-026)

3.3.18 Unassisted Suit Operation (RQMT-027)

3.3.19 Insight and Operability (RQMT-028)

3.3.20 Caution Warning Control System (RQMT-029)

3.3.21 xEVA System-Induced Injury (RQMT-030)

3.3.22 Transmit/Receive Status (RQMT-031)

3.3.23 Airlock Reconfiguration (RQMT-032)

3.3.24 Interface Reconfigurability (RQMT-033)

3.3.25 Standards Compliance (RQMT-034)

3.3.26 EVA System Compatibility (RQMT-092)

3.3.27 ISS EVA Generic Tools and Crew Aids Interfaces (RQMT-035)

3.3.28 Artemis EVA Generic Tools and Crew Aids Interfaces (RQMT-036)

3.3.29 Science Sampling (RQMT-037)

3.3.30 Don/Doff Volume (RQMT-038)

3.3.31 EVA Crewlock Volume (RQMT-039)

3.3.32 xEVA System Consumables Recharge (IVA)(RQMT-093)

3.3.33 Purge Efficiency (RQMT-104)

3.4 Contingency

3.4.1 Emergency Life Support (RQMT-040)

3.4.2 Pressure Garment Breach (RQMT-041)

3.4.3 Microgravity EVA Self Rescue Capability (RQMT-042)

3.4.4 Incapacitated EVA Crewmember Rescue (RQMT-043)

3.5 Safety and Health

3.5.1 General Program Safety (RQMT-044)

3.5.2 Fault Tolerance (RQMT-045)

3.5.3 Tether Points (RQMT-046)

3.5.4 Toxic Substance Cleanup (RQMT-048)

3.5.5 Cut Resistance (RQMT-094)

3.5.6 Shock Hazard (RQMT-095)

3.5.7 Decompression Sickness Prevention (RQMT-049)

3.5.8 Decompression Sickness Treatment Capability (RQMT-050)

3.5.9 Heart Rate (RQMT-051)

3.5.10 Radiation Monitoring (RQMT-053)

3.5.11 xEVA Suit System Body Waste Management (RQMT-054)

3.5.12 In-Suit Nutrition (RQMT-055)

3.5.13 Food Quality and Safety (RQMT-080)

3.5.14 Food Acceptability (RQMT-096)

3.5.15 In-Suit Water Provision (RQMT-056)

3.5.16 NASA-STD-3001 Applicability (RQMT-079)

3.6 Physical Characteristics

3.6.1 xEVA System Mass (RQMT-058)

3.6.2 Interface Requirements Control Documents

3.6.3 Unpressurized Hardware Transfer (RQMT-061)

3.6.4 External Identification of Hardware (RQMT-062)

3.6.5 External Identification of Crew (RQMT-063)

3.6.6 Compatibility with ECLS Systems (RQMT-098)

3.7 Information Management

3.7.1 Suit Engineering Data Storage (RQMT-064)

3.7.2 Information System (RQMT-065)

3.7.3 Vehicle Based Wireless Data Communication for Low Earth Orbit International Space Station (RQMT-066)

3.7.4 Dedicated EVA Radio Frequency Communication for Low Earth Orbit International Space Station (RQMT-067)

3.7.5 Simultaneous Two-Way Communications (RQMT-068)

3.7.6 Voice Mode (RQMT-099)

3.7.7 Hardline Transmit and Receive (RQMT-100)

3.7.8 Audio Feedback (RQMT-101)

3.7.9 Programming Updates (RQMT-102)

3.7.10 Reconfigurable Communication (RQMT-069)

3.7.11 Vehicle-Based Wireless Data Communication for Exploration Destinations Beyond Low Earth Orbit (RQMT-070)

3.7.12 Dedicated EVA Radio Frequency Communication for Exploration Destinations Beyond Low Earth Orbit (RQMT-071)

3.7.13 High-Resolution Video (RQMT-072)

3.7.14 Powered Sensor Interface (RQMT-103)

3.8 Task Management

3.8.1 Microgravity Worksite Lighting (RQMT-073)

3.8.2 xEVA System Partial Gravity Integrated Lighting Capability (RQMT-074)

3.9 Mission Integration

3.9.1 ISS Launch/Return Packaging (RQMT-075)

3.9.2 ISS Launch/Return Allocations (RQMT-076)

3.9.3 ISS Onboard Stowage Allocation (RQMT-077)

4.0 VERIFICATION REQUIREMENTS

4.1 General 71

4.2 Responsibility for Verification

4.3 Verification Methods

4.3.1 Inspection (I)

4.3.2 Analysis/Similarity (A)

4.3.3 Demonstration (D)

4.3.4 Test (T)

APPENDIX A Acronyms and Abbreviations and Glossary of Terms

APPENDIX B xEVAS SRD RQMT-024 Ability to Work in Suits Mobility Matrix

APPENDIX C NASA Standard 3001 Applicability Matrix

List of Tables

Table 2.1-1 Applicable Documents

Table 2.2-1 Reference Documents

Table 3.1.9-1 Crew Time Allotment

Table 3.3.2-1 Spacesuit PICO2 Limits

Table 3.3.5-1 Octave Band Sound Pressure Level Limits (NC-52)

Table 3.3.8-1 Standard Profile Numberical Value

Table 3.3.8-2 Front-End Loaded Profile Numberical Values

Table 3.3.8-3 Aft-End Loaded Profile Numberical Values

Table 3.3.14-1 Minimum Shielding (Filtration) Necessary to Prevent Injury From UV and IR

Table 3.3.17-1 Occupant Measurements

Table 3.5.11-1 Suited Body Waste

Table 3.5.13-1 Food Microorganiism Levels

Table 3.6.1-1 xEVA System Control Masses

Table 3.6.6-1 Chemical Compounds of Concern to ISS ECLS System Hardware and Processes

Table 3.9.2-1 xEVAS SRD RQMT-076 ISS Launch/Return Allocations

Table 4.3-1 Requirements Verification Cross Reference Matrix

Table A1.0-1 Acronyms and Abbreviations

Table B.0-1 xEVAS SRD RQMT-024 Ability to Work in Suits Mobility Matrix

Table C.0-1 NASA-STD-3001 Volume 1 Applicability

Table C.0-2 NASA-STD-3001 Volume 2 Applicability

List of Figures

Figure 1.5.1-1 xEVA System Interfaces to ISS

Figure 1.5.2-1 xEVA System Interfaces to the Human Lander System (HLS)

Figure 3.3.2-1 Example of a Notional EVA PICO2 Profile Evaluated Against the Spacesuit Limits Table24

Figure 3.3.8-1 Standard Profile 1230 BTU/HR [360W] Average

Figure 3.3.8-2 Front-End Loaded

Figure 3.3.8-3 Aft-End Loaded

Figure 3.3.31-1 EMU Reference Dimensions

1.0 INTRODUCTION

1.1 PURPOSE

The purpose of this document is to present the top-level functional, performance, and interface requirements which define the capabilities needed to accomplish Extravehicular Activity (EVA) services to the International Space Station and Artemis Programs. This document constitutes the technical requirements to be implemented by the National Aeronautics and Space Administration (NASA) Exploration EVA Services (xEVAS) contract.

Section 3.0 of this document contains the technical requirements for the xEVAS Contract, which are applicable to every International Space Station (ISS) and Artemis mission unless otherwise noted.

1.2 SCOPE

The scope of this requirements document is to define xEVAS requirements that meet or exceed the capabilities necessary to safely execute missions in Low Earth Orbit (LEO), cislunar space, lunar surface, and beyond. The xEVA System will be required to support safe and efficient EVA operations envisioned by NASA for human space exploration.

The xEVA System includes the spacesuit, tools, and vehicle interface equipment as defined in Figure 1.5.1-1, xEVA System Interfaces to ISS and Figure 1.5.1-2, xEVAS System Interfaces to the Human Lander System (HLS). Requirements applicable across each sub-system element are denoted as “xEVA System shall”. For example, this document includes requirements that drive key suit functions such as life support, but does not include the specific details on requirements for those functions as they are a part of the suit architecture and will be decomposed at the commercial provider level. For some of these requirements, the Government has provided thresholds (minimum requirements) as well as goals. The Contractor shall meet or exceed the thresholds. Goals represent the desired operational performance improvements above the threshold achievable at higher risk in cost, schedule, and technology. The Contractor shall obtain optimum performance between threshold and goal values. If a goal is not otherwise specified, the goal value for performance is the same as the threshold value.

The following summarizes the categories of requirements levied herein:

General Mission: Establishes the fundamental service requirements that drive system capabilities.

Environments: Protect the crewmember during exposure to the full range of environmental and gravitational conditions experienced at LEO, cislunar orbit, and Lunar surface destinations. Incorporate, where appropriate, design flexibility and modularity to allow for efficient incorporation of upgrades. Allow crewmembers to perform EVAs from existing ISS and future airlocks.

Performance: Autonomously sustain the life of the crewmember for a minimum of eight hours.

Safety and Health: Increase crew safety for training and flight operations over legacy systems. Enable effective performance of all EVA-related tasks and activities during training and flight without suit-induced discomfort, injury, or negative health consequences. Expand the range of flight crew anthropometries accommodated while improving mobility, fit, and comfort over legacy systems.

Information Management: Provide enhanced information, communication, and monitoring systems.

Task Management: Provide crew the accommodations to accomplish tasks effectively.

Mission Integration: Minimize crew time, stowage, and launch mass resources as well as design considerations for reductions in required on orbit maintenance activities.

Process based requirements: Multiple requirements call out minimizing or maximizing a given parameter. In these cases, for verification, analysis is expected. The analysis will be of the process the Contractor used throughout design, development, and test phases and how that process achieved the goal of the requirement.

1.3 EVA SERVICES OVERVIEW

NASA seeks to procure EVA as a commercially managed service similar to the approach used in the successful ISS Cargo Resupply Services (CRS), NASA Launch Services (NLS), and Commercial Crew Program (CCP) contracts. The commercial EVA service includes the development and integration of the xEVA System through launch, operations, and return/disposal.

Commercial EVA services provide NASA the capability to perform EVAs with the use of contractor-provided spacesuits, tools and equipment, vehicle interfaces, and support to training and real-time operations. Services includes post-certification EVA services for ISS/Artemis, including delivery/return of EVA hardware to and from the host vehicle, spacesuit unique interfaces to the Airlock including crew interfaces; planning, support for training, operations, and sustaining engineering; spacesuit donning and doffing equipment, tool kits consisting of EVA hardware necessary for the crew to perform microgravity EVAs, support to ground training and testing events at the Neutral Buoyancy Lab and other facilities; and other requirements to support EVA capability and operations. It is currently anticipated that the Government will have requirements for approximately ten ISS EVAs per year and 1 Artemis campaign per year.

NASA’s intent is to transition from the traditional Government-owned hardware model to an “EVA as a Service” model. Using SSP 51073, Exploration Extravehicular Activity (EVA) Suit Systems Requirements Document, as a basis, the pivot to commercial services triggered the need for adapting the requirements to open the design trade space for providers.

1.4 CHANGE AUTHORITY/RESPONSIBILITY

Proposed changes to this document shall be submitted via a Change Request (CR) to the EVA Configuration Control Board (CCB) for consideration and disposition. All such requests will adhere to the EVA Office Configuration Management Change Process documented in EVA-PLN- 012, EVA Office Configuration and Data Management Plan.

The appropriate NASA Office of Primary Responsibility identified for this document is the EVA Office.

1.5 SYSTEM INTERFACE DIAGRAM

1.5.1 ISS Interfaces

FIGURE 1.5.1-1 XEVA SYSTEM INTERFACES TO ISS

1.5.2 Artemis Interfaces

FIGURE 1.5.2-1 XEVA SYSTEM INTERFACES TO THE HUMAN LANDER SYSTEM (HLS)

2.0 DOCUMENTS

2.1 APPLICABLE DOCUMENTS

The following documents include specifications, models, standards, guidelines, handbooks, and other special publications. The documents listed in this paragraph are applicable to the extent specified herein.

TABLE 2.1-1 APPLICABLE DOCUMENTS

Document Number Document Revision/Date

Document Title

EVA-EXP-0035 Baseline 09/12/2018

EVA Tool Catalog

EVA-EXP-0039 Rev A 11/19/2020

Exploration EVA System Destination Environments Specifications

SSP 30256 Rev K 09/10/2020

ISS EVA Standard Interface Control Document (ICD)

SSP 51073/EVA-RD-001 Rev B 12/2019 xEVA Suit System Requirements Document

SSP 51721 Baseline 10/18/2019

ISS Safety Requirements Document

SSP 54004 Rev K 05/26/2021

ISS Interface Definition Requirements Document (IDRD) Blank Book

GP 10023 Rev A 08/23/2019

Gateway Program Safety and Mission Assurance Requirements

JSC 20584 Baseline 09/28/2017

Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

2.2 REFERENCE DOCUMENTS

The following documents contain supplemental information to guide the user in the application of this document.

TABLE 2.2-1 REFERENCE DOCUMENTS

Document Number Document Revision/Date

Document Title

NASA TM - 2003-

212058

09/2003 EMU Shoulder Injury Tiger Team Report

NASA/SP-2010-3407 Rev 1Rev 106/05/2014

Human Integration Design Handbook (HIDH)

NASA-STD-3001, V2 Rev B 09/09/2019

NASA Spaceflight Human-System Standard, Volume 2:

Human Factors, Habitability, and Environmental Health

SA-18-014 02/06/2018 Johnson Space Center Health and Medical Technical Authority (HMTA) Position Regarding Heart Rhythm and Heart Rate Monitoring for the Exploration Extravehicular (xEMU) Project Advanced Extravehicular Activity

Document Number Document Revision/Date

Document Title

Exploration Extravehicular Mobility Unit (AdvEVA xEMU)

SA-18-076 N/A

10/10/2018

HMTA Concurrence with Exploration Extravehicular Activity (EVA) Suit Systems Requirements Document

SLS-SPEC-15 N/A Cross Program Design Specification for Natural Environments

EVA-EXP-0032 Baseline 06/05/2018

EVA-ISS Interface Definition

EVA-EXP-0034 Rev C 04/28/2021

Extravehicular Activity (EVA) Office Exploration EVA System Technical Standards

EVA-EXP-0042 Rev B 10/19/2020 xEVA System Concept of Operations

EVA-EXP-0055 06/28/2019 xEVA Crew Time Assessment Methodology

EVA-EXP-0056 06/25/2019 xEVA System Overview: Inspired CO2 presentation

EVA-EXP-0057 06/25/2019 xEVA System Overview: Anthro Range presentation

EVA-EXP-0058 02/23/2021 Lunar Ejecta

EVA-EXP-0066 06/28/2017 UV/IR Visor Protection xEVA-EXP-0067 Rev A 10/20/2020

HLS xEVAS IRCD

EVA-EXP-0074 06/25/2019 xEVA System Overview: Dust Mitigation

JSC 27181 Rev F April 2003

Space to Space Communications System Specification

SSP 42097 Rev F 06/30/2011

Pressurized Mating Adapter 2 & 3 To U.S. Pressurized Elements (USL to PMA-2) Interface Control Document

SSP 50261 Rev L 09/2017

GGR&C and CCE Overview materials

SSP 50933 Rev D 04/15/2016

IDA to ISS and Visiting Vehicle IRD

SSP 51073 Rev B 12/11/2019

Exploration EVA Suit System Requirements Document

SSP 51073 Change 2 Rev B DRN 11/5/2020

Exploration EVA Suit System Requirements Document - Change 2: Quantify Maximum Rate of Pressure Change

SSP 51073 Change 3 Rev B DRN 11/5/2020

Exploration EVA Suit System Requirements Document - Change 3: Clarify 12-hour Suited Duration

SSP 51073 Change 4 Rev B DRN 3/3/2021

Exploration EVA Suit System Requirements Document - Change 4: Add Higher EVA Pressure Setpoint

Document Number Document Revision/Date

Document Title

SSP 51073 Change 5 Rev B DRN 1/20/2021

Exploration EVA Suit System Requirements Document - Change 5: Lunar Surface Communication

SSP 51073 Change 6 Rev B DRN 3/3/2021

Exploration EVA Suit System Requirements Document - Change 6: Lunar Surface PnP, Board/Panel: xEVAS Systems Panel

SSP 51073 Change 7 Rev B DRN 3/3/2021

Exploration EVA Suit System Requirements Document - Change 7: Lunar Surface Lighting

SSP 51080 Rev A 04/28/2021

DCN Attached xEMU-ISS Interface Requirement Control Document

SSP 57003 Revision M 08/20/2020

External Payload Interface Requirements Document

JSC 39233 (replaced by

SSP 50747)

Rev A 07/01/2009

CTBE IDD (IDD for ISS CTB)

JSC 66695 Rev B 05/21/2019

EVA Office EMU Water Quality Specification

3.0 XEVAS SYSTEM REQUIREMENTS

3.1 GENERAL MISSION

3.1.1 ISS EVA Capability (RQMT-001)

The xEVA System shall provide the capability for a mixed EVA crew complement to perform at least 10 two-person EVAs on ISS per year.

Rationale: Two EVA crewmembers are required to perform an EVA. To maximize operational flexibility, three or more EVA crewmembers will nominally be designated for each ISS Increment as defined in Increment specific IDRDs. Therefore, the capability to select any pairing of the available crew is required.

Planned and unscheduled/contingency must be considered in the 10 EVA total.

Applicability: ISS

3.1.2 Lunar EVA Capability (RQMT-003)

The xEVA System shall provide the capability for a mixed EVA crew complement to perform at least six (6) two-person EVAs on the lunar surface per Artemis mission.

Rationale: Exploration and Science mission objectives require EVAs for mission success.

Capability above six (6) EVAs must be allocated if an HLS vendor design requires EVA for jettison/clean-up or ascent performance mitigation. Note: The definition of an EVA does not change in the sustained architecture. For the purpose of scoping consumables, an EVA is defined as "two suited crew". For sustaining missions with four (4) crew, a four

(4) person EVA may be performed using a 2x2 buddy system and would use two (2) EVAs worth of suit consumables. Initial Artemis sortie missions will be up to six EVAs over a 6.5-day surface mission; Artemis sustaining missions will be longer surface duration with more EVAs.

Applicability: Artemis

3.1.3 EVA Rate (RQMT-004)

The xEVA System shall provide the capability to perform EVAs at rate of at least one EVA every day.

Rationale: Having the xEVA System available at this rate allows for minimizing the time to recover lost ISS capability. EVA operations are fatigue inducing activities for the suited crewmembers. For ISS, five (5) day spacing of EVAs has been established by the Flight Operations Directorate as a minimum duration to allow for crew recovery, EVA prep, and procedure review for subsequent EVAs. However, the xEVA System shall allow for a different pair of crew to perform an EVA in less time. The mission design case is an unscheduled/contingency EVA series to perform United States On Orbit Segment (USOS) critical maintenance. An estimate of the worst-case scenario is four EVAs to perform this critical maintenance.

For Artemis, the lander's length of stay on the surface is one limiting factor for surface EVAs. To maximize the science element of the mission, EVAs need to be performed on a pace of one EVA every day to allow for 6 EVAs for a minimum 6.5-day surface mission.

Applicability: ISS and Artemis

3.1.4 EVA Availability (RQMT-005)

The xEVA System shall be capable of supporting an ISS EVA(s) with two (2) designated crewmembers within 48 hours of notice.

Rationale: Reference SSP 50261, Generic Ground rules, Requirements, and Constraints (GGR&C) and Crew Contingency EVA (CCE) Overview. There are ISS contingencies that limit power, cooling, visiting vehicle traffic, crew rotations, etc. Recovery of ISS capabilities are critical to restore ISS systems and recover from a zero-fault tolerant state.

Applicability: ISS

3.1.5 Spacecraft Independent Operation (RQMT-006)

The xEVA System spacesuit shall sustain the life of the crewmember for a minimum of eight continuous hours of EVA operation independent of vehicle-provided life support functions.

Rationale: Eight hours has been determined to be an acceptable amount of time to complete an objective while considering consumables management and crew day. Intent of this requirement is that the eight-hour clock does not restart if the suit is connected for any reason, such as contamination bake out or consumable top off. This duration is not inclusive of the additional 1-hour contingency capability outlined in RQMT-040. The total suited duration for nominal operations in EVA configuration is 13 hours to account for Pre and Post activities (e.g., total time includes pre-EVA (suit donning, prebreathe, and depress), EVA, post EVA (repress and suit doffing)). This time does NOT account for contingencies such as DCS treatment. Note that for the purposes of this rationale statement it is assumed that the EVA duration is no more than 8 hours, the Prebreathe duration is no more than 3.5 hours, depress is no more than 0.5 hour, repress is no more than 0.5 hour, and no more than 0.5 hour for post EVA (suit doffing). This means that the entire suited duration could be as much as 13 hours and would use a mix of suit and vehicle systems to sustain the life of the crewmember.

Applicability: ISS and Artemis

3.1.6 Operation with Spacecraft Utilities and Consumable Resources (RQMT-081)

The xEVA System spacesuit shall sustain the life of the crewmember while in EVA configuration, drawing consumable resources from the spacecraft.

Rationale: This is intended to ensure the spacesuit can be operated when connected to parent spacecraft, which provides a source of consumables such as vehicle power. A spacecraft is considered to be any host vehicle such as habitats, rovers, landers, as well as orbiting and transit vehicles. This allows for spacesuit operations when the suit does not provide these consumables.

Applicability: ISS and Artemis

3.1.7 ISS Task Capability (RQMT-007)

The xEVA System shall enable all EV-qualified crewmembers to complete:

A. All ISS Contingency EVA Tasks (inclusive of Critical Contingency EVA Tasks) as defined in SSP 54004, ISS IDRD Blank Book, Rev K, section 6.2.4.2 (a), (b) and (c).

Rationale: Suited crewmembers will be required to perform mechanical and maintenance support, transfer, research, and inspection in the ISS microgravity environment. They will need the ability to execute scheduled, unscheduled, and contingency tasks of varying levels of complexity and difficulty, as described in SSP 54004, ISS IDRD Blank Book.

Designers should employ human-centered design processes (reference NASA/SP-2010- 3407, Human Integration Design Handbook (HIDH)) to ensure that user considerations, limitations, and capabilities are integrated into the xEVA System design to maximize end user performance and achieve mission objectives.

Applicability: ISS

3.1.8 Lunar Task Capability (RQMT-008)

The xEVA System shall enable all EV-qualified crewmembers to complete all general Task categories described in EVA-EXP-0042, xEVA System Concept of Operations sections:

4.0 - Exploration EVA and Mission Systems Overview, excluding any Vehicle Loop Mode (VLM) statements and assuming Vehicle Interface Suit Equipment (VISE) functions are provided by host spacecraft; if in conflict with SRD, SRD takes precedence

7.2 - EVA on Moon (initial missions), excluding any Vehicle Loop Mode (VLM) statements and assuming VISE functions are provided by host spacecraft; if in conflict with SRD, SRD takes precedence

Rationale: EVA tasks will include not only those for maintenance, pioneering, etc. but also those that will accomplish science objectives on the lunar surface. These science objectives will include, but are not limited to, handheld photography, general scientific descriptions, sampling using a variety of sampling tools, and science payload deployment.

Applicability: Artemis

Gateway Internal (Section 3.6)

Gateway Induced External Environment (Section 3.7)

Cis-Lunar Space Environment (Section 3.8)

Lunar Surface (Section 3.9)

HLS Internal (Section 3.10)

Rationale: xEVA System must meet their requirements either while exposed to the specified environment (for a planned operating environment) or after exposure to the specified environment (when the xEVA System will not be operated during exposure). Mission phases to which the suit will be exposed to include ground handling and processing, launch and landing, ISS Internal, ISS External, Exploration Mission/Vehicle, cislunar space, and lunar surface environment. Environmental parameters for each mission phase include, but are not limited to structural loading, neutral atmosphere, vehicle atmospheres, thermal effects, plasma, charged particle radiation, electromagnetic radiation, meteoroids, space debris, magnetic field, physical contents, gravitational field, dust, and plumes/thrusters. EVA-EXP- 0039, Exploration EVA System Destination Environments Specifications, also includes environment definitions for Mars Transit, and Mars Surface, but the suit does not need to meet its requirements in these environments except as noted above.

Applicability: ISS and Artemis

3.2.2 Lunar Surface Dust Mitigation (RQMT-014)

The xEVA System shall limit the amount of regolith liberated in the cabin environment to less than 100 grams for each two-crew lunar surface EVA.

Rationale: Extensive work has been done to establish a Permissible Exposure Limit (PEL) for per suit and the expectation that all lunar surface EVAs are conducted with two Acute and Chronic exposures of flight crew to lunar surface regolith. The total value per two-crew EVA in this requirement is established to provide a worst case bounding condition for nominal scenarios so that surface assets such as Human Landers can size Environmental Control and Life Support System (ECLSS) filters and other mitigation features provided by the vehicle can be designed to achieve the relevant Acute and Chronic PELs. 100 grams is based upon an allocation of no more than 50 grams crew. It is acknowledged that this requirement is for nominal scenarios only, contingency events which lead to the termination or abort of a lunar surface EVA will likely reduce or eliminate the time and ability to execute dust mitigation activities. See EVA-EXP-0074, xEVA System Overview: Dust Mitigation for an explanation of the planned approach and methodology to provide a practical and verifiable system-level solution.

3.2.3 Lunar Dust Contamination (RQMT-082)

During EVA operations, the xEVA System spacesuit shall limit the levels of lunar dust particles less than 10 μm in size inside the suit below a time-weighted average of 1.6 mg/m3 during daily exposure periods that may persist up to 7 days in duration.

Rationale: This is an intentional allocation to the suit and when a suit enters the vehicle and is doffed other elements of the xEVA System will address mitigation of lunar dust particles. The intent is to limit the amount of dust that goes in during don/doff and that the interior of the suits does not present a location for the collection of lunar dust that can be inhaled during EVA operations. Lunar dust poses a hazard in addition to that from ordinary particulates. This limit is based on a minimum currently expected permissible limit, as estimated by the Lunar Atmosphere Dust Toxicity Assessment Group (LADTAG) in 2007.

Although the standard is being conservatively applied to all inhalable particles (all particles ≤10 μm), it is most applicable to dusts in the respirable range (≤2.5 μm) that can deposit more deeply into the lungs. Studies show that the particle size of lunar dust generally falls within a range of 0.02-5 μm. Reference NASA-STD-3001, V2 standard V2 6053. This is similar to the intent of the 7-day JSC 20584, Spacecraft Maximum Allowable Concentrations for Airborne Contaminants, value in RQMT-087. The longer-term, such as the seven-day limits, are set to fully protect healthy crewmembers from adverse effects from continuous exposure to specific air pollutants. While conservative from a duration perspective for EVA, the seven-day limits are the shortest duration guidelines set to protect effects of lunar dust and therefore remain the most appropriate. The NASA-STD-3001 V2 standard V2 6053 are more applicable to a six-month Spacecraft Maximum Allowable Concentration (SMAC) value. See EVA-EXP-0074, xEVA System Overview: Dust Mitigation for an explanation of the planned approach and methodology to provide a practical and verifiable system-level solution.

Applicability: Artemis

3.2.4 Micro Meteoroids and Orbital Debris Probability of No Penetration (RQMT-015)

The xEVA System shall provide a Probability of no Penetration (PnP) of 0.9996 (risk odds of 1 in 2500) or better from meteoroids, orbital debris, and lunar surface ejecta while supporting eight hours of two person EVAs on the lunar surface or at ISS (419 km and 51.6 degree inclination for the average day in 2024), utilizing the Orbital Debris Engineering Model Release 3.1 (ORDEM 3.1) model, Meteoroid Engineering Model Release 3. (MEM-3) model, and the lunar surface ejecta model in SLS-SPEC-159, Cross Program Design Specification for Natural Environments.

Rationale: Micro Meteor Orbital Debris (MMOD) presents the largest natural contribution to Probabilistic Risk Assessments (PRAs) for loss of crew or loss of mission while EVA on ISS. “Penetration” for the exploration spacesuit is defined as any size leak of the bladder, or damage to Portable Life Support System (PLSS) or other EMU hardware, that leads to atmosphere leak or early EVA termination (same definition used for the EMU). It should be noted that the primary and secondary oxygen system for the exploration spacesuit will allow crew to survive holes of certain sizes in the bladder, and therefore MMOD penetrations will not necessarily result in a loss-of crew event, although penetrations would typically cause an unplanned EVA termination.

The values provided in the requirement were computed using the existing heritage EMU design and widely accessible models in an upcoming year relevant to the life of NASA’s xEVA System. This approach was taken in lieu of prior efforts which cited EVA MMOD risk on STS-125 in order to provide a new reference datum that is more readily accessible for future risk comparisons. Additional details are provided in EVA-EXP-0058: Lunar Ejecta.

Applicability: ISS and Artemis

3.2.5 Lunar Surface Permanently Shadowed Region (PSR) Minimum Exposure Time

(RQMT-083)

The xEVA System shall function nominally during and after exposure to at least 2 hours of the thermal environment of Permanently Shadowed Regions (PSR) of the lunar surface as specified in EVA-EXP-0039, Exploration EVA System Destinations Environment Specifications.

Rationale: Two hours is provided as a bounding case for lunar surface missions conducting EVA tasks within a PSR. The time duration is a balance between the harsh environment vs.

minimum viable time to do meaningful tasks. This length of time includes the time in shadow to enter and leave the PSR.

Applicability: Artemis

3.2.6 Quiescent Stowage (RQMT-084)

The xEVA System shall meet all requirements after being stowed in the internal vehicle environments defined in EVA-EXP-0039, Exploration EVA System Destinations Environment Specifications, in quiescent mode for a Threshold duration of 210 days with a Goal duration of three years without any services or human interaction.

Rationale: Equipment must function properly after being exposed to vehicle stowage environments and not operating. Equipment should not need periodic maintenance to satisfy this requirement. This requirement presents the capability to pre-position xEVA System hardware or survive long duration exploration transits. Two years is selected for current exploration DRMs to Lunar Distant Retrograde Orbit (LDRO). Quiescent stowage is included in the post-launch service life and is not intended to be considered as an addition.

It is intended that this be applicable to the period of time between launch and first use as well as after first use. However, special tasks not associated with nominal maintenance or EVA prep and post time allocation in RQMT-009 may need to be conducted in order to return a used suit to an appropriate configuration for quiescent stowage and to prepare it for reuse by crew following quiescent stowage.

3.3 PERFORMANCE

3.3.1 Suit Habitability (RQMT-016)

The xEVA System shall provide the crew with a safe and habitable environment within the spacesuit.

Rationale: A comfortable, breathable environment is critical to crew safety and habitability for suited crewmembers during EVA and is essential to achieving maximum productivity while executing mission objectives. The spacesuit system needs to be robust enough to regulate internal atmospheric quality and temperature within physiological ranges while ensuring adequate communications.

Applicability: ISS and Artemis

3.3.2 Spacesuit Inspired Partial Pressure of Carbon Dioxide (RQMT-085)

The xEVA System spacesuit shall nominally limit inspired partial pressure of CO2 (PICO2) to within all the criteria defined in the Spacesuit PICO2 Limits Table 3.3.2-1.

Rationale: Spacesuit design and crewmember metabolic rate and other human factors affect the extent to which CO2 accumulates and is inspired by crewmembers inside a spacesuit.

Excessive levels of inspired CO2 can lead to elevated blood CO2, known as hypercapnia, which can cause adverse health and performance effects. The (PICO2) in this requirement is defined as the Time-Weighted Average (TWA) Partial Pressure Carbon Dioxide (ppCO2) measured at the mouth during inspiration and accounting for absolute pressure. Spacesuit PICO2 Limits Table values are based on utilization of a specific standardized human-in-the-loop test methodology for quantification of spacesuit inspired CO2 (Bekdash et al, 2018) and not based on measured ppCO2 at the spacesuit ventilation inlet since imperfect helmet washout of exhaled CO2 adds to the inspired ppCO2 concentration and increases the actual

PICO2.

This requirement is based on a comprehensive review and community discussion of existing industry standards, literature data, and a detailed characterization of terrestrially inspired ppCO2 in 19 human subjects in the EMU spacesuit (Bekdash et al, 2018; Bekdash et al, 2017;

Bekdash, EVA EMU Panel, 7/24/18). The terrestrial characterization data were then used to model predicted PICO2 from a data set including 138 flight EVAs and 205 Neutral Buoyancy Laboratory (NBL) training runs to characterize historically experienced PICO2 levels in the EMU. These data, in combination with the successful completion of more than 450 EVAs using the EMU and absence of any identified symptoms directly attributable to CO2 during these EVAs, suggest a very low likelihood of adverse acute hypercapnia symptoms at or below the levels for the given duration limits defined in the Spacesuit PICO2 Limits Table. The allowable CO2 concentration at the inlet to the spacesuit is not specified in this requirement.

However, as a point of reference, the inlet ppCO2 for the EMU spacesuit is ≤ 2.0 mmHg, which is analogous to and consistent with standards for ambient atmospheric CO2 in habitats.

3.3.4 Trace Contaminants (RQMT-087)

The xEVA System spacesuit shall control accumulation of gaseous pollutants in the suit produced by metabolic loads, system sources, and material off-gassing so that the total toxic hazard index (T value) is maintained below 1.0 unit during crewed activities based on the seven-day SMACs defined in JSC 20584, Spacecraft Maximum Allowable Concentrations for Airborne Contaminants.

Rationale: Airborne exposure limits for individual trace chemical contaminants and methods for assessing exposure to trace contaminant are defined to protect crewmembers from illness and injury. The SMACs provide guidance for short-term (1 and 24 hours), medium-term (7 and 30 days), and long-term (180 days and 1000 days) exposure to individual trace chemical contaminants. Short-term SMACs are designated as emergency SMACs and are intended to be used in emergency situations, such as accidental spills or fire. Medium and long-term SMACs are guidance levels intended to avoid adverse health effects, either immediate or delayed, and to avoid degradation in performance of crew after continuous exposure for the designated duration. The SMACs also consider unique factors for human space flight including the stress on human physiology, uniform good health of astronauts, and the absence of pregnant or very young individuals. The toxic hazard index, or total T-value, is the sum of the ratios of each predicted/measured pollutant concentration to the respective limit from JSC 20584. See EVA- EXP-0034, Extravehicular Activity (EVA) Office Exploration EVA System Technical Standards, for further data supporting derivation of metabolically generated contaminants.

Applicability: ISS and Artemis

3.3.5 Sound Pressure Level Limits for Continuous Noise (RQMT-088)

The xEVA System spacesuit shall limit the suit induced Sound Pressure Levels (SPLs), created by the sum of all simultaneously operating equipment, averaged over any 20-second measurement period inside the spacesuit, at the crew-member’s ears to the values in Octave Band Sound Pressure Level Limits Table or less, within each of the specified octave bands during all mission phases except launch and entry.

TABLE 3.3.5-1 OCTAVE BAND SOUND PRESSURE LEVEL LIMITS (NC-52)

Band Center Frequency (Hz) 63 125 250 500 1k 2k 4k 8k 16k

SPL (dB) 72 65 60 56 53 51 50 49 48

Rationale: This NC-52 requirement will limit noise levels within spacesuits to allow for adequate voice communications and habitability during mission operations. The octave band sound level limits from 63 Hz to 8 kHz are equivalent to NC-52 and the 16-kHz octave band has been added to extend the range throughout the audible frequency range. This requirement does not apply to alarms, communications, approved intermittent noise sources, or to any noise experienced during maintenance activities. The noise attenuation effectiveness of hearing protection or communications headsets may be used if this equipment is included in the nominal spacesuit design. This limit does not apply to impulse noise.

Reference NASA-STD-3001 V2 standard V2 11009.

Applicability: ISS and Artemis

3.3.6 Noise Limit for Personal Communication Devices (RQMT-089)

The xEVA System spacesuit shall limit the maximum A-weighted sound level at the crewmember’s ear created by a personal communication device to 115 Decibel a-Weighted (dBA) or less.

Rationale: Sound levels above 115 dBA have been shown to produce noise-induced hearing loss. Sound levels produced by personal communication devices can be at higher levels to overcome the noise generated during launch and descent. Volume controls will be included to allow for limiting the crews' noise exposure. A personal communication device may be an integrated part of the EVA helmet or an independent communication system. NASA-STD- 3001, V2 standard V2 6106.

Applicability: ISS and Artemis

3.3.7 O2 Partial Pressure Range for Crew Exposure (RQMT-090)

The xEVA System shall maintain inspired oxygen partial pressure (PIO2) of >149 mmHg in accordance with Suit Atmosphere Composition of FiO2 >95% oxygen atmosphere.

Rationale: The use of highly enriched or pure oxygen atmospheres for suited operations is a critical component of decreasing DCS risk to acceptable levels when combined with effective prebreathe protocols. Enriched oxygen also allows for lower suit pressures to be adopted to facilitate mobility and dexterity needed for the timely completion of EVA tasks without unacceptable crew fatigue and injury historically imparted by pressure suits at higher pressures. Finally, the normoxia PIO2 limit of 149 mmHg is a higher limit than the 127 mmHg permissible hypoxia limit allowed for IV exploration atmospheres due to the high risk nature of EVAs driving the need to preserve crew cognitive and aerobic performance (see NASA-STD-3001, V2, Rev B, V2 6003).

Applicability: ISS and Artemis

3.3.8 Metabolic Rate (RQMT-017)

The xEVA System shall accommodate the nominal metabolic profile as outlined in the following figures/tables: Standard Profile, Front End Loaded, and Aft End Loaded with an average metabolic rate of 351.68 W (1200 BTU/hr) for a duration of eight hours with up to a total of 30 minutes of rest inserted into the profile as needed over the course of the eight-hour EVA.

Rationale: The suit must be capable of providing variable and controllable heat rejection and carbon dioxide scrubbing equivalent to the levels defined in the three Metabolic Profile Figures: Standard Profile, Front End Loaded, and Aft End Loaded. The increase in metabolic load profile for the suit can be explained by the increase in metabolic loading seen on ISS EVAs. As EVAs evolve and become more complicated, metabolic rates have often exceeded the Metal Oxide (METOX) certification levels on ISS EVAs. Additionally, with a terrestrial (walking suit) it would be expected that metabolic rates can be higher than seen with microgravity suits. Consistent metabolic rates across gravity conditions ensures operational margin for expected lower metabolic rates experienced during microgravity EVA.

Heat rejection capabilities need to consider the suit's ability to remove a heat load from the crew member and dissipate that heat.

Applicability: ISS and Artemis

Figure 3.3.8-1 STANDARD Profile 1230 BTU/HR [360W] Average

TABLE 3.3.8-1 STANDARD PROFILE NUMBERICAL VALUE

Time (min) Qmet (BTU/hr) Qmet (W) 0 1025 300

30 1332 390 90 273 80

140 2493 730 155 1332 390 210 2049 600 240 1025 300 270 1332 390 330 2493 730 345 273 80 390 1332 390 460 1981 580 480 1981 580

FIGURE 3.3.8-2 FRONT-END LOADED

Note: This profile provides heavy loading at the front end of an EVA profile in order to simulate a difficult egress followed by labor intensive tasks near the beginning of the EVA. Some technologies, such as Lithium Oxide (LiOH) and METOX have difficulty with this type of profile if adequate water loading of the canisters is not achieved during the lower metabolic rate pre-EVA sequence.

TABLE 3.3.8-2 FRONT-END LOADED PROFILE NUMBERICAL VALUES

Time (min) Qmet (BTU/hr) Qmet (W) 0 1025 300

30 2493 730 50 2049 600

120 2254 660 140 1332 390 210 854 250 260 1434 420 270 854 250 310 683 200 345 273 80 390 854 250 460 1229 360 480 1229 360

FIGURE 3.3.8-3 AFT-END LOADED

Note: The aft end loaded metabolic profile will highlight issues with technologies of finite capacity relative to the specifications with particular interest to Partial Pressure Carbon Dioxide (PPCO2) removal. A finite scrubber bed such as LiOH and METOX will trend towards break-through with a profile close to the specified performance requirements and with a reduced number of reaction sites, will trend the PPCO2 levels with the metabolic rate.

TABLE 3.3.8-3 AFT-END LOADED PROFILE NUMBERICAL VALUES

Time (min) Qmet (BTU/hr) Qmet (W) 0 1025 300

60 1366 400 90 854 250

160 273 80 200 1639 480 210 1195 350 260 683 200 290 1639 480 320 1195 350 345 2493 730 365 1366 400 450 2049 600 480 2049 600

3.3.9 Suit Accommodation of Metabolic Loads (RQMT-091)

The xEVA System spacesuit shall accommodate crew metabolic loads provided in RQMT-017, Metabolic Rate, during all suited phases while maintaining a core body temperature between 36.1 °C and 38.06 °C (97 °F and 100.5 °F).

Rationale: Metabolic loads, in conjunction with the operational concept, provide an upper bound for oxygen (O2) demand, carbon dioxide (CO2) production and heat rejection requirements. This information is vital for spacesuits design. The performance focuses on cooling effectiveness, because core body temperature regulation is critically important to prevent heat-related illnesses. Guidance on the use of metabolic load data in the design process can be found in Section 4.11 of JSC 65995, EVA Office EMU Water Quality Specification. Heat load (increased core temperature and the consequent skin vasodilation) can cause a variety of human system issues.

Applicability: ISS and Artemis

3.3.10 Indicate Pressure (RQMT-018)

The xEVA System spacesuit shall indicate to the suited crewmember the internal pressure of the suit without the use of power.

Rationale: Internal suit pressure is considered a critical operating parameter and must be available to the crew during any suited pressurized operation.

Applicability: ISS and Artemis

3.3.11 Impact Performance - Microgravity (RQMT-020)

The xEVA System spacesuit shall not fail catastrophically following impact with a two-inch diameter steel ball when crewed, when operating at nominal EVA pressure, in microgravity, and translating at 0.43 m/s (1.4 ft/sec).

Rationale: This requirement ensures that the spacesuit will not fail catastrophically following an impact with structure during microgravity EVA. The two-inch sphere is consistent with the impact geometry assumed for the Shuttle/ISS EMU. To avoid replanning of EVA timelines, it is desired to retain the current EVA crew manual translation rates and ISS robotic arm assisted translation rates regardless of the suit configuration worn during translation. As of the writing of this document, the current ISS EVA crew manual translation rate of 0.43 m/s (1.4 ft/sec) envelopes the applicable relative velocity that robotic assisted translation near vehicle structure creates. The verification of this requirement should account for secondary impacts and the rigidity of attached EVA tools and equipment.

3.3.12 Impact Performance – Partial Gravity (RQMT-021)

The xEVA System spacesuit shall not fail catastrophically following impact with a 2-inch diameter steel ball when crewed, pressurized to nominal or elevated pressure, in lunar gravity, translating at 1.2 m/s (4 ft/s), and in the heaviest EVA configuration.

Rationale: This requirement ensures that the risk of the spacesuit failing following an impact during a partial gravity EVA is acceptable to the program. Additional analysis will be required to determine the effects of the design specific mass and CG. Efficiency of energy transfer to the impactor will also need to be calculated.

Applicability: Artemis

3.3.13 Visual Capabilities (RQMT-022)

The xEVA System spacesuit shall provide the crewmember with safe and accurate visual capabilities and head mobility to perform EVA tasks in both day and night-time conditions.

Rationale: Visual capability is required to ensure compatibility with specified workstations and includes the ability to work during both day and night-time conditions.

Spacesuits must allow for incorporation of hardware without interfering with the crewmember's visibility. This includes reduced visibility caused by helmet fogging and scratches or eye irritation. Reference NASA-STD-3001 V2, standard V2 5001 and SA/HMTA memo SA-18-076, HMTA Concurrence with Exploration Extravehicular Activity (EVA) Suit Systems Requirements Document SSP 51073/RD-001 Action Items (AIs) from the Exploration Extravehicular Mobility Unit (xEMU) Systems Readiness Review (SRR), for the HMTA position on visual capabilities.

Applicability: ISS and Artemis

3.3.14 Protection from Ultraviolet and Infrared (RQMT-023)

The xEVA System spacesuit shall filter the intensity of wavelengths by the percent shown in the Minimum Shielding (Filtration) Necessary to Prevent Injury from Ultraviolet (UV) and Infrared (IR) Table 3.3.14-1.

Rationale: Limits for crew exposure to the electromagnetic spectrum from the ultraviolet (180 nm) to the far infrared (1400 nm) are necessary to protect the eye and skin from injury caused by the overexposure to radiation. The filtration percentage required is dependent on the wavelength being filtered and the intensity of the electromagnetic spectrum specific to the destination where the mission architecture is occurring and does not pertain to incidents of light flash. Reference NASA-STD-3001, Rev B, V2 standard V2 6104. Reference SA/HMTA memo SA-18-076 for the HMTA position on the Minimum Shielding (Filtration) Necessary to Prevent Injury from UV and IR Table, reference EVA- EXP-0066, UV/IR Visor Protection.

TABLE 3.3.14-1 MINIMUM SHIELDING (FILTRATION) NECESSARY TO PREVENT INJURY

FROM UV AND IR

Destination Wavelength (nm)

% Filtration Required

% Reduction of EMU Helmet with Sun Visor

Up on ISS (For Reference Only)

Earth LEO and cislunar

180-330 99.99 100 335-345 99 100 350-395 95 100 - 96 400-695 10 83- 29.16

700-1400 5 29.14-72.99 1405-3000 5 29.14-72.99

General Notes:

1) Minimum shielding necessary to prevent injury is based on NASA –STD-3001 V2

Rev A and the HIDH which include the NASA amended numerical values used by the ACGIH publication “TLVs® and BEIs® Based on the Documentation of the Threshold Limit Values for Chemical Substances and Physical Agents & Biological Exposure Indices.”

2) With the EMU sun visor down additional filtration occurs with the lowest % reduction of ~89% occurring at 475nm and 550nm

3) Blue light values are included in the table, but are anticipated to be in the 380-500nm range

4) The range (180/190/200 to 3000nm) is typically used for the broadband hazard, but for the blackbody source of the sun, the constraining range is 700-1400nm (usually 700-3000nm). At higher wavelengths above 1400nm, filtering does not provide significant reduction of hazard from this specific source (blackbody sun). The astronaut will still have a time of roughly > 100 seconds, which is comparable to the current suit without the visor. Simple blink reflex and movement resets this hazard, since it is strictly thermal in nature and exceeding it is very unlikely. If additional comfort is needed, the visor may be used. This is intended to be a minimum to protect against injury.

3.