Textiles for Extreme Surface Environments and High Oxygen Atmospheres

Scope Title:

Textiles for Extreme Lunar Environments and High Oxygen Atmospheres

Scope Description:

The environmental protection garment (EPG) is the outer component of the current spacesuit, which is called the Extravehicular Mobility Unit (xEMU). The xEMU is the new spacesuit developed for returning to the Moon. The EPG is a multilayered component consisting of fabrics and thin films. Each layer of this component contributes to the protection of the xEMU from the extreme lunar environment while enabling xEMU functionality of its three subsystems: the Pressure Garment System (PGS), the Portable Life Support System (PLSS), and the informatics system. The EPG is the spacesuit’s first line of defense. It must be designed to perform in the harsh surface environment of the South Pole of the Moon. It incorporates more advanced technologies than the current EMU (designed for use in low Earth orbit.) The xEMU is designed to be the next-generation spacesuit to benefit several space programs, namely the International Space Station, Human Landing System (HLS), Artemis, Gateway, and Orion.

The return of humans on the Moon means that everything outside the lunar lander or a habitat in future missions must be resilient to the lunar surface challenges. The most problematic challenge is the lunar regolith that is everywhere, levitates as soon as it is disturbed, and settles on anything around it. The Apollo spacesuits not only collected gray dust but also deteriorated from the damaging effects of the fine penetrating particles. 

Lunar Environments

1. Thermal

The environment temperatures will be the temperature on the outside of the suit. The internal layers of the EPG are higher because of the suit heat leak provided by the astronaut, which warms the surrounding area.

 Extreme heat (260 °F, 127 °C)

 Extreme cold in permanently shadowed regions (-370 °F, -223 °C)

2. Regolith Terrain

The lunar regolith is a blanket of abrasive dust and unconsolidated, loose, heterogeneous, superficial deposits covering solid rock. The EPG fabrics must have sufficient resistance to abrasion and tear to last for multiple uses.

In the South Pole region of the Moon, the regolith is highly abrasive and prone to electrostatic and tribo-electrostatic charging. The electrostatic charges are produced by the photoemission of electrons due to vacuum ultraviolet (VUV) sunlight irradiation. The regolith becomes slightly positively charged. In the shadow, these charges reverse. In addition, the tribo-electrostatic charges are created by the friction of fabrics on the regolith.

3. Radiation and Plasma

The Moon does not have an atmosphere. Therefore, it receives unattenuated galactic and solar radiation. This solar radiation does not cause radioactivity. The annual Galactic Cosmic Rays dose in milli-Sieverts (mSv) on the Moon is 380 mSv (solar minimum) and 110 mSv (solar maximum). The annual cosmic ionizing cosmic radiation on Earth is 2.4 mSv. The EPG layers and particularly the outer layer fabric must be durable over hundreds of hours of VUV radiation exposure without a reduction in functionality.

Plasma is a concern due to the charged environment that may be in contact with the spacesuit. The plasma is explained in a PowerPoint document from Timothy J. Stubbs et al., “Characterizing the Near-Lunar Plasma Environment,” Workshop on Science Associated with the Lunar Exploration Architecture, Tempe, AZ, February 26 to March 2, 2007. https://www.lpi.usra.edu/meetings/LEA/whitepapers/Stubbs_charging_NAC_whitepaper_v01.pdf

4. Architecture

The architecture of the xEMU EPG is based on a “hybrid-segmented” design in which inner layers of the EPG are segmented, with breaks around specific bearings, disconnects, and other components. The goal is to develop an EPG outer layer, which itself may be multilayered, to prevent dust intrusion and accommodate a range of sizes using overlapping sections. These sections are connected by reusable dust barrier zippers.

The EPG layers currently are:

Orthofabric of density 14.5 oz/yd² for its mechanical properties of tensile and tear strengths, its optical properties that satisfy the thermal requirements, and to a lesser extent its abrasion resistance since the face of the fabric is made of Gore-Tex yarns.
Gore-Tex fabric of density 9.1 oz/yd² per layer with a total of two layers to protect the adjacent thermal layers from solar radiation.
Aluminized Mylar® of density 1.12 oz/yd² per layer with a total of seven layers for their heat transfer properties.
Neoprene-coated nylon with density 9.0 oz/yd²
Additional information on xEMU EPG architecture is given on this link: https://ttu-ir.tdl.org/handle/2346/89783

Requirements

1.    Thermal

• Solar absorptivity to infrared emissivity of 0.21. 
• Solar absorption is a value of 0.18 or less.

2.    Physical

 mass ≤42.57 oz/yd² xEMU EPG mass 

3.    Mechanical

•    Have properties such that the microns and possibly some submicrons size regolith particles cannot penetrate the EPG. 
•    Be made of a single material or multilayered materials rather than laminated or composite materials more prone to delamination at cryogenic temperatures. 
•    Be more resistant to abrasion than Orthofabric to the sharp glassy regolith from the lunar South Pole. 
•    Be as or more flexible than the Orthofabric in extremely cold temperatures.  
•    Survive 1,800 bending cycles at temperatures from -370 °F (-223 °C) to 260 °F (127 °C), and not snap from impact at the maximum cold temperatures. 

4.    Oxygen-rich atmospheres

The EPG outer layer shall not support combustion in the lunar lander’s atmosphere of 34% ±2% oxygen at a pressure of 8.2 psia (56.5 kPa). This oxygen concentration may even be higher. Hence, all materials directly exposed to the lunar lander atmosphere are required to be flame retardant.
 

A spacesuit is essentially a one-person fully equipped spacecraft. It is complex and consists of more than 100 components. One of the primary purposes of the spacesuit is to protect the astronaut from the dangers in space outside the spacecraft. Therefore, it is more than just clothing.

Expected TRL or TRL Range at completion of the Project: 2 to 6

Primary Technology Taxonomy:

• Level 1 06 Human Health, Life Support, and Habitation Systems
• Level 2 06.2 Extravehicular Activity Systems

Desired Deliverables of Phase I and Phase II:

• Research
• Analysis
• Prototype

Desired Deliverables Description:

Phase I:  Phase I offerors are expected to deliver written reports (Interim and Final) containing a plan or strategy that explains in detail their approach for solving the problems of the EPG and the crew clothing. Reports shall include rationale for approach, research, proof of concept, analysis, and any strategy leading to one or more prototypes. 

Phase II:  Phase II deliverables shall include prototypes or finished goods. The prototypes or finished goods shall be delivered to NASA Johnson Space Center with a “Material Inspection and Receiving Report” (Form DD250) OMB No. 0704-0248. Photographs of the delivered prototypes or finished goods shall accompany the DD250 form.  Deliverables shall also include complete documentation such as technical data sheets with a detailed description and composition of the material or product, with testing methods and testing data, design sketches or drawings, and full information on material and/or chemical sourcing. The Phase II deliverables shall also include a final report documenting all work accomplished for the Phase II effort and shall not duplicate the Phase II proposal.

Examples of the deliverables for the EPG and crew clothing may include:

• EPG: prototype textiles with coating, lamination, thin film, other new technology, composite structure, or fabrics integrated in a spacesuit.
• Crew clothing: novel fibers, yarns, and fabrics for everyday garment prototypes (e.g., T-shirt, pants, and sleepwear).

The proposers shall clearly state the Technology Readiness Levels (TRLs) at which they start their research and at which they expect to be at the end of Phase I and Phase II.  For the EPG, the TRL is expected to be the highest level possible at the end of Phase II. Reference for the TRL definitions are at the following link: https://www.nasa.gov/pdf/458490main_TRL_Definitions.pdf

State of the Art and Critical Gaps:

The gap is the lack of available commercial-off-the-shelf (COTS) textiles that satisfy spacesuit and crew clothing mitigation requirements for extreme surface environments and fire safety in a 36% oxygen atmosphere.

The second gap is the lack of knowledge of the effects of lunar dust on textile products with respect to their useful life in EVA applications.  Extent of wear and tear and levels of contamination and retention of the dust in the textile structure are not known.

The return of humans on the Moon means that everything outside the lunar lander or a habitat in future missions must be resilient to the lunar surface challenges.

Relevance / Science Traceability:

This scope is included under the Space Technology Mission Directorate (STMD). The xEMU project is under the Exploration Systems Development Mission Directorate (ESDMD) and Space Operations Mission Directorate (SOMD) .  

This work will benefit several space programs, namely the International Space Station, Human Landing System (HLS), Artemis, Gateway, and Orion.  Near term, the work on the EPG will directly benefit the xEMU project.

The textiles developed could be useful for other soft goods applications.

References:

References

1. “NASA’s Plan for Sustained Lunar Exploration and Development” (a_sustained_lunar_presence_nspc_report4220final.pdf (nasa.gov))
2. Chris Hansen, “Space Suit Developments for Future Exploration,” ASE 2019 Technical Session 7, Planetary Congress Session Replays, Houston, TX, 17 October 2019 (https://ase2019.org/session-replays)
3. Technology Readiness Level Definitions: (https://www.nasa.gov/pdf/458490main_TRL_Definitions.pdf)
4. J. J. Dillon, E. S. Cobb, “Research, Development and Application of Noncombustible Beta Fiber Structures,” Final Report, 17 April 1967–31 December 1974. 24 pp, NASA-CR-144365 (https://ntrs.nasa.gov/api/citations/19750021113/downloads/19750021113.pdf)
5. Mark J. Hyatt, Sharon Straka, “The Dust Management Report,” December 2011, 85 pp, NASA-TM 2011-217037 (https://ntrs.nasa.gov/api/citations/20120000061/downloads/20120000061.pdf)
6. Roy Christoffersen, et al., “Lunar Dust Effects on Spacesuit Systems, Insights from the Apollo Spacesuits,” 1 January 2008, 47 pp, NASA-JSC-17651 (https://ntrs.nasa.gov/api/citations/20090015239/downloads/20090015239.pdf)
7. William Lewis Miller, “Mass Loss of Shuttle Space Suit Orthofabric Under Simulated Ionospheric Atomic Oxygen Bombardment,” November 1985, 14 pp, NASA-TM-87149 (https://ntrs.nasa.gov/api/citations/19860004430/downloads/19860004430.pdf)
8. Andrew E. Potter, Jr., Benny R. Baker, “Static Electricity In The Apollo Spacecraft,” December 1969. 23 pp, NASA-TN-D-5579 (https://ntrs.nasa.gov/api/citations/19700004167/downloads/19700004167.pdf)
9. Timothy J. Stubbs, et al., “Characterizing the Near-Lunar Plasma Environment,” Workshop on Science Associated with the Lunar Exploration Architecture, Tempe, AZ, February 26–March 2, 2007 (https://www.lpi.usra.edu/meetings/LEA/whitepapers/Stubbs_charging_NAC_whitepaper_v01.pdf)
10. Guenther Reitz, Thomas Berger, Daniel Matthiae, “Radiation Exposure in the Moon Environment,” Planetary and Space Science, Volume 74, Issue 1, p. 78-83, December 2012. (https://doi.org/10.1016/j.pss.2012.07.014)
11. Lunar Reconnaissance Orbiter Camera (LROC :: QuickMap (asu.edu))

Scope Title:

Lunar Regolith Covers for Hardware

Scope Description:

Human space exploration is always associated with a large amount of hardware that the astronauts need to perform their work. This implies that some of this hardware must also be resilient on the lunar surface. Hence, most of the this hardware will also need protection from the lunar regolith. There will be many types of hardware. There will be simple tools, equipment deployed on the lunar surface like cameras, and machines like rovers. Each one will need a cover uniquely designed for its size, shape, and complexity. However, all of them will need covers to prevent contamination and damage from the lunar regolith. Depending on the type of hardware, the cover may not need to be as flexible and may be thicker. Some covers will have additional functions like thermal management of powered devices. The requirements of some covers may be exactly the same as those of the xEMU EPG and its outer layer. Other covers that do not have the mass and mechanical properties limitations as those imposed on the EPG may be developed quicker and serve as steps towards the development of the EPG outer layer. The two scopes will  benefit from each other. 

This scope invites the researchers to think about what they would develop to a cover for an articulated tool such that it does not loose its ability to be articulated, and then think about what they would do to cover a camera, etc., in the context of extreme temperatures as described in Scope 1.  

Expected TRL or TRL Range at completion of the Project: 2 to 6

Primary Technology Taxonomy:

• Level 1 06 Human Health, Life Support, and Habitation Systems
• Level 2 06.2 Extravehicular Activity Systems

Desired Deliverables of Phase I and Phase II:

• Prototype

Desired Deliverables Description:

Phase I: Phase I offerors are expected to deliver written reports (Interim and Final) containing a plan or strategy that explains in detail their approach for solving the problems of the EPG and hardware covers. Reports shall include rationale for approach, research, proof of concept, analysis, and any strategy leading to one or more prototypes.

Phase II: Phase II deliverables shall include prototypes or finished goods. The prototypes or finished goods shall be delivered to NASA Johnson Space Center with a “Material Inspection and Receiving Report” (Form DD250) OMB No. 0704-0248. Photographs of the delivered prototypes or finished goods shall accompany the DD250 form.

Deliverables shall also include complete documentation such as technical data sheets with detailed description and composition of the material or product, with testing methods and testing data, design sketches or drawings, and full information on material and/or chemical sourcing. The Phase II deliverables shall also include a final report documenting all work accomplished for the Phase II effort and shall not duplicate the Phase II proposal.

Examples of the deliverables for the EPG outer layer and /or hardware covers may include prototype textiles, thin films, and other materials. 

The proposers shall clearly state the Technology Readiness Level (TRL) at which they start their research and at which they expect to be at the end of Phase I and Phase II. For the EPG, the TRL level is expected to be the highest level possible at the end of Phase II. References for the TRL definitions are at the following link: https://www.nasa.gov/pdf/458490main_TRL_Definitions.pdf

State of the Art and Critical Gaps:

The gap is the lack of available commercial-off-the-shelf (COTS) textiles that satisfy spacesuit and crew clothing mitigation requirements for extreme surface environments and fire safety in a 36% oxygen atmosphere.

The second gap is the lack of knowledge of the effects of lunar dust on textile products with respect to their useful life in EVA applications. Extent of wear and tear and levels of contamination and retention of the dust in the textile structure are not known.
 

Relevance / Science Traceability:

This scope is included under the Space Technology Mission Directorate (STMD). The xEMU project is under the ESDMD and SOMD.

This work will benefit several space programs, namely the International Space Station, Human Landing System (HLS), Artemis, Gateway, and Orion. Near term, the work on the EPG will directly benefit the xEMU project.

The textiles developed could be useful for other soft goods and hardware applications.
 

References:

1.    “NASA’s Plan for Sustained Lunar Exploration and Development” (a_sustained_lunar_presence_nspc_report4220final.pdf (nasa.gov))
2.    Chris Hansen, “Space Suit Developments for future Exploration,” ASE 2019 Technical Session 7, Planetary Congress Session Replays, Houston, TX, 17 October 2019 (https://ase2019.org/session-replays)
3.    Technology Readiness Level Definitions: (https://www.nasa.gov/pdf/458490main_TRL_Definitions.pdf)
4.    J. J. Dillon, E. S. Cobb, “Research, Development and Application of Noncombustible Beta Fiber Structures,” Final Report, 17 April 1967–31 December 1974. 24 pp, NASA-CR-144365 (https://ntrs.nasa.gov/api/citations/19750021113/downloads/19750021113.pdf)
5.    Mark J. Hyatt, Sharon Straka, “The Dust Management Report,” December 2011, 85 pp, NASA-TM 2011-217037 (https://ntrs.nasa.gov/api/citations/20120000061/downloads/20120000061.pdf)
6.    Roy Christoffersen, et al., “Lunar Dust Effects on Spacesuit Systems, Insights from the Apollo Spacesuits,” 1 January 2008, 47 pp, NASA-JSC-17651 (https://ntrs.nasa.gov/api/citations/20090015239/downloads/20090015239.pdf)
7.    William Lewis Miller, “Mass Loss of Shuttle Space Suit Orthofabric Under Simulated Ionospheric Atomic Oxygen Bombardment,” November 1985, 14 pp, NASA-TM-87149 (https://ntrs.nasa.gov/api/citations/19860004430/downloads/19860004430.pdf)
8.    Andrew E. Potter, Jr., Benny R. Baker, “Static Electricity In The Apollo Spacecraft,” December 1969. 23 pp, NASA-TN-D-5579 (https://ntrs.nasa.gov/api/citations/19700004167/downloads/19700004167.pdf)
9.    Timothy J. Stubbs, et al., “Characterizing the Near-Lunar Plasma Environment,” Workshop on Science Associated with the Lunar Exploration Architecture, Tempe, AZ, February 26–March 2, 2007 (https://www.lpi.usra.edu/meetings/LEA/whitepapers/Stubbs_charging_NAC_whitepaper_v01.pdf)
10.    Guenther Reitz, Thomas Berger, Daniel Matthiae, “Radiation Exposure in the Moon Environment,” Planetary and Space Science, Volume 74, Issue 1, p. 78-83, December 2012. (https://doi.org/10.1016/j.pss.2012.07.014)
11.    Lunar Reconnaissance Orbiter Camera (LROC :: QuickMap (asu.edu))