Improved EVA Suit MMOD Protection using STF-ArmorTM and self-healing polymers (UD Space Suit Layup) - 12.06.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Spacewalks can be very dangerous, exposing astronauts to potential micrometeoroids and orbital debris that can puncture a space suit. Sharp tools, spacecraft edges and other hazards can also rip a suit and cause depressurization and injury. The Improved EVA Suit Micrometeoroids and Orbital Debris (MMOD) protection using STF-Armor and self-healing polymers (UD Space Suit Layup) investigation uses self-repairing composite materials that can resist damage and fix tears while in the harsh environment of space.
Science Results for Everyone
Information Pending

The following content was provided by Norman Wagner, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom:

Principal Investigator(s)
Norman Wagner, Ph.D., University of Delaware, Newark, DE, United States

Co-Investigator(s)/Collaborator(s)
Melissa Gordon, Ph.D., University of Delaware, Newark, DE, United States

Developer(s)
University of Delaware, Newark, DE, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Technology Demonstration Office (TDO)

Research Benefits
Space Exploration

ISS Expedition Duration
March 2016 - September 2016

Expeditions Assigned
47/48

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • EVA exposes astronauts to potential MMOD impacts ranging from 0.1-1 km/s to 1-15 km/s from secondary lunar ejecta, and from orbital debris and micrometeoroids at up to 70km/s. Puncture damage to space suits may also arise from other physical hazards such as tools, sharp edges on handrails or surface elements.
  • Backup suits and gloves can be used to support missions in near-Earth space, but such redundancy and increased mass is not practical for longer missions or deeper explorations. Addition of bulky or stiff individual layers to protect against each of the different threat types may be possible in specific cases, but a “one-material-for-one-threat” approach to reinforcement is parasitic and reduces the flexibility of the EVA suit and gloves. Flexible, lightweight, multi-threat protective materials are needed to provide the durability and protection that will be required in future space suits.
  • This research evaluates the stability and efficacy of advanced extra-vehicular activity (EVA) suit lay-ups in the extreme environment of outer space. This includes adding both puncture resistance and MMOD resistance, as well as self-healing functionality. The former is provided by incorporation of the recently commercialized STF-Armor™ nanocomposite textile that has proven to be a highly effective protective puncture and ballistic resistant material in soft body armor applications, as a 1 to 1 replacement of the current protective rubberized nylon layer in EVA suits. The latter, self-healing materials have tremendous potential to further improve safety and reliability, and are currently under development in our laboratory.
  • The primary goal of the Improved EVA Suit Micrometeoroids and Orbital Debris (MMOD) protection using STF-Armor and self-healing polymers (UD Space Suit Layup) investigation is to evaluate the stability of EVA suit lay-ups with enhanced MMOD-resistance and self-healing functionality in the LEO space environment.
  • One objective is the exposure of EVA lay-ups containing STF-textiles to the LEO space environment and evaluate the MMOD resistance before/after exposure using earth based laboratory puncture, mechanical and hypervelocity testing.
  • Another objective is the fabrication of pressure bladder layers with self-healing functionality, and testing the stability, mechanical strength and puncture resistance before and after space exposure in the LEO space environment.

Description

The Improved EVA Suit Micrometeoroids and Orbital Debris (MMOD) protection using STF-Armor and self-healing polymers (UD Space Suit Layup) investigates the stability and efficacy of advanced extra-vehicular activity (EVA) suit lay-ups containing advanced nanocomposite textiles and self-healing materials (being developed under a NASA EPSCoR award) in the extremethermal, vacuum, atomic oxygen and radiation environment of low-earth orbit (LEO). The proposed material testing is aimed at advancing the technology readiness level (TRL) of MMOD-resistant and self-healing materials that have been developed and tested on Earth. Proof-of-concept and prototype testing (TRL 3 to 4) has been performed on MMOD-resistant STF-textiles in the full EVA suit lay-ups using hypervelocity testing at NASA Marshall Space Flight Center and most currently, at White Sands Test Facility with the assistance of the NASA Johnson Space Flight Center’s Hypervelocity Impact Technology (HVIT) Group. One goal is to achieve TRL 6 by testing the material in low-earth orbit by deploying space suit lay-ups on the exterior of the ISS to determine the effects of the low earth orbit space environment on the nanocomposites under development.
 
The primary anticipated results of this research are improved MMOD protection for EVA suits with ancillary applications more broadly in improvements in spacecraft and habitat MMOD performance. This research is a natural extension of research conducted under a current NASA EPSCoR award to prove the concept that high strength-to-weight textiles impregnated with shear thickening fluids (STF) can improve the micrometeoroid and orbital debris (MMOD) and puncture resistance of extra-vehicular activity (EVA) suits.
 
Shear thickening fluids (STFs) are materials with flow behavior that is dependent on the applied rate of deformation. These materials exhibit a liquid-like response at low shear rates with a reversible rise in viscosity occurring at high shear rates. STFs made from concentrated colloidal dispersions can exhibit a sudden and violent transition from a flowing liquid to a ceramic-like solid in what is known as discontinuous shear thickening. The shear rate dependent flow behavior of these dispersions has made them attractive for use in soft body armor applications. Furthermore, the addition of self-healing materials based on the reversible addition-fragmentation transfer (RAFT) mechanism provides a means to repair damage and restore pressure bladder integrity.

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Applications

Space Applications
Spacewalks are among the most dangerous tasks undertaken by orbiting crew members, but they are a necessary part of space exploration. This investigation tests a new flexible, lightweight, protective material that may be incorporated into new space suits. The textile is made of a nanocomposite material that can protect against punctures and fast-moving projectiles like space junk, as well as a self-healing polymer that can fix tears on the spot.

Earth Applications
Nanocomposite textiles can provide unique advantages to clothing without adding extra bulk. The textiles in this investigation have potential for use in extreme environments on Earth and for protection against hazards. In addition, this investigation improves the materials used to build space suits, enhancing astronaut safety and ensuring continued access to space-based science and communications on the International Space Station (ISS).

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Operations

Operational Requirements and Protocols

No observations, but samples must be returned so earth-based testing can be completed.

No on orbit procedures, but samples must be placed on the exterior of the ISS and exposed to space conditions.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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Imagery

image
Schematic of Payload. The UD lay-up consists of Orthofabric, 7 Layers of Mylar, STF-Kevlar 1148, a self-healing polymeric layer (SHPL) and urethane-coated nylon. 

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