Mars Advanced Glove Engineers
NASA plans to put humans on Mars by 2032. For humans to explore, work and live on Mars, among other things, humans will need well engineered, maintainable, life supporting and highly tactile gloves. Making gloves for human use on Mars requires design. Design as a practice, is all about the design process. This, then, is the mission of this project: To Research and Develop a Process for Designing Gloves for Human Use on Mars.
M.A.G.E. Mars Advanced Glove Engineers, are a team of five senior undergraduate engineering students in the Department of Human Centered Design and Engineering. This project fulfils the Senior Capstone requirement for graduation. Our hand-picked team and this project were the brainchild of our Project Manager: Erin McClean.
My roles across this project included literature review, tracking down and interviewing subject matter experts, developing an off-world glove design process, learning to sew, purchasing glove making materials, 3D modelling, 3D printing, making patterns, building glove prototypes; co-facilitating usability studies, photography, videography, writing reports, and co-presenting our final design at the 2015 Capstone Showcase
We began by reviewing literature related to the research and design of space suits, pressure suits, and gloves for use in space; and literature related to learning about the tasks humans would be performing on Mars. We then sought out, scheduled time with, and interviewed subject matter experts (SMEs) in fields related to Mars, and trades which perform tasks like Astronauts. From our literature reviews and interviews, we learned that building a functional, serviceable prototype required significantly more time, expense and resources than we had available to us.
Gloves for off-world human user are complex feats of engineering, and there are myriad factors to consider: air pressure, temperature, agility, tear and puncture resistance, durability, tactile responsiveness, dust penetration, fit and mitigating fatigue. To keep things in perspective and to address a well-rounded set of design factors, we chose to focus on researching, designing and testing for: microgravity, tactile response, pressurization, temperature, dust penetration and fit.
Design and Test Methods
We worked out a plan to research, design and test for all of the design factors we chose to focus on.
Microgravity and tactile response would be simulated by putting the glove on a scuba diver and having them perform tasks underwater.
Presurization would be simulated by developing an internal presurizable bladder. The test glove would them be mounted inside a custom built vacuum chamber that simulated the surface air pressue on Mars.
Temperature would be regulated by a customized electronic thermal layer and circuit
We incorporated the feedback from our testing and construction experiences into our final prototype. Improvements included specialized stitching around the knuckles to help the glove stay in place by “crawling” the fabric towards the wrist during normal movements.
Hitting The Streets
Because travel to Mars is literally out of the question with current technology, we decided to study the harsh environments commercial divers work in, test our ptototypes using a professional diver, and build a Mars atmospheric simulation chamber.
Below is the list of works and interviews we cited in our research for Milestone 1. These sources also played a large part in our other milestones, ideation, prototyping, and conversations about space gloves. We would especially like to thank the people and institutions that granted private interviews. Without exception, everyone we spoke with was incredibly supportive and this project would not have been a success without their expertise. The staff at the Divers Institute of Technology in Seattle, Raymond “Boy” , Doug Irish and John Paul Johnston were extremely generous with their time and knowledge and the tour of their facility was amazing. Peter Homer was incredibly pleasant to converse with–he shared his experiences prototyping the NASA glove competition and his information was critical to our success. Also thanks to Elena Amador from the University of Washington’s Earth and Space Sciences Department. Elena provided us with a wealth of information on the surface and climate of Mars and suggested materials for the “dust test” of our prototypes. Bobby Jones from ILC Dover patiently explained more than we ever thought there was to know about the space gloves NASA currently uses, and his recommended readings further illuminated the subject matter. This project also received financial support, donations of materials, or logistical support from the following groups: UW College of Engineering UW Physics Department UW Department of Earth and Space Sciences UW Department of Human Centered Design & Engineering Sources:  D. Jenkins. 2012. Dressing for Altitude. [Online] Available: http://www.nasa.gov/pdf/683215main_DressingAltitude-ebook.pdf  J. Parker Jr. and V. West. Bioastronautics Data Book. Washington, DC: NASA Scientific and Technical Information office, 1973.  K. Mitchell, “Phase VI Glove Durability Testing”, 41st International Conference on Environmental Systems, no. 2450, pp. 1-15, 2011.  A. Anderson et al. “In-Suit Sensor Systems for Characterizing Human-Space Suit Interaction”. Proc. 2014 International Conference on Environmental Systems. Tucson, AZ, 2014. Available: http://hdl.handle.net/2346/59683  R. Jones et al. “Enhancements to the ISS Phase VI Glove Design”. Proc. 2014 International Conference on Environmental Systems. Tucson, AZ, 2014. Available: http://hdl.handle.net/2346/59677  National Aeronautics and Space Administration. 2009. “What is the Temperature of Space?”. [Online] Available: https://www.nasa.gov/audience/foreducators/topnav/materials/listbytype/What_Is_the_Temperature.html  P. Homer, Private Interview, April 2015.  E. Amador, Private Interview, April 2015.  Diver’s Institute of Technology Staff (Seattle, WA), Private Interview, April 2015.  R. Jones (ILC Dover), Private Interview, April 2015.
Wednesday April 8, 2015 our team journeyed to the Diver’s Institute of Technology (DIT) on Seattle’s Lake Union. We were given a first hand interview sessions with DIT’s Director John Paul Johnston, Instructor Doug Irish and Raymond “Boy” Kayona, Director of Training. After a 45 minutes question and answer session related to working in high pressure hostile environments, we were given an up close and personal tour of the DIT’s facilities. Along the way we took notice of the mechanical properties of the diving suits. Here we are shown the o-ring system used to connect gloves to the sleeves of the suits for a water / airtight fit. Here we are being shown one of the layers that can go inside the divers outer glove. We are interested in learning about layering. Part of out DIT tour included tours of different air control systems, gas storage facilities plus watching a diver be called up from the bottom of Lake Union, surface and climb up a ladder to exit the water. There is a long history at the DIT. The founders are featured prominently in oil paintings in the halls of the institution. Anu was sizing herself up against an antique diving suit. Not too far off from a 1960’s style poster of an astronaut headed for Mars. June 4, 2015 User Research Pt. 2: SME Research in the Field The second week of April, 2015 we took our research efforts into the field. We started out early Wednesday April 8th with a field trip to the Divers Institute of Technology on Lake Union in Seattle. We talked with John Paul Johnston the Director, Raymond “Boy” Kayona the Director of training and Doug Irish who specializes in deep sea dives and Helium-Oxygen Theory. After 45 minutes of Q&A we were given an up close and personal tour of the DIT facilities. We documented as much of the tour as we could through photography and note taking. All of our questions were addressed thoughtfully and thoroughly providing a solid start to our quest for first hand data from subject matter experts who work in pressure suits in hostile environments. These images show a diver coming up from a lesson and an o-ring seal system used to lock gloves onto the dry suits. At 1:30 on Wednesday April 8 we interviewed Peter K. Homer winner of the 2007 and 2009 Astronaut Space Suit Glove Competition. Without disclosing proprietary technical details, Peter engaged us in a discussion focused on his design thinking, methods and results. Another home run for our research team as we continue to collect data intended to help us inform our design decisions. On Thursday we interviewed Elena Amador, a PhD candidate in Earth & Space Sciences at the University of Washington. Elena’s focus is on the surface composition of Mars. She answered our questions about the Martian environment and potential hazards to human life. Additionally, we had a thoughtful discussion on the necessity for humans on Mars. Finally, on Friday, we interviewed Bobby Jones, who is the senior design engineer for spacesuit gloves at ILC Dover. We learned from him about the professional design process for the current iteration of space suit glove (Phase VI). Additionally, he gave us pointers on materials and processes to use for a medium fidelity ‘showcase’ glove. In addition to interviews, we reviewed five technical papers recommended to us by Geoff Nuun, a curator at the Museum of Flight, and Bobby Jones. Dressing for Altitude: A comprehensive history of pressure suits and their use in military, aviation, and aerospace from the early 1900’s to early 2000’s. Bioastronautics Data Book (Selected Chapters): One of the preliminary reference books for NASA on the effects of space and space systems on the human body. Phase VI Glove Durability Testing: Conference paper recommended by ILC Dover. Enhancements to the ISS Phase VI Glove Design: Conference paper recommended by ILC Dover. In-Suit Sensor Systems for Characterizing Human-Space Suit Interaction: Conference paper by Anderson, Hilbert, Bertrand, McFarland and Newman. Here are a few key findings from our readings and interviews: Space suit and gloves designs are iterative and have evolved based on experience. Better terrestrial testing and evaluation methods might accelerate the process. We have some information on how various equipment has been tested in the past. ILC has 63 “off the shelf sizes” but will still custom fit gloves if needed. Dust will be a challenge: “The gloves and suit components need to be protected from harsh environments, like dust and stuff…the apollo spacesuits were great but they couldn’t handle the environment really well and the dust tore them up pretty fast…” Divers Institute also talked about the “RMA” of equipment: Reliability, Maintainability, and Availability. Long term durability and repairability are important . Current materials may be adequate as temperatures on Mars are probably similar to what astronauts deal with on spacewalks. Outside “touch temperatures” of metal surfaces on the ISS exterior are covered to keep them between about 120C and -120C . Mars is as cold as -85C in the summer. Current gloves and spacesuits handle thermal issues in a vacuum–we need to better understand the thermal effects of Mars’ thin atmosphere. Gloves constructed in the straight hand position make it impossible to hold an object—such as a control stick—for more than 15–20 minutes while the glove is pressurized. A natural semi closed position for the glove allows the subjects to hold an object up to 2 hours without undue discomfort. Removable gloves prevent excessive moisture from building up during suit checkout and preflight inspections, Also make it easier for the pilot to doff the pressure suit by himself if that should become necessary. A punctured glove can be changed without having to replace the entire suit. Gloves are lined from the wrist to the base of the thumb and fingers with Gore Tex to distribute ventilation air. The wrist ring has a rotating bearing to provide more mobility. Spacesuits need to be multifaceted: e.g. work for launch, in-cabin activities, and extravehicular activity EVA. Phase VI gloves, which are the current gloves used on spacesuits, can be used for planetary missions but the outer layer is not suitable for dusty surfaces.
Mixing up my Sci-Fi references there with the title but it seemed appropriate since one of our participants for testing was my(Erin) dad (Dave). We have now completed two stages of evaluation: 1. Micro-gravity testing using a neutral buoyancy ‘lab’ and Mars atmospheric pressure simulation in Matt’s DIY vacuum box. These tests sufficiently evaluate the form and function of our glove in the context of Mars and the fidelity of our prototype. In other words, these evaluation methods test most of our main goals: Pressurizable, sealed against dust, sufficient articulation and flexibility for long durations of scientific and manual labor. Our first test was conducted this past Wednesday in the Pavilion Pool, or as we renamed it: The University of Washington Neutral Buoyancy Laboratory. Like us, astronauts have to conduct extensive testing of their custom fit gloves in the Johnson Space Center Neutral Buoyancy Lab, which is essentially a pimped out Olympic sized swimming pool. Since our budget restricts us from an all expenses vacation…err research trip to Houston, we made do with on campus resources. We recruited David McLean, a diver with thousands of hours under water conducting technical and research dives. Now a days he is a volunteer diver at the Seattle aquarium. I also dove in order to record and walk David through the tasks. We walked David through all the tasks on land first. Tasks included wrist and arm flexion and extension exercises, as well as manual tasks such as hammering and screwing. Our diver wore a dry suit in order to simulate keeping his hand dry and the glove pressurized Here he is underwater working on our tasks. David had a lot of great feedback for us, especially in regards to sewing techniques to increase articulation and decrease hand fatigue. (i.e. barbing the fingers around the knuckle so the glove doesn’t slip off). We were able to use his feedback to improve on our next TMG iteration. Our next phase of testing was conducted with ‘willing’ undergrads (I use quotes because sticking hands into loud boxes can be scary and encouragement is needed). We used a lot of the same tasks as before, including articulation tests and working with tools, only this time using the vacuum chamber. We used a different TMG layer this time, one with the improvements suggested by David. Participants seemed to have better wrist motion with this iteration, though completing some of the tasks one handed was difficult. Our new iteration of the glove has a neoprene palm grip, barbed fingers, and finger caps (affectionately called nubbins). It fits about a size 8 hand. Here is the glove in the vacuum chamber. Having it inflated for ~30min let us see where week points were in the design because the stitches would tear there. Some of our lessons learned from this round of testing include: 1. Our inflated glove should fit into all layers, not just the TMG. We had issues fitting in the restraint layer. 2. Finger nubbins need to be wider so they don’t cut off circulation. We attempted Mars Simulation Dust Storm testing with a leaf blower and simulant regalith. We ended up canceling testing due to weather and safety restrictions. A bag of Mars simulant regalith which is a spectral analog to rock on Mars.
Milestone 2 Report Sketching Below are some pictures of our sketches. Keep in mind that, based on our research, we concluded that the most important things to maintain in our design were dexterity, durability (repeated, extended use), adaptability to the environment, and the ability to repair on the surface of Mars if needed. (full glove/layers sketches) (finger/stitching sketches) (sketch of electronics schematic for temperature regulation in restraint layer) Ideation Initially, we started ideating by playing around with different materials (canvas, nylon) and beginning first with a single finger. We used different cuts and stitches, considering which ones would give the user the most flexibility. Though we have mentioned it before, it is important to again note that we used canvas in this stage to simply get things going and to be able to easily see our stitching, and that our actual glove design does not include such stiff and uncomfortable material. Layer Construction For this iteration, the bladder layer was a standard latex kitchen glove. However, we obtained several nitrile and drysuit gloves to act as our bladder in subsequent iterations because the can be pressurized. See pictures of these bladders below. The restraint layer (pictured below) was sewn from light weight nylon (fun fact: NASA also does this). Worked in with the restraint layer was the electronics (refer to schematic in sketches, and photos below). We chose to include these electronics as a method of temperature regulation because it can get very cold on the surface of Mars. Comfortable temperature is extremely important in maintaining dexterity, and as we learned from our research (particularly from our interview with SMEs at the Diver’s Institute of Technology) without dexterity, no work gets done. Finally, our thermal/micrometeoroid (TMG) is pictured below. For this iteration of the glove, the TMG layer was made of lightweight canvas. Pictured below is the layer cut, but not sewn. Additionally, we have provided layouts of what each cut of the outer layer looks like to clearly show what went in to the design of this layer. Also, it is important to note that throughout all of these initial attempts, we found proper sewing to be somewhat of a challenge. We then worked on new sewing techniques and specifically techniques for sewing fingertips. In our subsequent iterations we intended to have much more sophisticated sewing implemented in the glove. Take a look at the photos below for a view of our fully-sewn-together glove, with the completed and sewn outer TMG layer. To be clear: the TMG layer is sewn over the restraint layer in these photos (see excess material of the restraint layer protruding from the glove). Testing Environment Preparation We had to pivot on our pressure testing apparatus. Our original plan to pressurize the glove from within had three problems: -An unacceptable rate of leakage -Discomfort for the wearer during testing -Problems with accurately monitoring the pressure inside the glove Since we are human centered designers, it was particularly important to make sure that the testing apparatus doesn’t introduce difficulties for our testers. We decided to go with a glove box that can be taken to a vacuum 3.5 psi below atmospheric pressure (refer to picture below). The box is approximately 12×12 so it needed to be strong–even that small a surface area at a 3.5 psi differential is about 500 pounds of pressure on each side of the box (12^2 x 3.5). It was built with two by four lumber and oriented strand board–all the construction guides we looked at indicated these materials were more than adequate for the loads to which we be subjected them. As another part of our final deliverable, we planned to document this testing and include it in a video demonstration of our high-fidelity prototype. In addition to pressure testing via the methods described above, we also planned a quick test of our glove underwater and document it. We planned to reserve a pool on campus, and have two scuba divers twist of the lids of jars at the bottom of the pool while using our glove. Below is a photo of our storyboards for this video.
June 1, 2015 Ideation and Prototyping Pt. 3: Some Assembly Required We had to make a significant last minute change to our pressure testing apparatus. The original plan to pressurize the glove from within had three problems: An unacceptable rate of leakage Discomfort for the wearer during testing Problems with accurately monitoring the pressure inside the glove Since we are human centered designers it’s particularly important to make sure that the testing apparatus doesn’t introduce difficulties for our testers. We decided to go with a glove box that can be taken to a vacuum 3.5 psi below atmospheric pressure. The box is approximately 12 inches on each side so it needs to be strong–even that small a surface area at a 3.5 psi differential is about 500 pounds of pressure on each side of the box (12^2 x 3.5). It is built with two by four lumber and oriented strand board–all the construction guides we looked at indicated these materials were more than adequate for the loads to which we subjected them. Below is a photo of the glove box–the black ring is where the glove seals for testing–the lead weight was holding down the window while the sealant cured. We also completed a restraint layer for the glove. For this iteration, the bladder was a standard latex kitchen glove, and the restraint layer was sewn from lightweight mosquito netting. Below is a photo of the restraint layer with the heating elements attached (heating elements discussed later on). Our thermal/micrometeoroid layer (TMG) was also completed. The low fidelity version of this layer was lightweight canvas, and some of the “hard” parts were 3D-printed or fabricated form silicone RTV. The blue fabric in the photo below is a cut-but-not-yet-sewn TMG. We also assembled a heating element for the glove–In the first iteration the heater was “controlled” by its internal resistance, but temperature monitoring and control hardware were considered. We had some concerns about controls failures and looked at limiting the available current to the heating element so even if it were “stuck on” it wouldn’t damage the glove or the wearer. In any case, the electronics need to fail safely. The photo below is Erin’s sketch of the controls circuit:
Ideation and Prototyping Pt. 2: The Canvas Diaries We continued our low fidelity prototyping this week. Following Peter Homer’s advice, we decided to build our glove finger by finger, layer by layer. Shown below is an example prototype of how we wanted the cut of our finger to look like on the second layer, covering our bladder. Keep in mind, we don’t plan on using the canvas to be a part of our glove because it’s pretty stiff, uncomfortable, and exhausting trying to bend it over layers of fabric. We chose to use canvas for our prototype because it’s easy to see the stitching. The blue fabric is nylon ripstop. We cut out the back part of the finger and replaced it with nylon to allow flexibility and less friction when the finger bends. The nylon is ruched so it can stretch when the finger bends without having a bulk of fabric. The pictures above illustrates stitching practice. The problem with this form is that the palm puckers when we fold our hand in. This is just one type of stitching we looked at for the glove. We want our glove to have watertight/airtight stitching. From our research, cross stitching is the best option for us since it provides additional flexibility and is pretty strong stitch. Stitches alone would not make the glove completely airtight, so we considered other possibilities such as seam sealant. Above we are testing the glove with the bladder under pressure. The reading on the meter was not very accurate as this is was a pressure of 0.5 psi. There is still a good amount of leakage and that’s definitely something we addressed. Further iterations were made after this attempt.
Our Final Deliverable This is our final deliverable. Visible is the TMG layer showing the barbed fabric pattern designed to make the glove crawl down the hand and larger finger nubbins which help screw the glove down onto users fingers while protecting them from damage. Updates to Layers Restraint: Our restraint layer stayed mostly the same. The only change was fitting it to a size 11 glove (which was important for underwater testing). Electronics were slightly updated for this iteration. Due to time and material constraints, temperature sensitivity was not integrated. Instead, the palm heaters were set to 70F to prevent heat overloading. As we learned from reading Bioastronautics, it is better to be slightly chilly than sweating in a spacesuit. We kept the back of hand heaters at a toasty 127F (±5F), which through the layers could keep skin temperature within the 84-94F range. Additionally, the systems could only be turned on at user control with a button. Both heaters were sandwiched in between the restraint layer and a layer of neoprene. Each neoprene piece was cutout to fit with the curvature of the hand. The palm piece acted as a pseudo palm bar because it helped the pressurized glove retain its shape and now blow out at the palm. The neoprene also helped retain heat after the electronics had been turned off, which could help conserve power. TMG: The Thermal Micrometeroid Garment is the outer most layer of the current NASA Phase VI astronaut gloves. The TMG’s role is to protect users hands from thermal swings and impacts from high velocity space based objects less than 2 mm in diameter. This protective layer will benefit users on Mars by helping to regulate hand temperatures while protecting against cuts and tears from the rough jagged features of rock on the Martian surface. TMG fabrication improved over three iterations. Our first iteration was based only on literature reviews and subject matter expert interviews. This TMG was based off of a simple well known sewing pattern with gussets in between the fingers, a flat palm and a ‘cone’ shaped thumb. There were many problems to overcome: lack of knowledge on using a sewing machine to make a glove, challenges sewing in tight corners like in between fingers and consistent relative sizing across the fingers. Our second iteration featured a complete redesign and was heavily modified using empirical data from our test at the University of Washington’s Neutral Buoyancy Laboratory (See ‘Evaluation’ Section Below). Through the iteration 1 evaluations we learned how to cut fabric into a ‘barb’ pattern so our glove would ‘crawl’ down the back and front of users hands maintaining a tight fit. The triangular shapes in the image below are known as barbs. Barbs help pull the gloves down towards the wrists when the hand is closed insuring a tight fit especially in the fingers. We learned how to incorporate the idea of an accordion stitch into the wrist area so wrist movements did not distort the gloves fit on the hand. The forearm was widened and nubbins were added to the fingers. This revision, iteration 2, became to TMG that was tested in the Mars environment simulation chamber (See ‘Pressure Box’ Section Below). Our Third and final iteration of the TMG was built from scratch using our combined experience from iteration 1, the empirical data from the diving tests and data from the Mars simulation chamber. Evaluation Diving: Our first test was conducted in the Pavilion Pool, or as we renamed it: The University of Washington Neutral Buoyancy Laboratory. Like us, astronauts have to conduct extensive testing of their custom fit gloves at the Johnson Space Center Neutral Buoyancy Lab. Since our budget restricts us from an all expenses research trip to Houston, we made do with on campus resources. We recruited David McLean, a diver with hundreds of hours under water conducting technical and research dives. Erin also dove in order to record and walk David through the tasks. We walked David through all the tasks on land first. Tasks included wrist and arm flexion and extension exercises, as well as manual tasks such as hammering and screwing. Our diver wore a dry suit in order to simulate keeping his hand dry and the glove pressurized Here he is underwater working on our tasks. Diving Results: David had a lot of great feedback for us, especially in regards to sewing techniques to increase articulation and decrease hand fatigue. (i.e. barbing the fingers around the knuckle so the glove doesn’t slip off). We were able to use his feedback to improve on our next TMG iteration. Pressure Box:For testing the glove at pressure we fabricated a single glove box which can be taken to a vacuum 3.5 psi below atmospheric pressure. This effectively pressurizes the glove to 3.5 psi, which is what suit and glove pressure would be on Mars. The box is approximately 12×12 and sturdily built from two-by-fours and oriented strand board, with an acrylic window on one side. The box has to withstand 500 pounds of pressure on each side (12^2 x 3.5). The gloves attach to the box by rolling the cuff over a plastic insert sealed into one wall. The vacuum is provided by a standard commercial vacuum pump, and measured with a refrigeration service pressure gauge. Here are some photos of the box under construction and in service: Under Construction Glove under pressure Pressure Box Results:The glove generally held up well under pressure. Our first run didn’t result in any complete failures but a seam failure began and resulted in some bulging. The seam was repaired for the second run of testing and the glove held up well after about an hour of continuous use and numerous pressurization and depressurization cycles