My passion is getting people off our planet and into the vast reaches of outer space. How is it possible for humans to survive in the merciless environment of space? Bioastronautics is the field that not only answers this question but also manages to find ways for humankind to thrive in these extreme conditions. Challenges to life outside the cradle of Earth include radiation hazards, bone density loss, muscle atrophy, nutritional challenges, sleep deprivation, lack of a natural atmosphere and pressure, and mobility impairments. My research in this field focuses on the latter two conditions, life support and exploration mobility. Please click on the links below to check out my research in these areas.
The Extravehicular Activity Space Suit Simulator (EVA S3) is an exoskeleton developed by MIT and Aurora Flight Sciences as part of a Phase II SBIR Grant. The purpose of this robotic exoskeleton is to be a tool for simulating the resistive characteristics of space suits for training and research. Unlike most exoskeletons that are designed to assist a user in motion, this exoskeleton needed to resist natural motions. We achieved this resistance by using a combination of pneumatic "artificial muscle" McKibben actuators and pneumatic double acting cylinders. The system is tethered to a compressor and the pressure in each actuator is controlled by solenoid valves. My role on this project was to design and build the hip joint and backpack components of the exoskeleton and to interface it with the other systems. My range of motion and torque generation requirements came from the extreme ranges of space suit joint torque and position values complied from previous space suit characterization research. I used MATLAB and yes, even the Excel Solver function to perform constrained optimizations to produce designs that met my torque and position constraints while considering the cost functions for actuator size and structural loading. I also did a lot of design and FEA work in SolidWorks 3D modeling software. My goal was to make multiple iterations of each design and 3D printing made this possible. The final build in the machine shop took way longer than expected, but during that time I became very handy with a mill, lathe, and water-jet cutter.
We tested the EVA S3 on M-Tallchief, the MIT Man Vehicle Laboratory's robotic space suit tester. M-Tallchief has (or had, many joints are now in disrepair) 12 degrees of freedom with each joint having its own torque and position sensors. Fortunately M-Tallchief is the same robot that was used to test NASA's EMU space suit in the early 2000's so we had data that we could accurately compare. Sadly, the EVA S3 Exoskeleton is no longer with us at MIT as we had to deliver it as our final product to NASA at the end of the contract. There are still plenty of improvements to be made but this was a good first step in developing a completely programmable space suit simulator.
Space Suit Mobility
With the Robotic Space Suit Tester and the U2 flight suit
In the summer of 2010, I conducted a bioastronautics research project with Professor Dava Newman at MIT’s Man Vehicle Laboratory. I worked with graduate student Brad Holschuh and Dr. Shane Jacobs from the David Clark Company to develop a mobility testing procedure for a U2 reconnaissance aircraft pressure suit. Once the procedure was developed, I used a robotic space suit tester to collect suit torque data for different joint movements. I then analyzed the data and prepared a research report and poster on our methods and results. The purpose of this research was to characterize the joints in the U2 pressure suit to give insight into methods for the development of the next generation of space suits. Working alongside employees from the David Clark Company, I learned the benefit of collaboration between academia and industry. Sharing resources facilitates research that can be rapidly transformed into a new product. When I left MIT, I kept in contact with the lab and recently helped submit an abstract to the 41st International Conference on Environmental Systems entitled “Robotic Joint Torque Testing: A Critical Tool in the Development of Pressure Suit Mobility Elements” to be presented in July.
Another one of my projects at MIT was to create a real time motion tracking system using inertial sensors. The goal of this system is to track a person's natural movement and then relay the signal for the robotic space suit tester to mimic. At the end of the summer elbow flexion angles could be read and displayed in real time but there were still some hardware issues to work out before the signal could be actively transmitted to the robot.
The MIT Summer Research Program (MSRP) gave me a unique opportunity to be immersed in a graduate school environment. I was able to meet faculty, talk to graduate students, present scholarly papers, and conduct aerospace research at a world class institution. The greatest part of my experience was spending time with other interns in the program. My MSRP peers came from different backgrounds around the world. The diversity of our group made helped us grow as individuals as we worked together throughout the summer. Thank you to the MIT Summer Research Program (MSRP) and the MIT Man-Vehicle Lab for making this summer research experience possible.
Advanced Space Suit Helmet for the BioSuit
One of my projects my first year at graduate school was to look into the conceptual design of a helmet for the BioSuit, a mechanical counter pressure (MCP) space suit being developed by my advisor Dava Newman. I presented these findings at the International Astronautical Congress in Naples, Italy in 2012. The beautiful images in the publication were created by Dr. Michal Kracik. To see more view the paper in my publications section.
Inertial Measurement Units for Studying Astronaut Mobility
Inertial measurement units (IMU) are devices that measure acceleration and mathematically estimate velocity and position from this data. IMU's have been used as part of the guidance systems on aircraft and missiles for decades, but only recently been miniaturized as microelectromechanical systems (MEMS) devices. Now IMU's are in almost every cell phone for tilt perception, and smaller stand alone sensors are available as wearable devices. It is possible to wear a series of IMUs to estimate the position of a limb. If an astronaut is wearing properly placed IMU sensors, we now have the ability for the first time to essentially see how they are moving inside the space suit. In suit motion provides critical information on the astronaut-suit interactions that could potentially be used to determine the source of in-suit astronaut injury and to inform future design.
I used wireless IMU devices to look at elbow motions of a subject inside a test space suit built by the David Clark Company. I presented these findings at the International Astronautical Congress in Naples, Italy in 2012. See the paper in my publications section.
Copyright 2015-2018 Forrest E. Meyen Header Image Credit: NASA BioSuit Image Credit: Dr. Michal Kracik