Students Design Innovative Spacecraft Inspection System at Stevens
April 25, 2011
The next technology to keep astronauts safe is just around the corner at Stevens Institute of Technology, where a Mechanical Engineering Senior Design team of Regina Pynn, Tom Lakatos, Matthew Edwards, and Michael Dambakly, advised by Associate Professor of Mechanical Engineering Dr. Eui-Hyeok (EH) Yang, has created a rotational system of propulsion for a Remotely Operable Inspection Craft (ROIC). This small, reusable system could easily be deployed to capture images of the exterior of spacecraft in order to assess damage suffered in liftoff or flight. Able to remotely inspect damage to the craft, the ROIC supplants expensive, time-consuming, and dangerous methods, such as a spacewalk or rendezvous with another orbital satellite, such as the International Space Station (ISS).
ROIC would help to prevent a tragedy like the space shuttle Columbia disaster of 2003. After a free-flying piece of insulation foam struck the leading edge of the wing, scientists were unable to assess the extent of the damage. The ship disintegrated upon reentry to the atmosphere, resulting in the death of all seven crew members. The ROIC will be able to remotely inspect damage and alert the crew, with minimal expense and planning.
Tasked to design a system that allows the ROIC to rotate in space on three axes the team chose to use reaction wheels, proven technology used to position the Hubble Telescope and other satellites. Team member Regina Pynn explains the process: "If you use a power drill, you feel it try to move your arm because the motor is spinning, trying to create a counter-spin. In space, there is nothing to push against, so you can use that counter-spin to rotate a vehicle." The team came up with a system of three rings within the ball, each connected to a motor, which provides the angular momentum along a specific axis. This allows the ROIC to easily pivot to face the direction of suspected damage to a spacecraft.
The finalized rotational system comes in a surprising, yet convenient and inexpensive package: a hamster ball. The housing started out as a joke, but the design actually solved all of the team's problems, explains team member Michael. "It's cheap, sturdy, has holes for access, vents to cool electronics, and is easy to work with. Oddly enough, a hamster ball simply worked well!"
With this system implemented, further challenges needed to be overcome in order to demonstrate the craft's effectiveness. "The motors have to generate enough force against the rings to rotate this entire craft," team member Matthew explains. But, he notes, without a gravity-free environment, this is difficult to demonstrate. "Our hope is ultimately that this device will overcome friction and gravity to roll around on the floor," Matthew says. Overcoming the friction and gravity of Earth would easily satisfy the requirements for rotating in space.
The team views the project as the capstone of their learning at Stevens, incorporating and expanding on classes and even introducing them to related fields of study. "This project made us not only use our broad understanding of engineering that we've gained since freshman year, but dive deeper into some of these subjects than our undergrad classes ever dreamed of going," Michael says. "I've learned a lot, and this project is proof of our capabilities." The theoretical model incorporated forces, inertias, masses, torques, advanced control systems, and fluid flow dynamics. The prototype had them apply knowledge in computer programming, electrical, and communications.
"This proof-of-concept system is a pathfinder of future inspector microsatellite, which can be deployed to assess damage of the craft exterior, which supplants a spacewalk," says the team's advisor, Professor Yang. "The Senior Design team really did an excellent job in creating their own design and developing the control methods with minimal guidance."
The team says that Dr. Yang's NASA experience was essential for determining what was and was not feasible for their project. Other professors have offered help along the way: Dr. Cappelleri with the communications system and Dr. Zavlanos with the control system.
"I know that I would not have been able to do such amazing things without the help and assistance from both my teammates and the professors here at Stevens," Tom says. He views the project as another step forward in his fascination with space. "I have been interested in Space Systems ever since I was a child, learning about the space race and reading science fiction. It has always been a labor of love for me."
The team shares a passion for space systems engineering and attained real-world training in the field through Stevens renowned Cooperative Education program, through which they worked at corporations and organizations such as Hamilton Sundstrand, NASA, and the United States Navy.
Michael will graduate with a both Bachelor's and Master's Degrees of Mechanical Engineering, with concentrations in Aerospace Engineering and Robotics and Automation. He has spent his last three co-op semesters working at Naval Air Systems Command (NAVAIR), managing the installation of support equipment which the Navy used to test components of the F-18 fighter jet. He will be joining NAVAIR full-time after graduation.
Matthew will graduate with a Bachelor's Degree in Mechanical Engineering with concentrations in Aerospace Engineering and Robotics and Automation. Through the co-op program, he worked for both the Army and Navy. He hopes to enter either the aerospace industry or the field of robotics.
A Mercerville, NJ, native, Tom will graduate with a Bachelor's of Engineering Degree in Mechanical Engineering with a concentration in Aerospace Engineering. He spent three co-operative semesters at Hamilton Sundstrand Windsor Locks, where he worked on projects to aid the International Space Station (ISS), including working on the Water Processor Assembly and designing diagnostic tools to test the American Spacesuit onboard the ISS.
Regina will graduate Stevens with a Bachelor's of Engineering Degree in Mechanical Engineering, a minor in Law and Public Policy, as well as a master's degree in Systems Engineering with a graduate certificate in Space Systems Engineering. Through Stevens co-op program, she was able to pursue her passion for space systems engineering, working at NASA's Kennedy Space Center and Hamilton Sundstrand, which she will join after graduation as a project engineer working with aircraft engines. "My experience with co-op made me appreciate the scale and scope of the technical challenges in the aerospace industry," Regina says. "I became an engineer so I could work on world-changing, cutting-edge technology projects, and I can find no better place to do that work than aerospace."
Dr. E. H. Yang
Professor Yang has years of aerospace experience as an engineer at the NASA Jet Propulsion Laboratory (JPL) from 1999 to 2006. He also received the Lew Allen Award for Excellence for advancing the use of MEMS-based actuators for NASA's space applications.