Making it Work in Zero Gravity
A team from UB working with NASA design and build a specialized tool to be used in space.
Some engineering students dream of working with NASA and long to be involved in any activity related to outer space. Last year, three mechanical engineering graduate students were given that opportunity by Zheng (Jeremy) Li, Ph.D., Associate Professor of Mechanical Engineering, who involved the students in his project funded by the National Space Grant Foundation’s (NSGF) eXploration Habitat (X-Hab) Academic Innovation Challenge Grant program.
Li, who worked for more than a decade in industry research and development prior to his academic appointment, welcomed the challenge to develop a reduced gravity sample holder/manipulator tool for NASA’s Deep Space Habitat Geo-Lab. NSGF’s X-Hab is a NASA-funded program designed to engage students in the science, technology, engineering and math disciplines through participation in authentic engineering projects.
As one of four universities in the U.S. awarded a grant for 2012, UB’s team was charged with the design, analysis, manufacture, and assembly of a subsystem that would be able to function in a deep space environment. Other 2012 X-Hab grant recipients were the Ohio State University, the University of Maryland at College Park, and Oklahoma State University.
Since time constraints are a major issue for astronauts, automated tasks save precious time. To that end, Li and his team were charged with designing an automated microgravity sample holder and manipulator to be integrated into the existing Geo-Lab glovebox testbed. The holder/robotic-type manipulator needed to have the capability for Earth-based NASA personnel to explore the chemical composition of rock and soil materials by way of remote satellite communication during manned missions, thus freeing the astronauts for other important tasks. And, since the sample materials would almost certainly exceed the space required to return the samples to Earth, this tool could be used to help determine and prioritize which samples are most representative and should be kept. In addition, armed with important data secured in advance, Earth-based NASA scientists would have time to plan for appropriate storage, handling, and analysis for the extraterrestrial geological samples selected to make the trip to Earth.
The year-long project was held to a tight timetable with milestones, checkpoint reviews, and consultations with NASA engineers to produce a viable prototype. The project unfolded in stages, beginning with design, followed by manufacture and assembly, to culminate in product delivery, testing, and integration. Li and his UB research team first met with the NASA engineering team via virtual conferencing and immediately set out to develop preliminary design concepts for review and consideration. Li divided activities among the students into the areas of design and 3D modeling, materials selection, and cost-effective manufacturing planning, mirroring the actual process and procedures for prototype design and development used in industry.
Design versions were developed via CAD modeling, and 3-D FEA structural analysis was performed to produce multiple iterations that were evaluated through virtual technical meetings and correspondence between the UB and NASA teams. The best design option was selected—a small robotic arm attached to two linear slides and a vertical slide with a rotating table that can function as a zero-gravity sample holder and manipulator tool to handle geologic material from the moon and other bodies in the solar system. An important consideration of the design was the tool’s seamless integration with the existing Geo-Lab glovebox testbed.
The next stage involved transforming the virtual prototype into an actual prototype in a short time period. Product assembly took place on campus with parts that met specifications for weight, cost, materials and integration. Named the Sample Holding System, the completed tool consists of a cantilever arm, rotary arm, and gripper with three-axis translation to allow the rotation of six degrees of freedom of a geologic sample in microgravity, with motion controlled by two linear slides and a single vertical slide (with rotating table). Since the motor control systems for slides and gripper arm must work together, they needed to be configured into a fully integrated system that can be controlled from one computer, which UB tested successfully. NASA’s unique security system required additional modifications to be completed after delivery.
Li and his research team delivered the Sample Holding System prototype to NASA’s Houston Johnson Space Center for system integration and further testing in May 2012. During their visit, the team met with NASA scientists and saw the Deep Space Habitat in which the Sample Holding System will be housed and operated. In September 2012, the model made its first trip with the NASA Desert Research and Technology Studies unit to an undisclosed location in the desert of California, where it was tested in a vacuum-controlled environment similar to that of space. Li hopes the knowledge gained from the project can be applied to further studies in the realms of geosciences, contamination control, and microgravity operations. In addition, the monumental endeavor has helped to improve modern product design and fundamental material research to improve aerospace exploration.