Designing Spacecraft of the Future
In hopes of designing next-generation spacecraft that can explore our universe more fully and more efficiently than ever before, scientists like Suzanne Weaver Smith, an associate professor of mechanical engineering, have turned their attention to cellophane.
Not really cellophane, but strong, very thin, ultra-lightweight, and highly flexible materials referred to as "gossamer materials," which can be tightly compacted for launch and then deployed once in space.
These materials are planned for future spacecraft as solar sails. Large expanses of reflective gossamer material would capture solar energy to fuel the propulsion of these enormous yet lightweight spacecraft into deep space. Or, closer to Earth, this material might be utilized in support structures for telescopes or satellites.
For either application, the gossamer material must be ultra-lightweight, and yet strong enough to withstand the disturbances of spacefrom barrage by micrometeors to constant expansion and contraction from temperature shifts. Without such stability, the spacecraft could easily be thrown off trajectory, thus ending the mission.
This is where Smith's research comes in. With the help of supercomputers and a computer program called Automated Multi-Level Substructuring (AMLS)software designed originally to facilitate modeling new automotive designSmith worked to predict the gossamer material's motion response in the wake of dynamic disturbances such as those commonly found in space.
Predicting the motion of the entire gossamer spacecraft requires pinpointing the possible direction of motion at thousands of finite points within ita computational process involving hundreds of thousands of equations. One aspect of Smith's project involved testing whether the AMLS software, previously applied only in new-car design, could accurately compute such large-scale models for predicting spacecraft response.
"AMLS had been proven in the automotive industry, but it hadn't been tested for spacecraft," says Smith. "We found that it could be adapted very successfully to this field as well."
With a better understanding of the gossamer spacecraft's response to disturbance, Smith and her team could then redesign the material, including implementing intricate patterns within it, much like crimping a hair, to amplify its strength and stability.
"Ultimately, if you can compute the solutions and predict the motion response, you can help design stronger material," Smith says. "For a particular mission, we might already know the material will be subject to a particular disturbance. We can test for degradation and performance under those conditions and then change the design to get the type of response we need."
About Suzanne Weaver Smith
Suzanne Weaver Smith worked in spacecraft design with Harris Corporation, a Florida-based communications equipment company, before joining the UK faculty in 1990. Her current research is an evolution of her dissertation work at Virginia Tech, which focused on modeling the dynamic motion of the international space station. In addition to her work with spacecraft design, she also models the motion of Earth-bound dynamic structures, such as cable-stayed bridges. She currently heads the UK Dynamic Structures and Controls Laboratory.
Dynamic Structures and Controls Laboratory Gossamer Spacecraft Research Team