When it comes to solving problems for his job, the work done by Dr. Levi Moore actually is rocket science. As a research chemist with the United States Air Force Research Laboratory, he’s tasked with helping to develop new materials that make it easier and safer to launch rockets into space.
“In just one rocket, there are so many opportunities for new and improved materials—from low-temperature rubbers to composite resins with higher service temperatures that allow for lightweight, reusable rocket systems,” Dr. Moore says. “And the lessons we learn about these materials can find their way into other systems, like airplanes, as well.”
But discovering and testing these new materials is no simple task—and the demands placed on a rocket leave no room for error.
“Aerospace materials must be resilient in ever-increasingly tough operating environments,” Dr. Moore says. “Composite cases for rockets must be immensely strong to stand up to the high pressures and temperatures when in operation. On the opposite end of the spectrum, rubbery parts must maintain their flexibility and mechanical robustness even at very low temperatures in the upper atmosphere, and sometimes even down to cryogenic temperatures, depending on the application.”
To meet these stringent demands, Dr. Moore and his colleagues are continuously looking for innovative tools to help them better identify and evaluate potential candidates for new rocket materials. Computer modeling and simulation has already been widely adopted in this industry, but usually on a macro-scale, like using computational fluid dynamics to test aerodynamics. Dr. Moore is using computer simulation on a micro-scale, leveraging Schrödinger’s computational platform to simulate how certain materials might stand up to the stresses of space travel.
“The advantage of digital simulation is that it can eventually help cut down on the number of new molecules we’d need to synthesize, leading to a more efficient and less resource-intensive iteration cycle,” says Dr. Moore.
Harnessing digital chemistry allows his team to investigate materials in ways that otherwise would be both time and resource intensive. “We’ve been able to watch water diffuse into a crosslinked polymer matrix and see where the water molecules are most attracted to specific chemical groups. To do something like this experimentally, you would need access to extremely complicated setups only available at national labs, and even then, you would only be able to see the water on the macro scale without the fine atomistic detail the simulation affords.”
“The advantage of digital simulation is that it can eventually help cut down on the number of new molecules we’d need to synthesize, leading to a more efficient and less resource-intensive iteration cycle,” says Dr. Moore.
Dr. Moore and his team have used Schrödinger’s molecular simulation tools to advance research on new high-performance materials, such as composite resins that can enable aircraft to fly faster, higher, and further due to reduced weight and improved strength. His team also integrates computational methods to explore the potential of additive manufacturing, also known as 3D printing—the process of building an object in incredibly fine layers. This method could be used to reconfigure existing materials in new, more complex geometries that may make them more tolerant of harsh environmental conditions.
Digitally simulating material properties at a molecular level is a relatively new approach in aerospace, but one which is already showing compelling use cases for organizations like the Air Force Research Laboratory. And there is undoubtedly more innovation to come, Dr. Moore says, as computational approaches become exponentially more advanced.
“The greatest challenge will be the end goal of a system where you can input the desired properties of a material and the system would be able to find a solution in that space, and if that solution does not exist, then it can iterate through new, as-of-yet undiscovered materials, and output a target synthetic molecule that will possess the desired properties.”
