April 8, 2021 — Entry, descent, and landing technologies are critical to placing large payloads on other planets such as Mars. As a spacecraft enters an atmosphere of a planet such as Earth or Mars, collisions with the atmospheric atoms and molecules generate very high temperature in the leading edge of the entry vehicle.

To protect from the extreme heat, it is necessary to cover the vehicle with a thermal protection system, which consists of lightweight tiles that resist heat. Accurate modeling and simulation of atmospheric entry systems are critical and must continue to improve as part of the design and planning of these missions.

In conjunction, the new Advanced Computational Center for Entry System Simulation (ACCESS) Institute, announced recently by NASA, has provided $15 million in funding through a five-year multi-partner collaboration that includes The University of New Mexico to advance the analysis and design of NASA entry systems by developing a fully integrated, interdisciplinary simulation capability.

ACCESS will focus on thermal protection systems and develop game-changing capabilities through the use of high-fidelity, validated physics models. This advancement will be enabled by innovative numerical algorithms, high-performance computing, and uncertainty quantification methods, with the goal of enabling computational entry system reliability assessments. UNM’s part in this work is to help NASA understand the fundamental chemical processes involved.

“The idea is to design the next generation of materials to protect spacecraft traveling to Mars and on the other end, back to earth,” said Hua Guo, UNM Distinguished Professor of Chemistry and Chemical Biology. “These are called thermal protection systems and very little is known about the associated chemistry. The question is can we actually design these things computationally that will save a lot of money and maybe learn things that are more fundamental than what tests can tell us.

“As part of the work, we’ll conduct quantum chemical and reaction dynamics calculations to figure out what kind of reactions is going to take place and what products are going to come out, as high-speed oxygen and nitrogen atoms hitting the surface of the thermal protection systems. The ablation process needs to be understood in order to improve and to design next-generation thermal protection systems. That’s what we’re trying to do.”

Iain Boyd of the University of Colorado Boulder will serve as the principal investigator and lead the ACCESS team. Other partners in the new institute are the University of Illinois at Urbana-Champaign, the University of Minnesota Twin Cities, the University of Kentucky in Lexington, and several international collaborators from England, Italy and Portugal.

To ensure safety, NASA has incredibly demanding entry system reliability requirements that cannot be fully met with today’s approaches, Boyd said. Meeting those goals will require interdisciplinary work in the fields of aerospace engineering, chemistry, radiation, materials, structures and reliability, all within a single, comprehensive computational framework.

“We are thrilled to have this opportunity to work in partnership with colleagues across the country on the incredibly challenging and important problem of hypersonic entry system analysis for NASA,” Boyd said.

“We’re in the age of space exploration and not only is NASA doing all these kinds of exploratory studies, but there are also many commercial people who are doing these studies also. I think we’re going to take advantage of space and the last frontier, and chemistry is playing a big role in all these processes and adventures. I think UNM is chosen as a partner in these projects because we have the capacity and the reputation to help them to understand the chemistry,” added Guo.

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Source: UNM