Engineers Developing New Protective Coating for Spacecraft

University of Texas at Dallas researchers are developing a material to protect spacecraft in low Earth orbit (LEO) from harsh environments that can damage vehicles in space, such as satellites, shortening their lifespans.

The research project is supported by a two-year, $1 million grant from the Defense Advanced Research Projects Agency (DARPA).

The research is part of DARPA's Materials Investigation for Novel Operations in Space (MINOS) program, which supports the development of material systems with low-drag characteristics and significantly greater resistance to erosion and corrosion for use in LEO, which extends up to about 1,200 miles above Earth. The new materials are designed to protect satellites and other spacecraft components from two main threats: atmospheric drag and erosion.

When satellites collide with molecules and atoms in the LEO atmosphere, this causes drag, and the craft will lose its orbit and fall back to Earth. Atomic oxygen, formed in the lower atmosphere when ultraviolet radiation from the sun splits oxygen molecules into single atoms, is the most common particle in LEO. In addition to causing drag, these highly reactive oxygen atoms can bind to spacecraft surfaces and cause oxidation, or rust, and erosion.

The researchers are applying techniques currently used in other industries to design the material. One of the approaches, atomic layer deposition, originated in microelectronics manufacturing. The process allows manufacturers to build coatings one atomic layer at a time for greater control and precision.

Another approach is the sol-gel technique, which involves making solid materials from a liquid solution to create surfaces smooth enough to resist atmospheric drag. Sol-gel, used to create optical materials such as antireflective coatings, allows precise control over the composition and structure of the final material.

"This project marks a significant advancement in creating materials that enhance space resilience, providing long-term protection for essential components in upcoming space missions."

Dr. Rafik Addou, assistant professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science

"This project marks a significant advancement in creating materials that enhance space resilience, providing long-term protection for essential components in upcoming space missions," said Dr. Rafik Addou, assistant professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science and principal investigator on the project.

Results from independent testing have demonstrated that the UT Dallas coating can withstand atomic oxygen conditions better than those in space, Addou said.

Addou is collaborating with co-principal investigators and materials science and engineering professors Dr. Julia Hsu, a Texas Instruments Distinguished Chair in Nanoelectronics; Dr. William Vandenberghe; and Dr. Robert Wallace, the Jonsson School Distinguished Chair.

As the UT Dallas team continues its work to enhance the coating, Addou said he hopes the research can help extend the lifetime of satellites, which currently last about five years before falling back to Earth. Addou also dreams of enabling satellites to operate closer to Earth, in the lower end of LEO, where the environment is even harsher because of the much higher amount of atomic oxygen and increasing nitrogen concentration. Known as very low Earth orbit, this area is 60 to 280 miles above Earth.

The space-related research is a new area for the four investigators, who typically work on materials and interfaces for semiconductor science and technology. Hsu also conducts research related to solar-cell manufacturing.

Vandenberghe, who focuses on computer simulations and modeling, said he was eager to work on the project to help improve communication and navigation in space and to help monitor the space environment.

"Helping to make multiplanetary life possible is a childhood dream come true," Vandenberghe said.

Joslin Prasanna, a materials science and engineering graduate student, presented research - "Atomic Oxygen-Resistant Metal Oxide Coatings for Space Operations in Low-Earth Orbit" - from the team in September at the American Vacuum Society (AVS) International Symposium and Exhibition in Charlotte, North Carolina. Prasanna was recognized as an AVS Advanced Surface Engineering Division Rising Star for his presentation.

Media Contact: Kim Horner, UT Dallas, 972-883-4463, [email protected], or the Office of Media Relations, UT Dallas, (972) 883-2155, [email protected].