Aerospace and defense contractor Radian Aerospace, which is best known for its Radian One Single-Stage-to-Orbit (SSTO) concept spaceplane, has announced the creation of Dur-E-Therm, a next-generation material spacecraft coating designed to enable SSTO spaceflight and support hypersonic military or commercial applications.
“Dur-E-Therm enables high-speed flight of lightweight composite systems that can operate repeatedly without degradation, opening up a universe of opportunities,” Radian’s Chief Technology Officer (CTO) Livingston Holder told The Debrief.
Initially designed to protect the Radian One and similar delta-winged spacecraft during both ascent and descent, the new material also offers an option for horizontal takeoff and landing spacecraft due to its durability at extreme speeds and potential cost savings from its reusability.
“This innovation could reshape the future of reusable spaceflight and hypersonic military applications,” a company spokesperson told The Debrief.
Single-Stage-to-Orbit Flight Now Possible with Dur-E-Therm
Several spaceplane concepts, such as the Aurora, have proposed different methods and materials to overcome the various stresses and extreme conditions high-altitude aircraft designed to exit and re-enter Earth’s atmosphere will face. The U.S. military is also evaluating different configurations for hypersonic air-breathing missiles and hypersonic air-to-ground missiles that face similarly extreme conditions during high-speed atmospheric flight. Radian Aerospace says their new material is ideally suited for these applications.
In an email to The Debrief, Holder explained how Dur-E-Therm’s performance surpasses traditional spacecraft tiles used to coat modern re-entry vehicles. For example, a conventional thermal protection system (TPS) like shuttle tiles has a single-layer construction made with ablative materials designed to survive reentry only once. In contrast, Dur-E-Therm comprises several layers designed to perform several different purposes.
“Dur-E-Therm is a multilayer insulation system that features a durable external shell capable of withstanding the heat of reentry without damage, along with layers of lightweight material underneath that endure the heat of reentry without degradation,” Holder explained.
Radian’s marketing materials explain that the multi-layer design is comprised of three components: a Carbon Silicon Carbide (C/SiC) Ceramic Matrix Composite (CMC) outer shell, insulation layers of commercially available Opacified Fibrous Insulation (OFI), aluminosilicate aerogel and a Radian-proprietary formulation of polymeric aerogel insulation, and mechanical attachments to the underlying cold structure.
According to Holder, these materials make their TPS lightweight and durable, “allowing it to be used repeatedly without damage.” Holder added that this reusability can result in significant cost savings compared to the many hours of maintenance required between flights to replace traditional lightweight yet fragile TPS tiles.
High-Temperature Tests Reveal Material’s Benefits
Before testing Dur-E-Therm’s performance in the harsh conditions of high-speed atmospheric flight, Radian engineers worked with experts at the NASA GRC materials lab on several multi-cycle torch tests to evaluate its insulative properties and potential for reusability.
In those tests, engineers used a Natural Gas/Oxygen torch to expose a sample of Dur-E-Therm dubbed ‘engineering development unit (EDU) 1’ to temperatures exceeding 2,700F. Simulating exposure at these extreme temperatures represents “multiple ascent and descent profiles.”
After examining the results, the NASA/Radian Aerospace team deemed the tests successful. In addition to simply surviving the extreme temperatures of multiple cycles, the company said that Dur-E-Therm demonstrated “promising insulative properties and reusability potential.”
Testing for an upgraded version of Dur-E-Therm, EDU 1a, is already underway. In addition to potentially offering support for the team’s initial torch tests, the company says its new round of high-temperature torch testing is designed to evaluate insulation improvements over TPS EDU 1. The team hopes the tests also “establish the reusability of the CMC external TPS panels.”
Military And Commercial Applications
The new TPS that Radian is calling “a game-changer for SSTO (single stage to orbit) and HTL (horizontal takeoff & landing) spaceplanes” is not yet available for in-space applications. However, the company said Dur-E-Therm’s combination of reusability and advanced materials engineering makes it perfect for the emerging hypersonic marketplace, including potential military and commercial applications.
“It can be used to protect aircraft or spacecraft from the heat of flying through the atmosphere at hypersonic or reentry velocities, making it suitable for our vehicle or anything requiring atmospheric flight at hypersonic speeds,” Holder told The Debrief.
Learn more about Radian Aerospace’s mission and the Radian One experimental concept spacecraft, and look for upcoming announcements about Dur-E-Therm on the company’s website, www.radianaerospace.com.
“Radian is committed to contributing to missions that enhance life on Earth, including research and development, in-space manufacturing, and Earth observation, as well as critically emerging missions such as rapid global delivery,” the website says.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.