A New Heat Shield for Sierra Space Dream Chaser

In a recent press release, Sierra Space announced the development of an innovative Thermal Protection System (TPS) in collaboration with the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL). The silicon-carbide-based TPS has been designed to satisfy the commercial space industry’s requirements for reusable spacecraft, like the Sierra Space Dream Chaser.

Sierra Space and the Oak Ridge National Laboratory (@ORNL) are collaborating on a groundbreaking new technology that will enable exterior spacecraft tiles to withstand the high temperatures of re-entering Earth's atmosphere over multiple missions.

Link: https://t.co/i0Wd2lqHvo pic.twitter.com/Iwa7Rof6lD
— Sierra Space (@SierraSpaceCo) November 14, 2024

Made from advanced materials, the new heat shield will have to endure extremely high atmospheric re-entry temperatures over multiple, frequent travels. Its exterior tiles allow it to resist a huge heating load, and the insulating tile backside provides adequate protection to keep the other parts of the spacecraft at nominal temperatures.

“Our patent-pending Thermal Protection System is like nothing ever before created and essential to a near future where space travel becomes routine. Reusability of space vehicles is a key factor in expanding the commercial space industry and to do that we need new technology to keep spacecraft and crew safe.”

— Tom Vice, CEO at Sierra Space

A revolution in re-entry thermal protection

Dream Chaser’s famous predecessor, the Space Shuttle, was protected with heat tiles designed to fly for a maximum of five times a year, requiring huge maintenance efforts. Sierra Space and ORNL leveraged the knowledge and the lessons learned over the thirty years of the Space Shuttle program to develop the new technology.

The new TPS tiles are made with an innovative composite material based on silicon carbide, which is largely stable at high temperatures and in corrosive conditions, and carbon fibers, which have high strength and high-temperature consistency.

*A rendering of the Dream Chaser spaceplane during atmospheric re-entry. Credits: Sierra Space*

The tile’s light weight helps optimize the commercial payload, and its physical properties ensure that the spaceplane surface keeps its aerodynamic profile over multiple flights by withstanding changes in size and shape caused by extreme heat exposure.

“Keeping a consistent outer mold line is important for reusability. It keeps the aerodynamics the same to allow the vehicle to fly as designed,” declared Greg Larsen, ORNL principal investigator.

Further development steps before the full production

The first phase of the TPS’s development has been completed, and Sierra Space and OATL have filed the patent request. Next, the new tiles will undergo a series of tests at NASA’s Ames Arc Jet Complex, a unique facility that simulates the aerothermodynamic heating of hypersonic atmospheric entry.

*The Aerodynamic Heating Facility is part of NASA’s Arc Jet Complex. Credits: Cesar Acosta, NASA*

Subsequently, Sierra Space and OATL will work to lower the TPS production costs using advanced manufacturing techniques, and then they will be ready to equip a Dream Chaser spaceplane. Due to the current development stages, the first spacecraft to use the new TPS will be Reverence, which is currently being assembled at Sierra Space Dream Factory in Colorado.

*Dream Chaser Reverence is in production at Sierra Space Dream Factory in Colorado. Credits: Sierra Space*

The Dream Chaser Tenacity, the first ever produced, is equipped with the previous version of the heat shield and is in the final preparation stages for its maiden flight, a cargo resupply mission to the International Space Station. The launch is planned for no earlier than May 2025 on top of a ULA Vulcan rocket.