The Defense Advanced Research Projects Agency (DARPA) is asking for design proposals on heat protection technology for hypersonic vehicles. On the defense organization’s website, DARPA explains that hypersonic vehicles travel at high speeds. As they dart through the atmosphere at speeds of Mach 5 and above — 3,836.35 mph — they create friction with the air. Going back to the basics of physics, friction then creates heat, which can cause hypersonic vehicles to literally burn up.
To combat this problem, DARPA is hosting a Proposers Day in Arlington, Virginia. Scheduled for Jan. 22, 2019, companies are invited to provide DARPA with proposals on how to design a hypersonic vehicle that can withstand the substantial amount of heat to which it’s exposed during flight. Known as the Materials Architectures and Characterization for Hypersonics (MACH) program, it specifically covers two things: the development of thermal protection technology for hypersonic vehicles, and the development of new hypersonic vehicle materials.
Hypersonic technology is still in its infancy, primarily because of poor heat protection technology. There are aerospace vehicles are currently capable of flying at hypersonic speeds. However, experts are skeptical that these modern-day hypersonic vehicles can withstand the heat to which they are exposed during flight.
When discussing the MACH program, Bill Carter explained that experts have been trying to develop cooling technology for hypersonic vehicles for decades but have been largely unsuccessful. “For decades people have studied cooling the hot leading edges of hypersonic vehicles but haven’t been able to demonstrate practical concepts in flight,” said the program’s manager Bill Carter. “The key is developing scalable materials architectures that enable mass transport to spread and reject heat.” Hypersonic flight simply produces too much heat for vehicles to withstand. But that’s something DARPA is hoping to change with its MACH program.
Some people assume that hypersonic flight is the same as supersonic, but this isn’t necessarily true. The term “supersonic” refers to faster than the speed of sound, which is Mach 1 or faster. With hypersonic being Mach 5, it’s five times faster than supersonic. This almost-unthinkably fast speed creates a substantial amount of friction. Heat-related friction can be minimized by flying vehicles in higher levels of Earth’s atmosphere, such as the mesosphere or thermosphere rather than the troposphere. But hypersonic vehicles are simply too fast. Even when flying in an upper atmospheric level, the friction they produce causes intense heat.
You can learn more about DARPA’s plan to develop heat protection for hypersonic vehicles here.