CU, others to study hypersonic vehicles
University of Colorado Boulder researchers have partnered with universities both nationally and internationally as experts for the first time to study why communication blackouts occur to vehicles moving at hypersonic speeds — faster than the sound of speed.
“The British government is paying for the (University of) Oxford, and our government is paying for the work in the U.S. I think this may be the first time where we have two governments agree on the elements of a project like this. It’s pretty cool, so hopefully we don’t blow it,” laughed Iain Boyd, aerospace engineering professor and the director of the Center for National Security Initiatives at CU Boulder.
Boyd is leading the upcoming project funded by the U.S. Department of Defense’s Multidisciplinary University Research Initiative. CU received a fiveyear, $7.5 million grant to complete the project, which will begin this fall, Boyd said. The University of New Mexico, Ohio State University and Stanford University are the other U.S. colleges participating in the project.
Boyd and Tim Minton, a CU chemistry professor, are also part of a $15 million, five-year NASA project that seeks to improve entry, descent and landing technologies that will be used when exploring other planets with hypersonic vehicles.
As the U.S. continues to pursue projects like the one for NASA, the need to be able to communicate with hypersonic vehicles such as missiles, aircraft or spacecraft is crucial, Boyd said. But right now, constant communication isn’t always possible.
When a hypersonic vehicle travels through air, it heats it up to temperatures akin to the sun, forming plasma around the vehicle, Boyd explained.
“If you have a vehicle surrounded by plasma, it interferes with communication to and from the vehicle,” he said. “You can’t communicate with your vehicle under certain circumstances, and that’s bad for all kinds of reasons: if you need to control the vehicle, if you need to self-destruct, you can’t do it.”
This same phenomenon occurs with space shuttles, which travel faster than hypersonic vehicles, Boyd said. An airplane travels about Mach 0.8, a hypersonic vehicle flies at Mach 5 or above, and a space shuttle travels about Mach 25. During missions like the moon landing, communication blackouts occurred due to the speed the shuttle was traveling, but scientists have found ways around those blackouts by using satellites and other methods.
When it comes to communication blackouts for hypersonic vehicles, no research has been done, Boyd said.
“There is basically a gap in basic information,” he said. “We don’t know how plasma forms in these conditions.”
To study the issue, scientists like Minton will be conducting experiments. Minton will shoot molecular beams of oxygen and nitrogen atoms — the elements that make up air — at each other to get the same interaction as what happens when a hypersonic vehicle travels through air.
From there, they will need to increase the scale of the experiment to make it equivalent with what would actually happen around a hypersonic vehicle.
“That’s the exciting process of the project, is you go from one collision at a time and find a way to scale it up and do an analysis of the actual vehicle,” Boyd said.
Minton said what he enjoys about projects like these is they give him the ability to apply experimental data to a practical problem.
Boyd said in addition to communication issues, this research is also important to track other hypersonic vehicles such as missiles being constructed or used by countries like Russia and China and for space exploration.