Engineers at NASA have used one of the world’s lightest solid materials to construct an ultra-lightweight aerogel antenna that could be embedded into an aircraft's skin. This would create a more aerodynamic and reliable communication solution for drones and other future air transportation options. This antenna is designed to enable satellite communications where power and space are limited.

 Aerogel is made up of flexible, high-performance plastics known as polymers. The design features high air content (95%) and offers a combination of lightweight and strength. Researchers can adjust its properties to achieve either the flexibility of plastic wrap or the rigidity of plexiglass.

 A sample of aerogel is folded to demonstrate its flexibility during testing  

“By removing the liquid portion of a gel, you’re left with this incredibly porous structure,” said Stephanie Vivod, a chemical engineer at NASA’s Glenn Research Center in Cleveland. “If you’ve ever made Jell-O, you’ve performed chemistry that’s similar to the first step of making an aerogel.” 

NASA sandwiched a layer of aerogel between a small circuit board and an array of thin, circular copper cells, then topped the design off with a type of film known for its electrical insulation properties. This innovation is known at NASA and in the aviation community as an active phased array aerogel antenna. 

 NASA's Flat Aerogel Array Antenna

In addition to decreasing drag by conforming to the shape of aircraft, aerogel antennas save weight and space and come with the ability to adjust their individual array elements to reduce signal interference. They are also less visually intrusive compared to other types of antennas, such as spikes and blades. The finished product looks like a honeycomb but lies flat on an aircraft’s surface. 

In the summer of 2024, researchers tested a rigid version of the antenna on a Britten-Norman Defender aircraft during an in-flight demonstration with the U.S. Navy at Naval Air Station Patuxent River in Maryland. In October 2024, researchers at NASA Glenn and the satellite communications firm Eutelsat America Corp., of Houston, began ground testing a version of the antenna mounted to a platform. The team successfully connected with an Eutelsat satellite in geostationary orbit, which bounced a signal back down to a satellite dish on a building at Glenn. Other demonstrations of the system at Glenn connected with a constellation of communications satellites operated in low Earth orbit by the data relay company Kepler. NASA researchers will design, build, and test a flexible version of the antenna later this year. 

“This is significant because we are able to use the same antenna to connect with two very different satellite systems,” said Glenn researcher Bryan Schoenholz. Low Earth orbit satellites are relatively close, at 1,200 miles from the surface, and move quickly around the planet. Geostationary satellites are much farther – more than 22,000 miles from the surface – but orbit at speeds matching the Earth’s rotation, so they appear to remain in a fixed position above the equator.

“If an autonomous air taxi or drone flight loses its communications link, we have a very unsafe situation,” Schoenholz said. “We can’t afford a ‘dropped call’ up there because that connection is critical to the safety of the flight.”

Satellite testing was crucial for analyzing the aerogel antenna concept’s potential real-world applications. When modern aircraft communicate with stations on the ground, those signals are often transmitted through satellite relays, which can come with delays and loss of communication. This NASA-developed technology will make sure these satellite links are not disrupted during flight as the aerogel antenna’s beam is a concentrated flow of radio waves that can be electronically steered with precision to maintain the connection. 

As new types of air transportation options are brought to the market and U.S airspace from the small, piloted aircraft of today to the autonomous air taxis and delivery drones of tomorrow, these kinds of steady connections will become increasingly important. That’s why NASA’s Advanced Air Mobility mission and Transformative Aeronautics Concepts program are supporting research like aerogel antennas that can boost industry efforts to safely expand the emerging marketplace for these transportation systems.