Flight Engineers Give NASA’s Dragonfly Lift

By sending a car-sized rotorcraft to explore Saturn’s moon Titan, NASA’s Dragonfly mission will embark on an unprecedented journey of scientific discovery. And work to ensure this one-of-a-kind project can realize its ambitious exploration vision is underway at some of the nation’s most advanced space simulation and test laboratories.

Scheduled for launch in 2028, the Dragonfly rotorcraft is designed and built at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, with input from organizations around the world. Arriving in 2034, Dragonfly will exploit Titan’s dense atmosphere and low gravity to fly to dozens of locations, exploring diverse environments from organic equatorial dunes to an impact crater where liquid water and complex organic matter essential to life (at least as we know it) could have existed together.

Aerodynamic testing

When full rotorcraft integration and testing begins in February, the team will leverage a wealth of data collected from critical engineering tests conducted over the past three years, including, most recently, two campaigns conducted at the Transonic Dynamics Tunnel (TDT) facility at NASA’s Langley Research Center in Hampton, Virginia.

The TDT is a 16-foot-high, 16-foot-wide, and 20-foot-long multipurpose testing center that has hosted studies for NASA, the Department of War, the aviation industry, and numerous universities.

Over five weeks from August to September, the team evaluated the performance of Dragonfly’s rotor system – which provides lift for the lander to fly and allows it to maneuver – under conditions similar to those on Titan, examining aeromechanical performance factors such as stress on the rotor arms and the effects of vibration on the rotor blades and lander body. In late December, the team also completed a series of aerodynamic tests on smaller-scale Dragonfly rotor models in the TDT.

“When Dragonfly enters Titan’s atmosphere and the parachutes deploy after the heat shield has done its job, the rotors will have to work perfectly the first time,” said Dave Piatak, chief of NASA Langley’s aeroelasticity branch. “There is no room for error, so any issues with the structural dynamics or aerodynamics of the vehicle must be known now and tested in the field. With the Transonic Dynamics tunnel here at Langley, NASA provides the Dragonfly team with the ideal capability to collect this critical data.”

Critical Parts

During his three years as an experimental machinist at APL, Cory Pennington fabricated parts for projects around the world. But making rotors for a drone to explore another world in our solar system? It was new – and a little intimidating.

“The rotors are some of the most important parts of the Dragonfly,” Pennington said. “Without the rotors, it doesn’t fly and it doesn’t achieve its mission objectives on Titan.”

Pennington and his team cut Dragonfly’s first rotors on Nov. 1, 2024. They refined the process as they went: starting with waterjet cutting 1,000-pound aluminum blocks, followed by rough machining, fitting the cover, drilling the vent holes, and threading the holes. After inspection, the parts were cleaned, sent for welding and returned for final finishing.

“We didn’t have the time or materials to make test parts or extras, so every cut had to be right the first time,” Pennington said, adding that the team also had to find special tools and equipment to accommodate some material changes and design adjustments.

The team was able to deliver the parts a month early. Engineers installed and tested the APL’s rotors – attached to a full-scale model representing half of the Dragonfly lander – before transporting the entire package to NASA Langley’s TDT in late July.

“On Titan, we will control the speed of Dragonfly’s different rotors to cause forward flight, climbs, descents and turns,” said Felipe Ruiz, Dragonfly’s chief rotor engineer at APL.

“This is complex geometry intended for a flight environment that we are still learning, so wind tunnel testing is one of the most important places for us to demonstrate the design.”

And the rotors passed the tests.

“Not only did the tests validate the design team’s approach, but we will use all of this data to create high-fidelity representations of loads, forces and dynamics that will help us predict Dragonfly’s performance on Titan with a high degree of confidence,” said Rick Heisler, wind tunnel testing manager at APL.

Next, the rotors will undergo fatigue and cryogenic testing under simulated conditions on Titan, where the temperature is minus 290 degrees Fahrenheit (minus 178 degrees Celsius), before building the actual flight rotors.

“We’re not just cutting metal, we’re making something that goes into another world,” Pennington said. “It’s amazing to know that what we’re building will fly on Titan.”

Collaboration, innovation

Elizabeth “Zibi” Turtle, Dragonfly principal investigator at APL, says TDT’s latest work demonstrates the mission’s innovation, ingenuity and collaboration between government and industry.

“The team worked well together, under tight deadlines, to develop solutions, evaluate design decisions and execute manufacturing and testing,” she said. “There is still much to do between now and our launch in 2028, but everyone who worked on this should be extremely proud of these achievements that allow Dragonfly to fly on Titan.”

Dragonfly has been a collaborative effort from the beginning. Kenneth Hibbard, mission systems engineer at APL, cites Penn State University’s vertical lift expertise on initial rotor design, aeronautics-related modeling and analysis, and test support in the TDT, as well as NASA Langley’s 14 x 22 foot subsonic tunnel. Sikorsky Aircraft of Connecticut also handled aeromechanical and aerodynamic testing and analysis, as well as flight hardware modeling and simulation.

The Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, is leading the Dragonfly mission for NASA in collaboration with several NASA centers, industry partners, academic institutions and international space agencies. APL’s Elizabeth “Zibi” Turtle is the principal investigator. Dragonfly is part of NASA’s New Frontiers program, managed by the Planetary Mission Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on behalf of the agency’s Science Mission Directorate in Washington.

For more information on NASA’s Dragonfly mission, visit:

Dragonfly

by Mike Buckley
Johns Hopkins Applied Physics Laboratory