NASA has recently conducted tests on a coaxial pair of rotors at the Transonic Dynamics Tunnel at NASA’s Langley Research Center in Hampton, Virginia. 

The components that went under test are essential components to the future Dragonfly mission, a mission expected to complete a journey to Titan, the biggest moon of Saturn. Researchers at the Langley Research Center and the John Hopkins Applied Physics Laboratory (APL) operated many tests on a pair of rotors at the Transonic Dynamics Tunnel to validate computer models. This facility enables the use of full-scale flight hardware and the capability to test equipment at the expected conditions it will undergo during its mission.

Researchers simulated expected conditions for hover, descent, and ascend, and assessed aerodynamic loads for each rotor at a variety of wind speeds, rotor shaft angles, and rotor throttle settings. Failure modes were also considered as researchers simulated one rotor operating and the other stationery. Sensors and accelerometers on the test article measured the loads and accelerations created by each rotor under different wind speeds, orientations, and rotor speeds. Preliminary analysis of the data shows that CFD predictions of rotor performance and power requirements are valid, and similar predictions for operation on Titan are within expected mission tolerances.

“The testing at this one-of-a-kind facility was a crucial early step toward bringing this exciting mission to fruition,” said Richard Heisler, wind tunnel test lead for Dragonfly at APL. “The data we collected at the TDT will give us a much clearer picture of how we can expect Dragonfly’s rotors to perform in Titan’s alien atmosphere.”

About Dragonfly

Dragonfly is currently scheduled to launch in 2027 and is expected to arrive at Titan by 2034 when it is to begin an expected 3-year mission to explore and shed light on the complex chemistry of the exotic moon and ocean world which orbits Saturn. It was selected in June 2019 as part of NASA’s New Frontiers program, which also includes the New Horizons mission to Pluto and the Kuiper Belt, Juno to Jupiter, and OSIRIS-REx to the asteroid Bennu. Dragonfly is led by Principal Investigator Elizabeth Turtle at APL.

Similar to a drone, Dragonfly will travel across Titan’s dense atmosphere, landing, sampling, and examining various sites. Dragonfly will have four pairs of rotors, each with two rotors in a coaxial configuration, meaning one rotor above the other. It’s similar to but particularly larger than, a regular terrestrial drone, as the vehicle is over 3 meters long (12 feet).

It’s interesting to remember that key elements of Dragonfly were tested out as well with the Ingenuity Mars Helicopter, send to the red planet by JPL on July 30, 2020, and arriving at Mars on February 18, 2021; it completed its first flight on April 19, 2021, and has since then been breaking flying records.