January 13, 2022

Dragonfly in the Desert: Testing for Titan

Before the actual Dragonfly soars over the organic dunes of Titan, the team developing the NASA rotorcraft lander at the Johns Hopkins Applied Physics Laboratory is testing the concept by sending instrumented models over the sands of Earth’s deserts.

This is what sent nine APL engineers to Imperial Dunes, California, in September 2021. Over three days the team flew a “testbed” over the dunes to collect images and sensor data they’ll need to develop optical navigation algorithms for the real Dragonfly, set to embark for Saturn’s largest moon in 2027.

Working from sunrise to sunset, the team collected data from numerous flights in a variety of lighting conditions – and captured data critical to developing and testing the navigation algorithms. The natural dunes serve as an analog to the terrain that Dragonfly will encounter on Titan, and the environment is ideal for testing the navigation algorithms that will use camera images to sense the rotorcraft’s position and motion.

The Dragonfly team has built two identical, half-scale “Integrated Technology Platform” drones (called ITPs) with hardware and software similar to what will fly on the real thing – including eight independent rotor assemblies, a flight computer and digital image processor, a navigation camera, an inertial measurement unit with comparable gyroscopes and accelerometers, and initial versions of the image processing and flight control algorithms.

The ITPs are undergoing a graduated series of flight tests to evaluate their performance. In the past year, the drones have logged over 100 flights at multiple test sites and under varying wind conditions as their configurations have matured in complexity.