High-altitude solar aircraft HAP-alpha has completed its Ground Vibration Test, a key milestone in flight readiness, at DLR’s National Experimental Test Center in Cochstedt. Developed by the German Aerospace Center (DLR), the lightweight 138-kilogram platform with a 27-metre wingspan is designed to operate in the lower stratosphere and will undergo its first low-altitude flight in 2026, subject to weather.

DLR Executive Board Member for Aeronautics Markus Fischer says: “With HAP-alpha, DLR is demonstrating its comprehensive systems expertise in the complete design, development and operation of a new and innovative aircraft, incorporating all disciplines.”

Julian Sinske of the DLR Institute of Aeroelasticity adds: “The successful Ground Vibration Test is a significant step in the development of our high-altitude platform. It shows that we are on the right track to overcoming complex aeroelastic challenges and preparing the platform for flight.”

Sensor systems recorded dynamic properties as electromechanical vibrators triggered structural responses. The collected data will refine simulation models to better predict flight behaviour under turbulence and manoeuvres. HAP project lead Florian Nikodem of the DLR Institute of Flight Systems says: “It shows that we are on the right track to overcoming complex aeroelastic challenges and preparing the platform for flight.”

HAP-alpha will also act as a testbed for two onboard sensor systems, a high-resolution MACS-HAP camera and HAPSAR radar, aimed at long-term Earth observation and communications tasks.