The German Aerospace Center (DLR) has successfully completed a Ground Vibration Test (GVT) for its HAP-alpha high-altitude, solar-powered aircraft, marking a key milestone toward its first planned low-altitude flight in 2026.

HAP-alpha, built at DLR s Braunschweig site, features an ultra-light 138-kilogram structure with a 27-metre wingspan made entirely of carbon fiber-reinforced polymer (CFRP). The design incorporates wound round CFRP spars and CFRP sandwich-material ribs, optimising strength while maintaining minimal weight. The platform is intended to operate in the lower stratosphere at approximately 20 kilometres altitude. Designed for long-duration Earth observation and communications missions, it will also serve as a testbed for advanced sensor systems and platform technologies.

The GVT, carried out at DLR's National Experimental Test Center for Unmanned Aircraft Systems, evaluated the aircraft s vibration behaviour to ensure flight safety. Using numerous sensors and electromechanical vibrators, engineers collected dynamic response data to refine simulation models for predicting flight performance in turbulence, gusts, and manoeuvres.

This successful GVT confirms that we re on track to address the aeroelastic challenges of such a lightweight and flexible platform, said Julian Sinske of DLR s Institute of Aeroelasticity.

Alongside the platform development, DLR is integrating MACS-HAP (a high-resolution modular aerial camera) and HAPSAR (a synthetic aperture radar) for real-world testing in the stratosphere. These technologies are expected to support future environmental monitoring, disaster response, and communications applications.

Source: www.dlr.de