UAVOS Inc. and Stratodynamics Aviation Inc., have successfully completed the next stage of flights tests of the earth observation platform called the HiDRON to an altitude of 25 km (82,000 ft). The HiDRON also carried atmospheric measurement system onboard, in a collaboration with researchers from the University of Kentucky. The night-time flight lasted 4 hours, including the one-hour weather balloon launch period with an average climb rate at 6.8 m/s (22 ft./s). At release altitude the HiDRON was 36 km (22 mi.) away from the launch site where it headed home and was above launch area at an altitude of 18 km (59,000 ft.). The HiDRON then glided near the home position with a descent rate much slower than a comparable parachute-borne instrument. The return flight home lasted about 3 hours.
According to the mission team, the HiDRON stratospheric aircraft performed well in standard operational modes and in challenging BVLOS (Beyond Visual Line Of Sight) conditions. It operated in headwinds up to 180 km/h (112 mph), -60° C (-76° F) temperatures, experienced wing icing and reliably returned home and landed autonomously.
The HiDRON’s flight stabilization after balloon release and tuning the UAV controls and components for stratospheric flight were main objectives of the mission. During the flight, operators also checked the performance of the HiDRON’s avionic systems, flight characteristics, safety features, instrument integration, and auxiliary tracking systems including a transponder.
The HiDRON’s payload collected meteorological data and the atmospheric instruments were integrated with the autopilot telemetry and the sensors custom fitted to the aircraft. Data was collected at the ground station in real-time and compiled with the flight records. The instrument integration was also evaluated. While areas for further refinement were identified, the HiDRON and onboard measurement system performed well and demonstrated operability in high winds, cold temperatures, and low air density conditions. The obtained performance data will be used for the next stage of testing at an altitude of 30km (98,000 ft.).