In a groundbreaking achievement for aviation research, the German Aerospace Center (DLR), in collaboration with Airbus and the Perlan team, conducted the first-ever flight measurements of contrails from a hydrogen-powered turbojet engine in Minden, Nevada, USA. The experimental project, named Blue Condor, involved modifying an Arcus glider with a tank for gaseous hydrogen and a hydrogen-powered turbojet engine, allowing for direct combustion of hydrogen. These flight tests aimed to characterize the formation, properties, and effects of contrails from hydrogen engines, offering insights into the climate impact of hydrogen propulsion in aviation. Led by Dr. Markus Fischer, DLR's Director of Aviation, the research team successfully measured contrails and emissions from the hydrogen engine, comparing them with data from a conventional kerosene engine. The experiment revealed that contrails from hydrogen combustion engines form at higher temperatures and lower altitudes due to increased water vapor emissions, impacting the microphysical properties of contrails which influence their climate effects. The seven test flights conducted during the project provided valuable data on ice crystal formation, nitrogen oxides emissions, and aerosol particle formation in the exhaust plume. The research team is currently analyzing the collected data to publish detailed results, contributing to a better understanding of the environmental implications of hydrogen-powered aviation. The successful completion of the Blue Condor project marks a significant milestone in advancing climate-compatible flying technologies. By pioneering the measurement of hydrogen contrails in flight, the collaboration between DLR, Airbus, and the Perlan team sets the stage for future research in sustainable aviation and underscores the potential of hydrogen propulsion to reduce CO2 emissions and mitigate the climate impact of air travel.