The Airbus A320-232 D-ATRA, the largest member of the DLR research fleet. (DLR/Evi Blink)

NASA and the German Aerospace Center (DLR) are studying what happens with engine performance, emissions, and contrail formation when using different types of fuels in jet engines. The international collaboration uses Germany’s Advanced Technology Research Aircraft (ATRA) A320 aircraft burning alternative biofuels, while NASA’s fully instrumented DC-8 Flying Laboratory trails a safe distance behind, sampling and analyzing gases and particles within the ATRA’s wake.

Contrails, and the solar-radiation-reflecting cirrus clouds that evolve from them, have a larger impact on Earth’s climate than all the aviation-related carbon dioxide emissions since the first powered flight by the Wright brothers in 1903.