This is the challenge faced by zeroavia, one of several companies working to make hydrogen powered flight a reality. They retrofit existing planes with hydrogen engines. The company had several successful Test Flights with this plane last year. In the original frame, we would be able to fly about 19 passengers. It looks like a lot of kit in there. How would you fit in 19 people . Yeah, so in the retrofitted configuration, it will be about a dozen people. Daniela is one of the engineers working on the engine. Actually, the Fuel Cells are this one. The power is created in these small layers. So you have to build up your layers to create the power to take off an aircraft. This engine could almost provide enough power to get you from london to glasgow, but not quite. If you wanted to scale it up for international flights, would you just make the same thing bigger or is it a totally