G Warwick, Tech Take, Visualization aids understanding of hydrogen, Aviation Week & Space Technology, 23 February-8 March 2026, p 62

In US, Airbus together with Washington State University have developed a method of observing the behaviour of cryogenic  LO2 as it boils within a pipe.   Furthermore, a Canadian and German team has used high-intensity X-rays to observe the operation of a fuel cell, including the influence of gravity in removing water