Boeing today test flew a hydrogen-cell battery airplane, the first manned flight of such a vehicle. This is important for a few reasons, notably because it could lead to cleaner air travel across the nation, and because if it takes off it could drive innovation that would trickle down to cars and other forms of transport.
Right now hydrogen fuel cells are great for small planes, like the one Boeing tested with, and Boeing doesn’t think the technology is feasible for future jetliners.
That being said, this test puts hydrogen-cell technology one step closer to being a viable option as many would like.