Watch Japanese startup test engine that will run on cow-dung methane (video) 

 A Japanese space startup has taken a big step toward developing its first orbital rocket — which will be powered by gas from cow dung. 

https://cdn.mos.cms.futurecdn.net/ELAyyY7QadfiEvAR82m2p3.jpg

https://www.space.com/japanese-startup-biomethane-rocket-engine-test-video