We've covered [why the BE-4 uses methane as fuel](https://space.stackexchange.com/questions/18593/why-does-the-be-4-use-methane-as-fuel); what I want to know is, why did Blue Origin go with hydrogen for the BE-3? Liquid hydrogen is notoriously hard to work with; it seems like an odd choice for a new company's engine. It also doesn't seem like BO is taking advantage of hydrogen's biggest advantage, its great performance as an upper-stage fuel. So why'd they go with hydrogen instead of kerosene for the New Shepard's engine?