Blue Origin’s BE-4 could propel the next stage of space exploration

After five years of development, Jeff Bezos announced in Twitter this week Blue Origin has successfully completed a hot fire test of its fully reusable BE-4 engine. The hot fire test marks an important milestone for both Blue Origin and the next step in human exploration of space. https://twitter.com/JeffBezos/status/921114359119560704 Blue Origin's orbital rocket, the New Glenn, will use seven BE-4 engines in its first stage, and a single BE-4 in