One of SpaceX's biggest looming rivals is also the most secretive.
Founded by Amazon billionaire Jeff Bezos in 2000, Blue Origin has been most public about its smaller space tourism rocket system, New Shepard. But in September 2016, Blue Origin announced its plans for the enormous, reusable, and orbit-capable New Glenn rocket system.
Reusable rocket engines, called BE-4s, will power that launcher. Its biggest future iteration will stand about 313 feet tall, have three rocket stages, and possibly make voyages to the moon or Mars routine.
Bezos is planning to debut the first New Glenn rocket in 2020. Blue Origin has begun that work in a 750,000-square-foot hangar in Cape Canaveral, Florida (Business Insider asked to visit, but the company declined).
It's not certain how much a New Glenn launch will cost, though the booster will take off and land like SpaceX's, allowing it to get reused for future launches. That would save Blue Origin tens of millions of dollars in the process.
As of March 2017, Blue Origin had at least one customer signed up to launch a payload.