Elon Musk was upset Bezos did not invite him to visit Blue Origin's factory, after Bezos toured SpaceX in 2004, a new book saysMusk was upset Bezos did not invite him to Blue Origin's factory: book - Business Insider

In the 18 years since their first meeting, the two have sparred over their respective space ambitions, made public digs at each other, and traded places as the world's richest person.