Falcon 9, designed for reusability. Image source: SpaceX.

Last week, Jeff Bezos, CEO of Amazon, billionaire, and founder and CEO of spaceflight company Blue Origin, dropped his first words on Twitter, announcing the company had achieved an important milestone: landing a rocket that traveled to space back on Earth's surface. But SpaceX CEO and billionaire Elon Musk, who is also the CEO of Tesla Motors (TSLA 1.85%), had some beef with how the media is portraying the achievement.

Musk vents on Twitter
Musk couldn't help but chime in when Bezos announced his space company's accomplishment in his first-ever tweet, which included a video of the rocket's landing.

Musk began with a quick pat on the back for Bezos' successful vertical take-off and landing, or VTOL.

But the famously outspoken billionaire, who is a prolific tweeter, continued with obvious frustration, breaking down the difference between what Blue Origin achieved and what SpaceX is aiming for. He proceeded with some technical details and space history, just waiting for all the space nerds to devour and debate. 

The Verge writer Loren Grush detailed the source of Musk's frustration in layman's terms:

The Falcon 9 is designed to deliver payloads into lower Earth orbit, whereas the New Shepard only takes passengers into sub-orbital space. Objects in sub-orbit are still in space, but they cannot make a full orbit around Earth and will eventually fall back to the surface.

Musk conceded to programmer aerospace and virtual reality engineer John Carmack's point on Twitter that traveling "100km and safely back to the pad is a first," responding, "Yep, good points." And Musk couldn't help but add in his conversation with Carmack, "I hope you get back into space some day!"

And thus go the deliberations, frustrations, and back and forth of accomplished billionaires, entrepreneurs, and engineers.

SpaceX: Musk's true passion?
While Musk is obviously passionate about his electric-car company, Tesla Motors, space travel is likely the entrepreneur's first love, as the CEO's passionate conversations on Twitter, like this with one with Bezos, as well as his interviews in the media suggest.

The CEO has said that after Tesla successfully ramps production of a lower-cost fully electric vehicle -- a goal Tesla hopes to achieve by around 2020 (several years after the lower-cost vehicle is supposed to begin initial deliveries) -- he may consider stepping down from the electric-car maker to run SpaceX full time.

Following an order from NASA last week for SpaceX to complete a crewed mission to and from the International Space Station in its Crew Dragon capsule, the stakes are rising at SpaceX. Further, if the company does successfully achieve rocket reusability, it could potentially shake up the entire space industry.

Will rising stakes at SpaceX and increasing competition from other private space companies distract Musk, and eventually lead him to resign at Tesla?