Blue Origin; NASA; Win McNamee/Getty Images; Mike Blake/Reuters; Samantha Lee/Business Insider
- Elon Musk and Jeff Bezos have feuded for years over each other's space-related ambitions and activities.
- The two billionaires weren't always so adversarial; in 2004, they even had dinner together.
- But tensions between them have risen with the growth of their space companies: Bezos' Blue Origin and Musk's SpaceX.
- They've criticized each other's rockets and plans to settle space, and also legally sparred over launchpads and patents.
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Jeff Bezos and Elon Musk, two tech moguls with grand visions for exploring and settling humans in space, have increasingly found themselves feuding over what our future in that final frontier should look like.
Their disagreements mainly arise because both are pursuing reusable rockets, next-generation spacecraft, and ambitious space-settling plans. In May, for instance, Bezos unveiled a moon lander design by his spaceflight company, Blue Origin; in that presentation, he criticized the idea of populating Mars - the overarching goal of SpaceX, Musk's rocket company.
That dig was made live onstage, but other times quarrels between Musk and Bezos appear on world stages like Twitter.
Most of the sparring seems innocuous. However, some of the billionaires' battles with the space companies they founded have worked their way into courts and government agencies.
The relationship between Bezos and Musk wasn't always so tense, though.
"As time has gone on and these companies have been successful, ambitions have grown," Ashlee Vance, who wrote a biography of Musk, told The Guardian in 2016. "Musk and Bezos used to be cordial, but they're vicious now."
Here's a short timeline of how they got to this point.