Musk, 51, said that he will fly Japanese billionaire Yusaku Maezawa around the moon in 2023. But his ultimate goal is to help people venture to Mars.

Blue Origin’s space plane can take six passengers and flies autonomously. The SpaceX Dragon can carry up to seven people.

All of the planned flights will allow passengers to experience weightlessness for a specific time period. Blue Origin’s flight will last 10 minutes after it separates. And the SpaceX flight will last three to four days from launch to its ending.

Virgin Galactic flights are publicly funded, and the company’s shares took off in June after the FAA updated its license.

Bezos, Amazon’s founder, has said he would sell $1 billion in Amazon stock annually to fund the venture. Musk’s SpaceX is also privately owned. Investors include Alphabet and Fidelity.

An earlier prototype of the Virgin Galactic rocket plane crashed during a test flight over California’s Mojave Desert in 2014, killing one pilot and seriously injuring another.

Reuters and The Associated Press contributed to this story. Contact the writer at [email protected].