Elon Musk prioritizes the development of human ships to Mars

Elon Musk aims to send people to the Moon and Mars with a rocket model and spacecraft Starship completely reused.

Elon Musk, the chairman of SpaceX, is calling on company employees to accelerate development of the next-generation rocket Starship in a collective letter on June 6. "Please consider SpaceX's top priority is Starship," Musk wrote.

The first Starship prototype in Boca Chica, Texas, in 2019. (Image: CNBC).

SpaceX company successfully conducted a historic flight carrying two NASA astronauts on May 30. The Falcon 9 rocket and the Crew Dragon spacecraft transport astronauts to the International Space Station and will bring them back to Earth in the next few months.

The Falcon 9 rocket has been SpaceX's key vehicle with 85 flights over the past decade. But Starship represents the company's ambition to go further. Falcon 9 is a reusable rocket partly because SpaceX often landed the propulsion and recovered the cone at the top of the vehicle. Musk's goal is to turn Starship into a fully reusable rocket, closer to commercial aircraft.

Last year, Musk announced the Starship prototype made of stainless steel with a larger size than the Dragon. SpaceX developed Starship with the aim of launching 100 people at the same time on flights to the Moon and Mars. However, SpaceX's Starship program in Boca Chica, Texas has encountered four major failures recently. Although the company improved after each prototype test, the latest version exploded after testing the engine on May 29.