For Elon Musk, the CEO and founder of the commercial spaceflight company SpaceX, mankind's capacity to send humans to Mars is no longer a question. For him, it is about working keeping humans alive on Mars and building a sustainable city on the red planet to help them thrive.

Earlier this year, space and tech mogul discussed the details on how he plans to send humans to Mars during his speech called "Making Mankind a Multiplanetary Species". He revealed how he wanted to harvest the resources available on the planet to make fuel and how his transporter will help send humans into deep space.

But in his recent entry published in New Space Journal, the businessman revealed that he is planning to build a city on Mars with one million colonizers and that it can be achieved in only 50 years.

Like the famous astrophysicist Stephen Hawking, Musk wanted to build a colony away from Earth to save the human race from "doomsday" and extinction. He further discussed that his intent is not only to build an outpost or a pit stop on Mars but an actual sustainable and functioning community.

Building a city on Mars

According to Musk, a fully functional city on the red planet could be established this century. SpaceX is already building an Interplanetary Transport System (ITS) that can send humans to Mars.

The company is planning on sending the spacecraft for its first manned mission in as early as 2023.

Aside from one million people, Musk revealed that he wanted to build a "Mars Colonial Fleet" composed of one thousand cargo ships. These ships will be designed to transport 200 people per journey. The fleet will also be used to carry materials needed to build homes on the red planet.

Sending one million people to Mars

However, sending a total of one million people to Mars could not be done in this decade. The billionaire said it could take 100 years to fill the city.

“The threshold for a self-sustaining City on Mars or a civilization would be a million people," Elon Musk said in the journal. "If you can only go every two years and if you have 100 people per ship, that is 10,000 trips,"

To complete the number, they should be able to send 100 people per trip.

But will there be enough Martian colonizers, to begin with? Apparently, yes. Even actor and famous environmentalist Leonardo DiCaprio expressed his interest in going to Mars. The SpaceX CEO himself also previously expressed his intent to live and even die on Mars.

Journey of a lifetime

But the journey from Earth to Mars won't be easy and it will definitely take years. This compelled Musk to make the trip really "fun and exciting" for future Martians. He promised to make the journey less cramped and less boring. Based on his journal, there would be compartments designed to be used for zero-gravity games to keep them entertained.

Currently, based on SpaceX' estimate it will cost about $10 billion to send one person to Mars. But Musk is confident that he can lower the price to $100,000. But future Martians should remember that moving to Mars is permanent and it is still a one-way ticket as of today.