An artist's impression of the interior of accommodation at the colony.

Skepticism

There also has been widespread online skepticism about the project. On May 20, Chinese media reported online speculation that Mars One is a fraud and has already been suspended.

Chinese applicants

In an e-mail to China Daily on Tuesday, Bas Lansdorp, the project's co-founder, insisted that Mars One is doing very well and is still committed to landing humans on Mars in 2023. But, as with many highly ambitious and complex projects, there is always the risk of delay and Mars One is working hard to stay on schedule.

Lansdorp said the 78,000 applicants had taken the time and effort to fill in the application form and show their interest in going to Mars, and even if some decided they didn't want to pay the application fee, that doesn't necessarily mean they don't still want to go.

"If the project fails or is even shown to be a fraud, I wouldn't regret applying," said Li, who has started working out, practicing English and reading astronomy books since he applied to join the project.

"I like my situation right now - hopeful and confident. I know the odds aren't good, but at least I have tried to grab the chance to contribute to the space industry and humanity."

Jiang Xueqing and Tang Yue contributed to this story.

Related: Voyage to Mars has its skeptics