More than 200,000 people from 140 countries have applied to go to Mars and never return, the group behind an ambitious venture to colonise the inhospitable red planet says.

Bas Lansdorp, a Dutch engineer and entrepreneur, plans to establish a permanent base on Mars in a mission he hopes will take off in 2022, if he can find the necessary $6.49 billion.

One in four of the 202,586 applicants for the one-way trip are Americans, says Mars One, a non-profit group which initiated the hunt for "would-be Mars settlers" in April.

There are also hopefuls from India (10 per cent), China (6 per cent) and Brazil (5 per cent), among other countries, the group says.

By 2015, Mars One expects put up to 10 four-member teams through intensive training, with the first of those teams reaching to Mars in 2023 on a high-risk journey that would take seven months to complete.

Countdown to take-off: 2011: Mars One is founded 2013: Crew recruitment process begins 2015: Training selected crew members begins 2016: Demonstration Mission to launch to provide proof of concept 2018: Rover launched to find the best settlement location. Once located it will prepare for the arrival of cargo missions. A communication satellite will also be launched. 2020: Cargo mission will be launched with living united, life support systems and supply units. 2021: Rover will set up the outpost to the cargo units to prepare for human arrival 2022: The first crew departs from planet earth. It will take 210 days for them to arrive. 2023: The first crew of humans lands on Mars 2024: The second crew departs from planet earth - they take 240 days to arrive.

If they survive the trip, the human Martians will have to deal with temperatures of minus 55 degrees C in a desert-like atmosphere that consists mainly of carbon dioxide.

They will also have to consent to being observed back on Earth full-time as stars of a reality TV show that would help cover expenses.

The project has the support of Gerard 't Hooft, the Dutch joint recipient of the 1999 Nobel prize for physics.

"The long-term aim is to have a lasting colony," Mr 't Hooft said.

"This expansion will not be easy. How soon that will be accomplished is anyone's guess."

Space agencies including NASA have expressed scepticism about the viability of Mr Lansdorp's plan, saying the technology to establish a human colony on Mars does not exist.

Mars One says on its website that the mission is a decade-long endeavour, with funding intended to come from the global audience of an interactive, televised broadcast of every aspect of the mission.

So far, there have only been unmanned missions to Mars undertaken by NASA, which has signalled its intent to send astronauts there within 20 years.

AFP