Ambitious plans for human migration to Mars are unaffordable and even if they do go ahead are likely to have a fatal ending, a local expert says.
The one-way trip from earth to the red planet would take more than a year, and transporting each kilogram of human bodyweight would cost tens of thousands of US dollars, said Professor Chan Kwing-lam, an astrophysicist at the University of Science and Technology.
Even if that hurdle was overcome, Chan believed that technology was not yet advanced enough to support human life on Mars.
"After landing on Mars, that is the point when other technical problems arise," said Chan, a former Nasa researcher who teaches in the university's mathematics department.
Even if the "human martians" survive, he said, they would face temperatures of minus 55 degrees Celsius and desert-like conditions. Breathing equipment would have to be worn permanently, as oxygen makes up just 0.13 per cent of the Martian atmosphere, as against 20 per cent on earth.
The project, organised by Dutch foundation Mars One, aims to send several teams of astronauts on a high-risk journey in just a decade and have them settle permanently on the planet.
The immigrants would star in a reality television show, which would also help to cover the astronomical costs.
But Chan believed technology would not be advanced enough, even in 10 years' time.
"We cannot even maintain a human station on the moon," he said. "Nasa has been planning to manage a human camp on the moon, and I believe they may eventually be able to do that after 10 years. How can we settle on Mars when we have not tried out the plan on the moon first?"
He said humans could reach the moon within three days, but on any longer voyage it would be difficult to keep the astronauts in a healthy psychological state.
But Mars One's co-founder and CEO, Bas Lansdorp, said the organiser would offer sufficient training to participants.
"Scientists often forget how much less complex a mission of permanent settlement is compared to a return mission," he said. "We do not need to send the big components required to fly from Mars back to earth. We only need a small increase in the landing capacity compared to the last Nasa rover."
He said the risk of "death by radiation" would be less than the acceptable limit set by Nasa for astronauts in low-earth orbit.