Dutch-based Mars One wants to establish a colony on the red planet by 2025 and six Canadians are among the 100 finalists still in the running.
The $6-billion project calls for the use of existing technology and would be funded through sponsors, private investors and a reality TV show.
But Payette said Wednesday that "nobody is going anywhere in 10 years."
"We don't have the technology to go to Mars, with everything we know today, so I don't think that a marketing company and a TV-type of selection, is sending anybody anywhere," she said.
"So, if you meet any of those people, don't tell them they're courageous because the only courage they had was to sign up on a website."
Engineers at Boston-based MIT, who analyzed the feasibility of the mission, have also suggested new technology will be needed to keep humans alive once they get there.
Payette made her comments during a speech that opened a three-day aerospace symposium at the Montreal headquarters of the International Civil Aviation Organization.
ICAO has teamed up with the United Nations Office for Outer Space Affairs (UNOOSA) to discuss emerging space activities and civil aviation.
"We are going to go to space on a commercial basis and it's at our doors," Payette said. "It's a reality that will become the norm in the next decades."
The 51-year-old urged those attending the symposium to work together "to make it happen in a safe, careful, efficient and intelligent manner."
Payette travelled into space twice — in 1999 and in 2009. She retired from the Canadian Space Agency in July 2013 to become chief operating officer of the Montreal Science Centre.
In his welcoming remarks, ICAO council president Olumuyiwa Benard Aliu said aerospace activity, such as tourism and research, is "without doubt the next frontier for aviation and potentially for ICAO."
Aliu sees a role for ICAO, the UN agency that regulates civil aviation.
"Ultimately it's expected that spacecraft will be taking off every day and operating on a point-to-point basis — potentially from urban centres," he said.
UNOOSA director Simonetta Di Pippo said the symposium's main objective is to explore regulatory mechanisms and practices in aviation and space transportation.
"It is becoming more and more evident that developments in future aerospace activities will impact on the application and implementation of space law and air law instruments," she said.