Space tourism could be a reality for the average person sooner rather than later, Australia's first professional astronaut says.
Aerospace engineer Andy Thomas told a World Science Festival crowd in Brisbane out of this world flights, while still extremely expensive, could soon be within reach.
"They won't be cheap," Dr Thomas said on Friday.
"But I assure you that there are people out there who can afford to buy a seat on some of these flights."
Space tourism had previously only been a reality for the ludicrously wealthy and even then only for a short time.
The last man to take such a voyage was Guy Laliberté, founder of Cirque de Soleil, in September 2009.
SpaceAdventures, the firm that ran that service, had not launched a customer since then.
However, the possibility of the average person reaching space was a hot topic of Mr Thomas' discussion during his Pioneers in Science talk, with the former astronaut declaring it would be the driving force behind space exploration in the future.
Private companies such as SpaceX, Blue Origin and Virgin Galactic, under the sponsorship of NASA, are already developing launch systems and cube capsules to resupply space stations with consumables as well as delivering human crews.
Dr Thomas said these companies would start to open up flights to tourists as soon as there was a system up and running.
He said once the business framework was established, space tourism programs would evolve, making them more cost effective and eventually available for the average person.
"I think infrastructure will start to be built in low orbit initially and out towards the moon in years to come," he said.
"Space tourism is going to be a central part of future human space flight."
Virgin Galactic is already pre-selling seats to space for the full price of US$250,000.
Mr Thomas took his first space flight in5 1995 on board the shuttle Endeavor and also spent 130 days in the Russian Mir space station.
The World Science Festival also heard from European Space Agency senior science adviser Mark McCaughrean on the potential for living in space.
He said asteroid mining could shift from sci-fi dream to reality, broadening the possibilities of space colonisation but suggested scientific energy should be directed closer to home.
"In principle you could mine asteroids, but we should turn our minds toward fixing this planet first," Mark McCaughrean said.
"I have young children and I love inspiring people about the possibilities of science but go and fix this planet because it's where we all live.
"It's where we're from."