The project, led by American millionaire Dennis Tito - who paid his own way to space in 2001 - aims not to land people on the surface of the Red Planet, but to take advantage of a rare planetary alignment that would allow a relatively easy, quick flyby of Mars.
Tito hopes to choose a space capsule and rocket from among those already on the market, and modify them to carry two people to Mars and back in 501 days.
And to combat the loneliness and isolation that would doubtless set in during such a mission, Tito is proposing something that's never been tried before: sending one male and one female, preferably a married couple.
"When you're out that far and the Earth is a tiny, blue pinpoint, you're going to need someone you can hug," Tito told SPACE.com. "What better solution to the psychological problems you're going to encounter with that isolation?"
For another, the mission will need novel life support systems and radiation protection technology to keep the crew alive and healthy.
In space.com - Wanted: married couple for private Mars Voyage in 2018 - Feb. 27