A private foundation is working to send a pair of non-NASA astronauts, possibly a married couple, on a slingshot journey to Mars, with blastoff slated for January 2018.

The nonprofit Inspiration Mars Foundation is starting work on life-support systems and other technologies that will be needed to keep two people alive and healthy for the 501-day mission. The flight path would put the spacecraft to within 150 miles of the Martian surface before automatically returning it on a direct approach to Earth.

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A launch vehicle and spacecraft have not yet been selected, but a preliminary technical analysis considered a Space Exploration Technologies Falcon Heavy booster, which is expected to debut this year, and a modified Dragon capsule, a report obtained by Discovery News shows.

Privately owned SpaceX already flies Dragon cargo ships to the International Space Station and is working under a NASA partnership agreement to upgrade the capsule for human transport. Other firms working on space taxis include Boeing and Sierra Nevada Corp. NASA hopes at least one system will be available by 2017 to fly crews to the space station.

“We’re in an amazing time in commercial space. We can actually go shopping,” Taber MacCallum, a project organizer and chief executive of Paragon Space Development Corp., told Discovery News.

Inspiration Mars founder Dennis Tito, a multimillionaire who in 2001 became the first privately paying passenger to visit the space station, says he’s willing to pay “whatever it takes” to get the project off the ground. Tito and MacCallum declined to disclose cost estimates for the endeavor, but said they expect it will be largely supported by philanthropic donations.

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NASA is developing a heavy-lift rocket called the Space Launch System and a deep-space Orion capsule to fly astronauts to an asteroid in the mid-2020s and to Mars a decade later.

“If those programs were to get canceled in two or three years for lack of enthusiasm for human spaceflight, America would really be in a pickle, space leadership-wise,” MacCallum said.

“We really see this as a steppingstone to those missions,” he added. “If we were flying this mission and we started to have the test flights and launches of SLS and Orion, that would be fabulous.”

MacCallum, 48, a long-time space enthusiast, engineer and entrepreneur, would like to take the trip to Mars along with his wife and business partner, Jane Poynter, 50. The couple, who married in 1994, lived for two years inside the experimental Biosphere 2 enclosed research laboratory.

“We’ll throw our hats into the ring, but there are a lot of skills this crew is going to need. They’re going to have to be mechanically great, be articulate. These are going to be very special people,” he said.

Tito, who is 72, said he is not planning to fly.

The purpose of the voyage is to “show the world that the human race has the vision and the means to become a multi-planet species,” Tito wrote in a paper to be presented Sunday at the IEEE Aerospace Conference in Montana.

“The mission will address one of the most fundamental technical challenges facing human exploration of space, keeping the humans alive and productive in deep space,” said Tito, who runs a California-based investment management and consulting firm.

The former aerospace engineer was researching lunar flyby flight paths when he came up a paper published in the mid-90s describing the Mars free-return. To make the trip, launch would have to take place around January 2018. The next opportunity isn’t until 2031.

“If we don’t make 2018, we’re going to have some competition in 2031,” Tito told Discovery News. “By that time, there will be many others that will be reaching for this low-hanging fruit -- and it really is low-hanging fruit.”

“I was looking for something to fill in the blanks in our human spaceflight program. Forty years ago, we went to the moon and we haven’t done anything (beyond low-Earth orbit) since.

“I’ve reach this age and I say ‘Look, I’m not happy with this.’ We’ve done some great stuff with robotic exploration of Mars and the rovers, but what have we done in human spaceflight? Nothing much, and nothing at all beyond the moon. This (Mars mission) is really the answer, no question,” Tito said.