The couple will embark on the 500-day journey which zooms past Mars and swings back to Earth as part of a historic "Mission for America" venture.

 

　　"We fly within a hundred miles of Mars. I mean that is essentially being there. It's just that easy, to go out, swing by, use the gravitational shift of Mars and come back to earth, just like a boomerang, you don't need to have any propulsive maneuvers. It's really simple."

 

　　Tito says the trip will begin when the planets are correctly aligned.

 

　　If they don't take the opportunity in 2018 to make the trip, another chance will not come until 2031.

 

　　Tito says the two crew members will be "ambassadors for humanity."