WASHINGTON – In less than five years, a married couple could be on their way toward Mars in an audacious but bare-bones private mission that would slingshot them around the red planet, under a plan announced Wednesday by a financial tycoon and his team.

The voyage to Mars and back would be a cosmic no-frills flight that would take the husband-and-wife astronauts as close as 100 miles to the planet, but it would also mean being cooped up for 16 months in a cramped space capsule half the size of an RV.

The private, nonprofit project, called Inspiration Mars, will get initial money from multimillionaire investment consultant Dennis Tito, the first space tourist. The team would not say how much the overall flight would cost, but outsiders put it at more than $1 billion.