The world’s first space tourist, Dennis Tito, has unveiled plans to send a manned mission to Mars and back, targeting a launch date less than five years away.

The two space travelers wouldn’t land on the Red Planet — or even enter its orbit — just fly through the vicinity and back, a trajectory Tito said would take 501 days, thanks to a rare planetary alignment.

The US space agency has aimed for the 2030s in its vague projections for a manned mission to Mars, and is focusing in the shorter term on sending robots, like the Curiosity rover that landed with much fanfare last summer.

Tito’s non-profit Inspiration Mars, by contrast, is starting essentially from scratch, with neither a vehicle nor a clear source of funding.

Still, the mission is “achievable,” insisted Taber MacCallum, the foundation’s chief technology officer and the head of Paragon Space Development Corporation.

Such a mission would likely cost between $1 billion and $2 billion, according to Robert Zubrin, president of the Mars Society, a group that campaigns for the exploration and settlement of the planet.

Inspiration Mars said it is not looking to NASA for the money, but will instead raise funds through “private, charitable donations.”