Mars Direct is a proposal for a human mission to Mars which purports to be both cost-effective and possible with current technology. It was originally detailed in a research paper by Martin Marietta engineers Robert Zubrin and David Baker in 1990, and later expanded upon in Zubrin's 1996 book The Case for Mars. It now serves as a staple of Zubrin's speaking engagements and general advocacy as head of the Mars Society, an organization devoted to the colonization of Mars.

Robert Zubrin is an American aerospace engineer, author, and advocate for human exploration of Mars. He is also an advocate for U.S. space superiority, writing that "in the 21st century, victory on land, sea or in the air will go to the power that controls space." and that "if we desire peace on Earth, we need to prepare for war in space."