A human mission to Mars has been the subject of science fiction, engineering, and scientific proposals throughout the 20th century and into the 21st century. The plans comprise proposals to land on Mars, eventually settling on and terraforming the planet, while exploiting its moons, Phobos and Deimos.

Exploration of Mars has been a goal of national space programs for decades. Preliminary work for missions that would involve human explorers has been undertaken since the 1950s, with planned missions typically being cited as taking place 10 to 30 years in the future when they are drafted. The list of manned Mars mission plans in the 20th century shows the various mission proposals that have been put forth by multiple organizations and space agencies in this field of space exploration.

In terms of the current U.S. space program, it has been stated by the publication Bloomberg Businessweek that “much of the hardware that can get humans to Mars already exists and is ready to fly.” NASA’s long-term program Orion has a projected pace of development such that, as of late 2014, human spaceflight to Mars is anticipated in about 2035. That mission will be preceded by a great deal of shorter flights for the four-person capsule involved, with experiments taking place to better the technologies protecting Mars-bound astronauts from the radiation of deep space.