According to this conspiracy theory, a manned mission to Mars took place in 1973 and no-one was told about it. It wasn't even the first and it wouldn't be the last one. But first, the circumstances that led to astronauts setting foot on Mars. After successfully landing man on the Moon, NASA and the U.S. Department of Defense initiated Project Horizon, an ambitious mission to set up a permanent stationary base on our satellite. In the following years, a similar project received funding but its destination was millions of miles away. Codenamed Project Redsun, its aim was to successfully colonize the Red Planet. The first mission saw three astronauts taking the journey aboard a modified Saturn V left over from the discontinued Apollo Program. Since Project Redsun was a joint operation between the U.S. and the USSR, a soviet cosmonaut accompanied the two famous American astronauts Buzz Aldrin and Neil Armstrong. The rocket was launched from a 'secret and absolutely isolated zone in Brazil