Manned mission to Mars              
   
Wikipedia    
Author Year of proposal Year of flight Period on Mars Weight on LEO [ton] Number of astronauts Number of Mars ships Number of launchers
Werner fon Braun 1956   2 years 3600 12 2 40
Koroljov 1962   2 years 1600   1 20
Sohn 1965 1982 2 years 1000 6 1  
               
Zubrin 1991 1996 2 years 220 4 2 2
NASA DRM 1.0 1993 2007 2 years 850 6 4  
NASA DRM 3.0 1998   2 years 500 4 3  
               
NASA DRM 5.0 2007 2029 2 years 900 6 3 8
SpaceWorks 2007 2033 2 years 500 3 3 5
Ajgl 2007 2050 2 years 1000 2 4 8