The Martian Piloted Complex or MPK was a Soviet Union human mission to Mars proposed in 1956-62 by Mikhail Tikhonravov.
[2][3] The craft would have a mass of 1,630 metric tons and employ traditional liquid propellants (LOX/Kerosene).
[2] It would take 25 N1 rocket launches to assemble the MPK in low earth orbit.
[2] When complete, it would travel from Earth to Mars on a 270 day Hohmann trajectory and maneuver into Martian orbit.
[2] Return to Earth would take 270 days and the re-entry vehicle would weight 15 metric tons.