Manned Venus flyby

The proposed mission would have used a Saturn V to send three astronauts on a flight past Venus, which would have lasted approximately one year.

In this concept, the interior of the fuel tank would be filled with living quarters and various equipment that did not take up a significant amount of volume.

Unlike the Apollo lunar missions, the CSM would perform its transposition and docking maneuver with the S-IVB stage before the burn to leave Earth orbit, rather than after.

The mission would have measured: The mission would have been implemented in a series of two development flights and one production flight, designated as phases A through C. Phase A of the plan would have launched a "wet workshop" S-IVB and a standard Block II Apollo CSM into orbit on a Saturn V. The crew would separate the CSM from the S-IVB by blowing off the SLA panels, then perform a transposition and docking maneuver similar to that conducted on the lunar flights, in order to dock with the docking module attached to the front of the S-IVB.

Phase B would test the Venus flyby spacecraft in a long duration mission in high orbit.

A Saturn V would launch a Block III CSM designed for long-term spaceflight and a modified S-IVB with the Environmental Support Module required for the real Venus flyby, and following the transposition and docking maneuver the S-IVB engine would carry the spacecraft to a circular orbit at an altitude of about 25,000 miles around the Earth.

[3][4][5][6][7] The Block IV CSM has LM engines replacing the Service Propulsion System engines, batteries to replace the fuel cells, and other modifications to support long-range communication with Earth and the higher re-entry velocities required for the return trajectory compared to a return from lunar orbit.

This would put the craft into a highly elliptical orbit which would typically bring it back to Earth for re-entry two or three days later.