Saturn II (INT-18)

Intermediate-18 INT-18

Mission Profile

The Saturn II (INT-18, Intermediate-18) was a proposed two-stage American launch vehicle in the Saturn family, studied under the Apollo Applications Program as a reduced-cost heavy-lift option using existing Saturn V hardware without the S-IC first stage. Standing approximately 58 m tall with a 6.6 m core diameter, it would have used the S-II and S-IVB stages to provide medium heavy-lift capability. Conceived around 1965, the Saturn II remained a paper study as post-Apollo budget cuts curtailed development of Saturn-derived vehicles.