This report covers three likely interpretations based on the "5X" modifier. In aerospace concept studies, adding "X" often denotes an experimental or enhanced version. The most relevant real-world concept is the Saturn V-23(L) or other evolved Saturn variants studied by NASA in the late 1960s, sometimes informally referred to with an "X" for extra thrust or payload.
| Feature | Detail | |---------|--------| | | 363 ft (111 m) | | Diameter | 33 ft (10 m) | | Mass at launch | 6.5 million lb (2.9 million kg) | | Stages | 3 (S-IC, S-II, S-IVB) | | First stage engines | 5 x Rocketdyne F-1 (kerosene/LOX) | | Total thrust (first stage) | 7.5 million lbf (33 MN) | | Upper stage engines | 5 x J-2 (S-II), 1 x J-2 (S-IVB) – both hydrogen/LOX | | Payload to LEO | 310,000 lb (140,000 kg) | | Payload to Moon (TLI) | 107,000 lb (48,600 kg) | | Successful launches | 13 (1967–1973), including 10 Apollo missions & Skylab | saturn5x