The Centaur stage was build by GD/Convair in San Diego. It was the first LH2/LOX stage to fly. Planned for the later cancelled US Army Advent comsat program, its development was taken over for the Surveyor program by NASA MSFC and later by NASA-Lewis. Following test flights of Centaur A,B,C models the standard Centaur D supported the Surveyor launches. The initial single-burn variant flew a direct ascent lunar trajectory; following tests of the two-burn parking orbit technique with AC-6, AC-8 and AC-9 this became the standard type. The D-1A/D-1T had improved avionics and structure. The D-1AR had reliability improvements. The Centaur I had modernized avionics. The Centaur II was stretched and swapped jettisonable foam panels for fixed. The Centaur IIIA was the first SEC (Single Engine Centaur); Centaur IIIB also came in DEC (Dual Engine) variant.
| Stage | Engines | Size | mass f | Flts |
| Centaur A | 2 x RL-10A-1? | AC-1 | ||
| Centaur B | 2 x RL-10A-3 | 3.05 9.1 | AC-2 | |
| Centaur C | 2 x RL-10A-3 | 3.05 9.1 | AC-3,4,5 | |
| Centaur D | 2 x RL-10A-3-1 | 3.05 9.1 | 16780f | AC-6,7,10,11 |
| Centaur D | 2 x RL-10A-3-3 | 3.05 9.1 | 16780f | AC-8,9,12 |
| Centaur D-1A | 2 x RL-10A-3-3 | 3.05 9.1 | 13950p | AC-13 to 29 |
| Centaur D-1T | 2 x RL-10A-3-3 | 3.05 9.1 | 13950p | TC-1 to TC-7 |
| Centaur D-1AR | 2 x RL-10A-3-3 | 3.05 9.1 | AC-30 to AC-61 | |
| Centaur D-1AR | 2 x RL-10A-3-3 | 3.05 9.1 | AC-62 to AC-68 | |
| Centaur I | 2 x RL-10A-3-3A | 3.05 9.1 | AC-69 to AC-79 | |
| Centaur II | 2 x RL-10A-3-3A | 3.05 10.1 | ||
| Centaur IIA | 2 x RL-10A-4 | 3.05 10.1 | 1840+16810 | AC-109,118,122,129,138,140 |
| Centaur IIA | 2 x RL-10A-4(N) | 3.05 10.1 | 1840+16810 | AC-105,107,108,110,111, |
| 114,120,121,124,126 | ||||
| Centaur IIA | 2 x RL-10A-4-1 | 3.05 10.1 | 1840+16810 | AC-130,136,137,139,142-144 |
| Centaur IIA | 2 x RL-10A-4-1(N) | 3.05 10.1 | AC-113,115,117,121,123 | |
| 126-128,133-135,141,146-167 | ||||
| Centaur G | 2 x RL-10A-3-3A? | 4.32 6.0 | SC-3 | |
| Centaur G' | 2 x RL-10A-3-3A? | 4.32 9.0 | SC-1,SC-2 | |
| Centaur "T" | 2 x RL-10A-3-3A | 4.32 9.0 | TC-8 to TC-22 | |
| Centaur "T" | 2 x RL-10A-4-1A | 4.32 9.0 | TC-23 | |
| Centaur IIIA | 1 x RL-10A-4-1 | 3.05 10.1 | 1720+16930 | AC-201 |
| Centaur IIIB DEC | 2 x RL-10A-4-2 | 3.05 11.7 | 2110+20830 | |
| Centaur IIIB SEC | 1 x RL-10A-4-2 | 3.05 11.7 | 2026+20830 | |
Centaur IIIA is the IIAS stage with one engine and modified TVC. Centaur IIIB is 12.7m with the extended nozzle.
The ISA (interstage adapter) on Centaur IIA is 3.05m dia, 4.0m length, mass 545 kg, with the Atlas Roll Control Module (ARCM). The IIIA/B adapter is 4.5m long, mass 465 kg. The V/400 short adapter is 3.05 x 3.13m, 374 kg above the Booster Interstage Adapter (3.05-3.83m dia x 1.65m l, 420 kg). The V/500 ISA (V/HLV-Upper ISA) is 3.83 x 3.81m, 1297 kg. The V/500 (V/HLV-Lower) BIA is 3.83 x 0.32m, 272 kg.