Saturn IB version
Saturn IB Saturn IB (Apollo flights, 1966–1968)
The five earliest Saturn IB vehicles, SA-201 through SA-205, flew from Cape Kennedy's LC-34 and LC-37B between February 1966 and October 1968. Between them they carried an uncrewed Apollo command and service module on two suborbital tests, the lunar module on its first orbital shakedown, and the first crew ever to fly an Apollo spacecraft. Rated at 19,000 kg to low Earth orbit once development was complete, this early block also flew the deliberately payload-less AS-203 mission. Its first stages still wore the black-and-white roll pattern that later vehicles dropped.
- February 26, 1966
- First launch
- 19,000 kg
- LEO capacity
- 7,100 kN
- Thrust
- No
- Reusable
History
Why it existed
When NASA settled on the C-5 for the lunar landing in July 1962, it also committed to uprating the Saturn I so that Apollo hardware could be tested in Earth orbit sooner. Two changes did the work: the S-IV second stage gave way to the S-IVB, whose single J-2 pushed 890 kN instead of 400 kN, and the first stage was lightened and fed 3.1% more propellant to reach 7,100 kN. The result — S-I becomes S-IB, Saturn I becomes Saturn IB — could orbit a partly fuelled command and service module, or a complete lunar module, years before the Saturn V was ready.
A test bed that happened to fly
SA-201 opened the series on 26 February 1966 with an uncrewed suborbital run of the Block I command and service module. AS-203 followed in July with no spacecraft at all: the point was to leave unburned liquid hydrogen sloshing in the S-IVB and watch how it behaved in weightlessness, because the Saturn V would need a restartable version of that very stage for trans-lunar injection. SA-202 repeated the suborbital CSM profile in August. None of the three flights existed to prove the rocket; each existed to prove something the rocket carried.
From the Apollo 1 fire to Apollo 7
SA-204 had been assigned the first crewed flight. The cabin fire of 27 January 1967, during a launch rehearsal, killed the crew and wrecked the command module; the launch vehicle survived and was reassigned, sending the uncrewed lunar module aloft as Apollo 5 on 22 January 1968. The block closed on 11 October 1968, when SA-205 launched Apollo 7 — the programme's first crewed mission and the orbital shakedown of the Block II CSM. All five launches used LC-34 and LC-37B.
What sets it apart
Outwardly the marker was paint: alternating black-and-white S-IB tanks and vertical stripes on the S-IVB aft skirt, both absent from the final production run. Inwardly it was performance: 19,000 kg to low Earth orbit, against the 21,000 kg the 1973 vehicles reached once their first-stage engines had been upgraded again.