Where did AS-206 go between 1967 and 1973?

Question

The Apollo program was a bit stressful. In 1967 a lot of things went wrong, especially with the delivery of the lunar module:

General Phillips's office originally planned to launch the first lunar module aboard Apollo-Saturn 206 in April 1967. Anticipating six months of checkout on the lunar module, Debus had requested a delivery date of September 1966. Development took longer than expected, however, and delivery slipped from month to month. The lunar module's arrival was still uncertain in January 1967 when KSC erected AS-206 on pad 37. In March AS-206 was taken down and replaced with AS-204, the launch vehicle from the ill-fated Apollo 1 mission. Lunar module 1 finally arrived on 23 June 1967.

(source: Moonport, chapter 20)

The Apollo 1 fire was on 27 January 1967 on LC-34. I imagine that AS-204 was just moved from LC-34 to LC-37, assuming that it spent a month or so there pending investigations.

Where did AS-206 (a Saturn 1B) go after being taken down? As far as I can tell, it was used for the first crew launch for Skylab on 25 May 1973, well over 6 years later. Where was it in the mean time? Did they send the stages back to the respective manufacturer plants? Did they leave them outside on a parking lot? Stored in a corner of the VAB?

Answer 1

• The first stage S-1B-6 was sent back to Michoud for storage.
• The second stage S-IVB-206 was sent back to SACTO (Sacramento Test Operations in California) for storage.

They were taken out of storage shortly after being sent there

to support contingency plans to launch test flights of the LM either by orbiting a second unmanned LM test flight (if LM-1 failed to meet its mission objectives) or supporting the first manned LM test flight as part of a dual-launch mission (if the Saturn V was not crew-rated in time).

But this did not materialize and the stages went back into storage until they were used for Skylab.

Source: SA-206 The Odyssey of a Saturn 1B

Answer 2

From Stages to Saturn ch. 13:

Developmental and technical problems created a delay in the anticipated launch date, which was finally rescheduled for the spring of 1973. Meanwhile the Saturn IB first stage for the first manned Skylab launch vehicle was taken out of an environmentally controlled enclosure at the Michoud Assembly Facility, where the stage had been in hibernation for three years. This particular booster was one of nine such Saturn IB stages stored at Michoud in December 1968. Altogether, four Saturn IB stages were designated for the Skylab project: AS-206, AS-207, AS-208, and AS-209. Refurbishment of each vehicle was estimated at approximately 10 months.

"Meanwhile..." is sometime in early 1970, judging from the previous paragraph. So it sounds like the Saturn IB was returned and then mothballed on site by 1968. "December 1968" may indicate it was not returned until the end of 1968 - perhaps it was kept at KSC until after Apollo 7 had successfully completed its flight in October, at which point they could be confident another Saturn IB launch would not be needed in the short term?

As of June 1975, the two surviving S-ICs were still stored at Michoud, as were three of the surviving S-IBs. (Appendix F)

It's not completely clear about the Saturn IVB stage, but later in the same chapter the one for Apollo-Soyuz (SA-210) is mentioned as having been mothballed:

The S-IVB second stage was of the same vintage, completed in 1967 by McDonnell Douglas at Huntington Beach, California, and was stored there until the fall of 1972, when it was shipped to the Kennedy Space Center.

This would seem to suggest that the S-IVB plant also had the facility for mothballing stages, so it may well have been sent back. But it's not explicit.