I recently came across this overview image of Saturn 1B missions:

Saturn 1B vehicle configurations

(source: NASA)

AS-212 is asterisked with the note (bottom-left of the image) that it is "scheduled to carry both a CSM and LM." However:

There are some variations in the reported weights and one should consider various "auxiliary hardware" like the nose cone, adapters, etc., but in any case the combined weight of CSM + LM exceeded the payload capacity of a Saturn 1B by a lot. Indeed, the Saturn 1B never actually flew with both the CSM and the LM. In fact, a dual mission was at some point considered (AS-207/208) to get a CSM and an LM in low Earth orbit to test operations (similar to the Gemini program):

The inability of the Saturn IB to toss the command and service modules and the lunar module into orbit together had forced planners to consider "LM-alone" flights. Gemini's successful dual missions suggested that it might be possible to launch a crew aboard a command module to hunt down a lunar module launched by a different Saturn IB. Two of the crewmen would then transfer to the lander and carry out an earth-orbital operation previously planned for a Saturn V flight.
Although the dual flight for Gemini had been greeted with enthusiasm, the proposal for an Apollo tête-à-tête met with resistance. John D. Hodge, Kraft's chief lieutenant in the mission control trenches, said there would be problems in simultaneously tracking four booster stages and in operating two mission control rooms. Planning continued, anyway, and Howard Tindall started working up flight rules - such as which launch vehicle would go first, the one with the command and service modules (AS-207) or the one with the lunar module (AS-208).

(source: Chariots for Apollo, chapter 8)

In the end, manned LM testing was done on a Saturn V (AS-504), AS-206, AS-207 and AS-208 were used to launch crews to Skylab and the S-IVB stage of AS-212 was repurposed as the Skylab workshop module.

Question: how was AS-212 supposed to carry both the CSM + LM? Was there a (massive) uprating envisioned, or new engines? Or am I misinterpreting the diagram?

Note that the diagram is reportedly from January 1968, just before the launch of AS-205, carrying the first LM.

  • $\begingroup$ My take on this is that the same configuration could carry either, not nesesarily at the same time. $\endgroup$
    – lijat
    Feb 3, 2022 at 5:40

2 Answers 2


In your question you say the CSM and LM weighed "at least X", but the figures you give for the CSM and LM are fully loaded launch weights for a lunar mission -- i.e. they weighed at most that.

This includes, on the CSM, fuel for lunar orbit insertion and lunar orbit escape, and on the LM, fuel for descent, landing, and ascent. It would be possible to fly both spacecraft with a much smaller fuel load, and do just a small amount of maneuvering, such as a practice transposition-docking-extraction maneuver -- the LM could be flown completely dry for such a flight, and since it certainly wasn't going to land anywhere, it's easy to imagine many opportunities for weight-saving by removing components.

The dry masses of the two craft are 4820 kg for the LM and 11900 kg for the CSM, so with a limited fuel load, both could be flown on a Saturn IB. The CSM used for the Apollo-Soyuz Test Project had a launch weight of 14,768 kg (I believe that was the lightest flown CSM); that would leave over 6000 kg for an LM from a 21000kg payload budget.

  • $\begingroup$ In combination with only bringing the ascent stage as mentioned in the other answer, this seems totally feasible. Makes sense. $\endgroup$
    – Ludo
    Feb 5, 2022 at 9:18

See the discussion: https://forum.nasaspaceflight.com/index.php?topic=37719.0

They may have been going for a suborbital flight, or an under provisioned CSM / LM combination. I suspect the latter and the above slide didn't go into that much detail.

Specifically see: http://www.collectspace.com/review/1962-10-16-ApolloMissionDesignationsSIBLEMascstage.pdf

Saturn C-1B enter image description here

Too many times I have seen presentations of fantasy, hopes and dreams from Aerospace companies. See Shuttle-C as a good example.


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