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When were the major aspects of the Apollo program decided? Multi-stage rocket, CM pulling the LM out of the rocket through a docking maneuver, LOR, and a parachute landing in the ocean.

I've seen answers to a few different pieces of this question, like the work of John C. Houbolt and the extensive coverage of the Rogallo wing in the excellent book Coming Home. I haven't seen an answer to when every piece was finally in place.

Andrew Breza
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Multi-stage rocket

This was already certain in the mid-to-late 1940s, if not sooner. There's no practical way to reach the moon on chemical propellants without a multistage rocket; the only alternative in that era would have been a Project Orion-style nuclear detonation rocket, which wasn't ever considered for Apollo.

CM pulling the LM out of the rocket through a docking maneuver, LOR

These two decisions go hand in hand; for the direct ascent strategy assumed prior to the LOR decision, the command/service module and the (much larger than the Apollo LM) lunar descent/landing module would have remained docked the way they were stacked on the launch pad all the way to lunar touchdown; there would have been no need for a transposition-docking-extraction maneuver.

LOR was a contender from 1960; Houbolt's "voice in the wilderness" letter was sent in November 1961. It was debated for several months; NASA Administrator James Webb approved LOR in early July 1962, and as Organic Marble notes, it was announced on July 11.

Parachute landing in the ocean

According to Chariots For Apollo, land touchdown was in consideration for a while:

Another decision that would influence both spacecraft was on whether to set the vehicle down on land or water, a question that had been under discussion since mid-1962. During a meeting in early 1964, a North American engineer reported that "land impact problems are so severe that they require abandoning this mode as a primary landing mode." That was all Shea needed to settle that debate. Apollo spacecraft would land in the ocean and be recovered by naval ships as Mercury had been.

Russell Borogove
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  • Good stuff! I was too lazy to look up whether the land landing was still in play. – Organic Marble May 12 '21 at 20:07
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    Me either -- I'm actually guessing on that; I just can't remember ever reading any mention of land touchdown being seriously considered. – Russell Borogove May 12 '21 at 20:13
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    @OrganicMarble Land touchdown was apparently in discussion for a while, but abandoned in "early 1964" (Chariots to Apollo, ch 5). Looking at the footnotes, it seems this was about the same point the Gemini wing & land touchdown was abandoned - possibly even the same decision (Shoulders of Titans, ch 8) – Andrew is gone May 12 '21 at 21:39
  • @Andrew Great find, thank you! – Russell Borogove May 12 '21 at 21:48
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    According to this article, the parawing idea was still alive even after the 1964 decision; a parawing landing was considered in the context of the Apollo Applications Program, and Northrop Ventura was awarded a contract develop the tech in 1967. (Also, I am delighted to have learned about the parawing idea, which I had never heard of before today.) – Michael Seifert May 13 '21 at 15:39
  • "multi-stage rocket -> mid-to-late 1940s". Tsiolkovsky would have given you the same answer in the 1890s. – SE - stop firing the good guys May 14 '21 at 17:22
  • @SE-stopfiringthegoodguys A high-specific-impulse engine would invalidate that answer, however; Tsiolkovsky never contemplated an Orion-style nuclear detonation rocket. – Russell Borogove May 14 '21 at 17:40
  • Was a LOR without a transposition-docking-extraction maneuver ever considered? – Charles Staats May 14 '21 at 19:59
  • I'm sure it was considered, but any such option screws up the launch escape system (if the CSM is between the booster and the LM as stacked at liftoff) or the safety of moving crew between the CSM and LM through a docking tunnel rather than via spacewalk (if stacked with the CSM on top). The TD&E maneuver isn't significantly more challenging than the lunar orbit rendezvous, so there's no particular reason to avoid it (and it proves that the docking hardware is working while still relatively early in the mission, which may be a benefit). – Russell Borogove May 14 '21 at 20:50
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Partial answer to LOR

1962

...

July 11 - NASA announced that the lunar rendezvous mode would be used for the moon mission. This new plan called for development of a two-man lunar module to be used to reach the surface of the moon and return the astronauts to the lunar­ orbiting command module. NASA administrator James Webb said this method was the most desir­able from the standpoint of "time, cost, and mission accomplishment."

Apollo Chronology

I don't think "multi-stage rocket" was ever in doubt.

Organic Marble
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    Re I don't think "multi-stage rocket" was ever in doubt: Yep. The debate early on was whether rendezvous should have been done in low Earth orbit versus lunar orbit. Determining how to do that rendezvous was pretty much the entire point of the Gemini program. I look at the Apollo vehicle as being a seven stage vehicle. My counting assumes one counts the never-used Launch Escape System as one of the stages. – David Hammen May 12 '21 at 16:44
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    When did the concept of “stages” enter rocketry? – uhoh May 13 '21 at 00:38
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The authoritative source of dates is The Apollo Spacecraft: A Chronology. Volume I (of the 4 volumes) ends at the spacecraft mode decision, which is what you are asking about. Volumes II and III are smaller design decisions. Volume IV starts with the Apollo 1 fire, and ends at the end of the program.

Looking at the key events page:

1957 October 4: Sputnik I, the first man-made satellite, successfully launched by the Soviet Union.

1958 October 1: NASA officially constituted and charged with responsibility for the U.S. civilian space program.

1960 January 28: NASA's Ten-Year Plan presented to Congress during testimony before the House Committee on Science and Astronautics. (includes landing on the moon in 1970)

1960 July 28-29: The announcement of the Apollo program to representatives of American industry.

1960 September 1: The Apollo Project Office formed under the Space Task Group (STG) Flight Systems Division.

February 7: Final report of the Low Committee outlining a manned lunar landing within the decade using either the earth orbit rendezvous or direct ascent technique.

1961 April 12: First successful manned orbital flight, by Cosmonaut Yuri A. Gagarin of the Soviet Union.

1961 May 5: First successful American suborbital flight, by Astronaut Alan B. Shepard, Jr.

1961 May 5: Completion of the first draft of the Apollo spacecraft specifications by STG.

1961 May 25: President John F. Kennedy's proposal to Congress and the nation of an accelerated space program including a manned lunar landing within the decade.

1961 June 10: Report of the Lundin Committee recommending a low-altitude earth orbit rendezvous mode using the Saturn C-3 to accomplish the manned lunar landing mission. (didn't happen that way)

1961 August: Report of the Heaton Committee recommending the earth orbit rendezvous technique and use of the Saturn C-4 for the manned lunar landing mission. (not that way either)

1961 November 20: Report of the Rosen working group to the NASA Office of Manned Space Flight, recommending direct ascent as the primary lunar landing mission mode with a backup rendezvous capability development. (nope, not that)

1961 November 28: Selection of North American Aviation, Inc., as principal contractor for the Apollo spacecraft under MSC direction.

1962 July 11: Selection by NASA of the lunar orbit rendezvous mode for the manned lunar landing mission.

1962 November 7: Selection of the Grumman Aircraft Engineering Corporation by NASA to design and develop the lunar excursion module under MSC direction.

The specific entry for July 11, 1962 is as follows:

July 11

NASA officials announced at a Washington, D.C., press conference that the lunar orbit rendezvous (LOR) technique had been selected as the primary method of accomplishing the lunar landing mission. The launch vehicle would be the Saturn C-5, with the smaller two-stage Saturn C-1B (S-IVB as second stage) used in early earth orbital spacecraft qualification flights. Requests for industrial proposals would be issued immediately on the lunar excursion module, The reasons for the decision on lunar orbit rendezvous were explained:

A higher probability of mission success with essentially equal mission safety was provided by this technique.

  • The method promised mission success some months earlier than other modes.
  • LOR costs would be ten to 15 percent less than other techniques.
  • LOR would require the least amount of technical development beyond existing commitments while advancing significantly the national technology.

In addition, it was announced that:

  • Studies would continue on the feasibility of using the Saturn C-5 to launch a two-man spacecraft in a direct ascent approach to the moon or in an earth orbit rendezvous mode.
  • An in-depth study would be made on a lunar logistics vehicle.
  • Investigations would continue on the development of the Nova launch vehicle.
DrSheldon
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