What were the early design concepts for the Apollo program?

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Discussion Overview

The discussion centers on the early design concepts for the Apollo program, focusing on initial proposals and their differences from the final design. Participants explore various aspects of the spacecraft's configuration, landing mechanisms, and re-entry processes, as well as speculative designs for additional components like a space-lab.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant describes an early proposal where the Command Module/Service Module assembly was intended to descend to the lunar surface, unlike the final design which utilized a separate lander.
  • The same participant notes the absence of a means for the crew to reach the lunar surface in the original plans, leading to the addition of a ladder in their renderings.
  • Another feature mentioned is the Service Module's incorporation of hinged radiator panels and deployable radar dishes, with a GIF demonstrating the deployment mechanism.
  • The landing mechanism was described as using a fixed J2 rocket engine and four gimballed thrusters, with details on how the landing legs would function upon touchdown.
  • Re-entry was discussed, with one participant explaining that it would occur similarly to the final design, but with a para-sail instead of parachutes.
  • A participant introduces the concept of a "space-lab" included in the plans, although its purpose remains unclear, and speculates on its appearance when docked to the Command Module/Service Module pair.

Areas of Agreement / Disagreement

Participants express appreciation for the visual representations and details shared, but there is no consensus on the purpose of the space-lab or the specifics of some design features. The discussion remains exploratory without definitive conclusions.

Contextual Notes

Some assumptions about the functionality of design elements, such as the airlock and ladder connection, are not fully resolved. The discussion reflects a variety of interpretations based on incomplete historical designs.

Janus
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In the TIL thread, I posted a link which had a number of imaged of an early proposal for the Apollo program.

I thought I'd use them to do a few renders of what it might have looked like, and point out some of the major differences from the final version.

First, what the craft in fully assembled configuration

Apollo_old_full.png


The plans where a bit shy on some of the cosmetic details, so a took some poetic license with that.
What immediately jumps out at you is that the whole Command module/service Module assembly was meant to descend to the Lunar surface. They hadn't come up with the separate lander and Lunar orbit rendezvous scheme at this stage yet.
Another thing to note is the plans showed no means for the crew to reach the Lunar surface, so took the liberty of adding a ladder. The only problem with this is that the designs included an airlock for the Command Module which exited through the nose. I'm not sure how they would have handled getting from airlock to Service Module ladder.

Another notable feature is that the Service Module incorporated hinged radiator panels and stored radar dishes the would deploy at some point. This GIF shows how this would work. The doors covering the radar dish compartments would close again after deployment.
apollo_old.gif


Though there were two dishes, only one is visible here.

Landing on the Moon used a fixed J2 rocket engine and four thrusters mounted on gimbals. The four smaller thrusters were pressure fed from a Helium tank.
In these images the lander legs are in the default extended position. On landing, hydraulic struts would compress causing the legs to splay out further.

The SM/CM would leave the Moon initially by a solid fuel booster pack ( as shown here attached to the bottom of the SM) and four gimballed thrusters.
Apollo_old_2.png


which would then detach, revealing another set of solid fuel boosters:

Apollo_old_3.png


Here is the whole system expanded and labeled:

apollo_expld.png
 
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dlgoff said:
Beautiful work @Janus.
Thanks.
 
That is beautiful.

How was re-entry supposed to work?
 
Vanadium 50 said:
That is beautiful.

How was re-entry supposed to work?
The same way it was finally done: The command module separates, turns around and reenters heat shield first. One difference was that it was equipped with a para-sail rather than parachutes.
 
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The plans also included a sheet for a "space-lab". I'm not sure exactly what its purpose was.
Anyway, here's what it might have looked like docked to the CM/SM pair.
SPACE_LAB.png

The solar panels would be folded over the end during launch. The arms they were mounted on could rotate on the lab's axis, and the panels rotated on the ends of the arms in order to keep them oriented to the Sun.
 
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