Early LM prototypes with round front hatch.

I've been working my way through the marvelous "Rocket Science" series from
Discovery TV Canada. It has a lot of great footage, is mostly accurate, and
has a lot of interviews (plus additional interviews.) Anyway, they showed
what appeared to be the assembly of a LM with a circular front hatch. It
looked pretty much like all the other LM's I've seen without their outer
skin, but the hole for the hatch was definitely circular. They showed both
the front of the cabin being lowered to mate with the rest, and also the
Ascent Stage on top of the Descent Stage, both of them without their outer
skins or mylar covering. In the later configuration, they showed someone
wearing one of the Dave Clark suits (AS-204/Apollo 1) with a shortened EMU
attempting to crawl through the hatch, and having problems.

So, what were these LMs? The best I can think of is that they are some sort
of construction prototype.


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