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6 September 2008
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I am researching the Atlas missile forerunners for a model project. I have some illustrations of the X-12 "Atlas", which had 4 boost engines plus the central sustainer engine; plus a diameter of 12 feet as opposed to the final atlas of 10 feet: but I would like some dimensioned drawings or any pictures.
If the US had not reduced the warhead size and weight, they would have had a "beefier" space launcher. I wonder how the early space race would have progressed then!

Here is the site from where one of the images came:-http://jpcolliat.free.fr/x11/x11-5.htm
For general information:
X 11
diam.: 12'. 3.66 m
length: 96', 29.26 m
engines: 1 North American XLR43 NA 5
max. speed: Mach 10.6

The X 11 was an experimental single stage ballistic rocket to provide design data for the XB 65 Atlas. The programme originated in 1953 when it was envisioned that the operational Atlas would have five engines. The X-11 was the single engined version.
Some reference sources have suggested that the X 11 programme covered only one flight, ie. the prototype of the Atlas A, which was launched on 11 June 1957. The Atlas A had, however, three engines rather than the single engine specified for the X 11. The launch took place from Cape Canaveral and the vehicle was destroyed after one on the two outboard engines failed. The suggestion that this was the X-11 is certainly incorrect.

X 12
diam.: 12', 3.66 m
length: 103', 31.39 m
engines: 3 North American XLR43 NA 5
max. speed: Mach 18

The X 12 was a 1 1/2 stage rocket ballistic test vehicle for the SM 65. The programme was initiated in 1953 in parallel with the X 11 and was a three engined version. The 5-engined XB-65 version never materialised as nuclear warhead had become lighter.
Some reference sources have suggested that X-12 covered the second Atlas A flight which was launched from Cape Canaveral on 25 September 1957 and was destroyed during the flight. The suggestion that this flight was the X-12 is certainly incorrect.
See here:
An episode of 1970s' TV series Route 66 featured the 2 actors working on that floor, surrounded by bits of Atlas.
A nuclear powered Atlas was also studied under GE-ANP studies that began in 1954:

The nuclear rocket engine uses hydrogen propellant, a graphite-moderated core, and had a claimed thrust of 300,000 lbsf. Nuclear-powered ICBMs are generally considered a bad idea, and not just for the obvious reasons. Nuclear thermal rockets have a poor thrust-to-weight ratio, which is a problem for something trying to reach outer space from the Earth's surface. Particularly odd is that the missile is two-stage, and the first stage is nuclear-powered, while the second stage has a conventional rocket engine. A nuclear rocket might make some sense as an upper stage, firing once you're out of the atmosphere, but it's a decidedly odd choice for a lower stage. Presumably there's a reason for this, but darned if I know what it is. Incidentally, I've seen references elsewhere to a Soviet study of a nuclear-powered ICBM, called the YaRD, but all of the source material seems to be in Russian.

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Just posted on YouTube by the San Diego Air & Space Museum (SDASM) Archives, here is a 1960 Convair / General Dynamics film detailing the (until then) development history of the Atlas Missile.

I took the liberty of embedding the video for ease of access:
The Japanese Firm, Raccoon Models has produced resin models of X-11/X-12 (one choice ine the box) in 1/72 scale in the late '80s. I have the kit, quite basic, it could be a good model with some improvement. However, I don't know if it is still in production.
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