X-11, X-12, Atlas missile forerunners

DarkLord

DarkLord

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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
Specifications:
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
Specifications:
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:
http://www.up-ship.com/drawndoc/drawndocspaceother.htm#spacedoc50
sdoc50ani.gif
 
A nuclear powered Atlas was also studied under GE-ANP studies that began in 1954:
1-png.583231

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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hesham said:
atomic-skies.blogspot.com.eg

APEX-901

Excursions into the history of atomic energy.
atomic-skies.blogspot.com.eg atomic-skies.blogspot.com.eg
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Boxman said:
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.
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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.
 
First test-flight of an Atlas A (X-11):



Film from the Atlas Centaur Heritage Film Collection which was donated to the San Diego Air and Space Museum by Lockheed Martin and United Launch Alliance. The Collection contains 3,000 reels of 16-millimeter film.
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More recent documentation finds may have changed historians' views, but here goes.

From The X-Planes - X-1 to X-45 by Jay Miller, Midland 2001:
In order to accomodate the accelerated development and test schedule, Convair suggested that a series of test articles, (to be designated temporarily X-11 during 1954) be built and flown. Having no sustainer engine and a dummy, non-weaponized nose-cone, the X-11 would serve as an airframe/systems/propulsion testbed with the singular purpose of verifying the viability of the basic Atlas missile configuration.
When told that the X-11 would cut nearly a year off Atlas development time, the Air Force quickly agreed to the Convair proposal. During May of 1953, with the initiation of the definitive Atlas design effort, the DoD confirmed the X-11 designator (use of this designator would be short-lived - 1954 only - as Air Force and Convair publicity releases almost immediately began referring to the new missile as simply the Atlas, and later, as the B-65 [bomber] Atlas, and still later as SM-65 [strategic missile] Atlas).
[...]
On January 14, 1955, the program was given an official go-ahead. The Air Force formalized this approval with contract number AF04(645)-4. Now known as the WS-107A (Weapon System) Atlas
[...]
By June 3, 1958, a total of eight Atlas As had been launched [...] With the end of this initial segment of Atlas flight testing, the X-11 program, as such, was terminated and its contribution to the Atlas missile was conaidered fully consummated. The Atlas program went through A, B, C, and D series development vehicles, and D, E, and F operational vehicles.
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The book says X-12 was designed as predecessor to the operational prototype XB-65, but none were flown under that designator, instead 13 Atlas Bs were built, 10 flown.
If Jay Miller's account has since been superseded by more recent research, I would honestly like to know.
Every day is a school day.
 
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Andreas Parsch said:
The Wikipedia article about the Atlas A doesn't mention the X-11 at all. Do you even read what you quote?
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If you type in Convair X-11 you're redirected to the Atlas A article also it has been pointed out by other posters that the X-11 was used in reference to the Atlas A however that designation was only used in 1954.
 
Arjen said:
More recent documentation finds may have changed historians' views, but here goes.

From The X-Planes - X-1 to X-45 by Jay Miller, Midland 2001:

The book says X-12 was designed as predecessor to the operational prototype XB-65, but none were flown under that designator, instead 13 Atlas Bs were built, 10 flown.
If Jay Miller's account has since been superseded by more recent research, I would honestly like to know.
Every day is a school day.
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Jay Miller has not been "superseded". But unfortunately, he could have stated it a bit clearer, that the Atlas A/B were not the X-11/12. But he does say things like "No X-11 was actually built or test flown", but continues with the date of the first Atlas A launch. This imperfect separation of X-11 and Atlas A almost certainly comes from the fact, that in the very first edition of his book ("X-Planes - X-1 to X-29"), Miller did indeed equate the X-11 with the Atlas A. He corrected that in later editions.

Miller also includes a table about the characteristics of the X-11, X-12 and XB-65 - see attached photo (sorry for the bad quality - I just made a quick photo with my phone). You can easily see, that the specs (like length, weight and, in case of the X-11 and XB-65, even the number of engines) is totally different from Atlas A or Atlas B.

The initial Atlas design was significantly larger than the Atlas missile as built. It was to be a 5-engine rocket, and the USAF wanted to take incremental steps via single-stage (X-11) and 3-stage (X-12) test vehicles. Before any of these were built, Atlas was downsized, and the X-11/X-12 were cancelled. The new initial test vehicle was the XB-65A (redesignated XSM-65A, before the first one was completed). That the first two versions for the original (and cancelled) Atlas design were named X-11/X-12, does not imply that the first two versions of the revised (and built) Atlas were named the same. Fact is, they were not.

NMaude said:
If you type in Convair X-11 you're redirected to the Atlas A article also it has been pointed out by other posters that the X-11 was used in reference to the Atlas A however that designation was only used in 1954.
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Some redirection on Wiki does not mean, that Atlas A was actually ever designated X-11.
 

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Andreas Parsch said:
The initial Atlas design was significantly larger than the Atlas missile as built. It was to be a 5-engine rocket
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I know, it would've been interesting to see if the original five-engine design had been built (Would've been the US equivalent of the Soviet SS-6 Sapwood IMO) as it would certainly have been able to loft quite a large payload into orbit for example.
 
Chuck Walker, in his 2005 book 'Atlas, The Ultimate Weapon' does not even mention the X-11 or X-12.

Tony Landis, Dennis Jenkins and Jay Miller in their 2003 monograph 'American X-Vehicles. An Inventory - X-1 to X-50'
have a page on X-11 and X-12 each. This monograph can simply be downloaded from the NASA website:

I attach the relevant pages in case the url might not work anymore in the future:
 

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Ok, so...
- circa 1954 they feared that H-bombs may be so heavy, they designed the Atlas with 5 engines, and, accordingly...
- X-11 was to be a single engine test vehicle
- X-12 was a three engine test vehicle introducing the risky droppeable engines
- In the end H-bombs become light enough the 5-engine Atlas was dropped
- so the X-11 and X-12 monikers were dropped, too
- for B-65, in the bomber sequence, later changed to SM-65
- with the test vehicles being designed with letters (SM-65A, and on)
 
Details of 5 engine Atlas
 

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Archibald said:
- circa 1954 they feared that H-bombs may be so heavy, they designed the Atlas with 5 engines, and, accordingly...
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The lightest 1st-generation TN-warhead was the TX-15 ZOMBIE device test-fired in the Castle-Nectar shot of Operation Castle and at only 6,520 Lb in weight (the production Mk-15 was 7,600 Lb) it was a lightweight design (34.5 inches in diameter, 110 inches long), it yielded 1.69MT (Design yield 1.8MT).

Archibald said:
- In the end H-bombs become light enough the 5-engine Atlas was dropped
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That dramatically changed in 1956 in Operation Redwing where several much smaller TN designs were tested with the TX-28 tested four times (It became the Mk-28 (Later B28) and W28 warhead) this particular design was modified to become the W49 ICBM/IRBM warhead.

Archibald said:
- with the test vehicles being designed with letters (SM-65A, and on)
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And under McNamara's tri-services designation system (One the few good things he did as SecDef IMO) it became the CGM/HGM-16.
 
I wish the lightweight nukes had come after the five-engine Atlas was put into production. Still a bit less than R-7 though?
 
publiusr said:
I wish the lightweight nukes had come after the five-engine Atlas was put into production. Still a bit less than R-7 though?
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Why? We won the Cold War because of smaller nukes and rockets. We had better satellites, more diverse and better launch vehicles, subs etc. We got better electronics out of it.
We might not have got the Saturn family with that outcome.
Your fixation on bigger rockets is not logical. It wouldn't mean we would be further "ahead" in spaceflight. We passed the Soviets in the early 60's despite Kruchiev's public human spaceflight firsts.
 

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