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Updated November 2008

Sizing of the Discovery spacecraft.

I first went to see the movie 2001 a space odyssey as a child, in about 1968 (when it first came out) and have been a fan of the movie ever since. I have built several models of spacecraft from the film including, the Orion Shuttle Aries 1-B, and the famous Aurora Moonbus (which I had about the time that I first saw the film), I always planned to scratch build the Discovery, Aries etc , However I may as well present some of what I have done so far (Mostly a lot of research) towards my Discovery model , which I intend to build in 1/144th scale to 'go' with my other 1/144 scale 2001 stuff.......

Dimensions when given in books etc can differ greatly, for example, the length of Discovery I have seen given at  324, 400ft, 700ft, or anywhere in- between. Mostly I have tried to get back to basics, and have lifted dimensions straight from the 'screen', using a technique I developed years ago to lift dimensions of Real spacecraft from photos and pictures......

 I have done a lot of research in light of new information and detail that has come my way. Past readers of this page will I hope, be pleased to know that the dimensions that were given here on this page (for several years) were not far off the mark....However due to the 'new info.' all the previous sizes are now revised... and more accurate than ever.....

It turns out that the length of the Discovery is nine  (9) times the diameter of the pressure sphere*, and the Pressure sphere is 6 times the Dia. of the Pod... (These important 'ratio's' were determined by careful measurement of movie stills, and frame grabs of the 'smaller filming model', and by the 'known' size of both  the 'small and large' original scale models...

* I am pleased to report that my 9/1 ratio is now being widely used by others in 2001 'fandom'

The 15 ft model   (or is it 12 ft*.)

I have a 'Side on'  B&W studio photograph of the 'smaller' studio model  see it here  The picture is of the opposite side of the model to that seen in the movie !  The model is mounted on a 'multiple rod support stand ' (to prevent bending of the long thin model )... and there is no sign of any distortion by the camera lens to the model, or to the stand, and even the planking on the studio floor is not 'bent' in any-way due to any discernable 'camera effects, (except the normal 'vanishing point effect' that you would expect). This picture proves that there is also NO camera distortion to this same model as it is seen in the movie (other than a slight vanishing point effect mentioned )

The point of all the above is that by dividing the Sphere diameter  into the overall length of Discovery,  you get a ratio of  9.....this can be accurately done by measuring pixels of the picture on the computer screen.....  BUT.... You don't actually  need to measure any pictures at all to do this... Just divide the sphere diameter into the length, if you  know the size of both ......which for the 15 ft model is a 20 inch sphere, (for which I have separate 'evidence'... and so I will 'go' with this size... until I see better proof for otherwise..)   9 X 20 inches is 15 feet....  and the same is true for the 'Big' model (see below)  

The 15 ft model would be 1/24 scale (of a 'real' Discovery) 

* In fairness there are a also lot of sources that quote a 12 ft length for this model (in which case the CM would be 16 inches dia.)  Interestingly Con Pederson one of the original model makers on the movie 'remembers' that the smaller model was "one fifth" the size of the large one....Well Five Times 12ft  is 60ft.... ( 60ft ??? read on...)       (a 12 ft model would be 1/30th scale (of a real Discovery)


The Command Module (CM)

The CM  becomes 40 ft dia. The 'driver' for this being the ratio of  6 X the diameter of the Pods (80 inches). But is this true?.......(Well the 2001 book' does say 40 ft Dia.) and ("Nearly 400ft" for Discovery's length)

If so a 15 ft Discovery model (mentioned above) would have to be 1/24th scale ....  eg. 24 X 20" dia. = 40 ft  dia. CM. and  24 X 15ft = 360 ft long (full size if real...... )

Scaling the 'main dish antenna diameter'  (using the same picture and same pixel 'counting' technique see it here ) the 'real size' antenna dish would have to be 12 ft dia*.

 (does anyone have any information regarding the full size Dish Set... please mail me if you do )


NEW. 2012*

This picture  became available a couple of years ago, but one thing and another I have only just gotten around to putting it here.  It shows the studio prop of Discovery's Dish Antenna 'full size'* with a person standing close to it. 

I took a guess at his height...lets say 'average' at 5' 8'' or 68 inches...  ( so in pixels on the photo, the persons height is 286 pixels).

The big Dish measures 635 pixels top to bottom (so 635 in diameter)...The picture is not distorted in vertical height !!!

Dividing 286 into 635 gives a 'ratio' number of 2.24. Times this number by the persons height gives a dish diameter of  152 inches or 12.69 feet.

Doing this I did not know in advance what the size for the dish would turn out to be. There are a lot of 'variables' the persons height for example. However the answer is very close the 'expected' diameter. (see above)


* like the ' Discovery's Interior sets' and the Pods, (and of course the  'Astronaut' crew) the Dish can be regarded as 'full size' e.g. 1/1 actual size to the Dish that a 'real' full size Discovery would have.


The Pods

The pods were built Full size (1/1 scale) and so can be considered 'real'...

After careful measurements and other things which I need not go into here,  I have the Pod diameter at 80 inches . The pods (along with the ' 9' ratio mentioned above)  are the 'drivers' for all the other ratios.... By careful measurement I have the pod to CM ratio as 1/6th  the diameter of the CM (pressure-sphere) if real, the Discovery CM (command module) would be 6 X 80 inches = 40 ft. diameter. The Smaller model pods  are scale models of the full size pod.

The 'larger' of the pod models, is often quoted as being ~ 13.5 inches in diameter... well at 1/6th scale 6 X 13.5 = 81 inches ... (and so near enough to my 80")

The Pod Deck

The Pod deck (like the pods themselves) was built full size (so can also be considered 'real')...Up until about 2005, I had taken what I believe to be the correct diameter for the CM (40ft)...and 'made' the interior to fit into it as well as I could.... However...... for the first time thanks to the prompting of a fellow 2001 fan Adam Johnson (USA), I have drawn what is probably the most accurate floor plan of the pod room yet drawn by anyone, (not shown on this site yet)... drawing what I saw, with no view to 'make it  anything' other than what I observed and what it was.

It has taken dozens of drawings to get it right... but Everything on it works ...lines of sight along edges.. everything....and the pods at 80 inches dia. fit into it . And more,  the Pod door aperture sizes have become apparent... they are 11ft 6 inches diameter. But there is a snag... a surprise to me  !!!! and maybe to others too (or not) .....(More on this lower down see ' Pod deck surprise ' below.).

The 'big'  (54ft) studio model

Ok... Everything I have done on this page in the past #2003 (and why I have now updated it # 2005)  has been to accommodate the statements below, which appear 'constantly' in 2001 fandom, that, QUOTE

"The large model is 54 ft long and has a sphere 6 ft diameter (and is 1/6th scale and has a pod at the same scale of ~13.5 inches diameter"

proportionally the above is correct,  but it does not tally with a (real) discovery with a 40ft. CM and 360 ft long !

I have had a 'Eureka moment' and decided that its this very information that's wrong (and what to do about it)'s why.....  6 ft divided by 54 ft is indeed a ratio of  9 (same as the small Discovery)............and you can 'feed in' any number you like into this formula to get a Discovery proportionally right of any size you want.  But at 1/6th Scale to match the pods scale  The CM at 6 ft Dia. will give a Sphere of Only 36 ft dia. (and 36ft X 9 ratio is 324 ft long) The diameter for the CM is clearly would be way too small  seen against the pod which was built full size (e.g. 'real').

The 'Fix'........

Everything... and I mean everything  works, if the Big Discovery model were 60 ft long... and not 54 ft... The scale's become consistent...the ratios of length to CM diameter work (see below),  the pods are to scale etc.  The model would become at 1/6th scale 360 ft long and have a sphere 40 ft dia. and for the first time becomes consistent with the RATIOS of the 'small ' model. The pod doors for both models also scale to the full size of 11ft 6" (as described above) 

Wow factor....

 But how about this as a whammy of a consequence , that 'feels' Sooooo right......the CM Sphere becomes 80 inches in diameter ........which is the same diameter as the full size Pods !!! Handy for making (at least) four glass-fibre sphere's (for pods and  CM)  from the same mould... I have pictures of the CM seen clearly being made separately from the main 'body' of the Discovery..... and the length of the body of the Discovery without the D shaped CM attached  is...............54 ft long !!!! and the 80 inch diameter sphere measured from the 'front' to the 'Flat of the Back' of the D shape Is near  6 ft!!! ......54ft + 6ft = 60* ft...    Coincidence???       Well if you worked on the 'body' (in a separate shop to the sphere) would you not still call it a 54 ft model if that's what it was.....perhaps the '54 ft' name stuck !!!!

*actual... doing the math,  the  front to back of the CM  is about 3 inches less than 6 ft...therefore the body maybe longer than 54 ft by the same amount in order to total exactly 60 ft

Also there are precedents for the large Discovery being quoted as 60 ft long...... from two separate articles dated 1969 (By people who worked on the movie) sent to me by fellow 2001 fan Eliot R Brown (USA) ...

The Pod deck Surprise.

The Big surprise is this.... Having drawn the Pod deck I can say for absolutely sure that the Full size deck will only fit into a sphere  (CM) that is 60 ft in diameter !!!!  (The actual floor of the pod deck having a radius of 26 feet up to the Bay doors)......The Pod bay doors being  radialy positioned on the interior set at 1/10 th's of a circle,  and are 11ft 6inches diameter.

The Pod diameters, and the Pod bay door apertures are the only things on a consistent scale with the 40 ft CM exterior of the Discovery, and the '60ft' interior

A full size Pod deck will in no way fit into the Interior of the Discovery at the 40ft external size... and, on the outside of the 40ft CM, the pod bay doors are centred on 1/8ths of the sphere (not 1/10th's as is the interior)... No wonder I that have had to 'fudge' in the past  to get the interior to fit.

 So it seems to me you can have two separate but correct models.... one for the outside which is what I think  most modelers would want, and 'fudge' the interior to fit...(See below) Or.... have a model of the Pressure sphere interior on its own, that will  contain a  accurate scale model of the Pod Deck and Pods and pod bay Doors as seen from the inside... (and I have to say all the rest of the CM interior too... Centrifuge, Cockpit, HAL etc).    However the Discovery cannot be scaled up to 540 ft long (9X60ft ) to accommodate a 60 ft Dia. CM .....the Pods and the Bay doors would be proportionally much too small as seen from outside

Stargazer August 2005  (revised 2008)


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