Page 1 (of 5)

Click here to go to Front Page





Updated July 2018

Sizing of the Discovery spacecraft.

Dimensions, when given in books etc. can differ greatly, for example, the length of Discovery I have seen given at 324, 400ft, 700ft, 800 ft, (or anywhere in between) . Mostly I have tried to get back to basics, and have lifted dimensions straight from the 'screen',

It turns out that the length of the Discovery is nine times the diameter of the pressure sphere*, and the Pressure sphere is 5.33 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 and the known size of the pods... 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, (or counting 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 CM size, and length of the studio models.


HERE (CLICK) is a LARGE SIZE picture of the 'Smaller' Studio Discovery Model. I have carefully 'measured' it by pixel count, the total number of pixels between two indicated points are marked as such on the picture. (There is no such 'Side on' picture of the 'larger'studio model)

I have done the same 'measurements' on many of the 'side on' discovery pictures (found from different sources over many years, including screen grabs from the movie). All the pictures give very close (to each other) proportional' measurements, and I am very confident that anyone who does the same, will get the same results.


I have made a spreadsheet* using Data from the 'side on picture' and from 'known' sizes. (on studio plans)
The spreadsheet contains calculations using 'measurements' and other 'Known' Data from actual studio plans, for example, the 6 ft diameter of the 'Larger' studio models CM (Command Module)

CLICK HERE DATA spreadsheet of the 'Side on picture'

Here are some sizes from the spreadsheets (that are themselves taken directly from actual original studio plans/drawings).

Sphere 1/6 scale & 72 inches Dia....  Full size pod 81 inches Dia.... Model pod 1/6 scale &13.5 inches Dia....Spine Module 27 inches long...Dish antenna (for smaller discovery model) 6 inches dia.

I don't think that these sizes can be disputed, (as they are on actual studio plans) So the sizes can be used as a 'key' for the side on model picture to provide a means to accurately extrapolate the sizes of other (Size unknown) parts.

Although there is no 'side on' picture of the 'large' studio discovery model, it seems from the data, that the large and small models were build in exact proportion to each other. (setting aside small detail changes) I also have many other pictures such as the Full size Dish antenna, (see it towards the end of this write up), that I have done pixel counts and ratios on.  (They also fit closely the sizes taken from the 'side on' picture).

all the evidence points toward a much smaller scale for discovery than both Moebius and The 'new'Japanese kit are are scaled at. I have done ratio numbers for both these kits (and my stargazer one) on the spread sheet... and at their stated scales they clearly do not match the actual studio models.


Scott (Captain Cardboard) of 'Atomic City' Makes very large size 2001 models ! (very fine!!)

His Discovery models have a Sphere (CM) that if scaled up to 'full size' would be 36 ft in diameter.

This is the same size as the two studio models scale up to....

Below, is how this is worked out.... The 'Large' studio model had a CM (command module) 6 ft (72") in dia. It had a pod made for it 13 &1/2 inches in Dia...

Both the Large studio model and Pods made to go with it, were made at the same scale which was
1/6th Of full size...

This being the case … the CM at 6th X 6ft = 36 feet, & Pods at 6 X 13.5= 81 inches. (The full size pod was indeed made 81 inches)

The model Pods are also known to be 1/6 scale and are 13.5 inches dia.  The pods were made for the 'large' Discovery, and both were filmed together in a single take. (not added together photographically)

The Large studio Discovery had a CM 6ft (72 inches) Dia. and as the Pod and the CM are both 1/6 scale.  That makes a full size Discovery Sphere 36 ft Dia. and a full size studio Pod made at 81 inches dia.....  (these sizes are derived totally from the scale and physical size of the studio models.  (6 X 72" + 36ft.)

There are two ways to determine the length... The 1 to 9 ratio ( 9 x 36ft =324ft)... or simply take the often quoted length of 54ft (given by those who worked on the movie). 6 th X 54ft = 324ft

The same calculations holds true for the 'smaller' studio model and the pods made to go with it.

SO WHY IS MY OWN STARGAZER model of Discovery's CM LARGER THAN 36 ft.

(and longer than 324 ft) ??

I had many e-mail conversations with Scott (ATOMIC CITY) in the past, whereby I insisted to him that the Discovery 'looked' larger than 36 ft on screen!!! Also I said to him that  AC Clarke stated in his book that the CM was “40 ft dia”. (& had a “slowly rotating drum” (centrifuge) “35 ft Diameter”) and was “almost 400ft long”.... these dimensions were the only size reference given anywhere at the time! (pages112 & 113 of my 1970 copy of the novel)

I think though, that Kubrick purposefully made the Discovery seem to be larger (than the scaled up size of the studio models), on the screen by using photographic 'tricks' which he is Known to have done elsewhere in the movie (for example) with the Space station compared to the Orion, by make the Space station to look larger by making the Orion* look smaller seen against it photographically.

*The station and the Orion models were made at very different scales, so the models needed to be 'photographically adjusted' anyway!!

SO I made my 'Stargazer Discovery model to the A.C.Clarke quote and the size it appears to be on screen, also, I figured that the centrifuge measuring 36 ft across (floor to floor known studio set size) would have to 'fit' into a sphere larger than itself... e.g. into 40 ft, (not the 36ft size of the scaled up large studio model CM). (Another thing to note are the size of the pod bay doors.  It says 10 ft Dia.on the studio interior drawing, and also scale to 10 ft on the studio Discovery models... and my Stargazer Model, at my models size the pod bay doors scale to 10 ft). SO I made my own kit slightly larger than (the above) calculations, for these reasons, as I said before. At the time I made my model the Only known 'cannon' size reference for Discovery was from the man himself A.C. Clarke, where he wrote " the Discovery has a sphere 40ft in diameter and is almost 400 ft in length”. Also, at the time it was known that the Centrifuge that was supposed to fit into the CM was 36 ft Dia. floor to floor surface, and (at least) 38 ft overall, (36ft being the diameter of the CM.) So that the centrifuge will not fit into a sphere smaller than itself !... but could fit into one slightly larger*...the CM LOOKS larger than 36 ft as seen in the movie. This was I believe (as said above) done deliberately using photographic tricks e.g. a persons head seen in the window, and by a pod bay set that was physically sized larger than could possibly fit into the CM exterior size, done again I think, to give an overall illusion of greater CM size (as with the Space station V against the Orion). So I made my discovery at 1/144 scale... so that the CM would scale to 40 feet dia. and 360 ft long ("almost 400 ft"). Also the pod bay doors on the interior set were 10 ft diameter.  Having my Discovery sphere at 40ft made the exterior pod bay doors also 10 ft Dia.

(My Discovery CM is just 4 ft larger in dia. than (see above) studio model 'calculation'... whereas the Moebius Discovery CM is a whopping 16 feet larger!!! at the stated scale moebius give it). (See below)

*Dont get me wrong... I would have prefered Kubrick to have had the Discovery made to have been even more 'impressivably' sized, to be much much bigger... say 800 ft in length, and have a cm some 65ft dia. (with 10ft dia. Pod bay doors) In order to fit the entire full size interior sets into. But this is just not what you see on screen, nor what the two studio model were scaled to.


As of 2018 TWO new model kits of Discovery have been announced.

# The Moebius Discovery at a stated scale of 1/144 and is 41 inches long with a CM 4.3 inches would be 492ft long, if 'real'

# and a Japanese Discovery (Kaiyodo) stated scale of 1/96 . and so is 63 inches long with a CM almost 7inches Dia. So would be 503 ft long if 'real' !!!

Correcting the 'new models' sizes scale to conform to the original studio models known scale.
The Moebius kit

... 41 inches divided into 324ft = ~95... so 1/95 scale. (not 144)

However the Moebius CM is 4.3 inches Dia. So 4.3" divided into 36ft =
1/100 (giving a slight scale discrepancy between the Moebius. CM and length)

(My Discovery CM is just 4 feet larger in dia. than the above studio model 'calculation' ... whereas the Moebius CM is a whopping 16 feet larger!!! at the scale they have given it.)

The Kaiydo kit

The 'new Japanese KAIYODO Kit' is 63 inches long with a CM almost 7inches Dia. so 63” divided into 324ft is ~ 62 so 1/62 scale and a 7 inch CM divided 36 feet is again ~1/62 (not 1/96)

NEW information. august 2019 The Kaiyodo Discovery is to be marketed at “1/10th studio scale* . e.g. 10th of the 54ft large studio Discovery model. So the Kaiodo Discovery would by definition be 324 ft long if 'real'*


CLICK HERE DATA spreadsheet of the 'Side on picture'

'Old' musings From. 2012

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*.

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'... 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 ...

The Pod Deck

The Pod bay deck (like the pods themselves) was built full size (so can also be considered 'real')

However the Full size Pod (81 inches dia) was filmed inside a Pod bay which it turns out, was 52 ft to the outside (exterior) of the 'curtain wall'  this is the size that the Moebius Discovery* is made at and is taken from the interior pod bay deck drawing and not from the studio models.

Having drawn andmade models of the Pod deck I can say for absolutely sure that the Full size deck will only fit into a sphere  (CM) that is a minimum 60 ft in diameter !!!!  (The actual floor of the pod deck having a radius of 26 feet)......The Pod bay doors are 10ft diameter.The Pod diameters, and the Pod bay door apertures are the only things on a consistent scale with the exterior of the Discovery, and the interior

 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... Or.... have a model of the Pressure sphere interior on its own, that will  contain an  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) (*and again 2018)





Buy a 2001: Model Kit from me

My 'other' 2001 Models

Links to other 2001 sites

Click here to go to Front PageClick here to go to Front Page

page under  constant construction....