Tag Archives: Technology

The Design and Construction of Epcot’s Spaceship Earth

13 Sep

“Hey, that’s that golf ball thing!” is a phrase I hear a lot when people see my desktop background of Spaceship Earth.  Instead of giving more information about what that person is looking at, I usually just smile and say, “Yep, that’s that golf ball thing.”  But Disney Nerds will agree that it’s much more than that.  It took countless hours to design Spaceship Earth (SE) and a full 26 months to build it.  This article is dedicated to the design and construction of both the structure itself and the attraction housed within.

Photo credit: livinginagrownupworld.wordpress.com

After the success of Magic Kingdom Park in Walt Disney World, Disney Imagineers decided to use portions of Walt Disney’s idea for the Experimental Prototype Community of Tomorrow (EPCOT) to develop a new theme park that would be called EPCOT Center.  Today it’s simply known as Epcot.  Just like Magic Kingdom’s Cinderella Castle, WED Enterprises wanted Epcot to have a central icon to embody the theme of the park and to draw guests in.  They wanted a “logo” or focal point of the park, and they wanted it to be in place for Epcot’s grand opening on October 1, 1982.

The designers at WED expressed interest in the design of the Expo ’67 dome in Montreal.

Photo credit: britannica.com

They liked the geodesic design and decided they wanted Spaceship Earth to have a comparable look.  WED’s project designer for SE was a man named Gordon Hoopes.  He said that his intention was to “create an atmosphere for our guests that raises their spirit and kindles an excitement for the human experience in the future.”  WED played with the idea of a dome but soon decided they wanted a full sphere.  They settled on the size of a 160-ft. diameter geodesic sphere elevated above the ground.  The title of the icon was not developed by WED alone.  The term was popularized by Buckminster Fuller in his 1968 book Operating Manual for Spaceship Earth.

Epcot’s Spaceship Earth is not simply an architectural icon; it also houses an attraction of the same name.  WED enlisted the help of several third-party entities to collaborate on the concept and development of the attraction.  Along with Buckminster Fuller, Disney Imagineers worked with science fiction writer, Ray Bradbury on its structure and storyline.  They also consulted with Los Angeles’ Huntington Library, the University of Southern California, the University of Chicago, and the Smithsonian Institute.

Because a geodesic sphere (as opposed to a dome) was a novel concept and there was little engineering data on this type of structure, WED also hired MIT to conduct wind tunnel studies on a 1/16” = 1’ scale model.  They did this to determine pressure coefficients for the design and to test wind pressure underneath the sphere – where the guests would be walking.  They didn’t want the wind to knock guests down as they passed under the structure.

Photo credit: intercot.com

Essentially, SE is two separate structures: the external shell which is the sphere itself and the internal ride system and show scenes.  From now on in this article, I’ll refer to them as either the Shell or the Show.  Besides being a full sphere, SE was unique in another way.  WED wanted to put an attraction with moving vehicles inside the sphere, and they wanted SE to be elevated above the ground on six legs.

Their first concern was how they would carry the load of the Shell.  If they allowed the six legs to bear the full load alone, it would put too much stress on those individual sections of the sphere.  This could cause the Shell to buckle in the areas of concentrated force; they needed to distribute the weight more evenly.  They decided they would keep the Shell structure completely independent of the legs.

First, they drove the six legs supported on pile groups between 100’ and 160’ into the ground.   They connected the top of each leg with trusses to form a hexagonal truss and reinforced it with additional interior trusses which formed a platform.  At this point, SE looked sort of like a six-legged table.

Photo credit: land.allears.net

The hexagonal trusses, or the perimeter of this “table”, are what carry the load of the Shell structure.

This table including the interior trusses also bears the load for the Show structure.  Because this platform was so crucial, they needed to apply some dead load to the hexagonal trusses before erecting the Shell.  They were able to build the majority of the Show structure before beginning construction of the Shell.  They erected the interior columns and most of the ride helix onto the platform.  This ended up working well for WED because the construction of the Show and the Shell could occur together.

Photo credit: mickey-mouse.com

I should also mention that there is an elevator shaft that runs vertically through SE that is not associated with the hexagonal trusses. The base of the truss that forms the shaft is covered by mirrored panels that you can see as you pass underneath SE.

Photo credit: en.wikipedia.org

Once most of the Show structure was completed, they had to begin transitioning from the hexagonal trusses to the Shell. They used what they called “quadrupods” which are shaped like pyramids formed from pipe.  The bases of the quadrupods were connected to the outer perimeter of the hexagonal trusses and the tops of the quadrupods were connected through support hubs on the Shell to make an interlocking ring of sphere struts.

Then they were ready to build the Shell.  The Shell is basically two geodesic domes – one on top of the other.  The top ¾ of the sphere rests on the table and the bottom ¼ is suspended below the table.  The geodesic dome maintains its shape simply by the nature of its design.  It does not require reinforcement.  The larger the dome, the stronger it is.  When SE was built, the construction of the Shell first traveled upward from the support hub level in rings of struts until the entire top portion was complete.  Then the remaining portion of the sphere was completed below the support hub level.

Photo credit: magicalmountain.net

Construction then continued to complete the exterior of the Shell.  The Shell structure is actually a sphere-within-a-sphere – the larger (exterior) sphere has a radius about two feet greater than the smaller (interior) sphere.  The “double-skin” came about as a solution to a few problems WED had explored during the design.  They needed a waterproof and fire-resistive exterior to protect the occupants, sets, and attraction vehicles.  And most importantly, it had to look good.  There was no one material that could accomplish it all, so the sphere-within-a-sphere concept was born.

Steel closure panels with a waterproofing neoprene sheet were attached to form the inner skin.  The outer skin would be purely for show.  They needed an aesthetically pleasing material that could withstand the elements of central Florida.  They chose a material called Alucobond which is polyethylene plastic sandwiched between two sheets of aluminum.  They used aluminum pipe standoffs to create the gap between the inner and outer skins and attached the Alucobond facets to them.  The inner shell’s basic structure is an array of large triangles.  For the outer shell, John Hench (WED VP for Creative Development) decided to subdivide each of the large triangles into four smaller triangles on which they placed triangular pyramids.  What we as guests see are the small triangular pyramids.

Photo credit: simplydifferently.org

The sphere-within-a-sphere design also addressed another issue: runoff of rainwater underneath SE.  By leaving one inch gaps between the Alucobond facets, rainwater trickles down to the waterproof inner skin where it accumulates at a hidden gutter system near the “equator” of the sphere and is then carried out to the World Showcase Lagoon.

Photo credit: flickrhivemind.net

Photo credit: mainstgazette.com

Spaceship Earth, the attraction, takes guests on a journey through time highlighting the ways in which humans communicate.  The ride structure is arranged in two helixes that serve as the track for the ride vehicles.  The vehicles spiral up to the top of the sphere and back down to the unload area.

Photo credit: amusementauthority.blogspot.com

Along this slow-moving journey up into the sphere, guests encounter various props, projections, and Audio-Animatronics.  If you want to know more about how Audio-Animatronics work, you can check out my post about AA’s.

The ride vehicle utilized on Spaceship Earth is Disney’s Omnimover system.  Imagineer Bob Gurr combined two terms already in use, OmniRange and PeopleMover, to create the term Omnimover.  The true root of the term Omnimover comes from the Latin term “omni” meaning “all” or “every” and “mover” meaning… well, “mover”.  The technology itself was developed and patented at WED Enterprises by Roger Broggie and Bert Brundage in 1968.

Each vehicle is capable of rotating or tilting to a preprogrammed position.  This system is advantageous for Disney in that they are able to control what scenes guests will view in order to tell a story while obstructing portions of the attraction that are meant to remain hidden.  SE’s ride system also includes speakers on each individual ride vehicle.  Disney can cue a portion of the soundtrack/narration at predetermined locations along the track.  This gives each guest the same ride experience.  Then, the 2007 renovation of SE added interactive displays to each vehicle.

Photo credit: amusementauthority.blogspot.com

Every time I see Spaceship Earth in photos or when I visit Epcot, I have a huge appreciation for the complexity of the structure itself, the attraction, and the story behind its design.  So next time you hear someone say “Hey, that’s that golf ball thing!”, you can direct them to this article to help them understand why we Disney Nerds think it’s much cooler than a golf ball.

If you have anything you wish to add, please feel free to comment below.  I am not affiliated with the Walt Disney Company.  All thoughts and opinions are my own.

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The Imagineering of Audio-Animatronics

27 Jul

Anyone who has visited a Disney park has undoubtedly been captivated by Audio-Animatronics (or AA’s).  My fascination with AA’s started at a young age, and I’ve always enjoyed learning about them.  I also love to discuss them with other people, so I’ve decided to put together a high-level overview of their constantly evolving technology.

Control Systems

To understand machines as complex as Audio-Animatronics, it helps to first understand control systems.  A control system in its most basic form is an input that produces a desired output.  Inputs and outputs are classified as either binary (also called digital) or analog.  A binary input or output is one of two discrete values (i.e. on or off).  An analog input or output is a varying value.  How do you know if the value is designated as an input or an output?  You have to think like a controller.  The controller is the reference point.  Information that the control system receives is an input and information that the control system sends is an output.  Simple enough?

To illustrate, I’ll use an example that most people can relate to before moving on to the inner workings of AA’s.  A control system that most people encounter on a daily basis is the thermostat in your home.  Your thermostat is a controller.  Inside that controller is a temperature sensing element.  Since temperature is a varying value, it is considered analog.  Your thermostat receives an analog input from the temperature sensing element.  Your thermostat has been programmed to maintain a specified room temperature, so when it receives that analog input, it will confirm whether or not the specified room temperature has been satisfied.  Your thermostat then sends a binary signal (on or off) to your air conditioning unit.  Your air conditioning unit will continue to cycle on and off to satisfy the specified room temperature.

Asleep yet?

A-1’s: The First Audio-Animatronics (for Disney fans, the Dancing Man is not considered a true AA)

One of Walt Disney’s first endeavors with AA’s was with Walt Disney’s Enchanted Tiki Room in Disneyland back in 1963.  What made this control system so revolutionary was how WED Enterprises combined movement with sound – hence the “Audio” in Audio-Animatronics.  In this instance, a score is prerecorded and programmed on magnetic film/tape.  The control system is a group of gigantic machines that play back the programmed film in the desired sequence.  The film produces a set of signals or tones.  Every time a tone sounds, a metal reed vibrates.  The signal and metal reed are the system’s binary input.  This metal reed closes an electric circuit which triggers a solenoid.  The solenoid actuates a pneumatic valve which opens and allows air to flow.  The Tiki Room’s outputs are its pneumatic valves/cylinders.  That’s why you can hear air hissing sometimes in many of the attractions with AA’s.  This particular system is fully binary, so the valves (the outputs) are two-position: open or closed.  A simple movement that results from opening a pneumatic valve might be to open a bird’s beak.  To summarize: control signal closes circuit and solenoid actuates air valve which opens beak.  That’s just one movement.  The Tiki Room is full of countless other movements set to a full musical score.  Mechanically, it’s a simple system, but it takes a lot of time and effort to make everything work properly and to produce an entire show.

Still with me?

The 1964 World’s Fair

We’ve made it through the basics, and each new development builds upon the previous incarnation.  Next comes the 1964 World’s Fair in New York with WED’s first human AA (which were called A-1’s by the company internally), President Abraham Lincoln.  Abe presents new challenges.  First, this AA is considerably larger and heavier than the Tiki Room’s birds, and second, a human’s movements are not two-position.  Our movements vary.  To address these challenges, WED uses hydraulics in lieu of pneumatics on some of the heavier/larger limbs and they develop an analog control system.   Both a binary system and analog system are used for Mr. Lincoln.  The way the analog system works is by varying voltage to the actuators of the pneumatic or hydraulic valves which results in a full range of motion.  The control signal is not on/off; it fluctuates.  Every analog input is programmed individually on the magnetic film.  Then each piece of tape is combined into a single reel and synched with the dialogue and music.  You can see the finished product in Walt Disney’s Wonderful World of Color “Disneyland Goes to the World’s Fair”.  Walt gives a great introduction and we get to see Blaine Gibson, the sculptor who created Lincoln’s face.

In the same special, Walt goes on to discuss the Carousel of Progress.  This is where we get to see one of the methods by which WED was able to program the desired analog movements.  Wathel Rogers, an Imagineer, is shown wearing a harness device that records his movements onto the magnetic film.


The next major milestone is in the late 1960’s with the introduction of the Digital Animation Control System or DACS.  DACS has the capability to program movements on computer disks rather than tape.  With the advances in computer technology, Imagineers can program AA’s from a control board instead of wearing the cumbersome harness.  Also, eliminating the tape allows for easier addition, deletion, and shifting of movements in a sequence.

Side note: This system is still in use today but has gone through multiple upgrades and improvements.  DACS does not only control AA’s; it also cues lighting, sound, and other effects.  This is the control system seen in almost every Walt Disney World television special when the cameras go inside the Utilidors.


We’ve made it to the 1980’s!  At this point, Imagineers are a bit annoyed by the seemingly harsh movements that most of the AA’s exhibit.  If the movements are quick, the limbs shake which makes the whole AA move.  They end up having to slow the movements down to prevent shaking.  This is not a desirable solution, so Imagineers develop a better technology to correct these issues.  They call it “Compliance”.  Compliance allows limbs to move slightly past their programmed end location to absorb shock and soften the finish of the movement.  This is all made possible due to more robust computer systems and programming technology.  In 1989, the first AA to incorporate compliance shows up in Disney’s Hollywood Studios (Disney’s MGM Studios at the time).  The Wicked Witch of the West is unveiled at The Great Movie Ride.  The company calls this type of AA an A-100.  Because of the exponential increase in channels of movement, it can take up to eight hours to animate one second of an A-100.  Keep in mind that up to this point, every AA’s inputs are prerecorded.

A-100’s are still the most recent incarnation of AA’s, but as materials are refined, control systems become more sophisticated, and Imagineers continue to tinker, AA’s movements become more realistic.  I was really impressed when I saw a clip of Ursula in The Little Mermaid: Ariel’s Undersea Adventure which opened in Disney California Adventure in June 2011.

Living Character Initiative

In the early 2000’s, Disney comes up with what they call the “Living Character Initiative”.  This encompasses both AA’s and traditional motion picture animation.  It’s a way to enhance the in-park experience by allowing guests to interact with characters.  The difference between standard AA’s and Living Character Initiative AA’s (or animated images) is that some of the inputs for the LCI characters are NOT prerecorded.  These inputs rely on operator intervention.  Typically a cast member is camped out nearby programming inputs in real time.

An example of a development from the Living Character Initiative is Lucky the Dinosaur.  Lucky is the first AA that can walk independently.  The cart he tows behind him conceals the control system and power source.  One of the reasons Lucky can roam freely is because his limbs are actuated electrically, so compressed air and hydraulic pumps are not required.  Lucky uses some prerecorded movement sequences but some of his actions are controlled by a hidden operator.  This allows Lucky to interact with guests.  Other LCI creations include Turtle Talk with Crush, Monsters Inc. Laugh Floor, Push the Talking Trash Can, WALL-E, and Muppet Mobile Lab.

Here comes the cool part…


The future of AA’s is so advanced that Disney had to come up with a new name for them: Autonomatronics.  By the way, both “Audio-Animatronic” and “Autonomatronic” are trademarked by Disney.  The Autono- prefix is used because these characters do not rely on operator intervention; they function autonomously. The term is first mentioned on Twitter in reference to the D23 Expo in 2009.  Disney introduced a new Autonomatronic named Otto.  The control system for this new generation is capable of receiving inputs from various sensing devices.  Devices might include occupancy sensors, cameras, or microphones.  The system first receives input information.  Then the controller analyzes the input, selects the desired output, and sends a signal to trigger the end device.

If you remember the thermostat example from way back in the beginning of this post, the new Auto’s are similar in regards to inputs and outputs.  They operate in response to external stimuli as sensed by the system instead of by a human operator or by using a prerecorded sequence.  However, the Auto’s have a lot more data and much more complex control algorithms than a home thermostat.

I came up with a possible scenario of how Autonomatronics might be used.  I’m not sure if Disney is already implementing this sequence; this is simply to illustrate the technology.  An Auto might have a thermal imaging camera imbedded in it.  The control system could then use that image to identify how many bodies are in the immediate area.  That quantity would serve as the analog input to determine what dialogue and/or movements are performed.  Again, this example is completely arbitrary; I don’t know if the company is actually using thermal imaging in this way.

I look forward to the future of both Audio-Animatronics and Autonomatronics.  Who knows what their capabilities will be?  Maybe we’ll be able to hold entire conversations with them and be BFF’s.

Home Stretch

I know this is a pretty dry topic for a blog post with a lot of emphasis on technology and all-around nerdy stuff, so I appreciate anyone who suffered through reading the whole thing.  If you have any comments or anything you wish to add, please post them below.

Oh yeah, and I guess I’m supposed to say something like “I am not affiliated with the Walt Disney Company. All thoughts and opinions are my own.”

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