Delphic Expanse sphere The Delphic Expanse spheres were a series of artificially - created spherical objects that were scattered around the Delphic Expanse . The spheres , each one nineteen kilometer s in diameter , generated massive amounts of gravimetric energy and were collectively responsible for the web of spatial anomalies which constituted the Expanse . Each sphere was surrounded by a cloaking barrier which kept it hidden from outside observers . According to the Xindi - Primate Degra , the Xindi knew of seventy - eight spheres , at last count . ( ) Starfleet first encountered the spheres in 2153 , when entered the Expanse in search of the Xindi . The first sphere they came across was being used as a base for Osaarian pirate s . " Enterprise " engaged in battle with an Osaarian vessel within the cloaking barrier of the sphere , and was able to take a series of detailed scan s . Quantum scan s of the sphere indicated it was nearly one thousand years old . ( ) Upon further investigation , the " Enterprise " crew was able to determine that the spatial anomalies which riddled the Expanse occurred at points where the waves of gravimetric energy were being emitted from the intersected spheres . This led T ' Pol to hypothesize that the spheres were created for the express purpose of creating the Expanse . " Enterprise " later encountered the Triannon s , who held that supernatural beings whom they referred to as " the Makers " had created the spheres to reconfigure space in preparation for their eventual return . The " Enterprise " crew later discovered that the Triannon myth was based in fact , and that the spheres had been created by a race of trans - dimensional beings who were attempting to make the Expanse habitable for their species as a prelude to invasion . ( ) Captain Archer learned from , a temporal agent from the 31st century , that , in the 26th century , the Expanse would grow to encompass fifty thousand light year s of the Milky Way Galaxy , and that the Sphere - Builders were trying to manipulate the Xindi into destroying Humanity in an attempt to prevent the founding of the United Federation of Planets , which would ultimately defeat the Sphere - Builders . With this information , Archer was able to form an alliance with some of the Xindi against the Sphere - Builders . ( ) The crew learned from Degra that the spheres were controlled by a network of artificial intelligence , and that each sphere held a redundant memory core . A team from " Enterprise " was able to gain access to the interior of a sphere through an exhaust port which was holographically disguised . The team was successful in retrieving the memory core , but not before Corporal Hawkins was killed by an automated defense system . ( ) With the information retrieved from the memory core , T ' Pol was able to determine that each sphere was connected by an interspatial manifold on its surface , and that four of the spheres were integral to the connection . " Enterprise " was able to disable the manifold of the sphere designated " Sphere 41 " with a deflector pulse , causing a chain reaction resulting in the destruction of the entire sphere network , and eliminating the spatial anomalies in the Expanse . ( ) Background information . Scripting the spheres . In the final draft script of , the first description of a Delphic Expanse sphere ' s exterior referred to it as " a large , gleaming , METALLIC SPHERE the size of a small moon . " In the final draft script of , the exterior of another sphere was initially described in much the same way as that of the first sphere , except it was referred to as " giant " rather than " large " . The same script additionally described the exterior as " sleek " and " a vast , gleaming , metallic landscape with a mild but noticeable curvature . " In the final draft script of ( which was initially called " Untitled Sphere Story " ) , another of the spheres was described as " vast , metallic , mysterious , hanging in space . " The interior of the sphere , in the final draft script of " Anomaly " , was described as a " dark , cavernous interior " which was absolutely enormous and " easily spans a major metropolis . " The script continued , " " At the CENTER of the Sphere , we see an assembly of SEVEN exotic , high - tech STRUCTURES that tower outward in various directions . Only three of the towers are ACTIVE , PULSING with POWER like some kind of skyscraper - sized nuclear reactors ; the other four are dark , inactive . A deep , percussive RUMBLING sound echoes through the interior . " " Illustrating the spheres . The usual appearance of a Delphic Expanse sphere ' s exterior was designed by production illustrator John Eaves . He drew a total of six concept sketches before the fourth one was approved . The first of these proposed designs was heavily influenced by the look of an unapproved initial design for the Suliban helix , illustrated earlier in the series run of " " . " " The first drawing of the sulibon " [ sic ] " helix ship had this sphere drawn in as the core of the ship , " " recalled Eaves . " " When it came time for the xindi sphere ' s to go in for approval I borrowed the sulie core and offered it as a choice . " " The sketch for the sphere even had a massive opening that , in the original Helix design , had been intended to allow access for s . The sphere ' s interior was designed by Doug Drexler . He later explained that an early digital concept painting for the sphere ' s innards had " a more linear and ' constructed ' looking central core " than the final design , which instead looked as if it had been grown . Not only was the accepted design generally approved but Drexler himself preferred it . " " Frankly , I really wanted to do the organic looking one because it reminded me of Vgr , " " he reminisced . After being given the go - ahead , the digital artwork was delivered from the art department to Eden FX , by whom it was then adapted for television usage . Drexler also created a cutaway view of a sphere , showing the seemingly organic interior beneath a portion of the sphere ' s outer skin . Visualizing the spheres . The Delphic Expanse spheres were visualized almost entirely with CGI . Green - screen was used for some shots of environmental suit ed " Enterprise " crew members walking on one of the spheres . " " Their entire environment is created by us . There ' s nothing practical , " " explained Director Roxann Dawson , during production . " " It ' s all created by visual effects . So , in order to do that , it has to be planned with everyone in mind , so that we all know what we ' re doing on shots like that . " " ( " A Day In The Life Of A Director - Roxann Dawson " , ENT Season 3 DVD special features ) For foreground portions of a sphere ' s interior in the episode , large metallic - looking set pieces were reused , having been created for the earlier season three installment to represent parts of " Enterprise " s hull . The pieces were re - detailed for their inner - sphere usage and later went on to be included in the interior set for the Xindi weapon . ( )