The Epsilon IX station was a 23rd century Federation comm station operated by Starfleet. This space station, in Federation space, was located between Earth and Klingon territory. In the mid-2270s, the station's commander was Commander Branch. This station was protected by deflector shields.
In the early 2270s, as the V'ger crisis unfolded, Epsilon IX transmitted detailed information to Starfleet Command about the engagement, and subsequent destruction by V'ger, of a Klingon patrol led by the IKS Amar. Probably misinterpreting the station's sensor scans as a hostile action, V'ger subsequently destroyed Epsilon IX as it passed near the station. (Star Trek: The Motion Picture)
In 2285, two models of an Epsilon IX-type station were mounted on two separate walls of the Starfleet Officers' Lounge. One was near where Admirals Kirk and Morrow had a conversation, while another was in the lounge's entry room. (Star Trek III: The Search for Spock)
In 2369, Geordi La Forge, when investigating the murder of Lieutenant Keith Rocha, requested a display of the personal records of the lieutenant from the Relay Station 47 computer for stardates 46455 to 46460. One of these records mentioned this station's replacement.
In the log entry, Rocha wrote, "More heavy traffic to the Epsilon IX station. I think Starfleet's got some big science project brewing there with at least half a dozen starships running around." (TNG: "Aquiel")
Epsilon IX personnel
According to the shooting script, Epsilon IX was a monitor station located on a rocky planetoid. The monitor station was described as a "...small Starfleet outpost, antennas sprouting everywhere." Workers working on an antenna would have established the size of this outpost.
The set for the interior of Epsilon IX was built on Paramount Stages 12 and 14, the set's construction costing US$40,000. (The Making of Star Trek: The Motion Picture, p. 95) The footage filmed on this set was shot during The Motion Picture's postproduction period. (The Making of Star Trek: The Motion Picture, p. 193)
Upon visiting the set for the scenes aboard Epsilon IX, Susan Sackett stated that "The set they work in is so crisp and clean that it takes some getting used to. It's bright, well-lit, with beautiful floors and colorful consoles. But I notice that the art department had some fun with this one, too. Above one of the consoles is a panel showing the duty roster for the outpost. Among the names up there (which I doubt were picked up by the camera) are the following: R. D. Enberry, M. Minor, L. Cole, R. McKenzie and Gort. In case you're wondering, Mike Minor, Lee Cole and Richard McKenzie are all members of the Star Trek art department. As for R. D. Enberry and Gort, I'll leave those for you to figure out!" (Starlog #27, October 1979, p. 29)
According to the Star Trek: Star Charts (p. 62) and the Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), Epsilon IX was located in the Beta Quadrant. In the Star Trek: Star Charts (p. 62), Epsilon IX was one of the Epsilon Outposts. These eleven outposts were located near to the Federation-Klingon border.
Three studio models of the Epsilon IX station's exterior were built, to show the outside of the station at different scales. (text commentary, Star Trek: The Motion Picture (The Director's Edition)) These were designed and built at John Dykstra's company, Apogee, Inc. Up until then that station had not even been envisioned as being space based in the storyboards of Astra Image Corporation, but rather as a location on the surface of a planet. (Star Trek: The Magazine Volume 2, Issue 8, pp. 64-65) It was one of the very few, if not only, designs not executed by either Astra or Magicam for the movie.
When asked about them Dykstra stated, "Actually, there were about two or three of them. There was the entire station which you saw from a distance in the early shots. That was about six feet long and three-and-half feet wide–and just unbelievably detailed. On top of that, Roger Dorney, our chief optical guy, came up with a way to pull bluescreen mattes off that sucker–which was really awesome. With all the latticework and stringers that thing had, the registration had to be incredibly accurate, and he came up with results that damn near exceeded the resolution capability of the film." (Cinefex, issue 2, p. 59)
In regard to the complete, main model, Dykstra later added in somewhat more detail, "This was about a six-foot long model, and it was an interesting technique we used to create it. We used acid-etched brass. The reason we used this acid-etching technique was, that it gave us very square edges. And square edges in fact are a dead give-away on miniatures. If they are not square, if they're round, then you get the sense that the scale of the miniature is not what it's being represented as." (Star Trek: The Motion Picture (The Director's Edition), "audio commentary")
The envisioned visuals and script requirements necessitated the build of additional enlarged sections of the station. Dykstra, also praising his crew of model makers, continued,
"In addition to the basic Epsilon 9 miniature, we also had one isolated panel for the closer shots that was about five feet wide and six feet long. And there was a larger-scale version of the conning tower where we used straight rear projection to put the people in. We made an inordinate number of miniatures for this picture and Grant McCune and the dozens of people he had working for him back in the model shop did just a phenomenal job.
"They were literally working around the clock, just days ahead of the camera crew. As one end of a model was being rolled onto the stage to be photographed, the other end of a model was getting a last shot of spray paint. And the fact that they made those things work under those kind of circumstances, and put the stuff together so they would last through the shots–but not by putting so much time into any one thing that it kept them from completing all the other stuff–well, it was just a miracle."
The demise of the station in the movie, being digitized by V'ger, was executed utilizing the same methodology as has been used with the digitizing of the Klingon K't'inga-class battle cruiser model at the start of the movie. "Essentially, though, what happens to Epsilon 9 was a replay of what happened to the Klingons–the electrical discharge material and the laser scan stuff. There were a couple nice shots that didn't get into the film, where the puppets are being chased by the destruction in a different way than we've got them appearing now. But we ran out of time, and weren't able to get them to go together right." Dykstra concluded. (Cinefex, issue 2, p. 59)
Not having been involved with the design, Andrew Probert nevertheless managed to get some of his input in, "The communications station "Epsilon-9" was briefly looked at but the design and building went to John Dykstra's Apogee group. I had a second brush with that station however, when Trumbull asked me to write some appropriate dialogue to run over scenes of the station as background chatter. This introduced the station without a big sign hanging on it. I wrote several levels of dialogue and even stuck my own name in a lower level, but when Trumbull saw it, he had that level moved to the top, and you can hear a message from Commodore Probert if you listen closely." (Starlog photo guidebook Special Effects, vol. 5, p., 96)
Two of the studio models were reused as the display models on the walls of the Starfleet Officers' Lounge in Star Trek III: The Search for Spock, the master model on the wall in the room itself, while the enlarged panel section model was in the lounge's entry room, only ever so fleetingly seen as Admiral Kirk leaves the lounge. (Star Trek III: The Search for Spock (Special Edition) DVD, text commentary)
None of the Epsilon IX models were afterwards ever sighted again, either in a production or outside of one, and their fate or whereabouts are currently unknown.