(written from a Production point of view)
While the series of Star Trek: Enterprise was being conceived, the appearance of the NX-class was being thought up. Because the "hero" vessel for the new Star Trek television series was designed as an NX-class vessel, the ship class was meanwhile foremost on the minds of the creative team. Shortly before the series began airing, co-creator and Executive Producer Rick Berman related, "These are all things we have had to give serious thought to – the look of the ship, the look of the corridors, the transporter room, the ready room, etc." (Star Trek: Communicator issue 134, p. 14) Thus, what turned out to be an arduous process to define the look of the NX-class began.
As the new series was supposed to be a precursor of Star Trek: The Original Series, all designs to be featured had to reflect this, including the configuration of the "hero" ship that was to be featured in the new series, Enterprise NX-01.
Along with Brannon Braga (the series' other co-creator), Rick Berman decided they would like the NX-class to look appealing and convincingly retro. "At the same time," he noted, "we had to marry a little bit of contemporary technology with what we know is going to be coming and take some poetic license and come up with a ship that is certainly a step backwards in technology from the ships we've been used to." (Star Trek: Communicator issue 134, p. 76) Braga commented on the prospect of making the NX-class seem "like something out of 1950s science fiction," stating, "I just don't think 99 percent of the audience would have bought it. So you need to take some license and say, 'We're going to make it look like a ship that would be a hundred years more advanced than something today [...]' rather than say, 'We're going to make it look like something that's a hundred years before a show that was done in the 1960s.' That's definitely a creative license that we took. But I think those kind of things are necessary." (Star Trek: Communicator issue 139, p. 51)
While admittedly making it seem slightly more advanced than the original Star Trek USS Enterprise NCC-1701 from the 1960s, the producers still wanted to have the NX-class be similar to that ship as well as other earlier-depicted vessels. Production illustrator Doug Drexler offered, "Rick and Brannon wished to borrow from the original Enterprise, the motion picture Enterprise and some elements from other ships in the movie series." (Star Trek: Communicator issue 136, p. 34) Berman himself clarified, "We spent a lot of time studying the Enterprise from the [original] television series and then the Enterprise from Star Trek: The Motion Picture, and then the subsequent ships and a variety of other vessels. We wanted something that was reminiscent; we wanted something that people could believe would, 90 years later, evolve into Kirk's Enterprise, but obviously we wanted to make the ship with the same degree of sophistication that computer modeling can do today, as opposed to the way wooden modeling was done in the 1960's." (Star Trek: The Magazine Volume 2, Issue 7, p. 13)
Rick Berman's marching orders for Production Designer Herman Zimmerman to begin considering how the NX-class Enterprise would look included advice that the "new" ship should be "both retro and cool at the same time, gritty and utilitarian with space-efficient interior and hands-on equipment. A ship which shows the audience a lot more nuts and bolts than other Star Trek series while still having an incredibly futuristic look. In a subtle, very recognizable way, the ship must foreshadow the design of Enterprises to come." (Broken Bow, paperback ed., p. 259)
In the script for "Broken Bow", the NX-class is introduced with the description, "More rocketship than starship, Enterprise is lean and masculine – yet its deflector dish and twin warp nacelles suggest the shape of Starfleet vessels to come." (Broken Bow, paperback ed., p. 262) However, this statement was later revised to remove the references to both the deflector dish and the class appearing more akin to a rocket ship than a starship. In the revised final draft script of "Broken Bow", the class was additionally referred to as "great" and "majestic." 
Initial designs Edit
Herman Zimmerman once commented that the terms "retro and cool" were "two buzzwords very easy to slip off the tongue, but not so easy to conceive on paper and then in the reality of the scenery onstage." (Star Trek: Communicator issue 135, p. 59) To assist with the concept work, he brought illustrator John Eaves onto the project. "Herman called me really early on," remembered Eaves, "and said we needed a retro Enterprise, somewhere between the Phoenix and Captain Kirk's ship, and he needed sketches for it." (Star Trek: Communicator issue 136, p. 32) Despite the numerous influential starting-points already discussed, Zimmerman gave Eaves free reign to experiment with virtually every design concept he could think of. "Orders were to try everything under the sun and don’t go for the obvious," Eaves admitted. 
An initial conceptual image John Eaves sketched took its direction straight from Herman Zimmerman. Explained Eaves, "He had found a shape he liked in one of Syd Meads’ many books and thus had me translate the shape into a starship [...] I was so glad that after he saw it on paper he changed his mind and we started to pursue a more traditional starship look." 
Another early concept for the exterior of the class took its cue from Brannon Braga having recently noticed, at a Los Angeles car show, how the then-new 2002 model of Ford Thunderbird modernized a classic design that he was very familiar with. Braga remembered, "We discussed it and we thought, Well, let's take Kirk's ship, the original Enterprise, and let's soup it up and make it more futuristic and bring it into the twenty-first century. And we worked on that for a while, but it ultimately looked just too much like the other ships." (Broken Bow, paperback ed., pp. 262-263) According to Herman Zimmerman, this version of the class especially "looked very similar to the original motion picture Enterprise." (Star Trek: Communicator issue 135, p. 60) Due to this approach making the class appear insufficiently new, the team entirely abandoned it and opted to start from scratch. "That was a really cool ship and the series would have been well served by it," Zimmerman evaluated. "But, I don't think it represented what Rick and Brannon see as the vision of this new Enterprise. So we went to work again." (Broken Bow, paperback ed., p. 263)
Ultimately, John Eaves invested much time and effort in trying to design the exterior of the NX-class. "Many many versions came and went and all were getting the boot with little to no direction on what they wanted to see from the producers end," Eaves observed. "By now, time was getting critical."  He said further, "I did lots of sketches, and they'd go too far Phoenix or too far [Kirk's] Enterprise, and it wasn't really what Mr. Berman wanted to see. He shot down almost all of the drawings and in his mind there was something he really wanted to see that was going to be different but he couldn't really put it into words, so Herman would take what he would say and translate it to me and I'd work on it." (Star Trek: Communicator issue 136, p. 32) Zimmerman himself remarked, "We went to several different styles of combinations of nacelles and saucers and engineering sections and airframes." (Star Trek: Communicator issue 135, p. 60) He also stated, "We had about a month of sketches and computer-generated images roughly showing shapes of different ships that eventually evolved." (Broken Bow, paperback ed., p. 263)
The final concept sketch that John Eaves created for the NX-class while working under Zimmerman's aegis looked far more like a typical Star Trek starship than Eaves' initial sketch had. "It was a fun piece just to [do] for concept sake," explained Eaves.  His successor (and personal friend), Doug Drexler, has added, "Before I came on board, Johnny Eaves drew 30-40 different NX ships that were all cool, and all rejected. They exhausted him."
Change of designer Edit
Eager to collaborate on the new series, Doug Drexler was able to start participating in the design process for the NX-class about a month after it began.  "When I was brought onto the Enterprise design project it had literally reverted to square one," Drexler expressed. "Most of John and Herman's time up until that point was spent exploring very different ideas that harkened more toward rocket ships and submarines. Rick and Brannon had dutifully explored the possibilities of an entirely different direction but, and I think most wisely, decided that they were loosing something by abandoning the traditional starship configuration [....] At this point it was time for Herman to move John on to conceptualizing the new starship sets. I think Mike Okuda suggested to Herman that he might give me a call, thinking that a CGI approach to conceptualizing the ship might help break the stalemate." Thus, the fact that Drexler had been learning how to build CGI models while working on Star Trek: Voyager at visual effects house Foundation Imaging was instrumental in his invitation to participate in the design process for the NX-class. (Star Trek: Communicator issue 136, p. 32)
With the overall look of the NX-class having been somewhat decided upon via a process of elimination, Doug Drexler was tasked with working out the finer points of the class. "Rick [Berman] and Brannon [Braga] had a pretty good idea of what they were looking for," he remembered. "The devil was in the details. Our job was to take familiar geometry and restyle it." (Star Trek: The Magazine Volume 2, Issue 7, p. 30)
After receiving advice on how to proceed with the design, Doug Drexler went directly to 3d modeling of the class, preferring to model the ship digitally instead of continuing with concept drawings. He believed that working in CGI was a massive benefit to the development process, easily enabling dramatic alterations to the craft's dimensions and for the art department to show the vessel to the producers from every angle and lighting condition. However, Drexler started designing the prototype CG model of the NX-class while under the erroneous impression that it would just be a quick mock-up, only to discover the truth as he continued to refine the model. (Star Trek: The Magazine Volume 2, Issue 10, pp. 25-26) Starting with the familiar basic elements of a Starfleet vessel – to wit, a primary hull saucer section, a secondary hull engineering section, and two warp nacelles – Drexler started to experiment with the configuration of these elements, much like original Enterprise designer Matt Jefferies had done. Starting with a configuration that very much resembled the classic starship, Drexler even considered a three-engined configuration, knowing full well that this went against Gene Roddenberry's dictum about odd-numbered warp engines on a starship. (Bandai model kit no. 122721, Instruction booklet, p. 8) Roddenberry had, off the record, stipulated that starships had warp engines that operated in tandem, something that other long-time Star Trek production staffers, like Andrew Probert and Michael Okuda , were quite familiar with. "The first thing we did was play around with a model of the original ship that I had in stock. Before investing tons of time on restyling, we wanted to look at various configurations. None of these were meant as final designs," Drexler clarified.
Doug Drexler committed to work on developing the NX-class, on the side. "I was working at Foundation during the day and thrashing out various designs at night," Drexler related. "I was doing some late nights. Herman would drop by the house two evenings a week and we would go over our leaders' reactions and make various adjustments: shorten the nacelle, raise the bottom of the saucer, more metallic, etc." (Star Trek: Communicator issue 136, p. 34) Michael Okuda pointed out, "It should also be noted that Doug worked a LOT of unpaid hours during the design of the NX-01, because he took this job very, very seriously. He started meeting with production designer Herman Zimmerman several weeks before he was officially hired. Doug, who was already working a full-time job during this period, stayed up late every night to work at home on the ship. This went on for weeks, with Doug busting his hump to capture Herman's vision and our producers' wishes, melding them with his own sense of starship heritage. By the time Doug was actually on payroll, he and Herman had already gone through several design cycles, buying precious time to refine the ship during the inevitable last-minute frenzy of deadline." Drexler, in turn, considers Okuda to have had considerable influence on the development of the class. "Mike Okuda and I really did spend a lot of time thrashing things out," Drexler mused. "I think Mike probably had more input into this starship than any other, due to our close friendship."
John Eaves was thrilled to witness Doug Drexler enthusiastically evolve the appearance of the NX-class. (Star Trek: Communicator issue 136, p. 34) Eaves commented, "His work was very impressive and filling the voids of time and history with great ease [....] Sadly none of his beauties were getting anywhere either." Eaves also called Drexler's initial designs for the NX-class "perfect" and enthused, "His designs were exactly retro enough to not only compliment the [Original Series] version but made a great Starship for its century." 
Final exterior design Edit
The producers finally determined that they wanted the NX-class to be of essentially a single hull, incapable of saucer separation. Herman Zimmerman commented, "It took us a good three months of trial and error before we arrived at the shape we now have [....] We decided to eliminate the engineering section as a separate entity and make it part of the hull. Brannon and Rick decided they didn't want a ship that would separate; that would be something that would happen some time in the future." (Star Trek: Communicator issue 135, p. 60)
The eventual twin-boomed shape of the NX-class was partly influenced by the Lockheed P-38 Lightning, an aviation source of inspiration that Doug Drexler pointed the design toward. John Eaves offered, "It was a great idea, I thought, to go with that P-38 look. Doug's first passes on that were just dead on, and exactly the shape it needed to be. He kept working on that for months and he did an awesome job." (Star Trek: Communicator issue 136, p. 34)
Given the concern that the NX-class not look so different from the typical starship layout as to seem out of place, the final design concept for the class was also heavily influenced by the look of a certain previously established starship class, though that backfired on an earlier design configuration Drexler was homing in on. "We had a basic configuration for another ship that was very close to the 1701, although still too futuristic to my mind," Drexler recalled. "Apparently someone walked into Mr. Berman’s office and said, 'Cool! It looks just like Kirk's ship!', and that was the end of that. That was a real beating. 'Use the Akira!' came the order. They really thought no one would notice." In effect, the producers at first wanted to reuse the Akira-class without any changes, "lock stock and barrel" according to Drexler. When informed of this decision, he and other members of the art department chose to oppose the imperative. Herman Zimmerman subsequently commented, "We found a ship [the USS Thunderchild] that was in our archives – a minor vessel that had been used in a battle in one of the features that had been created by ILM. We did not use that ship, but we took ideas from it and from those ideas eventually – and this process took about four months, all week and weekend CGI work by [...] Doug Drexler – we finally came up with [the eventual] shape." (Behind the Scenes of Enterprise)
To differentiate the NX-class from the Akira-class, the art department demanded that it meanwhile resemble the original Constitution-class. Drexler specified, "Our mission was to get it more towards the TOS ship [....] I always saw the task as not designing a new ship, but rather a 'restyling' job. I drew my inspiration from the great industrial designer Raymond Lowey [sic] who took the turn of the century steam locomotive and restyled it into the streamliner." Drexler also characterized his agenda of injecting as many small facets from the original series design into the NX-class as he could to have been his "main mission." He also recalled, "It was thanks to Herman that we got a blessing on going ahead with the restyle. He fought for it."
Once the plan of paying homage to the TOS Enterprise via the NX-class was approved, Doug Drexler was pleased to move the design in that direction. "I made sure that the basic dynamic between the saucer and the nacelles was the same," he declared. Other aspects that echoed the original Star Trek ship included the placement of the join between the warp nacelles and the nacelle pylons, the shape of the saucer impulse cones at either side of the saucer section's aft, and the lower sensor dome on the bottom of the saucer section's midpoint. Drexler also horizontally squeezed the TOS Enterprise's deflector dish, moving it to the front of the saucer, and reused the idea of the ship having an airport-style control tower dome towards the aft, building such a dome into both the underside and upper side of the saucer section, rather than the singular dome that is atop the Constitution-class' secondary hull. He additionally kept spheres at the back of the nacelles, also slightly changing them by dividing both spheres in two. "If the fronts of the nacelles look like penises, I compounded that by making the ends of the NX nacelles look like a girls butt in a thong," he noted. "I thought that was fair."
Doug Drexler wanted to make a couple of elements more clearly influenced by the TOS Enterprise than they ultimately were allowed to be; he was interested in making the nacelle pylons decidedly thin, which ultimately motivated him to highlight a thin portion of both pylons' leading edge, and the Bussard collectors more orange but volatile-looking than they wound up.
At first, the blue glow on the warp nacelles was resisted by the art department. However, they came to think of it as "fulfilling an original dream," as Gene Roddenberry had intended for a similar glow to be featured on the TOS Enterprise, a wish that had been too expensive to realize for that vessel.
The minute detailing done to the NX-class included the paneling on its hull. "Like Andy [Probert]'s 'D', every panel was designed and fitted painstakingly to the function and form of the ship," Doug Drexler explained. "All sections have their own distinct personality and are not simply cloned and repeated."
Doug Drexler's development of the first CG model of the NX-class was during an abundance of disputes between the art department and the producers, concerning how the ship should look. "Nearly every single detail was haggled over," Drexler recounted. "Color, texture, plating... you name it [....] The dome on the bridge was lit up originally. The producers thought the audience would mistake that for windows. I wanted a more porcelain, smooth finish. The producers wanted plating more like the TMP ship. I wanted lighter pylons, the producers wanted heavy pylons." Eventually happy with the extent to which he affected the design, Drexler didn't take long to digitally map the surface details for the NX-class. While Drexler was proud of his creation, he once admitted, "It was a frustrating experience. I'm a 'canon' kind of guy. I would have liked to have seen the Daedalus style ship. You know... the sphere instead of saucer. The producers wanted it to be a saucer because they wanted it 'recognizable'."
Despite Doug Drexler's frustration with the design process, Geoffrey Mandel has noted, "Having been around then, I also know that Doug Drexler and John Eaves did EXACTLY what the producers asked them to: Rick and Braga had very strong opinions, and knew exactly what they wanted. There was an earlier version of the NX-01 with a secondary hull and dorsal fin, but the general feeling was that it looked too much like the TOS Enterprise." Nevertheless, Drexler's dogged determination to bring the project to successful fruition also solicited an accolade of high praise from Michael Okuda, who stated, "That’s dedication, but that's what Doug brings to every project. And it earned him a place among such luminaries as Jefferies, Probert, Sternbach, Eaves, Taylor, Zimmerman, and James."
In total, the process of designing the NX-class took almost a year. (Star Trek: The Magazine Volume 2, Issue 7, p. 13) Nevertheless, when fans were presented with Enterprise NX-01 for the first time, they still were struck with how much the exterior design of the NX-class resembles the Akira-class, and for a time, the new ship was – in certain fan circles – endowed with the somewhat derogative sobriquet "Akiraprise". 
After his tenure on Star Trek, Doug Drexler went on to work on Ronald D. Moore's revamped Battlestar Galactica franchise, in which the Cylon theologians, that franchise's antagonists, frequently quoted their adage, "What has happened before, will happen again". As it turned out, this adage was applicable to the design Drexler had created, and the producers had signed off on, as well. A strikingly similar Enterprise design had already been conceived previously, by an unidentified production illustrator for Harve Bennett's 1989/1990 Star Trek: The First Adventure (aka "Star Trek Academy") movie project, and like Star Trek: Enterprise, intended as a prequel production, but which was scrapped in favor of what was to become Star Trek VI: The Undiscovered Country. It is highly unlikely though, that either Drexler, Berman or Braga had even been aware of the previous design, as none of the men had formally been affiliated with the movie franchise prior to 1993/1994. The design of the unidentified production illustrator itself, only became common knowledge in 2004, when his sketches were featured in the "It Started With a Story"-special feature on the Star Trek VI: The Undiscovered Country (Special Edition) DVD release.
On an additional side note, the NX-class also shared a more that passing design resemblance with FASA's 1983 gaming miniature No. 2514, the Loknar-class (β), part of their Star Trek: The Role Playing Game.
Production CGI model Edit
Shortly thereafter, the NX-class model was sent to Foundation Imaging, where it underwent final refinements by modeler Pierre Drolet, under the supervision of Visual Effects Producer Dan Curry and Foundation's Robert Bonchune. (Star Trek: Communicator issue 136, p. 34) Originally, it was Bonchune who was slated to do the final version, as Drolet recalled; "Initially, I was not suppose[d] to build the Enterprise NX-01. Rob Bonchune was the one originally assigned to build it however, because he was the visual effect supervisor for the show Enterprise, it would have been too much to manage. I know it was hard for him to let it go but Rob gave me the privilege to build it."  Doug Drexler added, "The art department’s 'foam core' proof of concept model acted as understudy for the super-high detail version [...] in Valencia, California. This CG concept model had been through battles to rival any that the fictional ship had been through during its four year television voyage. It had been volleyed back and forth between art department and producers. It had been pulled, stretched, cut, and pounded before it had been given a go for throttle-up, and shipped off to the CG facility where it would be built with extreme attention to detail [...] Once the bloody battles between art department and production were over, the high rez version of the ship could be built in relative peace [...] The high resolution model was built with laser precision."
Rob Bonchune noted, "Pierre Drolet was dedicated wholeheartedly to building [the NX-class]." (Star Trek: The Magazine Volume 2, Issue 10, pp. 25-26) Drolet took plenty of time over translating Drexler's low-resolution approval model into the version meant for production. The approval model continued to see service throughout the entire run of Star Trek: Enterprise, as the main NX-class model's digital stand-in for pre-visualization or animatics work; being of lesser resolution, that model was more suitable for that kind of work for cost efficiency reasons, as it took up less computer rendering time. The fact that the NX-class was built as a CG model rather than a practical studio model meant that it turned out to be more detailed than a physical model would have been. (Star Trek Monthly issue 86, p. 22) In fact, on his , Drolet himself referred to this digital model as "what (at least at the time) was the most detailed computer generated model in television history" and he went on to say, "Taking up 200 megabytes of RAM merely to load, the digital model consists of 500,000 polygons with 156 separate images painted on it." As proud as Drolet was of his build, he did concede that the chore was a daunting one, saying, "I have been asked by a lot of people what was my experience building the Enterprise NX-01, which was a bit stressful. The visual effect schedule was tight and, on top of that, while I was building the NX-01 I found out that there were many Star Trek technical specifications I was not aware of. I also had to deal with a lot of expectations coming from different people [....] After adding a lot of details all around and played as much as I could with the proportions issues, the NX-01 was presented to Rick Berman. Fortunately for me he liked it and his only comment was to add some more windows on the saucer. A lot of pressure lifted off my shoulder after that." 
Repeatedly asked to devise the best shots of the NX-class, Foundation Imaging viewed the ship from almost every possible camera angle, early in the series run. They found that the class was highly photogenic. "We were really trying hard to find a bad camera angle," mused Foundation's Aram Granger. (Star Trek Monthly issue 86, p. 22)
Enterprise's hull was originally meant to have only a slight bronze tint, as was favored by both Herman Zimmerman and Doug Drexler, but its appearance was changed to become more clearly bronze-colored, for reasons unknown to Drexler. It was not until the advent of Columbia NX-02 that an NX-class vessel with a hull featuring merely a slight shade of bronze was depicted. Drexler at first was not convinced there was even a color change, remarking, "Truthfully I am not sure if the NX1, and 2 are different. it may just be the lighting condition." Nevertheless, Koji Kuramura set him straight, observing, "The color of the NX-02 is different than from the NX-01. It's slight. But back then Rob, me and Mitch Suskin, thought it would be cool to change the color to give them a different look. Especially since they [were] going to be in the same shots."
The first time the Columbia was featured was in a scene that showed her under construction, designed by John Eaves, who gleefully remarked, "This was a fun drawing.... It was great to put Doug's NX into the space dock and have a new ship being built from the same class of Starship."  Though Eaves, naturally, closely followed the lines as established by Drexler and Drolet, there was one noticeable exception; Eaves endowed the second class vessel with a larger deflector dish, which was met with sympathy by Drolet. "Later on," he said, "I was glad when John Eaves redesigned the skinny dish attached on the front of the NX-01 and introduced it on the NX-02 Columbia under construction."  The CG Columbia construction model, using the NX-01 for a base, was built by Koji Kuramura (who also adapted the model for it to become the ISS Enterprise in "In a Mirror, Darkly"). He commented, "The shot of the Columbia in the Drydock was one that I did. I took some extra time to relight the shot so that the Columbia showed better in that set up. I don't remember who did the one for the Enterprise launch. But I added more lites and changed how [they were] [...] lighting the ship."
Refit NX-class design Edit
Doug Drexler designed an extensive refit-NX-class which had an added secondary hull reminiscent of that of the Constitution-class, with nacelles moving closer in appearance to those on that class.  Starting to appear on from January 2010 onward and presented to the general public in the 2011 Star Trek: Ships of the Line calendar,  it has given rise to the assumption in certain circles that, had the series been renewed for a fifth season, the refit design would have been featured. Drexler himself has dispelled that notion, pointing out, "Keep in mind that there were no official plans to refit the ship. This is something that I would have liked to have seen. In my world, Engineering as seen in the first four would have remained intact. Certainly an upgrade would happen. If the secondary hull was jettisoned, the ship would still be warp-capable. Needless to say, the secondary hull would have contained a much more powerful warp core."
The fact that Doug Drexler – an avid fan of Star Trek: The Original Series – embarked on his redesign project was in line with his "I'm a 'canon' kind of guy" remark, and, while not overtly apparent at the time, was indicative of the elevated stress levels during the design stage, due to the raised tensions between producers and creative (fan) staff on what a "proper" prequel visual style or design lineage should look like. Some production staffers, Robert Bonchune having been one of the more vocal ones , did vent their after-the-fact frustration and criticism, years later, on several Internet blogs. Even the usually diplomatic Drexler could not refrain from making an acerbic riposte, "You'll make a fine producer!" to one fan's criticism of his refit-NX design, speaking volumes in that respect.
Doug Drexler's refit NX-class struck a chord with former creative staff colleagues, who helped him out with some of the details, like Mike Okuda, who designed signage graphics that were reminiscent of what was seen on Federation ships in Star Trek: The Original Series and which Drexler had always wanted to do in the first place. "I wanted Starfleet style markings from the start," he revealed, "but the idea was nixed." Also involved was Pierre Drolet, reprising his role as builder of the highly detailed CGI model. Drolet too was like-minded, though not from a fan's perspective, but rather from that of a cinematographer, and thereby disagreeing with co-worker Aram Granger's assessment. "Rob [Bonchune] and I realized soon enough that the 'Akira Class' basic shape was not as interesting looking as the elegant horsy neck of the 'Constitution Class' Enterprise NCC-1701 they used in the first Star Trek movie. The camera did not like the full frontal and side view of the NX-01 low profile shape. This is why most of the camera shots in the TV show were almost always at 45 degree view from the bottom or the top. I included the Enterprise NX-01 upgraded with a secondary hull attached, which was redesigned by the NX-01 designer Doug Drexler. I personally think the upgraded NX-01 look[s] better [....] I also used the new dish on the upgraded NX-01." 
The refit design began to appear in officially licensed merchandise and was initially featured in the 2014 Star Trek: Ships of the Line calendar. In January 2014, licensed model kit company Polar Lights released a complete kit of the refit, in the wake of a "conversion kit" produced by unlicensed "garage kit" maker Starship Models in December 2010. The ship was also produced as a starship miniature and special issue of the Star Trek: The Official Starships Collection as the "NX-Class Refit" in 2016. On both licensed occasions Drexler served as technical consultant and CGI illustrator.
- Star Trek: The Official Starships Collection
- Issue 4, 2013
- Issue SP6, 2016