Based on the official Star Trek Chronology, the series begins 10 years prior to the founding of the United Federation of Planets and 90 years after the events of Star Trek: First Contact (1996). Episode one takes place approximately 115 years prior to the start of Star Trek (1966) and 213 years before Star Trek: The Next Generation (1987).
It was later revealed that if the series had returned for another season that one of the major story lines would have been the beginning of the war with the Romulan empire as originally explained in Star Trek: Balance of Terror (1966).
The episodes Star Trek: Enterprise: Home (2004) and Star Trek: Enterprise: Daedalus (2005) both reveal that Earth and Vulcan are 16 light-years distant from each other. According to Gene Roddenberry, James Blish (who wrote short-story adaptations of episodes from the original Star Trek (1966) series, plus one original novel, "Spock Must Die!"), and multiple background sources (including endorsements from various scientists from the Harvard - Smithsonian Center for Astrophysics), planet Vulcan would likely be in orbit around the trinary star system 40 Eridani, a real-life trinary star system located 16.45 light years from Earth.
Because the show is 100 years before Kirk, some old technology has reappeared: - flip-open communicators - manual sliders on the transporter - the science station viewfinder - Most of the sound effects for the Enterprise come from original 1960s Star Trek (1966) series - including all the bridge sounds, doors, communicator chirps, and most of the panel sounds. - Instead of shields, the Enterprise has polarized hull plating and instead of hand-held phasers, the crew are introduced to phase pistols. - There are no photon torpedoes, simply torpedoes. (Until the start of season 3) - The transporter has only recently been approved for transporting bio-matter (people)...and no one on the crew trusts it. It has 4 docking doors for shuttlepods. The design of 22nd century Enterprise NX-01 bears a striking resemblance to the 24th century Akira Class starship, first introduced in Star Trek: First Contact (1996). Enterprise carries a designation of NX-01 which, according to established canon, indicates a prototype starship. It also indicates the first Starfleet starship to use this naming convention. Enterprise is the first Starfleet vessel to use the new warp 5 engine developed by Zefram Cochrane and Jonathan Archer's father, Henry.
During filming of the pilot, Star Trek: The Next Generation (1987) actors Brent Spiner (Lt. Commander Data) and Jonathan Frakes (Commander William T. Riker) visited Scott Bakula on the set to give him advice about what to expect while working on the series. Both Brent Spiner and Jonathan Frakes guest starred in season 4 with Brent Spiner playing Data's creator's grandfather Dr. Arik Soong and Jonathan Frakes playing his original character.
Longtime Trek actor Vaughn Armstrong (famous for his many alien roles on various Trek series) appears here as a human for the first time. His character, Admiral Maxwell Forrest, is the commander-in-chief of the fledgling Starfleet.
The first name of Captain Archer was initially to have been Jeffrey. While the (American) producers of the show didn't see any problems with this name, UK fans pointed out the link to disgraced author, actor and politician Jeffrey Archer after learning of the name over the Internet. The name was changed to Jackson, but there was exactly one person in the country named Jackson Archer. To avoid lawsuits, Jonathan was chosen for a name because there were 20 Jonathan Archers.
In the wake of the destruction of the US Space Shuttle Columbia on 1 February 2003, an opening screen was added to the episode Star Trek: Enterprise: Stigma (2003) (first air date 5 February 2003), which read "In memory of the Columbia crew...You will always be an inspiration." Further, just as the original US Space Shuttle prototype (which never reached space) was named "Enterprise" after the ship in the original Star Trek (1966), so it was revealed in Star Trek: Enterprise: The Expanse (2003) (first air date 21 May 2003) that the second Starfleet prototype ship (designation NX-02) was named in honor of the "second" Space Shuttle (actually the first to reach space), Columbia. Although the initial glimpses of NX-02 were of an incomplete ship in dry dock, she was seen more extensively in a story arc in season 4. It should also be noted that an "SS Columbia" was mentioned in the original "Star Trek" pilot, Star Trek: The Cage (1986), and a scout ship "USS Columbia" (designation NCC-621) appears briefly in Star Trek: The Motion Picture (1979).
Originally Jolene Blalock's character of T'Pol was supposed to be called T'Pau. This was the name of a character that appears in Star Trek: Amok Time (1967), an episode of Star Trek (1966) written by Theodore Sturgeon. They changed it at the last minute because if they used the character of T'Pau, they would have to pay royalties to Sturgeon's estate every time T'Pau was used, i.e. every episode of "Enterprise." Incidentally, the character of T'Pau later made an appearance in the three-part Vulcan renaissance story arc in season 4.
The theme song to the show, called "Where My Heart Will Take Me" and performed by Russell Watson, was composed by Diane Warren for the film Patch Adams (1998), and was recorded under the title "Faith of the Heart", by Rod Stewart, for that motion picture.
In various episodes, we see a small statue on top of a shelf inside Captain Archer's office. The statue is that of a man standing with his arm reaching out towards the sky. This is a smaller-scale model of the 20-meter tall statue of Zefram Cochrane that Geordi describes to Cochrane himself in Star Trek: First Contact (1996).
T'Pol held the rank of Subcommander. This rank is traditionally associated with the Romulans; however, since the Romulans and Vulcans were originally one race, it would make sense for them to have similar terminology or military structures.
This was the first Star Trek series to have an actual theme song, a fact that caused controversy among fans, who were split on the idea. The pilot episode used a different piece of music for the closing credits (in fact, an instrumental of the opening song) from the rest of the episodes. Beginning with the third season, the theme was revised to be more upbeat.
The American astronaut shown in the opening credits is Alan Shepard, the first American astronaut in space, and later commander of Apollo 14. There is also archive footage of: Charles A. Lindbergh next to his plane Spirit of St. Louis, the Enterprise Shuttle, Amelia Earhart next to her plane, the Wright brothers flight combined with Robert H. Goddard the father of modern rocketry writing his theories on a blackboard, Chuck Yeager and the Bell X-1 with which he broke the sound barrier and astronauts Neil Armstrong, Buzz Aldrin and Michael Collins as they board Apollo 11 to become the first men on the moon.
The Chief Medical Officer of the Enterprise is Doctor Phlox. The name Phlox was a character of the Hierarchy race from the Star Trek: Voyager (1995) episode Star Trek: Voyager: Tinker Tenor Doctor Spy (1999). However, the name of the character in the Voyager episode was only used in the script and was never mentioned on screen.
The arm patches for the Enterprise crew, which features an overhead view of the Enterprise, is based upon the NASA Mission Patches which features the image of the rocket, capsule, or space shuttle used on the mission.
Scott Bakula jokingly suggested prior to the filming of the two-hour premiere that Captain Jonathan Archer's middle name might be Beckett, a reference to his previous television series, Quantum Leap (1989), in which his character was Dr. Sam Beckett.
T'Pol's age became a matter of some debate among fans (and a minor running joke on the series itself) during the show's first 3 seasons. According to the original writers' "bible" for the series, she is 67 years old at the time of Star Trek: Enterprise: Broken Bow: Part 1 (2001), a fact confirmed by Jolene Blalock in interviews. In the season three finale, Star Trek: Enterprise: Zero Hour (2004), however, T'Pol revealed that she is actually 65 years old (and will turn 66 on her next birthday). It has been speculated that either the writers shaved a few years off her age (since bibles are only guidelines), made a mistake, or T'Pol is lying about her age and is really 70.
Julia Rose, who has a recurring role as a space marine (MACO) in the 2003-2004 season, wears a uniform previously worn by Hilary Swank in The Core (2003). According to a September 2003 interview with Rose, the uniform still has a label with Swank's name on it.
The captain's chair used in the fourth season was originally from the Enterprise-E bridge set in a deleted scene from the ending of Star Trek: Nemesis (2002) which included Steven Culp, who had played Major Hayes in Enterprise's third season, as Picard's new first officer.
In many of the ready-room shots, a common modern-day CD rack can be seen on Captain Archer's desk. In fact, these common CD racks make another appearance (slightly modified) to appear as computer circuits onboard the Vulcan vessel Seleya during the 3rd Season episode Star Trek: Enterprise: Impulse (2003).
Several episodes feature clips from classic movies as the crew enjoys occasional "Movie Night" diversions. Most of the films that have been featured, such as For Whom the Bell Tolls (1943) and The Court Jester (1955) are, naturally, Paramount films (and Enterprise is produced by Paramount). However, one episode prominently featured footage from Frankenstein (1931), a Universal Studios production. By using films from its own libraries, Paramount thus avoided having to pay royalties.
Had the series been renewed for a 5th Season, one idea that was pitched was to have the Enterprise undergo a 180-day refit to add a secondary hull attached to the ventral side of the saucer section, which would've included an improved warp core, and a larger, more powerful deflector dish. The NX-01 refitted redesign would have resembled the Constitution-class USS Enterprise from Star Trek (1966).
This series did not use the traditional sound stages reserved for Star Trek series, because one of the stages, which last held the Star Trek: Voyager (1995) sets, was demolished following filming of the last Voyager episode Star Trek: Voyager: Endgame (2001).
Malcolm Reed was named for a minor character in C.S. Forester's Horatio Hornblower books, which were also a major inspiration for the original Star Trek (1966). Both characters were English and came from families that had generations of career Navy men, although Malcolm Reed in Enterprise was the first to join Starfleet.
There was an incorrect rumor during the final season that William Shatner would make a guest appearance on the show in a desperate attempt to boost ratings. Shatner's role was said to be an ancestor of Kirk, or perhaps a time displaced version of Kirk. Both Shatner and the show's producers denied that this was ever even considered.
Anthony Montgomery (Travis Mayweather) once auditioned for two different roles on Star Trek: Voyager (1995), one of which was Tuvok's son Sek. Montgomery was the last actor to read for the role of Mayweather.
This was the first Star Trek series whose opening credits was did not consist of a series of dramatic camera flybys of the ship or space station. Rather it is a build up of historical (and make-believe-historical) events that led to the show's era.
In Star Trek: Voyager: In the Flesh (1998) it was revealed that there is a member of Starfleet in the 24th century named Valerie Archer. It has been speculated that this is a descendant of Jonathan Archer.
The trivia item below may give away important plot points.
Executive Producer Manny Coto has stated that if the show were renewed for a 5th season, Commander Shran (Jeffrey Combs) would have been made a member of the Enterprise crew and become a regular on the show.