At the end of the second season (May 2003), Paramount announced that "Enterprise" would undergo a major "redirection" in hopes of boosting ratings. The new 9/11-influenced story arc included a revival of the "Starfleet Marine Corps" idea, in the form of the Military Assault Command Operations personnel, called MACOs. (pronounced like the shark in dialog). Major cosmetic changes for T'Pol (including a new hairstyle and wardrobe, and the introduction of more emotion into her character) and a revised version of the controversial theme song were also introduced.
This episode was nominated for an Emmy Award for Outstanding Special Visual Effects for a Series. Dennis McCarthy's music composition also received an Emmy nomination.
The scene where the Enterprise NX-01 leaves the drydock reused the footage from Broken Bow, Part 1 (2001), when the ship first launched.
T'Pol's eyebrows change appearance between the second and third seasons, becoming more arched and Vulcan-like. In a 2004 interview with Femme Fatales magazine, Jolene Blalock revealed she and her makeup artist together decided to sneak a change in T'Pol's eyebrows amongst the character's pre-third season hairstyle and costume alterations, and no one from the production office complained.
The Enterprise's sister ship (the NX-02, seen under construction in the episode "The Expanse") was finally given a name, Columbia, towards the end of the third season. The ship was named after the space shuttle Columbia, in honor of its late crew. This leads some to speculate that all NX-class ships will be named after space shuttles, because this is actually also the order in which the orbiter fleet was built. Enterprise came first, as a test vehicle not flown in space, then Columbia. In the order they were produced, the orbital vehicles (popularly known as spaceshuttles) made after the first two were Challenger, Discovery, Atlantis, and Endeavour (built to replace the loss of the Challenger). With NX-01 being Enterprise, and NX-02 Columbia, it is within reason that NX-03 will be Challenger, NX-04 Discovery, NX-05 Atlantis, and NX-06 Endeavour.