Under intense scrutiny, the debut season of Enterprise earned a passing grade from critics and Star Trek fans alike. Voyager ended its seven-season run just four months earlier, and fans were skeptical when Enterprise premiered (on Sept. 26, 2001, on UPN) with a theme song ("Where My Heart Will Take Me," composed by Diane Warren and performed by Russell Watson) that defied Trek's revered theme-music tradition. This and other early reservations were dispelled when "Broken Bow" got the series off to a satisfying start, beginning in the year 2151 and establishing a pre-Federation focus on humanity's delicate relationship with the Vulcans, the controversial launch of the NX-01 Enterprise on an exploratory mission, and the potentially devastating consequences of the mysterious Temporal Cold War involving a time-traveling splinter group of the Suliban, a nomadic alien race. While establishing a testy relationship between Enterprise Capt. Jonathan Archer (Scott Bakula) and his smart-and-sexy Vulcan Sub-Commander, T'Pol (Jolene Blalock, in a short-banged wig and form-fitting "cat-suit" that were later redesigned), the series introduced engineer "Trip" Tucker (Connor Trineer), whose surprise pregnancy in "Unexpected" made him a fan favorite; communications officer Hoshi Sato (Linda Park); helmsman Travis Mayweather (Anthony Montgomery); weapons expert Lt. Malcolm Reed (Dominic Keating), and chief surgeon Dr. Phlox (John Billingsley), a well-mannered Denobulan recruit from Earth's Interspecies Medical Exchange.

As a "prequel' series that predates the original Star Trek by 150 years, Enterprise built upon established Trek lore with episodes involving Vulcans ("Breaking the Ice"), Klingons ("Sleeping Dogs"), the blue-skinned Andorians ("The Andorian Incident," "Shadows of P'Jem"), and the Ferengi ("Acquisition") while offering stand-alone episodes (notably "Dear Doctor," "Fortunate Son," and "Shuttlepod One") that further acquainted fans with the Enterprise regulars. Early Trek technology is also introduced (including "phase pistols" and the rarely-used, still-risky transporter), and the series drew strength from what many felt would be its primary weakness: unwritten history and the initial indecisiveness of Archer's bold foray into the unknown. Ending with a dazzling "Shock Wave" cliffhanger that leaves Archer stranded in a decimated Temporal Cold War future, Enterprise set a strong foundation for the events of Season Two.