Set in the 26th century, the series follows the nine-person crew of the Firefly-class vessel, a small transport ship, as they earn a living through various legal and illegal means.

[citation needed] Two contiguous sets were built, between them containing the entirety of the ship's interior, which provided several advantages to the cast and crew during filming.

Serenity first appeared in the pilot episode of Joss Whedon's Firefly, which is set in the year 2517, in a star system to which humanity migrated after using up Earth's resources.

She is the property of Malcolm "Mal" Reynolds (Nathan Fillion), a former sergeant who served on the losing side of a civil war that ended six years before the series began.

[2] Mal acquired Serenity from a used-spaceship dealer after the war (as depicted in flashbacks during "Out of Gas"), intending to hire a small crew and take various jobs to support himself and wartime comrade Corporal Zoe Alleyne, while keeping out of the way of the Alliance, the multi-planetary government they were fighting.

[3] Other flashbacks in "Out of Gas" show how the rest of the main crew came to join the ship; pilot Hoban "Wash" Washburne (Alan Tudyk), mechanic Kaylee Frye (Jewel Staite), and mercenary Jayne Cobb (Adam Baldwin), as well as Inara Serra (Morena Baccarin), a courtesan who rents one of Serenity’s two shuttlecraft.

At the start of the series, the episode "Serenity" depicts the arrival of the other three members of the ensemble cast as passengers aboard the ship: the preacher (or shepherd) Derrial Book (Ron Glass), the fugitive doctor Simon Tam (Sean Maher), and his psychic and psychotic sister River (Summer Glau).

[16] Whedon also wanted to quickly establish how much space there was aboard the ship, and how its rooms sat in relation to each other, to avoid the impression that there were "1,400 decks and a holodeck and an all-you-can-eat buffet in the back.

[19] For secondary propulsion, to allow such a large object to fly gracefully in atmosphere and perform controlled landings, the group added two engines, each on a stubby wing.

A network of gantries around the walls of the cargo bay extend from the nearby stairwells, and also provide access to the ship's two short-range shuttlecraft, one of which is hired out to Inara as her place of residence and business.

Whedon came up with the idea of building each deck of Serenity as a contiguous set, so that he could establish the size of the spaceship, and film scenes where the actors could be followed as they moved around the ship.

[20][28] Director of photography David Boyd chose to use small hand-held cameras for interior filming, which in turn enhanced the 'documentary' feel Whedon wanted for the series.

[36] This was used twice: first in "Bushwhacked" to 'connect' Serenity to a disused Power Rangers spaceship set adapted for the episode, then again in the film for the ship's second visit to Haven.

[40] The lower deck was built on Stage 16, which was modified during the filming of Alien Resurrection to include a 36-by-45-metre (118 by 148 ft) water tank under the floor for underwater scenes.

[21] Loni Peristere from Zoic Studios was brought in early during the design process to co-ordinate the visual effects from the series, including those related to Serenity.

[48][49] The scene was filmed as miniature effects, and was enhanced digitally by Illusion Arts, who added sparks, debris, and an exploding engine.

[45][51] After Firefly, Zoic had upgraded their computing infrastructure to be capable of producing effects at the level required for high-definition television, primarily for work on the reimagined Battlestar Galactica.

[53] Most of the changes to the sets were minor, although the combined effect was described by Morena Baccarin, who played Inara Serra, as "like coming into your living room and your mom rearranged all the furniture and things aren't where they were but you're still home.

"[52] Many of the reviewers of the series and movie reflect the common in-universe opinion of the ship; describing Serenity as a "battered old jalopy of a space craft",[54] "a rattletrap transport ship ... held together by 26th-century chewing gum and duct tape",[55] or "a ship that seems to be held together with baling wire and paper clips",[56] Some reviewers, while making comparisons between Firefly’s Malcolm Reynolds and Han Solo from Star Wars, invoke the Millennium Falcon when talking about Serenity: "a scrap heap of a spaceship in the Millennium Falcon mold",[57] or "a Millennium Falcon-style rust bucket".

In the 2003 Battlestar Galactica miniseries pilot, a ship resembling Serenity appears in the background of the scene where Laura Roslin (Mary McDonnell) is diagnosed with breast cancer.

[61] As Dr. Horrible was created by Joss Whedon and involved Nathan Fillion as one of the cast (both people associated with Firefly) it was assumed by fans that the silhouette was an actual Serenity model, or that the pans were deliberately hung to resemble the starship.

[8] The creation of the blueprints was "a nice side effect" of research done by Quantum Mechanix and The FX Company as part of a project to produce an 18-inch (46 cm, approximately 1:180 scale), screen-accurate collectors model.

[66] The hand-built and -painted model, completed after three years work and titled Serenity: The Big Damn Replica, was unveiled online on 21 July 2009, then physically at San Diego Comic-Con a few days later.