They briefly considered but quickly decided against an appearance significantly different than Jefferies' original design. Eaves created 10 relatively similar sketches that streamlined the original "Enterprise" to appear more consistent with the sleek "Discovery" aesthetic; they selected one of the sketches to refine further. They developed the vessel with the assumption that components like the warp nacelles and impulse engines would be replaced over time; the modules for the "Enterprise"s appearance in "Discovery" are meant to appear more primitive than what is depicted in "Star Trek". The designers tried to incorporate elements from other ships that precede and succeed the "Enterprise", such as the 21st-century "Phoenix" in "" (1996), the 22nd-century NX-01 "Enterprise" from "Star Trek: Enterprise" (2001–2005), and the successor USS "Enterprise"-B from "Star Trek Generations" (1994). They also included elements from the "Enterprise" refit for "The Motion Picture". One distinct challenge was the hull: Jefferies' design featured a smooth hull, but the lack of features would appear too simple on modern high-definition displays. The designers added details, such as phaser banks and control thrusters, that "must have been there" on the original "Enterprise" but were not depicted on the "Star Trek" models. The ship's scale also fluctuated, which meant the designers had to adjust the window sizes and patterns.