78km (48miles, from a cut dialog and the novel adaptation)
Especially thickened up to print in Steel materials.
This is the giant V'ger spacecraft from "Star Trek: The Motion Picture". The length of 78km was given in dialogue cut from the theatrical version of the movie, Decker says the spacecraft was seventy-eight kilometers ( about forty-eight miles) in length. The novel adaptation of the film (written by Gene Roddenberry himself) gives the same dimension.
If you need this in another material, size, quantity or combined with one or more of my other parts for cheaper printing, just let me know. I will try to make it as you need.
If you want to see my custom-made Star Trek Tactics ships, visit my thread on hcrealms.com.