Description Most sizes are from Memory Alpha, Ex Astris Scientia or Wikipedia. 7/21/13: Updated to include Odyssey class from STO (Enterprise-F). 12/10/17: Update to include Crossfield class (USS Discovery) and Walker class ((USS Shezhou) from Star Trek: Discovery. Crossfield class size extrapolated from this Reddit discussion Walker class is a complete guess on my part. I can't currently find any info other than that it has 15 decks (mentioned in an episode).