That picture is the one currently ingame from the Sovereign Class, there might be a galaxy class warp core in some future update, but i am not currently working on the mod, and i am not sure when i get back to it - but it is not dead/abandoned, just being busy IRL right now.
You have my support for the star trek mod i love so dose my wife and roomate, i wish i could contribute to it but i have not the skills, but ask if you need any thing ill try to help, :)