Mirror modifer on NURBS surface?

I’m trying to create a standard bilaterally symmetric spaceship using NURBS surfaces. Generally I do one side of the spacecraft, and make a linked mirror image duplicate for the other side.

But the new cool technique that everybody is telling me about is to use the modifier stack and use the mirror modifier.

This seems to work just fine on ordinary mesh objects. But when I try it on the NURBS surface, “mirror” is not one of the allowed options in the stack’s create-a-new-modifier pull down menu.

Can one use the mirror modifier for a NURBS surface, and if so, any suggestions on why Blender is being uncooperative?

You’re right, there’s no Mirror Modifier for Curves. You can Shft-D and Scale it along X (or whatever) by -1. Curves have a problem Centering the Object Center so use “Center Cursor” to flip it around the Cursor. You may have to Switch Direction (W in Edit mode) on the Duplicate after flipping and before joining them.