I feel there should be something inside the rocket, launching rocket for rocket itself does not make much sense, rockets usually carry something.
- leave victory conditions as is and add red text somewhere around launch button that rocket is empty, or confirm dialog on empty launch.
- Have something to put in the rocket.
- For example communication satellite for win - from already researched materials like advanced circuits and stuff, but without space science.
- OR science satellite for science packs AND win.