Actually, in the originals, you could research a new weapon before even doing
a mission (at least in TFTD).
Xenonauts seems to take it a bit slower, at least for the laser weapons. You need
to research a bunch of other stuff first, like power sources and alien alloy fabrication
before you can start manufacturing your own higher tech weapons.
Of course, that all might change later on as the tech tree gets finished.
