Board Thread:Questions and Answers/@comment-98.125.218.166-20130425090354/@comment-4632427-20130426222331

There are no missions that have the Heavy Weapons Factory mission as a prerequisite. The only reward for building it is that you get to be rid of the annoying mission icon on your screen. If you don't want the troops it unlocks, it's definitely not worth the nanopods and population to build the factory.