Flight Master

Squadrons are sets of autonomously controlled fighters that are hosted by and launched from a base of yours - either a fixed base in orbit on a colony, or from a Carrier capital ship, or as an upgrade to a capital ship or titan.

You can reach 100 by expanding your empire and adding squadron-hosting defences to the colonies in each gravity well (which unit provides this will differ by which faction you're playing as), as well as building out your fleet of capital ships and upgrading accordingly.

This is best done on a larger map so you've got the time and space to build it all up.