Rockets are fast. Rockets can go long distances. Why not take advantage of this and make your factory INTERPLANETARY?
Longer TL;DR
With access to new moons, and planets, new resources and power systems could be exploited! Tired of things being too easy with robots? Why not build a massive, automated rocket system stretching for thousands of kilometers, akin to that of your factory's train setup?
In addition, why not have interplanetary enemies as well? Orbital-Strike systems that require 25 nuclear reactors and a constant stream of Uranium? Superpowered Laser Turrets to blast your enemies out of the sky? Or Upgrades for your rocket that increase buildable space inside (Think Top-Down normal Factorio, limited area), storage area for items, rocket speed, or weapon power?
Pressurizing your rocket capsule for human safety and keeping it pressurized against space biters sounds like a thing everyone wants to have to handle! Or just let them off on ‘easy’ (standard, space biters only for Factorio vets, as they would hopefully be super powerful) mode with no space biters if they choose too, but who doesn’t want to spend half an hour putting armor on a ship?
With rockets, Factorio would become an even bigger game! Even if this were like a DLC, a rocket update would add a lot to the game.
Thank you for your consideration and time.
(P.S.) Definitely not ripping off of the Subnautica DLC for this idea...
(P.P.S.) Doing this update would get Factorio a cool 'Space Game' tag on steam, showing it to more people...
(P.P.P.S.) Hopefully this idea doesn't stray too far from the game...