Being a dedicated spacer I've never had much interest in the base construction aspect of Starfield, but that was before I learned that you can spacewalk by means of console commands, aka cheats. Reddit user WeirdConcern4666 made history on this front yesterday. Here's how you do it: 1) get up from the cockpit controls, 2) hit the tilde key to open the command console at the bottom of the screen, 3) type "player.setpos x 10" to teleport your character outside the ship, then hit return and 4) type "setgravityscale 0" to engage zero gravity and stop your character plummeting endlessly. Then hit the tilde key again to close the command console, and well, there you go.
Space sure is bigger outside a spaceship, isn't it? Just as well you brought that jetpack. If your vessel of choice is on the bulky side, like mine, you might need to increase the number on the end of "player.setpos" to escape the invisible barriers around your craft's exterior. Witness my character Mary Read's first attempts at a spacewalk below. If you've somehow discarded your jetpack, you can always punt yourself about with the recoil from an appropriately chunky firearm.