How to increase crew member damage and armor?

Sometimes colonists and surrendered enemies ask to become crew members on your ship. I found them to be quite useful as they act as meat shields help engage enemies in combat. However, I'd like to outfit them with better/different weapons and armor. Is there any way I can upgrade their weapon or armor?

Currently as of 1.0 stable there is no way to change the crew's weaponry or armor. Instead, their armor and damage scale as you progress through the game.

Note: As of version 1.0.2, crew damage will be normal when you recruit them, but as soon as you beam up to your ship and back down again, their damage falls off really strongly (see this Reddit post for details). This is a bug, and has been fixed in 1.0.3.