Resources are vital to keeping your ship running in Railjack missions. They allow your crew to repair the ship, make more ammo, keep your avionics and weaponry running, and more. While all Tenno can make resources in their Dry Dock, there are times when you need more during the mission.
Enemy fighters and crew ships can drop resources when they die, so make sure you grab these as you are fighting. Another way to acquire supplies is to get them from asteroids. You can visit the levels with Railjack battles, which have plenty of asteroid belts. Some of the asteroids are glowing, highlighting them. Destroying them causes bundles of resources to drop for you to pick up. Asteroids don’t only have standard resources like Cubic Diodes and Pustrels. They sometimes contain resources like Titanium, which you need to research new equipment for your ship.
To use these resources, head to the Forging Bay, where you will find four Forges. You can use these to make Revolite, Flux Energy, Dome Charges, and Munitions using Cubic Diodes, Pustrels, Carbides, and Copernics. There is a Refine button, which you should only hit on extremely rare occasions, such as the end of a play session. This option splits all the available resources between the crew, preventing you from using them to craft resources anymore.
Between missions, it is better to return to the Dry Dock so that all Tenno can restock. It is much quicker to do it in the Dry Dock than in the Forging Bay because all Forges have a cooldown timer between uses.