Galacticraft is best when either Basic Components, IndustrialCraft 2 or Thermal Expansion are installed as well (optional).
You will also need to download:
minecraft.jar).coremods folder.minecraft.jar don't exist more! Use the Official installer!).mods folder in .minecraft or a costumized directory. Note, the coremods folder doesn't exist if you're using Minecraft 1.6.1 or earlier.mods folder.
Once you have all of these mod installed and your Minecraft loads up and doesn't crash, you may start your adventure to space!
Read on with the Galacticraft Getting Started Guide to get you started with all the basics.
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