We need 16 aluminium for a space station but we need galactic craft aluminium,EX Nihilo one doesn't work. And there's no way to make galactic craft one!

We tried using minechem it still gives the Ex Nihilo one.

Is this issue occuring at the MyM Network or on an own server?
MyM could have deliberately disabled the recipe as every Space station gets its own Dimension (and Dimension creation is disallowed on the network)

If this Issue is happening at the MyM-Network, please close this issue and instead submit a ticket using the /ticket create comman ingame

Did you try using the usual ore dictionary converting methods?
Not sure, but I think there was a way involving minechem

On my own server

Should be obtainable on the mars and via Ex Nihilo.