Hi Jesse,
And welcome to the orekit community 
I played a bit with the attachCurrentThread but can’t seem to find the code. Orekit is based on the JCC tool, which describes the method shortly at:
Before PyLucene APIs can be used from a thread other than the main thread that was not created by the Java Runtime, the attachCurrentThread() method must be called on the JCCEnv object returned by the initVM() or getVMEnv() functions.
Basically you get an object returned from the vm=orekit.initVM() call, which you then pass to the new thread and call the vm.attachCurrentThread() on, or get it via orekit.getVMEnv() in the new thread. You can use the orekit.getVMEnv() to see if there is a java engine has been started as well.
Regards
/Petrus