No, it's not totally impossible....you can optionally store a copy of the originals locally (either all of them or on a per album basis). See the Preferences>Local Storage tab, where you can additionally choose to change the storage location from the default (on your system drive) to another location of your choosing.
However, you need to understand that the local copy, if accessed by another application, will not show any of the edits that you may have applied. Lightroom is a "non-destructive" editor, meaning that edits are stored in the catalog and the original image is never changed....what you see in the Lightroom app would be a preview created from the original and incorporating your edits. But those edits are only usable by Lightroom, so your other programs would only see the unedited original. If you want those other programs to see the edited file, you would have to export them, and that is generally true for all non-destructive editors.