Aperture3 ->External Editor (?)

I set Photoshop to be used as Aperture's external editor and from my understanding, it creates a duplicate of the master file and then allows me to edit changes in PS and then when I hit save in PS, it saves it back into my A3 Library.

I am not too keen on having a few copies of each image in my library, so when I save and am done Photoshopping, will I be able to delete the old master, since it created a new copy of the master? (the edited one)

Don't want to take up unnecessary space...

Thanks

From what I have observed with Aperture external editing it creates a completely new, separate <oldname>.tiff image file. So yes I think you will be ok with deleting the unedited version.
Just remember, you can't undo anything in the future doing this if you ever decide you don't like it ;P

Thanks for the help