Currently Being ModeratedFeb 22, 2013 8:22 AM (in response to DVX100Shooter)
Vaults need to be restored in order to access the contents. It has been reported that vaults and libraries are similar enough that if you change the extension of the vault from .apvaullt to ..aplibrary Aperture will open the vault as a library.
I have never personally done this so I can't say if there are any negative side effects. But if you are tight of space and can't restore the vault this might work.