Apart from having rare manuscripts that were written by notable and obviously important Christian figures, they also happen to have a collection of rare Chinese scrolls that were collected by early papal explorers. In addition, do expect to see a reasonable number of working documents that have been confiscated from early scientists, as well as ancient, illustrated versions of non-Christian holy texts.
It remains to be seen whether after making use of the digital file format which was developed at NASA to stash and view scientific documents, that these files will be made public for general viewing. Known as the FITS format, it basically enables extremely large files to be stashed, as well as offering support for large and complex metadata tags in order to make more sense of the associated image. It looks like it will require approximately €50 million or so to complete this entire project that is said to potentially take decades to complete.