PDFGear might be able to handle this if your link is available in the page footer.

Open the file, click edit, header & footer then update and make your changes globally across all 500 pages.

Just calling out the sensationalised headline here. It’s not an absurd reason why but in fact something completely grounded and expected.

That’s because the US enacted a law called the Wolf Amendment in 2011, which prevents NASA from using government funds to cooperate directly with China

Laws are stupid apparently