The Arweave blockchain is designed to store data in perpetuity. Through an endowment, which your storage payment goes towards, it can continue to pay miners in the network to preserve your data indefinitely.
As Sam Williams, founder of Arweave, says:
[Arweave is] a new type of storage that backs data with sustainable and perpetual endowments, allowing users and developers to truly store data forever – for the very first time.
Read more about the protocol here: