Why did my Ripple (XRP) transaction fail?
The XRP Ledger applies reserve requirements, in XRP, to protect the shared global ledger from growing excessively large as the result of spam or malicious usage. The goal is to constrain the growth of the ledger to match the improvements in technology so that a current commodity-level machine can always fit the current ledger in RAM and the full ledger history on disk.
To submit transactions, an address must hold a minimum amount of XRP in the shared global ledger. You cannot send this XRP to other addresses. To fund a new address, you must send enough XRP to meet the reserve requirement.
The current minimum reserve requirement for a Ripple address is 20 XRP. (This is the cost of an address that owns no other objects in the ledger). Thus, if these requirements are not met, the transaction will fail. For more details, please refer to Ripple Reserves: https://developers.ripple.com/reserves.html.