A major part of the F-35's weaponry, the SDB II (Small Diameter Bomb II) won't be deployed on the F-35 until 2022 because the software isn't ready yet and in addition, the SDB II won't fit in the F-35B's weapon bay without major modification. Until the F-35 is capable of carrying the SDB II, it won't be capable of full close air support and only able to provide basic support.