The Chinese DF-5 ICBM and DF-4 IRBM are filled with liquid hypergolic fuel. Newer missiles are solid fueled. I'm sort of surprised that the old liquid ones have

The Chinese DF-5 ICBM and DF-4 IRBM are filled with liquid hypergolic fuel. Newer missiles are solid fueled. I'm sort of surprised that the old liquid ones haven't been retired. I thought the silos where lids don't work are more interesting since China has building lots of silos for newer ICBMs.