 Some U.S. analysts believe that the DF-21D doesn't fly any faster than Mach 5.The DF-21D reentry vehicle appears to bear similarities to the American Pershing II missile's RV, which was withdrawn from service in 1988.The Pershing II's RV weighed and was fitted with four control fins to perform a 25-G pull-up after reentering the atmosphere, traveling at Mach 8 and then gliding to the target to pitch into a terminal dive.