<Table> <Tr> <Th_colspan="2"> UGM - 133A Trident II </Th> </Tr> <Tr> <Td_colspan="2"> A Trident II launch from a submerged Royal Navy submarine . </Td> </Tr> <Tr> <Th> Type </Th> <Td> SLBM </Td> </Tr> <Tr> <Th> Place of origin </Th> <Td> United States </Td> </Tr> <Tr> <Th_colspan="2"> Service history </Th> </Tr> <Tr> <Th> In service </Th> <Td> March 1990 </Td> </Tr> <Tr> <Th> Used by </Th> <Td> United States Navy Royal Navy </Td> </Tr> <Tr> <Th_colspan="2"> Production history </Th> </Tr> <Tr> <Th> Manufacturer </Th> <Td> Lockheed Martin Space Systems </Td> </Tr> <Tr> <Th> Unit cost </Th> <Td> $37,320,070 (2014) </Td> </Tr> <Tr> <Th> Produced </Th> <Td> </Td> </Tr> <Tr> <Th_colspan="2"> Specifications </Th> </Tr> <Tr> <Th> Weight </Th> <Td> 130,000 lb (59,000 kg) </Td> </Tr> <Tr> <Th> Length </Th> <Td> 44 ft 6.6 in (13.579 m) </Td> </Tr> <Tr> <Th> Diameter </Th> <Td> 6 ft 11 in (2.11 m) (1st stage) </Td> </Tr> <Tr> <Th> Warhead </Th> <Td> 8--12 thermonuclear MIRV (Multiple Independently Targetable re-entry Vehicle), W88 or W76 thermonuclear weapons </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Engine </Th> <Td> Three solid - fuel rocket motors; first & second stage--Thiokol / Hercules solid - fueled rocket; third stage--United Technologies Corp. solid - fueled rocket </Td> </Tr> <Tr> <Th> Propellant </Th> <Td> Nitrate ester, Plasticized Polyethylene Glycol </Td> </Tr> <Tr> <Th> Operational range </Th> <Td> More than 7,500 mi (12,000 km) (exact is classified) </Td> </Tr> <Tr> <Th> Speed </Th> <Td> Approximately 18,030 mph (29,020 km / h) (Mach 24; 8,060 m / s) (terminal phase) </Td> </Tr> <Tr> <Th> Guidance system </Th> <Td> MK 6 astro - inertial guidance which is able to receive GPS (Global Positioning System) updates </Td> </Tr> <Tr> <Th> Steering system </Th> <Td> Single movable nozzle actuated by a gas generator </Td> </Tr> <Tr> <Th> Accuracy </Th> <Td> 90 m with Mk5 RV </Td> </Tr> <Tr> <Th> Launch platform </Th> <Td> Ballistic missile submarine </Td> </Tr> </Table> <Tr> <Th_colspan="2"> UGM - 133A Trident II </Th> </Tr>

How many warheads are on a trident missile