The US Navy has conducted an unusual test on 9 December in which four Trident-C4 missiles were fired in rapid sequence from the USS Ohio. The submarine was near Cape Canaveral and used the Eastern Test Range. This follows a test last June in which three larger Trident-D5s were fired from USS Louisiana. The smaller C4s are carried by six submarines in the Pacific, while the remaining Trident-class submarines operate in the Atlantic with the larger and longer-ranged D5.--Stephen V Cole