A former national security adviser says Washington βmust test new nuclear weapons for reliability and safety in the real world,β while critics say the move could incite a global arms race that heightens the risk of war.
A drop test of a B61 nuclear bomb. An aide to Mr. Trumpβs former national security adviser said a redesign of this type of bomb, the B61-13, announced in October, was in need of explosive testing.
A year after the first deaths of divers who ventured into the oceanβs sunless depths, an industry wrestles with new challenges for piloted submersibles and robotic explorers.
A 2003 expedition by a piloted submersible to the wreckage of the Titanic on the sea floor, as documented in the James Cameron film βGhosts of the Abyss.β A pair of robots are scheduled to revisit the site next month.