The Russian navy said Friday that a new-generation Bulava intercontinental ballistic missile was test-fired from a submerged submarine and hit its target - the second consecutive successful test of the troubled weapon. Russian officials have hailed the Bulava as a key future component of the nation's nuclear forces, but several failed test-launches over the past two years have cast doubt on the missile. The Bulava reportedly is designed to have a maximum range of about 10,000 kilometers and to carry six individually targeted nuclear warheads. Navy spokesman Capt. Igor Dygalo said in a statement that a Bulava was launched on Friday from the nuclear submarine Dmitry Donskoi beneath the White Sea surface and hit its test targets on the Kamchatka Peninsula, some 5,500 kilometers to the east. Also Friday, Russian news agencies quoted the head of the country's Strategic Rocket Forces as saying the planned US missile defense system in Europe and other perceived threats have prompted Moscow to work harder on missile development. Interfax quoted Col.-Gen. Nikolai Solovtsov as saying Russia has stepped up efforts to lay a groundwork for new missiles that could be deployed after 2020. Solovtsov also said plans are on track to put a new RS-24 missile equipped with multiple nuclear warheads in service next year. He says the RS-24 will improve Russia's capability of penetrating missile defense systems.