The current U.S. SLBM (Sea Launched Ballistic Missile) is the 58 ton, 44 foot long Trident II, and it just set another record. For the 122th consecutive time, a Trident II was launched. Since 1989, none of these test launches have failed. The Trident had two failures during its 49 development test launches, but since then, it has been the most reliable SLBM to ever enter service. Each Trident II costs about $65 million. The Trident II entered service in 1990. Some of them are fired every year, to insure that the current configuration (of hardware and software) still works as it is supposed to.

In contrast, the latest Russian SLBM, the Bulava, is having an awful time in testing. While the overall (out of over 5,000 of them) failure rate for test launches of Russian rockets is eight percent (and the U.S. Trident I had a failure rate of 13 percent while in development), nearly a third of Bulava's development test launches have failed. The 48 ton, 56 foot long Bulava costs about the same as the Trident II.

Such reliability is a crucial aspect of weapons, just like range and accuracy.