Ballistic Missiles

With the exception of submarine-launched ballistic missiles (SLBMs), ballistic missiles are categorized according to range. Five commonly-accepted categories of ballistic missile, with their associated ranges, are as follows: (1) battlefield short range ballistic missiles (BSRMBs: <93 mi [150 km]); (2) short range ballistic missiles (SRBMs: 93–497 mi [150–800 km]), (3) medium range ballistic missiles (MRBMs: 497–1490 mi [800–2400 km]), (4) intermediate range ballistic missiles (IRBMs: 1490–3416 mi [2400–5500 km]), and (5) intercontinental range ballistic missiles (ICBMs: >3416 mi [> 5500 km]).

Alternatively, the U.S. Department of Defense defines ballistic missiles with ranges less than 683 mi (1100 km) as SRBMs, those with ranges between 683 and 1708 mi (1100–2750 km) as MRBMs, those with ranges between 1708 and 3416 mi (1100–5500 km) as IRBMs.

Ballistic missiles can be launched from submarines, silos (i.e., vertical underground tubes), ships, or trailers. All ballistic missiles launched from submarines, regardless of range, are categorized as SLBMs; modern SLBMs have ranges comparable to those of ICBMs. The purpose of mounting ballistic missiles on submarines is to make them secure from attack. Modern missile submarines, such as those in the U.S. Trident class, are difficult to locate and can launch their missiles without surfacing.