Case a we called here is a type of srmcs based on designing method a . case b was redesigned based on case a in order to meet the needs of enhancive warhead mass , but it burst under low pressure 由设计方案a研制的发动机壳体称为a壳体。为满足弹头质量增加的需要，在设计方案a的基础上研制了b壳体，但b壳体在试验中发生了低压爆破。
