The basic building block of the MK 41 VLS is an eight-cell missile module. Each module is a complete, standalone dual-redundant launcher. A module includes a Launch Control System, gas management system, missile canisters, ballistic deck & hatches with deluge and sprinklers, and walkways. Modules can be combined to form launchers tailored in size to meet individual combatant mission requirements.

Each VLS module contains a plenum base and uptake hatch to vent the exhaust gases from a fired missile. The plenum and uptake are lined with ablative material to protect the structure from the missile exhaust.

An armored deck with armored hatches above each missile cell and the exhaust gas uptake protects the module. The Launch Sequencer (LSEQ), part of each module, responds to the Launch Control Unit command to launch a missile by preparing the module and missiles for launch.

If a missile warhead in a canister should overheat or ignite accidentally, a safety deluge system sprays water on it and any empty canisters. A separate sprinkler system provides fire protection for the external launcher space.