Vertical Launching System (VLS; for Missiles) on Surface Ships

choi

Surface Forces: Keeping VLS Current. Strategy Page, July 22, 2014.
www.strategypage.com/htmw/htsurf/articles/20140722.aspx

Note:
(a) "Basically a VLS is a square cell that can accommodate the sealed canisters [which] missiles are shipped, stored and fired from."

I add the word to make it easier to understand.
(b) This article is all about ships--not only the title says that, but the text, too. In other words, possibly excluded is submarine’s launch system, which may be either vertical or through torpedo tubes--I say “possibly” because I am clueless whether the VLS on surface ships and on submarines are the same.
(c) vertical launching system
en.wikipedia.org/wiki/Vertical_launching_system
(The most widespread vertical launch system in the world is the Mk 41, developed by the US Navy; section 1 Hot launch and cold launch: American surface-ship VLSs have the missile cells arranged in a grid with one lid per cell and are "hot launch" systems)

In section 2 Systems in use by nations, the VLS on all surface ships worldwide most often (but not always) have cells in the number of multiples of 8, particularly “United States: Surface [ships] : Arleigh Burke class destroyer - Mk 41 (96 cells), Ticonderoga class cruiser - Mk 41 (122 cells), Zumwalt class destroyer - Mk 57 (80 cells)."

(d) The above article of Strategy Page “The most common VLS user is the American Burke class destroyer, with 90 VLS cells. A smaller number of cruisers have 122 VLS cells each."
(i) This are the number on each ship. The next paragraph of the article says it is almost impossible to reload at sea. Thus it is not as if a ship might have, say, ten cells, fire, reload and fire again.
(ii) But wait a minute, 90 or 96 cells for Arleigh Burke?
(iii) Arleigh Burke-class destroyer
en.wikipedia.org/wiki/Arleigh_Burke-class_destroyer

The column on right margin states, “Armament: Missiles--Flight I: 90 cell MK 41 Vertical Launch System (VLS); Flights II and IIA: 96 cell MK 41 VLS.”

This Wiki page never explains “flight.”
(iv) Fact File: Destroyers-DDG. United States Navy, undated
www.navy.mil/navydata/fact_displ ... p;tid=900&ct=4.<br
(“Features unique to DDG 1000 [or Zumwalt-class destroyer]: Eighty peripheral vertical launch system (VLS) cells [among other features] ; DDG 51 [or Arleigh Burke class] * * * is comprised of three separate variants or "Flights": DDG 51-71 represent the original design and are designated Flight I ships; DDG 72-78 are Flight II ships; DDG 79 and Follow ships are built or are being built to the Flight IIA design. The Flight III baseline is planned for the second ship in FY16”)

(e) Mark 41 Vertical Launching System
en.wikipedia.org/wiki/Mark_41_Vertical_Launching_System
("Launcher cells are fitted to ships in 8 cell (2 rows of 4) modules that share a common uptake hatch (exhaust system) sited between the two rows. Mk 41 VLS adopts modular design concept, which result in different versions that vary in size and weight due to different 'canisters' in various modules")

This explains VLS in multiples of eight cells. Where do the variants come from, such as 90 cells for Flight I of Arleigh Burke class (see (d)(iii)) and 122 for Ticonderoga class cruiser (see (c))?  I have no idea.