The question would be - what purpose does it serve?
Missiles resemble SA-2 Guidelines, so all I can think of is that it is a part of mobile air defence battery.
I could see this being mooted as a way of helping consolidate territory gained during rapid advances, or as a way of keeping the planners of strategic recce overflights on their toes - but at great monetary cost, and technical risk.
Alternately, it might be a VHLH with a modular payload, one of which is the above configuration. Much as the Boeing Spanloader was planned for the support of oil extraction in remote areas, perhaps this beast was planned for use in hard-to-access parts of the SU.