AF Mars has not moved to VHF as primary operation. In areas where there is a base, or a large number of members there is probably VHF operation either on a repeater or simplex, but the primary operation is HF. I am a long time AF Mars member, since 1972. Our operation , though small is primary HF. One of the reasons is probably that our frequencies have usually been somewhat removed from the amateur bands, and , not reachable within the VFO band coverage overlap of 1950-1980 generations of equipment.
It is primarily run by volunteer affiliates handling the day to day business as their schedules allow. The primary net operation is the region HF net. Once a person finishes training, there are digital nets, digital pbbs operations, a daily Transcon net, and phone patch nets (authorization required).
I and would be glad to provide whatever information I can to anyone considering AF MARS.