Answers Your Questions
From: Syed Idros, of Johor
Support groups work in each center. There is a Houston Support Group that works in MCC-M, and a Russian Support Group that works in MCC-H. These groups provide a working-level interface between the different control centers.
At all times, MCC-M and MCC-H can interface on a higher-authority level through the flight directors. MCC is manned 24 hours a day, 365 days a year. The control centers are supported by teams operating in shifts comprised of both government employees and contractor personnel. A shift is typically nine hours long, which allows for a one-hour handover from the off-going team to the oncoming team. This will be maintained for the duration that ISS is in orbit. There are additional control centers dedicated to payload operations in the United States, and in the near future, there will be International Partner control centers in Japan and Europe.
Steven Johnson, International Space Station Flight Controller, U.S. Electrical Power System.