Communicating among the individual components of the space station takes place in the manner previously indicated either through signalling with lights or by either radio or wire. Accordingly, all three substations are equipped with their own local radio stations and, furthermore, are connected to one another by cables that include electric power lines.
Finally, each one of the three substations carries reserve supplies of food, oxygen, water, heating material and electricity (stored in spare batteries) in such a manner that it can house the entire crew of the space station for some time in an emergency, if, for instance, each of the other two substations should become unusable at the same time through an accident. In this manner, the tripartitioning of the space station, originally chosen for technical reasons, also contributes considerably to safety. In order to enhance the latter still further, provisions are mace to ensure that each substation not only can communicate with the ground through the central radio station, but also independently via its own flashing mirror system.