1.   Fans would replenish leaked air.

2.   However, severe icing only occurs when either the frigid air cannot be dislodged or gelid surface air is replenished from a new source.

3.   It could also be used to replenish air aboard the rest of the space station in an emergency or to provide oxygen to a stricken crew member.

4.   The gas is needed to repressurize the air lock following spacewalks and to replenish air in the rest of the space station if needed.

5.   The gas tanks are needed to repressurize the air lock after spacewalks and to replenish air in the rest of the space station if needed.