Intra-Vehicular Activity
Intra-Vehicular Activity (or IVA) is the term for any activity during a mission that involves astronauts venturing into modules of the Habitat that have been depressurized or vented. IVAs are less common and shorter than EVAs, as they usually occur only in the case of a disaster.
Reasons for IVAs
IVAs are usually only undertaken to perform maintenance. This differs from EVAs, which can involve the collection of rock samples or the repairing of complicated mechanisms outside the habitat. IVAs are usually initiated by the decompression of a room by meteorite collision.
IVA Protocol
Prior to deciding to embark on any EVA, the Habitat crew must inform Mission Control of their intentions, their choice of astronauts for the EVA, and obtain Mission Control's approval. After said approval is obtained, the astronaut or astronauts chosen to go on the IVA must place an IVA helmet over their flight suit, thereby completing a pressure suit. Then they must seek permission from the acting Astronaut Commander to embark.
