Abstract: A modular space structure having a central enclosed area is erected in outer space from expandable modules transported by a reusable space shuttle or an expendable rocket. Each module comprises an outer member and one or more inner members carried telescopically therein forming a complete enclosure to serve as a small self contained space structure capable of being equipped for life support. Each inner member has slightly less volume than the outer member in which it is nested. As each inner member is extended, the interior volume is increased and a larger enclosure is formed. A two member module, when extended, would nearly double the amount of initial enclosed usable space, and an extended three member module would nearly triple the amount of initial enclosed usable space.