Abstract: A modular shelter system (10) used for the purpose of providing a substantial internal volume insulated from external environmental conditions. The modular shelter system (10) includes at least a pair of base members (12) having base rod support mechanisms (24) mounted in releasable fashion thereto. Support mechanisms (34) joined each to the other and to base members (12) provide for a generally hemispherical envelope. Support mechanisms (34) are coupled each to the other in releasable fashion and in a pivotal manner in order that they may be folded in contiguous mounting each to the other for compact storage and/or transportation. The support mechanisms (34) are secured to covering member (102) which is mounted on top of the generally hemispherical envelope provided by the mounted support mechanisms (34).