A temporary passageway utilized to join two starships in the void of space for inter-ship transit was called a docking tube. It also went by alternative names like boarding tube, suction tube, transport tube, or umbilical tube. These tubes had the capability to extend, forming a connecting tunnel between spacecraft, and retract when their use was complete. Certain boarding tubes were designed with transparent sections. Occasionally, the regions surrounding the tube's connection points required re-pressurization prior to opening a port door for tunnel entry. If individuals were present inside during a disconnection, they faced the risk of rapid and forceful decompression. These connections also presented a vulnerability, enabling the transmission of an explosion within the tube to both connected starships.