Space Station Freedom Node 2 Fire Detection and Suppression System Design and Performance

McDonnell Douglas Aerospace has developed an innovative piccolo tube system approach to fire detection and suppression (FDS) in Space Station Freedom Node 2. In a gravity environment, smoke travels by natural convection and triggers an alarm; however, in a microgravity environment there is no mechanism for smoke to move from a remote distance to the sensor without assistance. In addition, the Space Station nodes contain closed-out, odd-shaped regions that have surprisingly large free air volumes in which smoke can “hide.” We have overcome these problems by drawing the smoke to the alarm sensors through piccolo tubes that sample all regions of the node. Similarly, we release fire suppressant through piccolo tubes to ensure an even distribution throughout the fire area.

This paper will first give an overview of the Node 2 architecture. The middle section will describe the detection and suppression systems, including the avionics architecture and operations. The last section will describe analysis used for sizing the equipment in the system.