Status of the International Space Station Nodes 2/3 Environmental Control and Life Support System 2002-01-2490

The International Space Station (ISS) modules Nodes 2 and 3 are progressing through the design phase into integration, test, and verification. This paper gives a status of the Nodes 2 and 3 Environmental Control and Life Support System (ECLSS) design progress since 1999 (ICES paper 1999-01-2146). The Node 2 Design Review 2 was completed in March 2001. Node 2 is currently in the hardware integration/test phase at Alenia Spazio. The ECLSS for Node 2 includes inter- and intramodule ventilation, temperature and humidity control, distribution of atmosphere samples, low pressure and recharge oxygen and nitrogen, fuel cell and wastewater, and fire detection and suppression. Changes/challenges since 1999 have included the addition of a low temperature loop coolant bypass around the Common Cabin Air Assembly condensing heat exchanger and resolution of common hardware and verification issues. The current status of hardware integration and testing is also discussed.

In addition to providing the same functions as Node 2, the ECLSS for Node 3 includes carbon dioxide removal, trace contaminant control, atmosphere monitoring, atmosphere pressure control, oxygen generation, urine and potable water processing, and potable water distribution. Scarring for future incorporation of carbon dioxide reduction and waste management is also included. Since the July 1999 Design Review 1, significant work has been accomplished to mature the Node 3 ECLSS design, particularly in the area of rack integration. Planning for Node level integrated testing is also underway and creates some significant challenges for the ECLS system. The latest design, accomplishments, and remaining challenges are discussed.