In the frame of a collaboration with ASI, NASA and ESA, Alenia Aerospazio is responsible for the design of several pressurized elements of the ISS: MPLM, COF, Cupola, Node 2 and Node 3.
For Node 2 and Node 3 a “design synergy“ has therefore been pursued to exploit the gained experience as well as the day by day achieved know-how.
Node 2 and Node 3 are pressurized elements of the ISS; they provide passageway among berthed habitable volumes, distribute electrical power and commands, collect and transport thermal energy by rejecting waste heat to ISS radiators.
The Node 2 attached elements are the USL, the PMA2, the MPLM, the JEM, the COF, and the CAM. The Node 3 attached elements are the Node 1 (“Unity”), the CRV, the MPLM, the HAB and Cupola.
Figure 1 shows the Nodes and the other Alenia developed elements integrated in the ISS.
Both Node 2 and Node 3 Passive Thermal Control System architecture provide adequate barrier to the space external environment through MLI blankets and electrical heaters. Owing to similarity in structural shape, an high design commonality is possible.
The Node 2 and Node 3 Active Thermal Control System both consist of two water loops that supply coolant mass flow to the attached modules, provide cooling to Avionics cold plate mounted equipment, cabin air and some Environmental Control & Life Support System racks (Node 3 only). However, due to different specific tasks each Node has to comply with, a lower level of design commonality can be achieved.
Purpose of this paper is to compare the Node 2 and Node 3 thermal design, both for active and passive sections, as resulting from the imposed requirements, design constraints and mission external environments. The thermal designer major difficulty is, therefore, to trim a basic design to different needs.
A comparison between the Node 2 and Node 3 software for thermal control is also provided to cover all the commonality aspects.