Proposal for Increasing the Capability for Water Transfer to the International Space Station via Orbiter Radiator Flow Control Assembly Logic Redesign 2001-01-2434
Projected deficiencies of water required for the International Space Station (ISS) once it reaches the assembly complete (AC) phase necessitate alternative methods of generating, reclaiming, processing, or transporting water. The Space Shuttle Program (SSP) Orbiter is expected to provide a significant portion of required ISS water throughout the assembly and AC phases.
Currently, the Shuttle Orbiter provides water as a byproduct of power generation by the Fuel Cells (FCs). The water not required by the Flash Evaporator System (FES) for cooling or by the crew for consumption is available for transfer to the ISS. The amount of water required for cooling by the Orbiter FES is dependent upon the Orbiter flight attitude and heat load; though, once the ISS has reached the AC configuration, the ISS (and thus the Orbiter docked to it) flight attitude will be restricted to a small envelope.
Until now, there has been no significant motive to change Radiator Flow Control Assembly (RFCA) design, as there has been no significant water deficiency within the scope of the SSP. However, projections for water required by the ISS Program, especially for the ISS AC configuration, may provide the motivation for redesigning the RFCA logic in order to transfer more water to the ISS.
Depending upon ISS flight attitudes, the projected increase of water available for transfer to the ISS could be as much as 500 lb. (227 kg.) per Orbiter mission. Although altering the RFCA control scheme would require investigation, it is believed that this could be accomplished without major impact to Orbiter design or safety considerations.
Citation: Dunaway, B., "Proposal for Increasing the Capability for Water Transfer to the International Space Station via Orbiter Radiator Flow Control Assembly Logic Redesign," SAE Technical Paper 2001-01-2434, 2001, https://doi.org/10.4271/2001-01-2434. Download Citation
31st International Conference On Environmental Systems