Space Station: Repair spacewalks analyzed
Flight Engineer Doug Wheelock worked outside the International Space Station in August 2010 to install a spare pump module. --NASA Image
A flow control valve in the starboard pump module that enables the flow of ammonia to cool station systems stopped positioning itself properly last week, resulting in a drop of temperature in Cooling Loop A. That necessitated the shutdown of some support systems on the station.
The temperature must be warm enough in the cooling lines to allow the system’s heat exchangers to dissipate excess heat from the station through the external radiators on the complex. The primary heat rejection capability for station systems shifted last week to Cooling Loop B, which uses a fully operational Pump Module on the port truss.
Efforts overnight to fine-tune the position of an isolation valve associated with the flow control system in the pump module into a “sweet spot” to assist the faulty flow control valve in regulating the affected cooling loop’s temperatures were still being evaluated as engineers continue to review the data, valve positioning techniques and additional methods of temperature management in the loop.
Meanwhile, parallel work is ongoing to either enable Orbital Sciences Corp. to launch its Antares rocket and the Cygnus cargo craft from the Wallops Flight Facility, Va. Dec. 19 on its first resupply mission to the space station, and for astronauts Rick Mastracchio and Michael Hopkins to mount spacewalks to replace the faulty pump.
The International Space Station Program continues to keep both options on the table pending further engineering analysis and troubleshooting efforts on the station’s cooling system.
The temperature must be warm enough in the cooling lines to allow the system’s heat exchangers to dissipate excess heat from the station through the external radiators on the complex. The primary heat rejection capability for station systems shifted last week to Cooling Loop B, which uses a fully operational Pump Module on the port truss.
Efforts overnight to fine-tune the position of an isolation valve associated with the flow control system in the pump module into a “sweet spot” to assist the faulty flow control valve in regulating the affected cooling loop’s temperatures were still being evaluated as engineers continue to review the data, valve positioning techniques and additional methods of temperature management in the loop.
Meanwhile, parallel work is ongoing to either enable Orbital Sciences Corp. to launch its Antares rocket and the Cygnus cargo craft from the Wallops Flight Facility, Va. Dec. 19 on its first resupply mission to the space station, and for astronauts Rick Mastracchio and Michael Hopkins to mount spacewalks to replace the faulty pump.
The International Space Station Program continues to keep both options on the table pending further engineering analysis and troubleshooting efforts on the station’s cooling system.
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