Urine processor re-started in critical test of water system
After work to remove rubber vibration dampers from a centrifuge assembly inside the space station's new urine recycling system, the astronauts and flight controllers began another test run Sunday evening to find out if the improvised fix will eliminate a vibration-related problem that triggered pre-mature shutdowns.
The urine processor facility is designed to run about four hours at a time converting urine in a standard Russian container into potable water. During test runs Friday and Saturday, the motor driving a centrifuge in the processor's vacuum distillation sub-system slowed down after about two hours, forcing shut downs.
Telemetry indicated the problem involves physical interference between the spinning centrifuge and a speed sensor, possibly caused by thermal effects and/or a frequency mode the device gets into after extended operation.
