Out-of-Spec ISS Cabin Pressure Decrease: Last night, the ISS cabin pressure started dropping at the rate of one mmHg/hr. This morning the crew performed leak isolation steps via a series of hatch closures and determined the leak was in the Soyuz 55S habitation module [БО]; a pressure check of the 55S descent module was nominal. Further investigation with the Ultrasonic Leak Detector (ULD) revealed a 2 mm hole behind a panel in the Soyuz Toilet [ACY]. After completing a 10mm repress using 70P Progress, the Russian crew installed of a patch over the hole and ISS stack pressure appears to have stabilized. Ground teams continue to monitor and have started another repress, using Progress resources, to bring ISS atmosphere back to nominal levels.

H-II Transfer Vehicle (HTV)-7 Proximity Communication System (PROX) Review and Checkout:

Today the crew checked PROX Baseband functionality and performance by sending commands to a HTV Simulator at a ground site in Tanegashima, Japan. HTV missions use the PROX system for communication with ISS via a Portable Computer System (PCS) version of the Hardware Command Panel (HCP). This week’s checkout is required to meet the Launch Commit Criteria (LCC) required prior to HTV-7 launch planned on 10 September.

Completed Task List Activities:

None

Ground Activities:

All activities are complete unless otherwise noted.



HTV-7 PROX Checkouts

NORS O 2 Repress [Aborted]

Two-Day Look Ahead:

Friday, 08/31:

Payloads

EXPRESS Rack 5 Rotate and Payload Valve Inspection

PCG 13 microscope ops

GRASP reconfiguration to free floating and troubleshooting

Sextant Navigation Session 5

Systems

EMU 3006 and 3008 Loop Scrub and Iodination

EVA Systems Operations Data File (SODF) Update

Eye Exams

Saturday, 08/31: Crew Off-Duty, Weekly Housekeeping

Today’s Planned Activities:

The following activities were aborted due to today’s off-nominal event on ISS.