All ISS systems continue to function nominally, except those noted previously or below.

CDR Whitson & FE-2 Tani started out with the daily reading of SLEEP (Sleep-Wake Actigraphy & Light Exposure during Spaceflight) experiment data accumulated during the night, for logging and filling in questionnaire entries in the SLEEP session file on the HRF-1 laptop for downlink. [To monitor the crewmembers' sleep/wake patterns and light exposure, Dan and Peggy wear a special Actiwatch device which measures the light levels encountered by him as well as his patterns of sleep and activity throughout the Expedition. The log entries are done within 15 minutes of final awakening for seven consecutive days, as part of the crew's discretionary "job jar" task list.]

At ~2:55am EST, the FE-2 again activated the VDS MPC (Video Distribution System/Multi-Purpose Converter) with its four downlinks to allow the ground to conduct HDTV (high-definition TV) playback and downlink operations. Later (~12:15pm), the MPC was powered off again. [The end-to-end test of the system, conducted by the crew and ground specialists on 1/17 to verify the MPC HDTV (Multi-Purpose Converter/High-Definition TV) capability all the way to the NASA TV satellite, was very successful, yielding an overall end-to-end audio latency (delay) for the MPC System of 3.2 seconds. This is the delay from the crewmember to JSC/MCC-H to NASA Headquarters and out to the NASA TV satellite in high definition (including, but are not limited to, CNNHD, ABC, NBC, CBS, and Discovery HD Theater), i.e. the sum total of the audio delay the interviewer and interviewee will "feel" during an interactive event. This Japan/JAXA originated system will be utilized soon for downlink messages and in-flight interviews based on client capability.]

In Node-2, the CDR terminated the overnight leak check on the N2 (nitrogen) recharge system. An overnight leak check of the ISS oxygen recharge line verifies the integrity of the Node-2 N2 recharge system installation. [Node-2 N2 recharge system fine leak checkpass criteria requires real-time analysis to confirm that the N2 supply pressure decay remains less than 124 kpa (18 psia) over 10 hours.]

Using the SKDS CMS (Pressure Control & Atmosphere Monitoring System/Countermeasure System), the FE-1 took the periodic readings of potentially harmful contaminants in the Service Module (SM). The hardware was then returned to initial stowage. [The CMS uses preprogrammed microchips to measure Formaldehyde (H2CO, methanal), Carbon Monoxide (CO) and Ammonia (NH3), taking one measurement per microchip.]

Dan Tani conducted the periodic checkout/verification of IP-1 airflow sensors in the various RS (Russian segment) hatch openings (8) in the SM (Service Module), FGB and DC1 (Docking Compartment).

Dan also terminated the depressurization of the PMA-2 (Pressurized Mating Adapter 2) in front of Node-2 with the depress pump set up yesterday after the successful completion of vestibule outfitting for the upcoming 1E Flight, and performed the standard ~1 hr leak check.

The CDR closed the Lab science window shutters as protection against today's planned thruster firings.