Lighting Effects: Upon wakeup, the 49S subject provided a sleep log entry and began the first half of a 48-hour urine collection to support the Sleep Shift and Biochem Profile/Repository portion of the Lighting Effects investigation. Subject conducted four urine collections which are performed within a 24-hour period. Each sample was stowed in the Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI) for freezing for return and analysis. The Lighting Effects experiment hopes to better quantify and qualify how lighting can effect habitability of spacecraft. The light bulbs on the ISS are being replaced with a new system designed for improved crew health and wellness. The Lighting Effects investigation studies the impact of the change from fluorescent light bulbs to solid-state light-emitting diodes (LEDs) with adjustable intensity and color and aims to determine if the new lights can improve crew circadian rhythms, sleep, and cognitive performance. Results from this investigation also have major implications for people on Earth who use electric lights

Device for the study of Critical Liquids and Crystallization (DECLIC) Hard Drive Exchange: The crew exchanged hard drives for the DECLIC investigation. DECLIC High Temperature Insert (HTI)-Reflight (R) studies water near its critical point, the point beyond which water loses its distinction between liquid and vapor and begins to behave as a dense gas. Salt tends to precipitate out from water at temperatures and pressures beyond its critical point. Understanding this behavior will assist designers in building extended-life and low-maintenance supercritical water oxidation (SCWO) reactors that will provide more environmentally friendly waste management systems and reduce operating costs of power plants that use supercritical water for its working fluid.

Dose Tracker: The crew launched the Dose Tracker app before completing entries for medication tracking on an iPad. This investigation documents the medication usage of crewmembers before and during their missions by capturing data regarding medication use during spaceflight, including side effect qualities, frequencies and severities. The data is expected to either support or counter anecdotal evidence of medication ineffectiveness during flight and unusual side effects experienced during flight. It is also expected that specific, near-real-time questioning about symptom relief and side effects will provide the data required to establish whether spaceflight-associated alterations in pharmacokinetics (PK) or pharmacodynamics (PD) is occurring during missions.

Expedite the Processing of Experiments to the Space Station (Express) Rack 6 (ER6) Improved Payload Ethernet Hub Gateway (iPEHG) Installation: The crew removed the Payload Ethernet Hub Bridge (PEHB) from ER6 and installed an Improved Payload Ethernet Hub Gateway (iPEHG) in its place. The iPEHG provides additional payload data band width needed for the TangoLab payload arriving on SpX-11. The iPEHG was checked out and is performing nominally. The PWD was removed and reinstalled back in the same ER6 location, to allow access for installing the iPEHG. While preparing for the iPEHG installation, the crew found damaged threads on one of the Microgravity Rack Barrier Posts and its threaded insert. The plan is to replace the Standoff Bridge Bracket to provide a good installation location for a spare Microgravity Rack Barrier Post.

Remote Power Control Module (RPCM) S11A_C Remote Power Controller (RPC) 3 Status: Yesterday, RPCM S11A-C RPC 3 tripped, removing power from the Starboard Thermal Radiator (STR) Multiplexer/Demultiplexer (MDM). Due to unusual temperatures in the RPCM after the trip, specialists suspected that the trip might have been caused by an RPCM failure rather than a true overcurrent. Multiple attempts to reclose RPC 3 were unsuccessful. Teams are reviewing data to attempt to isolate the failure to the RPCM or the STR MDM.

Nitrogen Repress from Nitrogen/Oxygen Recharge System (NORS): Today, the crew performed the first nitrogen repress from a NORS N2 tank. The tank is now empty and ready for return on SpX-11.

Today’s Planned Activities

All activities were completed unless otherwise noted.

Troubleshooting possible cause of generating inadvertent command in FGB Program-Logic Control Device [УПЛУ] via SM-FGB – X Docking Assembly, preparation.

ISS HAM Radio Power Up

COTS UHF Communications Unit Removal

Dose Tracker Data Entry Subject

HRF Generic Urine Collection – Subject

Meteor Shutter Open

WHC UR and Insert Filter (IF) R&R

PILOT-T. Preparation for the experiment.

HRF Generic Sample MELFI Retrieval Insertion Operations

ExPRESS Rack 6 Rack Preparation

PILOT-T. Experiment Ops

ARED Cylinder Flywheel Evacuation

IPEHG Hardware Install

PILOT-T. Closeout Ops

Verification of ИП-1 Flow Indicator Position

Filling (separation) of ЕДВ (КОВ) for Elektron or ЕДВ-СВ.

HRF Generic Sample MELFI Retrieval Insertion Operations

Microgravity Science Glovebox Equipment Inspection and Cleaning

EMU Radio Frequency (RF) Camera Assembly (ERCA) Inspect

CONTENT. Experiment Ops

ExPRESS Rack 6 Rack Reconfiguration

HRF Generic Urine Collection Female – Subject

Galley Potable Water Dispenser (PWD) Installation

HRF Generic Sample MELFI Retrieval Insertion Operations

DECLIC Removable Hard Disk Drive Exchange

Atmosphere Control and Supply (ACS) Nitrogen Manual Valve Open

Completed Task List Items

Advanced Resistive Exercise Device (ARED) Quarterly Inspection [Completed GMT 98]

Treadmill 2 System (T2) Monthly Inspection [Completed GMT 98]

Data Prep for Return [Completed GMT 98]

ESA Active Dosimeter Area Monitoring Mobile Unit Stow [Completed GMT 98]

ESA PAO Recorded Message “150 e du Canada” [Completed GMT 98]

ESA PAO Message – Martian Meteorite video [Completed GMT 98]

ESA PAO Message – St. Exupery writing contest winners [Completed GMT 98]

EVA Hardware Audit [Completed GMT 98]

Health Maintenance System (HMS) Automated External Defibrillator (AED) Inspection [Completed GMT 98]

NOD1S4 Zero-G Stowage Rack Strap Install [Completed GMT 98]

Station Support Computer 1 Reseat Hard Disk Drive [Completed GMT 98]

Health Maintenance System (HMS) Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) Test [Completed GMT 99]

RED Video Card Swap [Completed GMT 99]

SSC 4 Primary Hard Drive Swap [Completed GMT 99]

EXPRESS Rack 6 Locker Removal [Completed GMT 100]

NOD1D4 Audit – Part 2 [Completed GMT 100]

Rodent Research Inventory Audit [Completed GMT 100]

Strata Final Card Changeout [Completed GMT 100]

Ground Activities

All activities were completed unless otherwise noted.

SSRMS walkoff to N2 PDGF

IPEHG ER6 Activation and Checkout

NORS N2 repress

Three-Day Look Ahead:

Wednesday, 04/12: Cognition, ER6 locker install/CUCU install, Man. Device feedstock canister, extruder, print tray exchange, GLA visual performance test

Thursday, 04/13: Rodent Research inventory, ELF removal, MSL sample cartridge exchange

Friday, 04/14: Lab/N2 JSL router R&R, CB2 hardware setup

QUICK ISS Status – Environmental Control Group: