Human Research Facility-2 (HRF-2) B-Rack Interface Controller Install: Today the crew installed the new BRIC into the HRF-2 rack to resolve Rack Interface Controller (RIC) issues that started back on March 25th. Following the installation, the ground attempted activation but was not able to establish communication with the High Rate Link Card (HRLC) within the BRIC. A power cycle of the rack and a restart of the bootloader were performed in an attempt to establish communication with the HRLC card, but were unsuccessful. The crew reconnected the HRF1 and HRF2 Portable Computers (PC)s back into the previous configuration to aid in further troubleshooting. Two subsequent reboots of the RIC bootloader recovered the HRLC, and HRF has been recovered to a normal state and software loads are in process. The next planned operations for the HRF2 rack are on May 14th.

Center for the Advancement of Science in Space (CASIS) Protein Crystal Growth (PCG)-9: The crew removed PCG-9 sample bags containing Copper Sulfate from a Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI) and checked them for crystal growth. Since one of the bags contained no crystal growth the crew reprocessed that bag and returned all of the sample bags to the MELFI for additional growth time. These were the same sample bags that previously had shown no observed crystal growth. If crystals are observed today in the sample bags, they will be photographed and water extracted prior to the samples being returned to the MELFI. The Wisconsin Crystal Growing Contest-Wisconsin Space Crystal Mission (CASIS PCG 9) investigation provides student researchers the opportunity to explore crystal growth in the microgravity environment of the ISS. Crystals grown without the influence of gravity have shown to contain fewer imperfections and grow to larger sizes. Middle and high school students compete to grow the most perfect ground-based crystal, as judged by experts in the crystallography field. The students who present the crystals with the fewest imperfections have the opportunity to fly their experiments to the space station.

Circadian Rhythms: Today, a crewmember began a Circadian Rhythms experiment session by configuring the armband monitor and donning the watch and Thermolab double sensors, which will be worn for the next 36 hours. The objective of the experiment is to get a better understanding of any alterations in circadian rhythms in humans during long-term space flights. Such knowledge will not only provide important insights into the adaptations of the human autonomic nervous system in space over time, but also has significant practical implications by helping to improve physical exercise, rest- and work shifts as well as fostering adequate workplace illumination in the sense of occupational healthcare in future space missions.

Waste and Hygiene Compartment (WHC) Pre-Treat Tank [E-K] Remove and Replace (R&R): As part of USOS crew handover, a 53S crewmember familiarized a 54S crewmember with this regularly scheduled maintenance activity. The crew routinely R&Rs the E-K tank as part of nominal WHC preventative maintenance. Each tank contains five liters of pre-treat solution, a mix of acid, chromium oxide, and water, used for toilet flushing and required for nominal WHC operation.

Joint Station LAN (JSL) Firewall Install in NODE 2 (N2): Today the crew installed the second set of hardware JSL firewalls, power supplies, and networking cabling in N2 in preparation for the upcoming JSLv11 transition. These firewalls will provide additional security to ISS computer assets and facilitate smoother integration of Commercial Off-the-Shelf (COTS) hardware into the ISS JSL network.

Regen Urine Processing Assembly (UPA) 6.3 Software Update: Today the crew deployed a Space Station Computer (SSC) and prepared the UPA for a ground commanded upload of new software and firmware. Following the update, the UPA was powered-up and controllers updated necessary software parameters. UPA was confirmed operational after the update.

Extravehicular Activity (EVA) Tether and Bag Inspection: Today the crew inspected for damaged cords on equipment tethers and tools with integral tethers. They also inspected rivets on all EVA bags required for the upcoming EVAs. Each tether and bag must be inspected prior to EVA use in order to prevent loss of hardware and liberation of Foreign Object Debris (FOD).

Today’s Planned Activities

All activities are complete unless otherwise noted.



Hematocrit Test

FAZOPEREKHOD. Preparation steps and starting the experiment

ISL Ethernel Cable swap of the AstroPi Vis in COL

Configuration following Water Processing Assembly (WPA) Activation

24-hour ECG Recording (start)

Powering up of AstroPi Vis in Columbus

SPHERES Rechargeable Battery Install

Waste and Hygiene Compartment (WHC) Pre-Treat Tank Remove &

HRF2 BRIC Retrieve

24-hour Blood Pressure Recording (start)

Cleanup HRF-2 rotation path

Verification of ИП-1 Flow Sensor Position

High Definition (HD) Config LAB Setup

HRF2 Troubleshoot Disconnect

IMS Update

Replacement of БРП-М in СРВ-К2М

Crew Prep for PAO

COL1A4 HRF2 Rack Rotate Down

TV-Conference with the Plenum of the Supreme Court of the Russian Federation (Ku + S-band)

Retrieval of PCG-9 Hardware from MELFI

SPHERES Rechargeable Battery Charge and Stow

Second Inspection of Sample Bags for Crystal Growth – Rerun of GMT 108

HRF2 BRIC Change

FAZOPEREKHOD. Closeout Ops

Extraction of Liquid from Sample Bags and Association Photos – Rerun of GMT 108 [Deferred]

Interest Photos and Recorded Video for Downlink

ABOUT GAGARIN FROM SPACE. HAM Radio Session with the Artek tour campers

Regen Urine Processing Assembly (UPA) 6.3 Setup

DAN. Experiment Session

Lab Light Connector Capping

COL1A4 HRF2 Rack Rotate Up

Medical Consumables Tracking Battery Change-out

MATRYOSHKA-R. Replacing Personal Hygiene Items (СЛГ) in the Bottom Store of the Protective Screen Experimental Hardware (middle left, middle right, and upper) and photography in the starboard crew quarters

Recovery of Condensate Feed Unit (БПК)

MERLIN Desiccant Swap

Regen Urine Processing Assembly (UPA) 6.3 Initiation

Columbus Bay 4 Restore

Public Affairs Office (PAO) Event in High Definition (HD) – Lab

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

Multi-use Variable-g Platform Desiccant Replace

SPHERES Rechargeable Battery Charge and Stow

Regen Urine Processing Assembly (UPA) 6.3 Teardown

СОЖ Maintenance

US Extravehicular Activity (EVA) Tether Inspection

Oxygen Generation System (OGS) Oxygen ORU Flight Support Equipment (FSE) Removal

US Extravehicular Activity (EVA) Tether and CL Bag Inspection

Joint Station Lan (JSL) Firewall Install in NODE 2

SPHERES Rechargeable Battery Charge and Stow

Checking БД-2 treadmill carriage position

Downlink via RSPI of audio files recorded by acoustic logger during Soyuz 738 flight

Circadian Rhythms Instrumentation with Armband

SPHERES Rechargeable Battery Charge and Stow

Completed Task List Activities

Vacuum Debris Bag R&R Label Attachment

Ground Activities

All activities are complete unless otherwise noted.



N2 Atmospheric Control System (ACS) nitrogen leak check

UPA 6.3 Software update

PVTCS Pump swaps on all channels

HRF2 RICS Load update commanding [Deferred]

Three-Day Look Ahead:

Wednesday, 04/25 : Veggie Ponds Exp, Dragon cargo ops, ETVCG teardown, Mouse Stress Defense

Thursday, 04/26 : Node 3 LTL PPA R&R, SM 8.10 TBM and ЦВМ SW loads, WRM water balance, EVA preps (EMU swap, EMU water dump), locker reconfig, Dragon Cargo Ops, Dragon LiOH install, Meteor hard drive swap, Mouse Stress Defense, Circadian Rhythms.

Friday, 04/27: N3 EWCS installation, Dragon cargo ops, N3 MCA Maintenance, CUCU checkout, MISSE MTT removal and stow, JEM camera robot checkout, JEMAL Ops: MISSE-TT Removal 7 JEM active mechanism install, Dust sample collection, Crew Qtrs RAM retrieval, Tango Lab-1 card 1 removal.

QUICK ISS Status – Environmental Control Group: