Integrated Communications Unit (ICU) R4 Transition: Yesterday, a software patch was loaded for the Ku-Band Command and Data Processer (KCDP) to correct the anomaly experienced where large packets of data were disrupting Ku Band forward data flow. After the load was complete, ground teams transitioned from KU Comm Unit (KCU)1 to KCU2, which contains the new R4 software, without issue. Two sporadic events were noticed, however, shortly after the transition: Intermittent Ku Forward Link Dropouts and KU Return power fluctuations impacted all Ku return end items. Engineering is monitoring the data as we continue to operate on KCU2. Ultimately, ICU R4 is expected to double the return link rate and storage record and playback rates from 256 Mbps to 517 Mbps.

Veggie Passive Orbital Nutrient Delivery System (PONDS): The crew installed the Veggie PONDS experiment hardware and then initiated the experiment. Organisms grow differently in space, from single-celled bacteria to plants and humans. Future long-duration space missions will require crew members to grow their own food. Understanding how plants respond to microgravity and demonstrating the reliable vegetable production on orbit are important steps toward that goal. Veggie PONDS uses a newly developed passive nutrient delivery system and the Veggie plant growth facility aboard the ISS to cultivate lettuce and mizuna greens which are to be harvested on-orbit, and consumed, with samples returned to Earth for analysis.

Miniature Exercise Device (MED-2): The crew set up cameras in Node 3 and the Cupola to capture video from multiple views of the Advanced Resistive Exercise Device (ARED). They applied body markers, performed exercises and then transferred the video for downlink. The ISS’s exercise equipment is large and bulky, while the MED-2 aims to demonstrate small robotic actuators can provide motion and resistance for crew workout sessions, reducing the size and weight of exercise equipment for long-duration space missions. The MED-2 technology is critical for the design and development of second and third generation countermeasure hardware that is an order of magnitude lighter and smaller than existing ISS countermeasure hardware and that has significantly greater reliability.

Mouse Stress Defense: The crew provided water to the Mouse Habitat Cage Units and checked their water nozzles today. Microgravity provokes cellular mechanical stresses and perturbs cellular signaling, leading to reduction of muscle and bone density. To overcome these stresses, one of the promising strategies is to activate Nrf2, a master regulator of antioxidant pathway. Mouse Stress Defense investigates how Nrf2 contributes to effective prevention of space-originated stresses.

Radiation Area Monitoring (RAM) retrieve: The crew retrieved a total of 68 Radiation Area Monitors from all four Crew Quarters for return on SpX-14. Radiation exposure levels in the four Node 2 Crew Quarters (CQs) significantly differ between the highest and lowest as measured by the passive Radiation Area Monitors (RAMs). Measurements using active instruments reflects the differences in CQ radiation levels. It is well understood that these differences arise from a non-isotropic trapped radiation source, coupled with irregular shield factors. In the past there has been only one RAM located in each CQ, so as part of a CQ radiation assessment it was necessary to deploy several more RAMs inside each CQ to gather more data on radiation levels. Ground specialist hope to improve risk and exposure management based on the data from this assessment.

External TV Camera Group (ETVCG) Disassembly and Bulb R&R: This morning the crew disassembled the ETCVG that was R&R’d on the Node 3 External Wireless Communication (EWC) US Extra-vehicular Activity (EVA). The purpose of this disassembly was to remove the Video Camera Luminare (VCL) with limited life remaining, and replace with a new VCL for future use. The disassembly proceeded nominally, but issues arose when testing the E2 (secondary) location, which is the backup light, on the ETVCG. During checkout of the secondary blub, there was a fault experienced that caused the upstream Utility Outlet Panel (UOP)’s relay to open. To determine if the bulb was the cause, the old VCL with limited life located in E1 (primary) was placed in the E2 location, and a new bulb installed in E1. The E1 bulb successfully illuminated and is considered operational.

Dragon Cargo Operations: Today the crew continued with loading Dragon cargo scheduled for return. The crew worked via the third Dragon Cargo Message, uploaded yesterday evening; ground specialists estimate 10h 30m of cargo operations remain. SpaceX-14 is currently scheduled to unberth on 2 May at 9:32 AM CDT.

Extravehicular Activity (EVA) Preparation: Today the crew set up the Enhanced Caution and Warning System (ECWS) Onboard Trainer to review operations of the EMU (ECWS) and practice EVA Cuff Checklist procedures. This task was the start of EVA preparation for US EVA 50, currently planned on May 16.

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

None

Ground Activities

All activities are complete unless otherwise noted.



Nominal Ground Commanding

Three-Day Look Ahead:

Thursday, 04/26 : SM 8.10 uplink, MSS MTT Insertion to JOTI, Node 3 LTL PPA R&R, EVA Prep (EMU swap, EMU water dump), Dragon Cargo Ops, Dragon LiOH install, Meteor HD Swap, Mouse Stress Defense, Circadian Rhythms.

Friday, 04/27: N3 EWCS installation, Dragon Cargo Ops, N3 MCA ORU Removals, CUCU checkout, MISSE MTT Removal and Stow, JEM Camera Robot Checkout, Tangolab Card Swap, and RMCT/SPDM Stow for walkoff.

Saturday, 04/28: Housekeeping, DUST Sample Collection, SSRMS walkoff to Node 2 PDGF, Edge Router to BRI Troubleshooting, Crew Off Duty

QUICK ISS Status – Environmental Control Group: