ISS Daily Summary Report – 4/27/2021

75P Departure: Today at 6:11 PM CST, 75 Progress (75P) is set to depart from the SM-Aft port of the International Space Station. The Russian cargo vehicle will stay in orbit for roughly 25 hours before beginning its deorbit burn at 7:01 PM CT on Wednesday 4/28, before re-entering the atmosphere for re-entry disposal at 7:36 PM CST. 75P was launched to station on April 25, 2020.

Change of Command Ceremony: Today at 12:25 PM CST, the ISS crew performed a Change of Command Ceremony so that Endeavour Crewmember Akihiko Hoshide will become the commander (CDR) of the International Space Station. Former Commander and Resilience Crewmember Shannon Walker will resume her previous “FE-13” designation as she and her crew prepare for departure from the ISS on Friday 4/30 as part of the Resilience Crew Undock.

Resilience Crew Undocking Delay: It has been decided, due to inclement weather at the landing zone, that the Resilience Crew Undocking that was scheduled for Wednesday 4/28 is to be postponed until no earlier than Friday 4/30.


MSL SCA-Batch3b-ESA: The crew removed the used MSL Sample Cartridge and installed the new 3B Sample Cartridge. Crew then prepared the facility for the next experiment run. The Materials Science Lab Batch 3b (MSL SCA-Batch 3b-ESA) serves two projects investigating how different phases organize in a structure when metallic alloys are solidified. The Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) experiment aims to deepen the understanding of the physical principles that govern solidification processes in metal alloys. The Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) experiment aims to deepen the understanding of the physical principles that govern solidification processes in metal alloys.

Vascular Echo: The Blood Pressure Bio-Monitor wearable hardware was doffed and stowed completing a 13-hr data collection run. Cardiac and Vessel Structure and Function with Long-Duration Space Flight and Recovery (Vascular Echo) examines changes in blood vessels, and the heart, while the crewmembers are in space as well as follows their recovery on return to Earth. The results could provide insight into potential countermeasures to help maintain crewmember health and quality of life for everyone.


Crew-1 Dragon Prop Checkout: This morning ground teams performed a Dragon hotfire thruster test as a part of the propulsion system checkout in preparation for Crew-1 undock, now scheduled for 4/30.  Both Port and Starboard Solar Alpha Rotary Joints (SARJs) and Beta Gimble Assemblies (BGAs) 2B and 4A were positioned in support of the test.  Arrays were brought back to nominal stage configuration (autotracking) after completion of the test.

Completed Task List Activities:

  • None

Today’s Ground Activities:
All activities are complete unless otherwise noted.

  • Crew Dragon Prop Checkout
  • Crew Dragon System Undock Activation
  • PRO MSRR Deactivation Commanding
  • Columbus FSL high rate data downlink

Look Ahead Plan

Wednesday, April 28 (GMT 118)

  • AC touch (NASA)
  • Vascular Aging BioMonitor Stow (CSA)
  • Phospho Aging blood and urine collections (JAXA)
  • AWP Doff (NASA)
  • GRIP Supine session and partial stow (ESA)
  • Standard Measures Ambient Blood and questionnaire (NASA)
  • Food Physiology Fecal processing and HISD photo (NASA)
  • Story Time in Space-8 Software install (NASA)


  • Deroute SSC 23 drag-through cables and temp stow
  • On Board Training (OBT) ROBoT T&C Self Study
  • ADLINK Troubleshooting Gather activity
  • Contingency Manual Fluid Transfer from EDV to Resupply Tank

Thursday, April 29 (GMT 119)

  • GRASP Seated session (ESA)
  • Phospho Aging Blood and Urine collect (JAXA)
  • ACME Controller replace (NASA)
  • Story Time in Space Experiment with Thermal White Sphere (NASA_


  • In Flight Maintenance (IFM) Waste and Hygiene Compartment (WHC) Pre-Treat Tank Remove & Replace
  • ACME Controller Replace 1
  • Regenerative Environmental Control and Life Support System (ECLSS) Recycle Tank Drain

Friday, April 30 (GMT 120)

  • Crew Off Duty Day


  • Crew Off-Duty Day

Today’s Planned Activities:
All activities are complete unless otherwise noted.

  • Bio-Monitor Wearables Data Transfer and Removal
  • Bio-Monitor Wearables Stow
  • Campout Sleeping Bag Deploy / Stow
  • Change of Command
  • Crew Departure Preparations for Return to Earth
  • Crew Dragon Seat Actuator Checkout
  • Deactivation of TV system monitoring equipment, Close applications and downlink MPEG2 multicast and MPEG2 unicast recorded data via OCA
  • Deploy Sleeping Bag in Dragon
  • Dragon Camera Uncover
  • Dragon MegaHEPA Seals Install
  • Emergency Roles and Responsibilities Review
  • Handover of Increment 65 Crew
  • HRF Generic MELFI Sample Retrieval and Insertion Operations
  • HRF Generic Saliva Collection 10 Minutes
  • HRF Generic Urine Collection Male
  • IMS delta file prep
  • Material Science Laboratory Procedure Review
  • Material Science Laboratory SQF Exchange
  • MSL SCA Exchange Big Picture Words Review
  • On board Training Cygnus Emergency Procedure Review
  • Phospho-Aging HRF Centrifuge Frozen Blood Collection – Operator
  • Polar Transfer to Crew Dragon (from EXPRESS Rack) Overview
  • Public Affairs Office (PAO) High Definition (HD) Config LAB Setup
  • Roll Up and Stow Sleep Bag
  • Standard Measures Cognition Testing
  • Transfer Cygnus Cargo Ops
  • Unseal MegaHEPA Filter in Crew Dragon
  • Vascular Aging 13-hour Blood Pressure Monitoring Conclude