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H-II Transfer Vehicle KOUNOTORI (HTV)

Last updated:November 9, 2016

HTV6 Mission Timeline

Flight Day Major mission events
  • Launch, Orbit Insertion
  • Post-insertion auto sequence
    • HTV subsystem activations
    • Attitude control
    • Anomaly check
    • Establishment of communication with the Tracking and Data Relay Satellite (TDRS)
    • Initiation of communication with the HTV Mission Control Room (HTV MCR) at the Tsukuba Space Center
  • Initiation of Rendezvous Maneuver
FD1 to FD6
  • Rendezvous Maneuver with the ISS
  • Proximity Operations, Final Approach
  • Capture by the Space Station Remote Manipulator System (SSRMS)
  • Berthing to the ISS
    • Berthing to the Common Berthing Mechanism (CBM) on the Harmony's Nadir Port
    • Vestibule outfitting (connection of power and communication line)
    • Activation of HTV power supply from ISS
    • Switching of the communications line (Radio wave to fixed line)
Transfer of the EP
  • Removal of the Exposed Pallet (EP) from the HTV's Unpressurized Logistics Carrier (ULC)
Hatch open
  • Crew ingress to the Pressurized Logistics Carrier (PLC)
    • Removal of the Controller Panel Assemblies (CPAs) of the CBM
    • Hatch open
    • Activation of the Inter-Module Ventilation (IMV)
Cargo transfer
  • Cargo Transfer from the PLC to the ISS
  • Transfer of the ISS battery ORUs made of Japanese lithium-ion battery cells out of the EF using SSRMS
  • Nickel hydride batteries currently used on the ISS will be replaced by the lithium-ion batteries delivered by KOUNOTORI6.

Exposed Pallet
  • Removal and transfer of nickel metal-hydride batteries using the JEMRMS to the EP for disposal
  • Reinstallation of the EP back into the HTV's ULC
argo transfer
  • Cargo transfer / Trash loading
A day before
from the ISS
Preparation for departure
  • Preparation for the HTV Unberthing Operations
    • Installation of CPA of the CBM
    • IMV de-activation
    • Hatch closure
    • Switching of the communications line (Radio wave to fixed line)
Unberthing Day
  • KOUNOTORI6 unberthing
    • Deactivation of HTV power supply from ISS
    • Disconnection of power and communication line
    • KOUNOTORI6 grapple by the SSRMS
    • CBM bolts release
    • SSRMS moves KOUNOTORI6 to the release position
    • Activation of the Guidance Navigation Control (GNC), activation of HTV propulsion system
    • SSRMS releases KOUNOTORI6
    • KOUNOTORI6 begins separation maneuvers
After unberthing
1-7 days
  • HTV6 will perform Kounotori Integrated Tether Experiment (KITE)
    • Travel to an orbit more than 20km below the ISS
    • Deployment of the KITE endmass. Extension of the tether
    • Amplitude reduction of the tether
    • Tether cutoff after the experiment
  • De-orbit Maneuver
  • Fiery Reentry

* In-flight schedule of the HTV6 mission is subject to change depending on the ISS's operational timeline.
* Photos used in the table were taken during the previous HTV missions. Some Computer Graphics (CG) images are included.

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