New cargo racks developed for HTV-X which allows 30% more Cargo Transfer Bags to be carried in the Pressurized Logistics Carrier.
Cargo
Kounotori 8 carries about 5300 kg of cargo, consisting of 3400 kg in the pressurized compartment and 1900 kg in the unpressurized compartment. Cargo in the Pressurized Logistics Carrier include:
JAXA experiment Cell Biology Experiment Facility - Left
JAXA experiment Sony Optical Link for ISS, a satellite optical communication demonstration co-developed with
JAXA experiment Hourglass, which will investigate the behavior of soil and rock particles under low gravity conditions
The H-IIB launch vehicle carrying Kounotori 8 was initially scheduled to be launched at 21:33:29 UTC, 10 September 2019. During launch preparation, a fire broke out at the launch pad at around 18:05 UTC, and the launch was called off. The cause of fire was attributed to the static electricity on the heat resistant material under the mixture of liquid oxygen and gas oxygen for the engine pre-cooling. After the modification to the mobile launch platform to suppress static electricity, a new launch was scheduled at 23 September 2019, 16:30 UTC, but the collision avoidance check revealed that the 2nd stage of the launch vehicle might approach near the Soyuz MS-15 which was scheduled to be launched on 25 September. A revised launch schedule was set for 16:05 UTC, 24 September 2019. On 24 September 2019, 16:05:05 UTC, the Kounotori 8 aboard H-IIB was launched successfully.
Operation while berthed to the ISS
Kounotori 8 was captured by the Space Station Remote Manipulator System at 23:13, 27 September 2019, and berthed at Harmony's nadirCommon Berthing Mechanism by 17:55, 28 September 2019. The External Palette, which carries the lithium ion battery Orbital Replacement Units, was extracted from the Kounotori 8's Unpressurized Logistics Carrier by the SSRMS on 29 September 2019. The External Palette of Kounotori 7 was placed in the Kounotori 8's ULC.. EP7 was left on the ISS after the departure of Kounotori 7 due to the schedule change of extravehicular activity after the launch failure of Soyuz MS-10.
On 1 November 2019, Kounotori 8 was detached from Harmony's CBM by the SSRMS, and it was released into orbit at 17:20 UTC. It was disposed by the destructive reentry to the Earth atmosphere at around 02:09 UTC, on 3 November 2019.