HTV Pressurized Logistics Carrier (PLC)
About 3.9 metric tons of cargo will be loaded in the PLC. Each supply is packed in the Cargo Transfer Bags (CTBs) respectively, and the bags are stored in the HTV Re-supply Racks (HRRs) or strapped to the surface of HRRs. The main cargo includes the following:
- Experiment samples to be conducted on the Japanese Experiment Module "Kibo"
- Experiment equipments and system supplies
- Freezer-Refrigerator of Stirling Cycle (FROST)
- ISS Cryogenic Experiment Storage Box (ICE Box)
- Re-entry Data Recorder (i-Ball)
- Small satellites (CubeSats)
- 4K resolution camera
- Supplies for Kibo and NASA
A Stirling cooler that is able to keep under -70 deg C. New domestic refrigerants have been developed to keep cold even in a case of power outage.
A cool box made to keep the container cool without the electrical power during a flight to the ISS.
i-Ball aims to obtain various data of a spacecraft's re-entry into atmosphere on its return from space, such as its location, velocity, acceleration, temperature, and image data. It relayed its data during the fiery reentry of HTV3. This is the second time to carry an i-Ball.
4 CubeSats will be delivered to release them from Kibo, taking advantage of Kibo's airlock and robotic arm.
- Food (retort pouches, dried food, snacks, beverages), drinking water
This is the second time for HTV to deliver the drinking water. This time, the HTV4 increased the amount and delivers 480 liters of water.
- Commodities and clothes for astronauts
HTV Unpressurized Logistics Carrier (ULC)
The HTV Unpressurized Logistics Carrier (ULC) carries 1.5 metric tons of ORUs and experiment payload to be installed on the exposed area.
- Main Bus Switching Unit (MBSU)
- Utility Transfer Assembly (UTA)
- NASA's payload Space Test Program - Houston 4 (STP-H4)
Four MBSUs are placed on the S0 truss. The MBSU is an important hardware that distributes electronic loads to each system on the ISS. Astronauts Akihiko Hoshide and Sunita Williams exchanged one of the MBSUs during EVA between August to September in 2012.
The UTA is one of the Orbital Replacement Units (ORUs) that is placed on the Solar Array Rotary Joint (SARJ) and provides power and data interface to the P3-P4 and S3-S4 trusses.
Loading trash on the ULC
In addition to trash on the ISS, HTV4 will re-entry into the atmosphere loading U.S. experiment hardware STP-H3 (no longer necessary) on the ULC, which is the first time for HTV to use the ULC for disposal.