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H-II Transfer Vehicle KOUNOTORI (HTV)

Last updated: December 2, 2016

HTV6 Payload

The HTV6 delivers a total of 5.9 metric tons of cargo to the ISS, including 3.9 metric tons in the Pressurized Logistics Carrier (PLC) and 1.9 metric tons in the Unpressurized Logistics Carrier (ULC). The main types of cargo are described below.

*Photo credits on this page are JAXA unless otherwise noted.

Cargo in the Pressurized Logistics Carrier (PLC)

Utilization/experiment-related items

JEM Small Satellite Orbital Deployer(J-SSOD)
--Doubled its deployment capacity to open up advanced Kibo utilization

An upgraded J-SSOD with doubled deployment capacity from 6U to 12Uis delivered.

CubeSat specification: 10cm(W)×10cm(D)×10cm(H):1U; 20cm(H):2U; 30cm(H):3U

Upgraded J-SSOD

Microsatellites (CubeSats)

Seven CubeSats in total are delivered.

Missions of each CubeSat [PDF:119kb]

写真:より大きな写真へ 写真:より大きな写真へ 写真:より大きな写真へ
写真:より大きな写真へ 写真:より大きな写真へ 写真:より大きな写真へ 写真:より大きな写真へ

Seven CubeSats (photographed on November 7)

Payload for the Two Phase Flow experiment

Payload for the TPF experiment

Two Phase Flow experiment in Kibo

Thermal management systems offering high performance are indispensable for most sophisticated and larger spacecraft. Cooling methods using latent heat during boiling are considered prospective candidates for next-generation spacecraft.

An Ebullient cooling system will be demonstrated while studying its exhaust heat transfer and dependence on gravitational acceleration.

Position Sensitive Tissue Equivalent Proportional Chamber (PS-TEPC)


A compact, high-precision inboard dosimeter that enables real-time measurement is delivered for technological demonstration.

High Definition TV Camera - Exposed Facility 2 (HDTV-EF2)


This unit consists of two types of high-definition TV cameras (4K and 2K). Night photographing is possible.

System supplies

Carbon Dioxide Removal Assembly (CDRA) Orbital Replacement Unit (ORU)


At NASA’s request, the Orbital Replacement Units (ORUs) of the Carbon Dioxide Removal Assembly (CDRA) are delivered. The CDRA is one of the crucial assemblies for the life support of onboard astronauts.
Since the unit is large and has an unique shape, the loading method has been deliberated. By taking advantage of the “late accessing” function provided by KOUNOTORI and the team, CDRA ORUs are to be loaded about a week prior to launch.

Cargo for the onboard crew

Potable water

The water bags (Contingency Water Container Iodine: CWC-I) to be loaded into KOUNOTORI6

Followed by the HTV5 mission, KOUNOTORI6 also delivers 600 litters of water from Tanegashima island. This amount sustains three onboard astronauts for four months. The water will be recycled on orbit.
The annual rainfall of Tanegashima island, where the launch complex of the HTV is located, exceeds more than 2,000 mm. Local people enjoy abundant groundwater and springs, and use both water sources for their lives and agriculture.

Fresh food

Fresh food grown in Japan is delivered.

Cargo in the Unpressurized Logistics Carrier (ULC)

ISS battery Orbital Replacement Units (ORUs)

New six battery Orbital Replacement Units (ORUs) consisting of new lithium-ion battery cells manufactured by a Japanese company are delivered.
The nickel-hydrogen batteries currently used on the ISS are becoming old. The extension of ISS operations becomes possible with the supply of Japanese lithium-ion battery cells. Only the HTV is capable of delivering six battery ORUs at one time, and thus plays an important role in continuous ISS operations.
HTV’s Exposed Pallet (EP) has been renovated for the shipment of the new battery units.

EP loaded with six ISS battery ORUs


Orbital experiment hardware

KOUNOTORI6 not only delivers cargo for the ISS, but also delivers orbital experiment devices for further space development.

Kounotori Integrated Tether Experiment (KITE)
JAXA conducts on-orbit technological demonstration of the electrodynamic tether (EDT) to test its propulsion mechanism for alleviating growing concerns over space debris. The tether is extended from KOUNOTORI6 to a length of 700 meters. This pioneering test will be conducted for seven days after KOUNOTORI6's unberthing and before its reentry into the atmosphere.


See also: On-orbit demonstration of electrodynamic tether on the H-II Transfer Vehicle (HTV)

Solar Cell Film Array Sheet for Next Generation on Kounotori Six (SFINKS)


Waste disposal

The HTV undertakes the role of reentering the atomoshpere while loaded with up to 6 metric tons of waste and expired experiment devices that are no longer necessary. KOUNOTORI6 reenters the atmosphere carrying the old nickel-hydrogen batteries onboard that were removed from the ISS.

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