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H-II Transfer Vehicle KOUNOTORI (HTV)

HTV4 mission logo

HTV4 mission logo


The H-II Transfer Vehicle (HTV) "KOUNOTORI (white stork)," developed in Japan, is an unmanned cargo transfer spacecraft that delivers supplies to the International Space Station (ISS). The initial HTV1 (Technical Demonstration Vehicle) was launched on September 11, 2009. Afterward HTV has made continuous launches every year to a year and a half. KOUNOTORI4 was launched at 4:48 a.m., on Sunday, August 4, 2013.


Summary of the ISS Cryogenic Experiment Storage Box (ICE Box) demonstration results

Summary of the ISS Cryogenic Experiment Storage Box (ICE Box) demonstration results (March 7, 2014)

ISS Cryogenic Experiment Storage Box (ICE Box) was developed in Japan and carried aboard the HII Transfer Vehicle KOUNOTORI4 (HTV4) on August 4, 2013.

≫ HTV4 Mission News

*For more information about the final countdown status of H-IIB Flight No.4, please refer to the Mitsubishi Heavy Industries, Ltd. web site. :


Promotion Movie


FROST (credit: JAXA)


The HTV4 delivers about 5.4 metric tons of supplies to the ISS, including newly developed Freezer-Refrigerator of Stirling Cycle (FROST) and experiment samples to be conducted on the Japanese Experiment Module "Kibo." In addition, HTV delivers unpressurized Orbital Replacement Units (ORUs) the Unpressurized Logistics Carrier (ULC), which is one of the features of HTV, thus contributing to the maintenance and operation of the ISS.

≫Go to "Payload" detailed page

Features of HTV4


Advanced Technology On-orbit Test Instrument for space Environment - mini(ATOTIE-mini)

HTV development was completed in the HTV3, which was launched in 2012, as the domestic production of major components was sufficiently advanced. Through the process of manufacturing HTV in Japan, technology which is imperative for inter-orbit transportation, cost reduction, and stable procurement become possible. Henceforth, basic design of the HTV4-7 is same with the HTV3. The differences are described in the detailed page.

≫Go to "Feature" detailed page

Flight Schedule

HTV4 Mission Summary (Updated September 7, 2013)
All times are Japan Standard Time (JST)
Item Details and Plans
Launch Time 4:48:46 a.m., August 4, 2013
Launch Site Launch Pad2 (LP2), Tanegashima Space Center (TNSC)
HTV4 Capture 8:22 p.m., August 9, 2013
Berthing to the ISS 3:38 a.m., August 10, 2103
Separation from the ISS 1:20 a.m., September 5, 2013
3:37 p.m., September 7, 2013
Altitude Insertion Orbit: 200 km x 300 km (elliptical orbit)
Rendezvous: Approx. 410km
Inclination 51.6 degrees

*All times are Japan Standard Time (JST)

≫Go to "Mission Timeline" detailed page

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