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H-II Transfer Vehicle

The HTV is an unmanned cargo spacecraft which is used to deliver supplies to the International Space Station. A unique feature of the HTV is that it carries both pressurized and unpressurized cargo.

The first launch of the HTV, called a "Technical Demonstration Vehicle", took place on 10 September 2009. Re-entry and planned disintegration occurred 1 November 2009.
HTV-2, called "Kounotori" 2 gouki ("White Stork" Unit 2), was launched 22 January 2011. Re-entry and planned disintegration took place 30 March 2011.
HTV-3 (Kounotori 3) was launched 21 July 2012.
HTV-4 (Kounotori 4) was launched 3 August 2013.
HTV-5 (Kounotori 5) was launched 19 August 2015.
HTV-6 was launched 9 December 2016.
HTV-7 was launched 22 September 2018.
HTV-8 was launched 24 September 2019.
HTV-9 was launched 20 May 2020.

There are four modules making up the HTV.

  • The Propulsion Module has fuel tanks and is equipped with 32 thrusters for orbital control.
  • The Avionics Module has the electronics needed for power, communication, and navigation.
  • The Unpressurized Logistics Carrier carries the Exposed Pallet. The Exposed Pallet in turn will carry the unpressurized cargo. This can be payloads for Kibo's Exposed Facility, or ISS battery Orbital Replacement Units.
  • The Pressurized Logistics Carrier is used for supplies used on board the space station. The station crew can move back and forth between the station and the pressurized module.

Credit: JAXA

The HTV is launched with an H-IIB rocket. After launch, it is controlled from the ground for about 3 days as it makes its approach to the ISS. Once it is within range of the ISS (about 23 km), control shifts to the ISS. Once the HTV has closed to about 10 meters of the ISS, its thrusters are shut down and the HTV is grappled by the station's Canadarm2 and berthed to the Harmony Node 2.

While docked with the ISS, hatches are opened to allow free access to the pressurized module. The Canadarm2 is used to unload the unpressurized module. After all supplies have been unloaded from the HTV, it will be loaded with waste from the space station. It is then undocked and deorbited over the South Pacific where it will be destroyed upon reentry to the atmosphere.

Credit: JAXA
Credit: JAXA
Artistic representation of
HTV approaching the ISS
Artistic representation of
the HTV being unloaded

The H-IIB, is an upgraded version of the H-IIA launch vehicle currently in use by Japan.

Credit: JAXA
Credit: JAXA
H-IIA on the launch pad H-IIB concept drawing


HTV Launches

CraftLaunch DateLaunch TimeInitial Dock DateInital Dock TimeFinal Undock DateFinal Undock TimeReentry DateReentry TimeStationNotes
HTV-110 September 200917:01:4617 September 200922:12:0030 October 200915:02:001 November 200921:48:00ISSCaptured and berthed by ISS robot arm
HTV-222 January 201105:37:5727 January 201114:51:0028 March 201113:43:0030 March 201103:40:00ISSCaptured and berthed by ISS robot arm
HTV-321 July 201202:06:1827 July 201214:34:0011 September 201211:50:0014 September 201205:27:00ISSCaptured and berthed by ISS robot arm
HTV-43 August 201319:48:469 August 201315:39:004 September 201312:08:007 September 201306:37:00ISSCaptured and berthed by ISS robot arm
HTV-519 August 201511:50:4924 August 201517:28:0028 September 201511:53:0028 September 201520:33:00ISSCaptured and berthed by ISS robot arm
HTV-69 December 201613:26:4713 December 201613:57:0027 January 201711:00:004 February 201715:06:00ISSCaptured and berthed by ISS robot arm
HTV-722 September 201817:52:2727 September 201812:00:006 November 201823:32:0010 November 201822:06:00ISSCaptured and berthed by ISS robot arm
HTV-824 September 201916:05:0528 September 201914:09:001 November 201913:45:003 November 201902:09:00ISSCaptured and berthed by ISS robot arm
HTV-920 May 202017:31:0025 May 202014:46:0019 August 202013:51:0020 August 202007:07:00ISSCaptured and berthed by ISS robot arm


Page last modified: 09 April 2022 16:20:26.