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HTV-9 (H-II Transfer Vehicle-9) Mission / Kounotori-9

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Developed and built in Japan, the HTV-9, known as Kounotori-9 (meaning 'white stork' in Japanese) is an unmanned cargo transfer spacecraft that delivers supplies to the International Space Station (ISS). "Kounotori" provides very basic support for ISS operations by delivering up to six tons of cargo and has the world's largest transportation capacity. It also has the unique function of carrying multiple numbers of large-size experimental instruments on one flight. 1) 2)


Figure 1: Illustration of the HTV-9/Kounotori-9 vehicle in flight with a payload mass of 6200 kg and a size of 9.8 m long by 4.4 m in diameter (image credit: JAXA)

Launch: The ISS logistics flight HTV-9 was launched on 20 May 2020 (17:31 UTC, corresponding to 21 May at 02:31 JST) on the MHI (Mitsubishi Heavy Industries) vehicle H-IIB from the Tanegashima Space Center, LA-Y2, Japan. 3) 4)


Figure 2: A 56.6 m H-IIB rocket fires with the HTV-9 payload into the sky from Tanegashima Space Center, Japan (image credit: JAXA)

Orbit: Near circular orbit, altitude of ~ 400 km, inclination = 51.6º.

This is also the final flight of this class of resupply spacecraft, named “Kounotori” – the Japanese word for white stork. The cargo craft launched on its maiden mission to the orbiting laboratory in September 2009. JAXA is developing a new class of HTV vehicles that will provide a reusable pressurized cargo section and the ability to carry more cargo due to its lighter weight. The new HTV-X vehicles will dock automatically to the station’s International Docking Adapters with the first flight scheduled in 2022.

The H-IIB and the less powerful H-IIA rocket will be replaced by a new, less expensive Japanese launcher named the H3, which will launch the HTV-X missions. MHI and JAXA (Japan Aerospace Exploration Agency) are jointly developing the H3 rocket, which could be ready for an inaugural test flight before the end of 2020.

Arrival of the HTV-9 vehicle at the ISS is scheduled for 25 May. Controlled by station commander Chris Cassidy, the Canadian-built robotic arm (Canadarm2) will capture the Japanese cargo freighter.

The HTV-9 Payload

HTV-9 delivers a total of 6.2 metric tons (in the Pressurized Logistics Carrier (PLC) 4.3 metric tons and in the Unpressurized Logistics Carrier (ULC) 1.9 metric tons) supplies to the ISS. Major supply goods to be delivered on board are as follows: 5)

iSIM (integrated Standard Imager for Microsatellites). iSIM-170 is a new generation high-resolution optical binocular telescope developed by Satlantis Microsats S.L. of Leioa (Bilbao), Spain. The objective of this experiment is to demonstrate the technology, and its functionality, in the low-Earth orbit environment. Once on the ISS, iSIM-170 will be installed on the i-SEEP (Small Exposed Experiment Platform) , an external facility of the Japanese “Kibo” module and start its operations. iSIM-170 has a mass of <15 kg providing imagery of < 1 m spatial resolution. 6)


Figure 3: Preflight side view of the iSIM-IOD flight unit (image credit: Satlantis)

Confocal Space Microscope: This is a JAXA facility that enables fluorescence live imaging of biological samples aboard the station. Confocal microscopy eliminates out-of-focus light or glare in specimens whose thickness is greater than the immediate plane of focus. The microscope can produce data on the fundamental nature of cellular and tissue structure and functions in real-time. When combined with the heating chamber system, the microscope enables long term 3D observation of living cells. While biological experiments are the first area of concentration, the microscope could be used for chemical studies as well.


Figure 4: Photo of the Confocal Space Microscope being prepared for flight (image credit: JAXA)

SCEM (Solid Combustion Experiment Module). SCEM is a device to be used for the FLARE project (Flammability Limits at Reduced Gravity Experiment). This project will be implemented to scientifically determine the role of gravity in different modes of combustion such as ignition of solid materials and spreading of flames on various solid materials in the ISS's environment without natural convection (microgravity environment). 7)


Figure 5: Photo of SCEM (image credit: JAXA)

Materials related to space media business (for private purposes)

The basic components of the studio constructed for demonstration are a window of the Japanese Experiment Module "Kibo" facing the Earth (main view) and nearby tablet terminals. Technical demonstration tests will be conducted of the world unprecedented face-to-face two-way live streaming system, using a new dedicated ISS/Earth data communication protocol and a newly developed two-way communication application that can be activated in a short time. Demonstration tests in view of commercialization will also be conducted. These tests will be supported by some of the devices available on "Kibo." The HTV9 (KOUNOTORI9) will transport materials including an ND filter (used for adjusting the luminance between images on the tablet screen and the Earth image seen through the window), cables and fixing devices, which are indispensable for opening the Kibo Space Broadcasting Station as a space media business and exploitable for various future projects. Reference:


Figure 6: Live illustration of the ISS/KIBO position (image credit: JAXA)

The HTV-9 will also deliver fresh food and water to the ISS crew.

ISS battery ORUs (Orbital Replacement Units): Following HTV-6, HTV-7, and HTV-8, HTV-9 delivers new lithium-ion batteries for the ISS. The batteries are delivered on the Exposed Pallet (EP), placed on the Unpressurized Logistic Carrier (ULC).

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.

Later on, the old nickel-hydrogen batteries replaced by the new lithium-ion units will be loaded into the HTV’s external cargo pallet and disposed during the cargo ship’s destructive re-entry at the end of its mission.


Figure 7: Photo of the six new ORUs. These are lithium-ion batteries manufactured by a Japanese company. They will be mounted on an EP (Exposed Pallet) on JAXA/KIBO (image credit: JAXA)

EDR-2 (European Drawer Rack) is destined for the European Columbus laboratory and will provide even greater opportunities for science in space. As the ISS enters its 20th year of operations, EDR-2 is part of a comprehensive upgrade of Columbus to offer faster, easier and more flexible access to researchers on Earth. The rack was developed by an industrial team led by Thales Alenia Space Italy, based in Turin, Italy. 8)

The EDR-2 facility offers room to run experiments by supplying power, data communication, cooling, nitrogen and venting waste gasses.

The standard-sized racks that fit in all Space Station laboratories are the size of large fridges, and fly in the Japanese HTV to the International Space Station. Once on board they become easier to manipulate for the astronauts in weightlessness.


Figure 8: Photo of EDR-2 (image credit: ESA)

The first three experiments planned for installation in EDR-2 include a metal 3D printer, an instrument investigating granular materials and a facility looking into heat transfer.

The VIP-GRAN experiment will investigate how particles behave in microgravity to understand the underlying physics in detail. This involves looking at how particles jam together as they flow through small openings.

The Heat Transfer Host will continue ESA’s investigations into convection – how heat is transferred through air and liquids. Investigating the process in space allows researchers to look at the core mechanics without gravity getting in the way. This should improve future satellite cooling systems as well as confirm or fine-tune computer models that can be applied on Earth to improve cooling for electronics such as smartphones and computers.

These experiments are the first in a long line planned for the new facility.

More than double: The EDR-2 will not replace the original European Drawer Rack but run in parallel, increasing the possibilities of research and technology demonstration in space. EDR-2 will benefit from other Columbus upgrades to modernize data management and improve data-rates for scientists operating their experiments from laboratories on Earth.

The EDR-2 and most of its experiments will be operated from CADMOS, the French User Support Operations Centre located in Toulouse, France. A full-scale Engineering Model of EDR-2 is available at CADMOS to test instruments and prepare experiment operations, as well as run control versions of experiments on Earth.

NASA EXPRESS Racks: When the Japanese HTV-9 Kounotori cargo ship lifts off to deliver supplies and science equipment to the International Space Station, a landmark chapter in the station’s story will draw to a close — and a new chapter, helping to chart a course for Artemis-generation voyages into the solar system, will begin. 9)


Figure 9: Boeing engineers conduct checkout testing of NASA Basic EXPRESS Racks, the last of which will be delivered to the International Space Station in May aboard the Japanese HTV-9 resupply flight. The racks, developed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, have been integral to station science for 20 years — yielding a combined 85 years of rack operations. The 11th and final rack is expected to be in place and operational in fall 2020 (image credit: NASA/MSFC/Emmett Given)

EXPRESS Racks are a permanent fixtures on the station support a variety of research experiments — providing power, protective storage, cooling and heating, command and data communications and easy transport for up to 10 small payloads each.

“Since our earliest ventures into space, we’ve sought more efficient, longer-term ways to conduct cutting-edge science in low-Earth orbit and beyond," said Bobby Watkins, manager of the Human Exploration Development and Operations Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “The EXPRESS Racks have been a cornerstone of science on the space station, and a vital part of our mission to make space exploration safer and more comfortable for our crews, and also reap untold scientific benefits back home on Earth.”

Marshall oversees space station hardware development and implementation for NASA, and NASA personnel in Marshall’s Payload Operations Integration Center monitor experiments continuously, every day of the year. At any given time, up to 80 experiments can be in process, controlled by station crew members or from the ground. The racks operate at near capacity around the clock, and data compiled by Glasgow and his team reveals a staggering fact: Since installation and startup of the first space station rack in 2001, NASA has logged more than 85 total years of combined rack operational hours using these facilities.

“The sheer volume of science that’s been conducted using the racks up til now is just overwhelming,” said Shaun Glasgow, project manager for the EXPRESS Racks at Marshall. “And as we prepare to return human explorers to the Moon and journey on to Mars, it’s even more exciting to consider all the scientific investigations still to come.”

Once the new rack is installed, 11 total racks will be on the station — the eight original EXPRESS Racks and three Basic EXPRESS Racks, more streamlined and versatile modern versions. Each is about the size of a refrigerator and comes equipped with up to eight configurable lockers and two drawers to house payloads. Experiments can be conducted, removed independently and returned to Earth, depending on varying time requirements.

The new racks, developed at Marshall and built by Boeing in Huntsville, are called Basic Express Racks. These racks have been simplified to include only the most commonly required resources and feature more common connectors such as a standard Ethernet cable.

1) ”Launch Schedule of the H-II Transfer Vehicle KOUNOTORI9,” JAXA Press Release, 24 March 2020, URL:

2) Erin Winick, ”JAXA HTV-9 Spacecraft Carries Science, Technology to the International Space Station,” NASA, 12 May 2020, URL:

3) ”Launch Result of the H-II Transfer Vehicle Kounotori9 aboard the H-IIB Vehicle No. 9,” Mitsubishi Heavy Industries, 21 May 2020, URL:

4) Stephen Clark, ”Final H-2B rocket launch sends Japanese supply ship toward space station,” Spaceflight Now, 20 May 2020, URL:

5) ”HTV9 Payload,” JAXA, 14 May 2020, URL:

6) ”Disruptive microsatellite imager captures images of less than a meter resolution,” CORDIS, 30 June 2019, URL:

7) Osamu Fujita,Fundamental Research on International Standard of Fire Safety in Space
-base for safety of future manned mission (FLARE)

8) ”New European Drawer Rack set for Space Station,” ESA Science & Exploration, 18 May 2020, URL:

9) Janet Anderson, Lee Mohon, ”Last of NASA’s Vital, Versatile Science ‘EXPRESS Racks’ Heads to Space Station,” NASA/MSFC, 18 May 2020, URL:

The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (

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