, also known as HTV-7 was the seventh flight of the H-II Transfer Vehicle (HTV), an uncrewed cargo spacecraft launched on 22 September 2018 to resupply the

International Space Station The International Space Station (ISS) is the largest Modular design, modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos ( ...

Spacecraft specification

Major changes from previous Kounotori include: * Inclusion of HTV Small Re-entry Capsule (HSRC), described below. * Reduction of primary batteries to five units, down from six of

Kounotori 6 , also known as HTV-6, was the sixth flight of the H-II Transfer Vehicle, an uncrewed cargo spacecraft launched to resupply the International Space Station. It was launched at 13:26:47 UTC on 9 December 2016 aboard H-IIB launch vehicle from Ta ...

, seven of

Kounotori 2 Kounotori 2 (こうのとり2号機, "white stork" ), also known as HTV-2, was launched in January 2011 and was the second flight of the Japanese H-II Transfer Vehicle to resupply the International Space Station (ISS). It was launched by the ...

through Kounotori 5. * Replacement of Hardware Control Panel (HCP) by Portable Computer System (PCS). HCP was a dedicated control command box which allowed ISS crew to send control commands to Kounotori. For Kounotori 7, this is to be replaced by a portable (laptop) computer. To enable HSRC retrieval, the destructive re-entry of Kounotori 7 and the splashdown of HSRC is planned to take place in the northwestern Pacific Ocean near

Minami-Tori-shima , also known as Marcus Island, is an isolated Japanese coral atoll in the northwestern Pacific Ocean, located some southeast of Tokyo and east of the closest Japanese island, South Iwo Jima of the Ogasawara Islands, and nearly on a straight li ...

(Marcus Island), east of

Bonin Islands The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic rea ...

and

Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI; ch, Sankattan Siha Na Islas Mariånas; cal, Commonwealth Téél Falúw kka Efáng llól Marianas), is an unincorporated territory and commonw ...

, instead of the

southern Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

used by the previous missions.

Reentry capsule

Along with resupplying the ISS, this Kounotori flight tested the HTV Small Re-entry Capsule (HSRC), a

reentry capsule A reentry capsule is the portion of a space capsule which returns to Earth following a spaceflight. The shape is determined partly by aerodynamics; a capsule is aerodynamically stable falling blunt end first, which allows only the blunt end to re ...

similar in function to the

VBK-Raduga The VBK-Raduga capsule was a reentry capsule that was used for returning materials to Earth's surface from the space station '' Mir''. They were brought to ''Mir'' in the Progress-M cargo craft's dry cargo compartment. For return, the capsule wo ...

carried on board

Progress Progress is the movement towards a refined, improved, or otherwise desired state. In the context of progressivism, it refers to the proposition that advancements in technology, science, and social organization have resulted, and by extension w ...

flights to the

Mir ''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to&n ...

space station A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station ...

. Essentially a miniaturized HTV-R capsule, it was carried in the pressurized section of the vehicle. After departing from the station, ground control will remotely command Kounotori to release the capsule at an altitude of . The capsule incorporates

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

cold gas

reaction control system A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control and translation. Alternatively, reaction wheels are used for attitude control. Use of diverted engine thrust to provide stable attitude con ...

with

3D printed 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...

nozzles, and autonomously performs attitude control to mitigate shock during descent. Splash-landing off the coast of the

Ogasawara Islands The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic read ...

, the capsule will be retrieved by ship. It was then airlifted to Ibaraki Airport via

, from where the samples was delivered to researchers. The capsule can contain a total of 20 kg of material (5 kg if the payload requires refrigeration). The capsule has a diameter of 84 cm, a height of 66 cm, and a mass of less than 180 kg. Tiger Corporation developed the capsule's double vacuum insulated container by applying technology used in

vacuum flask A vacuum flask (also known as a Dewar flask, Dewar bottle or thermos) is an insulating storage vessel that greatly lengthens the time over which its contents remain hotter or cooler than the flask's surroundings. Invented by Sir James Dewa ...

s. Some samples produced in the

microgravity The term micro-g environment (also μg, often referred to by the term microgravity) is more or less synonymous with the terms '' weightlessness'' and ''zero-g'', but emphasising that g-forces are never exactly zero—just very small (on the ...

environment of the ISS deteriorate easily, thus a quick return to the surface is desired. For this demonstration flight, samples including ISS-manufactured protein crystals are planned to be placed inside. On 22 October 2015, a high-altitude drop test of the capsule was successfully conducted off the coast of Taiki, Hokkaido. A second test was conducted on 21 September 2016, with conditions and parameters closer to the actual capsule than the previous year's test. The third and fourth drop tests were done in July and November 2017, respectively.

Cargo

Kounotori 7 carries about 6200 kg of cargo, consisting of 4300 kg in the pressurized compartment and 1900 kg in the unpressurized compartment. Cargo in the pressurized compartment (PLC) include: * NASA EXPRESS Rack 9B and 10B * NASA Life Sciences Glovebox (LSG) * ESA Life Support Rack (LSR) * JAXA HTV Small Re-entry Capsule (HSRC), and a specifically designed hatch of the pressurized compartment to mount the HSRC on departure from ISS. * JAXA experiment Loop Heat Pipe Radiator (LHPR) *

CubeSat A CubeSat is a class of miniaturized satellite based around a form factor consisting of cubes. CubeSats have a mass of no more than per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats ...

s to be deployed into orbit from ISS: SPATIUM-I, RSP-00, STARS-Me In the Unpressurized Logistic Carrier (ULC), Kounotori 7 carries 6 lithium-ion batteries Orbital Replacement Units (ORUs) for replacing the ISS's existing nickel-hydrogen batteries. The transportation of replacement batteries is a continuation from the previous

, and will continue through to

Kounotori 9 , also known as HTV-9 was the 9th flight of the H-II Transfer Vehicle, a robotic cargo spacecraft to resupply the International Space Station (ISS). It was launched on 20 May 2020, at 17:31:00 UTC. Kounotori 9 is the last HTV of the original ...

Operation

Launch and rendezvous with ISS

Initially Kounotori 7 was scheduled to launch at 22:32 UTC on 10 September 2018, but was postponed due to bad weather forecast at a ground tracking station. It was rescheduled to 13 September 2918 at 21:20 UTC, but adverse weather forecast at the launch site pushed one day further to 14 September at 20:59:14 UTC. During the preflight check, a problem was found in the blowoff valve of the launch vehicle second stage oxygen tank, and the launch was scrubbed. After the problem was resolved, the launch was rescheduled to 21 September 2018 at 18:15 UTC. Bad weather forecast pushed it one day to 17:52 UTC on 22 September 2018. The H-IIB launch vehicle carrying Kounotori 7 launched at 17:52:27 UTC on 22 September 2018. It arrived at the proximity of

on 27 September 2018, and the station's

Space Station Remote Manipulator System The Mobile Servicing System (MSS), is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, supp ...

(SSRMS) grappled it at 11:36 UTC.

Operation while berthed to ISS

Exposed Pallet (EP), which carries the replacement batteries for ISS, was extracted from Kounotori's Unpressurized Logistics Carrier (ULC) by the

SSRMS The Mobile Servicing System (MSS), is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, su ...

(Canadarm2) and transferred to the

Mobile Base System The Mobile Servicing System (MSS), is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, supp ...

(MBS) Payload/Orbital Replacement Unit Accommodations (POA) on 28 September 2018. Due to the launch failure of

Soyuz MS-10 Soyuz MS-10 was a crewed Soyuz MS spaceflight that aborted shortly after launch on 11 October 2018 due to a failure of the Soyuz-FG launch vehicle boosters. MS-10 was the 139th flight of a Soyuz spacecraft. It was intended to transport two me ...

, planned

extravehicular activity Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA inc ...

to replace the batteries of ISS could not be performed while the Kounotori 7 was berthed to ISS. The Exposed Pallet will remain at the ISS after departure of Kounotori 7.

Departure from ISS and reentry to the Earth atmosphere

Kounotori 7 was demated from

Common Berthing Mechanism The Common Mechanism (CBM) connects habitable elements in the US Orbital Segment (USOS) of the International Space Station (ISS). The CBM has two distinct sides that, once mated, form a cylindrical vestibule between modules. The vestibule is ...

(CBM) of Harmony module by

at 23:32 UTC on 6 November 2018, and it was released into orbit on 7 November 2018, 16:50 UTC. After a series of trajectory control manoeuvres, the final deorbit burn completed at 21:14 UTC, on 10 November 2018. Separation of HTV Small Re-entry Capsule (HSRC) from Kounotori 7 was confirmed at 21:24 UTC. Estimated time of the reentry to

Earth atmosphere The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

(at 120 km altitude) of Kounotori 7 was 21:38 UTC, and the

splashdown Splashdown is the method of landing a spacecraft by parachute in a body of water. It was used by crewed American space capsules prior to the Space Shuttle program, by SpaceX Dragon and Dragon 2 capsules and by NASA's Orion Multipurpose Crew ...

of residual debris at 21:48 - 22:12 UTC. Splashdown of HSRC was confirmed at 22:06 UTC, and it was retrieved by the recovery ship at 02:25, on 11 November 2018. The ship arrived at

Minami-Tori-Shima , also known as Marcus Island, is an isolated Japanese coral atoll in the northwestern Pacific Ocean, located some southeast of Tokyo and east of the closest Japanese island, South Iwo Jima of the Ogasawara Islands, and nearly on a straight li ...

on 19:50 UTC, on 12 November 2018. The retrieved specimen was transported by aircraft to Ibaraki Airport, and finally arrived at Tsukuba Space Center on 13 November 2018, at 00:42 UTC.

References

External links

HTV7 Mission
(JAXA) * {{DEFAULTSORT:Kounotori 7 H-II Transfer Vehicles 2018 in Japan Spacecraft launched in 2018 Supply vehicles for the International Space Station