Japanese Kounotori 7 to deliver new batteries to International Space Station

Kounotori 7 at the Second Spacecraft Test and Assembly Building located at the Tanegashima Space Center in Japan. Photo Credit: JAXA.

The Japan Aerospace Exploration Agency (JAXA) is preparing its seventh resupply spacecraft bound for the International Space Station for a Sept. 10, 2018, liftoff. The mission, designated HTV-7, is slated to deliver more than six metric tons of cargo to the orbiting outpost, including several lithium-ion batteries to replace older units on the exterior of the complex.

HTV-7, also known as Kounotori 7 (Kounotori means white stork in Japanese), is expected to rise into orbit atop a medium-lift H-IIB rocket from Tanegashima Space Center in southern Japan. Liftoff is scheduled for 6:32 p.m. EDT (10:32 GMT / 7:32 a.m. local time Sept. 11). The spacecraft was unveiled to the public July 28, 2018, during a press briefing at the space center. Details about the mission were presented to journalists by Hirohiko Uematsu, director of HTV Technology Center at JAXA.

Kounotori 7 is transporting six lithium-ion batteries to the ISS, which are attached to the Exposed Pallet inside the Unpressurized Logistic Carrier. They will replace nickel-hydrogen batteries on the exterior of the station's truss segment. This will continue a process that was started in January 2017 with the Kounotori 6 mission. Photo Credit: JAXA

Kounotori 7 is now in the final phase of pre-launch preparations, which include the last checks of its electronics and flight control systems. A final reconfiguration of the spacecraft is expected be performed around an hour before the planned liftoff to prepare it for the automatic countdown sequence, which commences at about 4.5 minutes ahead of the launch.

After the planned liftoff, the H-IIB rocket is expected to complete a short vertical ascent before performing a pitch and roll maneuver and turning southeasterly. The flight should last about 15 minutes until the uncrewed cargo freighter is deployed into space. Separation from the launch vehicle’s second stage will start the spacecraft’s trek to the ISS, lasting approximately 3.5 days and culminating in rendezvousing with the outpost Friday, Sept. 14.

Two Expedition 56 astronauts, Drew Feustel and Serena Auñón-Chancellor of NASA, are expected to operate the station’s 57.7-foot (17.6-meter) long robotic Canadarm2 to capture the vessel at around 7:40 a.m. EDT (11:40 GMT). European Space Agency (ESA) astronaut Alexander Gerst, another member of the six-person ISS crew, will monitor Kounotori 7 and its systems during its approach to the 420-metric-ton complex. The spacecraft is expected to be installed to the Earth-facing port of the Harmony module located at the forward end of the outpost where it should remain until mid-November 2018.

The spacecraft is loaded with about 6.2 metric tons of supplies, fresh food, water, spare parts and experiments. Six new lithium-ion batteries for the ISS account for approximately 1.9 metric tons and are located inside the vehicle’s Unpressurized Logistic Carrier (ULC) while the rest, around 4.3 metric tons, is stored in the Pressurized Logistic Carrier (PLC)—the upper section of Kounotori 7.

Besides supplies for the ISS crew, the cargo in the PLC includes two EXpedite the PRocessing of Experiments for Space Station (EXPRESS) Racks, namely EXPRESS Rack 9B and 10B. These are multipurpose payload rack systems that store and support research aboard the space station and enable quick, simple integration of multiple payloads.

Also inside the PLC is ESA’s Life Support Rack (LSR), which includes equipment for a demonstration test of an “effective life support system” that produces oxygen from water using electrolysis, which involves using an electric current to separate water molecules into oxygen and hydrogen. From there, a Sabatier reaction with the hydrogen and carbon dioxide removed from the cabin is expected to create methane with water as a byproduct, which in turn can be recycled for electrolysis.

Another rack being transported is the Life Sciences Glovebox (LSG), which will be the second large-scale glovebox for scientific experiments on the ISS and is expected to be installed in the Kibo module.

An HTV Small Re-entry Capsule evaluation unit splashes down in the sea during a Nov. 16, 2017, high-altitude drop test off the east coast of Hokkaido, Japan's northernmost prefecture. Photo Credit: JAXA.

Other payloads inside this carrier include the Loop Heat Pipe Radiator (LHPR) technology demonstration system, the JEM Small Satellite Orbital Deployer (J-SSOD) and three CubeSats named SPATIUM-I, RSP-00 and STARS-Me, which were developed jointly by universities in Japan and Singapore.

Possibly one of the most important experiments that is being brought to the space station by Kounotori 7 is JAXA’s HTV Small Re-entry Capsule (HSRC). This cone-shaped container, with dimensions of 2 feet by 2.7 feet (0.61 meters by 0.82 meters), is designed to demonstrate re-entry technology and cargo recovery from the space station. After the departure of the freighter from the outpost this fall, HSRC is expected to separate from the spacecraft’s hatch for a parachute-assisted splashdown off the coast of Japan and before being recovered.

The experiments being transported inside Kounotori 7 include a new sample holder for the Electrostatic Levitation Furnace (JAXA-ELF), a protein crystal growth experiment at low temperatures (JAXA LT PCG) and an investigation that looks at the effect of microgravity on bone marrow (MARROW).

The 23,100-pound (10,500-kilogram), soda-can-shaped Kounotori 7 spacecraft is about 33 feet (10 meters) long and 14.4 feet (4.4 meters) in diameter. Built by Japan-based Mitsubishi Heavy Industries, the vessel also an Exposed Pallet (EP) inside the ULC, as well as an Avionics Module and a Propulsion Module.

To date, Japan has conducted six Kounotori missions to ISS—all of them were successful. The first, known as HTV-1, was launched nine years ago on Sept. 10, 2009, and arrived at the station one week later. After it’s mission, it was deorbited on Nov. 1, 2009. After, the Kounotori 7 mission concludes, the next mission, Kounotori 8, is scheduled for February 2019. The exact date is yet to be announced by JAXA.

The H-IIB rocket that will be used for Monday’s launch is a two-stage launch vehicle derived from the H-II rocket of the 1990s. Standing just slightly taller than both rockets in the H-II family at 183.7 feet (57 meters), it uses liquid oxygen and liquid hydrogen propellant to power its two LE-7A first stage engines and single LE-5B second stage engine. Additionally, four strap-on solid-fueled boosters are utilized for the first two minutes of flight. The rocket was designed to send Kounotori spacecraft into orbit and has been used exclusively for that purpose since its first launch in 2009 with HTV-1.

The launch of Kounotori 7 is expected to mark the fifth orbital mission for Japan in 2018. The country’s next launch is slated for Oct. 29, 2018, when an H-IIA rocket is planned to orbit several satellites, including CubeSats, for Japan and other countries.

Video courtesy of JAXA



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