Japanese Kounotori 6 set for launch to ISS
After discovering a leaking pipe during an early August pressurization test, prompting a delay, the Japan Aerospace Exploration Agency (JAXA) is ready to send its Kounotori 6, or “white stork 6”, skyward toward the International Space Station.
Liftoff of the H-IIB rocket with the cargo ship is slated for 10:26 p.m. Japan Standard Time (8:26 a.m. EST / 13:26 GMT) Dec 9, 2016, from the Tanegashima Space Center in Japan. Kounotori 6, also called HTV-6 in the U.S., will spend a week catching up to the ISS before being berthed with the outpost’s Harmony module on Dec. 13.
While the station is in a good position regarding consumables, even after the recent failure of the Russian Progress MS-04, the Japanese cargo ship will be carrying much-needed supplies and equipment to the outpost – 5.9 metric tons in total.
Inside the pressurized compartment, there will be 3.9 metric tons of cargo. This includes 600 liters of water, food, crew commodities, a Carbon Dioxide Removal Assembly, and a number of experiments.
Additionally, high-definition and 4K cameras, a new Small Satellite Orbital Deployer, along with seven CubeSats, are aboard.
In the unpressurized section of Kounotori 6 are six lithium-ion batteries and their associated adapter plates that will replace the station’s current nickel-hydrogen batteries.
Each of the new batteries is equivalent to two of the current batteries; therefore, the six lithium-ion will replace 12 nickel-hydrogen batteries out of the 48 in total on the outpost.
Two astronauts are scheduled to go out on two, possibly three, spacewalks in January in order to replace the batteries. Nine of the 12 old ones will be stowed in the unpressurized section of Kounotori 6 to be disposed of upon the destructive re-entry of the craft. The other three replaced batteries will remain on the space station.
The cargo craft itself will also have a number of changes compared with the previous Kounotori. The number of primary batteries on the spacecraft has been reduced from seven to six. Solar cell panels have been reduced to 48 from the previous total of 49. Additionally, some navigation and position lights have been omitted, specifically the Earth-side lights during the ISS approach.
The Exposed Pallet, inside the unpressurized section, has been strengthened to hold 1.9 metric tons, from the previous 1.6 metric tons, to carry the lithium-ion batteries.
There are also two built-in technology demonstration payloads: SFINKS and KITE. SFINKS stands for Solar Cell Film Array Sheet for Next Generation on Kounotori Six. This will test thin film solar cells in space.
KITE stands for Kounotori Integrated Tether Experiment. After the spacecraft departs from the ISS, it will test an experimental 700-meter electrodynamic tether with a 20-kilogram end-mass.
A maximum of 10 milliamps will run through this tether as Kounotori’s ISS rendezvous sensor measures how the end-mass moves during the test. The experiment will run for about a week, after which the tether will be separated to prepare for the spacecraft’s de-orbit maneuvers.
The goal of KITE is to demonstrate both the extending of an uncoated bare-tether and how it generates electrical current. Both technologies could someday be used to help remove space debris.
The Kounotori spacecraft and H-IIB rocket were built by Mitsubishi Heavy Industries in Japan.
The H-IIB itself was designed specifically to send Kounotori spacecraft to the space station. This two-stage rocket has flown five times since its inaugural launch in 2009. The Dec. 9 launch will be the sixth. The next spacecraft, Kounotori 7, is scheduled to launch in February 2018.
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a blog about the International Space Station, called Orbital Velocity.