An artist's interpretation of Japan's H-2 Transfer Vehicle arriving at the International Space Station.
Japan's first unmanned cargo ship is on track to arrive Thursday at the International Space Station (ISS) to deliver precious supplies and science experiments.
The H-2 Transfer Vehicle (HTV-1), which launched Sept. 10, is doing well and has been performing nominally so far, said Matsuo Naoko, spokesperson for the Japanese Aerospace Exploration Agency (JAXA).
"We conducted demonstration tests on last Saturday, Sept. 12," Matsuo told SPACE.com. "It did very well, so the mission management team will review the data of demonstration tests and they will decide whether we will 'go' or 'not go' to the space station."
The official go-ahead is expected in the next couple of days.
Once HTV-1 arrives at the ISS, it must be grabbed by astronauts controlling the station's robotic arm. The cylindrical freighter is due to stay at the orbital outpost for about 40 to 45 days, and then be let go to burn up in the Earth's atmosphere during re-entry.
The new spacecraft is about 33 feet (10 meters) long and 14 feet (4.4 meters) wide. This ship cost about $220 million, though JAXA has spent a total of about $680 million overall on its development since 1997.
Among the 3.5 tons carried by the cargo ship are science experiments to go in the station's Japanese Kibo laboratory, which contains an outdoor exposed facility as well as indoor pressurized compartments. The HTV craft is unique in its ability to transport items meant for both inside and outside environments.
"We have two big exposed facility payloads," Matsuo said. "One is a NASA payload and one is a JAXA payload. And in the pressurized section many crew items, food and clothes are packed."
The success of this ship is especially important given the expected retirement of the space shuttle fleet in the next year or two. After that, the HTV will join Europe's Automated Transfer Vehicles and the Russian Progress spacecraft as the main sources of cargo transport to the ISS.
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