The H-II Transfer Vehicle (HTV), also called , is an expendable, automated cargo spacecraft used to resupply the Kibō Japanese Experiment Module (JEM) and the International Space Station (ISS). The Japan Aerospace Exploration Agency (JAXA) has been working on the design since the early 1990s. The first mission, HTV-1, was originally intended to be launched in 2001. It launched at 17:01 UTC on 10 September 2009 on an H-IIB launch vehicle. The name Kounotori was chosen for the HTV by JAXA because "a white stork carries an image of conveying an important thing (a baby, happiness, and other joyful things), therefore, it precisely expresses the HTV's mission to transport essential materials to the ISS". The HTV is very important for resupplying the ISS because after the retirement of the Space Shuttle it is the only vehicle that can transfer new 41.3 in (105 cm) wide International Standard Payload Racks (ISPRs) and dispose old ISPRs that can fit the 51 in (130 cm) wide tunnels between modules in the US Orbital Segment. Design The HTV is about long (including maneuvering thrusters at one end) and in diameter. Total mass when empty is , with a maximum total payload of , for a maximum launch weight of . The HTV is comparable in function to the Russian Progress, ESA ATV, commercial Cargo Dragon 1, and Cargo Dragon 2 of SpaceX. Plus the Cygnus spacecraft, all of which bring supplies to the ISS. Like the ATV, the HTV carries more than twice the payload of the Progress, but is launched less than half as often. Unlike Progress spacecraft, Cargo Dragon 2's and ATV's which use the docking ports automatically, HTVs and American Dragon 1 approach the ISS in stages, and once they reach their closest parking orbit to the ISS, crew grapple them using the robotic arm Canadarm2 and berth them to an open berthing port on the Harmony module. The HTV has an external payload bay which is accessed by the robotic arm after it has been berthed to the ISS. New payloads can be moved directly from the HTV to Kibō'''s exposed facility. Internally, it has eight International Standard Payload Racks (ISPRs) in total which can be unloaded by the crew in a shirt-sleeve environment. After the retirement of NASA's Space Shuttle in 2011, HTVs became the only spacecraft capable of transporting ISPRs to the ISS. The SpaceX Dragon and Northrop