Japanese Cargo Ship Departs Space Station. Next Stop: Oblivion.

A robotic Japanese cargo ship cast off from the International Space Station Wednesday (Nov. 7) for a weekend date with oblivion to wrap up a successful resupply mission.

Astronauts on the station released the HTV-7 supply ship from the station using a robotic arm at 11:51 a.m. EST (1651 GMT) as both spacecraft sailed 254 miles above the northern Pacific Ocean. The Japan Aerospace Exploration Agency (JAXA) launched the cargo ship to the station in late September to deliver more than 5 tons (4.5 metric tons) of fresh food, science gear and other supplies. 

"The Expedition 57 crew would like thank the entire JAXA program and engineering teams for the flawless design and execution of the HTV-7 resupply mission," station commander Alexander Gerst of the European Space Agency radioed Mission Control after the successful undocking. The cargo ship, he added, is a vital part of a truly international effort to support the world's only outpost in space. Gerst used the robotic arm to release HTV-7 with support from NASA astronaut Serena Auñón-Chancellor. [Japan's Huge HTV Space Truck Explained (Infographic)]

JAXA's HTV cargo ships (short for H-2 Transfer Vehicles) are disposable spacecraft designed to haul tons of supplies to the space station, and then depart and intentionally burn up in Earth's atmosphere at mission's end. The spacecraft, also known as Kounotori (Japanese for "white stork") are part of a fleet of robotic cargo ships from Japan, Russia, Europe and the United States that have kept the station stocked with supplies over the last 18 years. 

HTV-7 delivered some critical supplies for the International Space Station's crew, including six new batteries for the orbiting lab's solar power grid. It also carried two tiny cubesats for a space elevator experiment (which were deployed Oct. 6) and a small re-entry capsule that, in a first for Japan, will attempt to return experiments to Earth. If all goes well, the capsule will be deployed just before HTV-7 falls back to Earth over the South Pacific on Saturday (Nov. 10), NASA officials said.

Called the HTV Small Return Capsule, the cone-shaped vehicle is 2.7 feet wide (0.8 meters), 2.1 feet tall (0.6 m) and weighs 397 pounds (180 kilograms). 

"The return capsule will be ejected from a hatchway after the deorbit burn," NASA officials said in a statement. "The experimental capsule will perform a parachute-assisted splashdown off the coast of Japan, where a JAXA ship will be standing by for its recovery."

NASA officials said the capsule is carrying protein crystal growth experiment results. 

Gerst wished the team behind the re-entry capsule luck in their upcoming technology test. It was he and his Expedition 57 crewmates who packed the capsule with its experiment cargo and attached it to the HTV-7 hatch.

"We congratulate all the participating engineers for the successful design and assembly of the small return capsule, and we wish all the best for the upcoming, most interesting, phase of the return capsule mission: the re-entry and descent."

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik. Follow us @Spacedotcom and Facebook. Original article on Space.com.