The Kounotori 7 unmanned cargo transporter departed the International Space Station on Thursday to return to Earth with experiment samples, in a first for Japan’s space agency.
The Japanese Aerospace Exploration Agency (JAXA) said the cargo vessel, the name of which is Japanese for white stork, has been loaded with waste from the ISS and is scheduled to burn up in a controlled manner when it re-enters the Earth’s atmosphere Sunday.
Before burning up, it will eject a capsule containing protein crystals that were grown in experiments carried out on the space station.
Launched Sept. 23 on an H-IIB rocket from Tanegashima Space Center in Kagoshima Prefecture, the vessel, formally called the H-II Transfer Vehicle-7, delivered some 6 tons of food, clothes and experiment supplies, including new lithium-ion battery cells, to the ISS that orbits some 400 kilometers above Earth.
The conical-shaped capsule, measuring some 84 centimeters wide and 66 cm high, is expected to make a parachute-assisted splashdown in the Pacific near Minamitorishima Island on Sunday and be retrieved by a JAXA ship. Previous models of the Kounotori transporters were unable to carry materials back to Earth unscathed by the heat generated during re-entry to the atmosphere.
The new capsule can withstand the extreme temperatures and keep samples inside cool using a vacuum insulated container covered by protective materials, according to JAXA.
It was jointly developed by JAXA and Tiger Corp., an Osaka-based home appliance maker known for producing vacuum insulation containers.
The successful re-entry and collection of samples are expected to contribute to Japan’s efforts toward the development of manned space missions in the future.
The nation has been holding tests at its own experiment module on the ISS named Kibo, which means hope in Japanese. But until now it has required U.S. and Russian spacecraft to bring back samples that were produced during the tests.
JAXA’s dependence on other countries has meant it has no control over when samples can be collected. If Kounotori 7 is successful on its seven-week journey, Japan will be able to transfer materials as needed.
It was feared the nation’s latest mission may be delayed by a manpower shortage, following the failed launch last month of a Russian Soyuz rocket carrying astronauts and supplies to the ISS.
The two astronauts aboard the Soyuz ejected safety, but it meant the ISS was left with only three astronauts to perform experiments and carry out work outside the craft.