cold sleep コールド・スリープ
ライフサイエンス / 宇宙活動 / ハイテクノロジー

An artificial sleep induced by lowering the body's temperature and having it use only the minimum amount of energy necessary to keep itself alive. As controlling the body's temperature is extremely difficult, this method requires a special capsule equipped with an electronic freezing device. Post-thaw muscle atrophy, among other issues, was a problem surrounding early cold sleep techniques, but this has since been overcome through studying the hibernation of bears. Cold sleep is also now called "hibernation" for this reason.

However, because certain aspects of cold sleep, namely its safety, still remain unclear, it has yet to be permitted for official use. Astronauts are therefore forced to endure long-distance space flights without the luxury of cold sleep, a fact that has led to the spread of illegal drugs throughout space.

The Yuri involved in the Yuri accident of 2013 was connected to an early version of the survival ball cold sleep unit. The accident turned out to be valuable test data for cold sleep, helping to improve the technology.

Astronaut Jonathan Ingram's 25 years is the record for the longest amount of time a person has spent in cold sleep.