Animals
Have tardigrades survived in open space?
The short answer
Yes. In 2007 the European Space Agency exposed dried tardigrades to the vacuum of low Earth orbit for ten days. Those shielded from solar UV revived at rates comparable to controls on the ground, and went on to lay eggs that hatched normally.
The experiment flew on the FOTON-M3 mission in September 2007, aboard ESA's Biopan-6 platform. Desiccated adults of two species were carried to an altitude of around 260 to 280 kilometres, opened to space vacuum, and in some samples exposed to solar ultraviolet as well.
Vacuum alone turned out to be survivable. Tardigrades exposed to space vacuum without solar UV revived at rates broadly comparable to dehydrated controls that never left Earth. Some specimens even came back from the combined assault of vacuum and full-spectrum solar radiation, which is the harder trick by far — UV, not vacuum, is what kills them.
The detail that lands hardest is what happened next. Eggs laid by animals that had been exposed to space vacuum hatched at normal rates. It is not just that they survived; it is that it did not cost them anything obvious.
Source
- Tardigrades survive exposure to space in low Earth orbitCurrent Biology