Study
Tardigrades survive exposure to space in low Earth orbit
Jönsson, K. Ingemar; Rabbow, Elke; Schill, Ralph O.; Harms-Ringdahl, Mats; Rettberg, Petra
Current Biology, 2008
Desiccated tardigrades were flown on a satellite and exposed for ten days in low Earth orbit to vacuum alone, or to vacuum plus solar ultraviolet radiation at different wavelength ranges, then returned and rehydrated. Ground controls were held desiccated in the same state.
- Studied in
- Richtersius coronifer, Milnesium tardigradum
- Sample size
- desiccated tardigrades flown in low Earth orbit
Survival of vacuum alone was high, comparable to ground controls. Adding full-spectrum solar ultraviolet radiation reduced survival drastically, with only a small proportion of one species recovering. Some survivors reproduced afterwards.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Anhydrobiotic tardigrades tolerate the vacuum of space, and the limiting factor for survival in orbit is ultraviolet radiation rather than vacuum or cold.
How NatureHQ reads it
This is the paper behind "tardigrades survive in space", and it says something narrower and more interesting. Vacuum turned out to be nearly survivable — which is remarkable, because vacuum boils water out of ordinary tissue, and a tardigrade in the tun state has already removed the water. Unfiltered sunlight was the thing that killed them, and it killed most of them. The animal was also desiccated, not active: an active tardigrade in space would die immediately. "Survived exposure to space" is true of dehydrated animals shielded from ultraviolet, and the qualifiers are the finding rather than fine print.
- Only desiccated animals were tested; the tun state is a precondition, not a detail.
- Ten days in low Earth orbit is not interstellar space, and the radiation environment differs substantially.
- Survival under full solar ultraviolet was very low, which the popular summary omits.
Ten days in orbit, dried out and unshielded
Can an animal survive direct exposure to space?
Taking space apart, to find out which part is lethal
Tardigrades survive exposure to space — but space delivers vacuum, cold and unfiltered sunlight at once. Which of them actually matters?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Tardigrade
They survived orbit dried out and shielded from sunlight — and most still died
Extreme survival
No animal is immune to anything. Every demonstrated survival of an extreme came from a particular starting state, lasted a measured time, and killed some fraction of the animals tested.
Extremophiles
Almost every record for what life can withstand belongs to a microbe. The reason is architectural: an animal is many specialised tissues that all have to keep working, and it dies when the first one fails.
Published by: Cell PressPublished in a Cell Press journal.
doi.org/10.1016/j.cub.2008.06.048
Checked against Crossref and OpenAlex on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-11.