List of microorganisms tested in outer space

Imagine tiny, invisible living things traveling through the vastness of space! Scientists are very curious about how these tiny creatures, called microorganisms, survive the harsh conditions outside Earth. They study this using special labs on Earth and by sending experiments into low Earth orbit on satellites.

Back in 1960, a Russian satellite carried some common bacteria like Escherichia coli, Staphylococcus, and Enterobacter aerogenes into space. This was one of the first times we learned that even simple life forms could endure a trip beyond our planet. Since then, many different kinds of microorganisms have been part of these amazing space experiments.

Sometimes, these tiny space travelers become weaker in space, but other times, they can actually become stronger or change in unexpected ways. Understanding these changes is super important for future human missions and for protecting astronauts' health.

Tiny Travelers: Microbes in Space

Why Study Microbes in Space?

There are two main reasons scientists study microorganisms in space. First, they look at microbes that normally live on or inside humans. This helps us understand how space travel might affect the health of astronauts. Did you know that a normal adult human body has ten times more microbial cells than human cells? These tiny helpers are everywhere, and they can even form slimy layers called biofilms.

Second, scientists study special microbes called extremophiles. These are like nature's "super-survivors" because they can live in some of the toughest places on Earth. Think of super salty lakes, dry deserts, the deep ocean, very acidic spots, or freezing cold polar regions.

Super-Survivors: Extremophiles

Extremophiles have learned to thrive where most other life cannot. Their ability to survive in such extreme places on Earth makes scientists wonder: could these tiny organisms also survive in harsh extraterrestrial environments? This research helps us imagine if life could exist on other planets, like Mars, or if life from one planet could travel to another inside rocks (a theory called lithopanspermia).

Protecting Other Worlds

Because bacteria are so common and tough, their tiny spores could accidentally travel on our spacecraft to other planets. This is a big concern for planetary protection, as we don't want to accidentally contaminate other worlds with Earth life. By studying how resistant these organisms are to space conditions, scientists can develop better ways to clean spacecraft and prevent unwanted "hitchhikers."

Learning about microbes in space could even help us with big ideas like directed panspermia (sending life to other planets on purpose) or terraforming (changing a planet to make it more like Earth).

What Kinds of Life Have Been Tested?

Scientists have sent many different types of tiny life forms into space or simulated space conditions. They've studied various Bacteria and their tough spores, which are like tiny protective capsules. They've also looked at Archaea, another group of single-celled organisms often found in extreme environments.

Even Fungi (like molds) and algae (tiny plant-like organisms) have been part of these experiments. Some studies included Lichens, which are fascinating partnerships between fungi and algae or bacteria. Scientists have even tested Bacteriophages (viruses that infect bacteria) and other viruses, as well as different types of Yeast.

Surprisingly, some tiny Animals have also been sent to space! For example, tardigrades, often called "water bears," are famous for their incredible ability to survive extreme conditions, including the vacuum of space. These experiments help us understand the limits of life and what it takes to survive beyond Earth.

Table

      indicates testing conditions

Organism	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions	References
Bacteria & bacterial spores
Actinomyces erythreus
Aeromonas proteolytica
Anabaena cylindrica (akinetes)
Azotobacter chroococcum
Azotobacter vinelandii
Bacillus cereus
Bacillus megaterium
Bacillus mycoides
Bacillus pumilus
Bacillus subtilis
Bacillus thuringiensis
Carnobacterium
Chroococcidiopsis
Clostridium botulinum
Clostridium butyricum
Clostridium celatum
Clostridium mangenotii
Clostridium roseum
Deinococcus aerius
Deinococcus aetherius
Deinococcus geothermalis
Deinococcus radiodurans
Enterobacter aerogenes
Escherichia coli
Gloeocapsa
Gloeocapsopsis pleurocapsoides
Haloarcula-G
Hydrogenomonas eutropha
Klebsiella pneumoniae
Kocuria rosea
Lactobacillus plantarum
Leptolyngbya
Luteococcus japonicus
Micrococcus luteus
Nostoc commune
Nostoc microscopicum
Photobacterium
Pseudomonas aeruginosa
Pseudomonas fluorescens
Rhodococcus erythropolis
Rhodospirillum rubrum
Salmonella enterica
Serratia marcescens
Serratia plymuthica
Staphylococcus aureus
Streptococcus mutans
Streptomyces albus
Streptomyces coelicolor
Synechococcus (halite)
Synechocystis
Symploca
Tolypothrix byssoidea
Archaea	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
Halobacterium noricense
Halobacterium salinarum
Halococcus dombrowskii
Halorubrum chaoviatoris
Methanosarcina sp. SA-21/16
Methanobacterium MC-20
Methanosarcina barkeri
Fungi and algae	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
Aspergillus niger
Aspergillus oryzae
Aspergillus terreus
Aspergillus versicolor
Chaetomium globosum
Cladosporium herbarum
Cryomyces antarcticus
Cryomyces minteri
Euglena gracilis
Mucor plumbeus
Nannochloropsis oculata
Penicillium roqueforti
Rhodotorula mucilaginosa
Sordaria fimicola
Trebouxia
Trichoderma koningii
Trichoderma longibrachiatum
Trichophyton terrestre
Ulocladium atrum
Lichens	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
Aspicilia fruticulosa
Buellia frigida
Circinaria gyrosa
Diploschistes muscorum
Rhizocarpon geographicum
Rosenvingiella
Xanthoria elegans
Xanthoria parietina
Bacteriophage / virus	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
T7 phage
Canine hepatitis
Influenza PR8
Tobacco mosaic virus
Vaccinia virus
Yeast	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
Rhodotorula rubra
Saccharomyces cerevisiae
Saccharomyces ellipsoides
Zygosaccharomyces bailii
Animals	Low Earth orbit	Impact event and planetary ejection	Atmospheric reentry	Simulated conditions
Caenorhabditis elegans (nematode)
Hypsibius dujardini (tardigrade)
Milnesium tardigradum (tardigrade)
Richtersius coronifer (tardigrade)
Mniobia russeola (rotifer)

See also