Can Bacteria Grow In Space? You Bet

Part (ii) of our two-part look at bugs in space.

Last Thursday evening, an Atlas V rocket blasted off from Cape Canaveral in Florida, carrying a spacecraft named OSIRIS-REx.

Now, OSIRIS-REx may sound like a dinosaur, but it actually has a very 21st-century mission – it’s headed for asteroid Bennu on an outward journey that will take the best part of two years.

When the spacecraft reaches the asteroid, it will grab a sample of at least two ounces of surface material, using a mechanism that might best be described as a crazy cross between a pogo stick and a vacuum cleaner.

The single-legged OSIRIS-REx will touch the surface of the asteroid for a mere five seconds – just long enough for a powerful blast of nitrogen to dislodge surface particles that will then be sucked into a collection container – then a spring will bounce the craft back up again.

Thereafter, the plan is for OSIRIS-REx to return the sample to earth, getting back here in 2023.

September 24th (a Sunday) if you want to put it in your calendar.

So what will the sample contain?

Well, we really don’t know.

However Bennu was chosen for the mission as it’s known to be a carbonaceous (carbon-containing) asteroid, so there’s a good chance of the NASA scientists receiving a delivery of organic material.

Sadly, they consider the possibility of it containing microorganisms “a very low probability event.”

Note that they don’t rule it out completely, however.

What’s slightly more possible, though, is finding fossilized remains.

We just don’t know, which is what makes missions like these all the more interesting.

By the way, there’s also a really slim chance that Bennu might one day (long in the future) collide with our planet, so another aspect of the mission involves looking for ways to prevent that happening.

It’s also interesting that we’re not only (perhaps) looking for bacteria in space, we’re also actively sending it up there in the first place.

In 2008, British scientists sent small fragments of bacteria-containing rock up to the International Space Station where they were placed on the exterior for eighteen months, then returned to Earth.

Professor Charles Cockell and his team then searched the samples for bacteria, finding a photosynthetic microbe they named OU-20 (they worked at the Open University, and this was the 20th microbe they discovered: their space-bound rock turned out to contain a previously unknown bacterium).

These microbes had continued living while stuck out in space for well over a year.

Then, in 2010 and 2011, colonies of bacteria were deliberately grown aboard Space Shuttle Atlantis, behaving in ways never observed on earth.

A species known as Pseudomonas aeruginosa formed biofilms which took on a mushroom-like “column and canopy” structure.

Compared to the exact same experiment performed on earth, the space bacteria colony contained a greater number of live cells, with more biomass, and a thicker biofilm.

Last, but by no means least, we jump to a little earlier this year when a brilliant UC Davis-based citizen science initiative, Project MECCURI*, asked members of the public to collect environmental microbial samples – mainly from sporting and other public events – then had them sent up to the International Space Station (again) to see how they’d grow in lower gravity conditions.

A total of 48 strains were sent on their way, most growing at a rate very similar to what you’d expect on earth, all except Bacillus safensis, however, which grew 60% better in space.

Curiously, strains of this novel species were first isolated in clean rooms at the Kennedy Space Center (next door to Cape Canaveral in Florida) and at the Jet Propulsion Laboratory in Pasadena.

Strange, huh?

Just as notable, perhaps, Project MECCURI found a previously completely undiscovered bacterial species – Porphyrobacter mercurialis – named after the project itself.

So, with an initiative that involved space shuttles and international space stations, was this species found somewhere really exotic?

Well, not exactly.

A citizen scientist collected it by swabbing a high school stadium seat in Coronado, California.

Hopefully the person who last sat in it wasn’t suffering from asteroids.

*Full disclosure: Dr. Jonathan Eisen of the MECCURI team is a member of the uBiome Scientific Advisory Board.

Further reading

Bacteria found to thrive better in space than on Earth

Beer microbes live 553 days outside ISS – BBC News

NASA – Bacteria Sent Into Space Behave in Mysterious Ways

NASA’s Trip to an Asteroid Could Reveal the Origins of Life on Earth


OSIRIS-REx Hoisted


Porphyrobacter mercurialis sp. nov., isolated from a stadium seat and emended description of the genus Porphyrobacter

Project MERCCURI – Examining the diversity of microbes on Earth

Q & A – OSIRIS-REx Mission

Space Versus Ground Microbial Growth Results – Project MERCCURI

Spaceflight Promotes Biofilm Formation by Pseudomonas aeruginosa

The Long, Strange Trip of Asteroid Bennu – NASA