161
On January 30, astronauts Suni Williams and Butch Wilmore will conduct a 6,5-hour spacewalk outside the International Space Station. Among other goals, they will collect samples of the station's surface to analyze for microbes.
The ISS “Surface Swab” is part of the ISS External Microorganisms Project. It was designed to understand how microorganisms are transported by crew members into space. It also seeks to understand what happens to these “mini-flaps” in the space environment. NASA will provide live coverage of the walk, as well as other station maintenance work along with the sample collection. You can watch the action below starting at 11:30 a.m. UTC (06:30 a.m. ET) on January 30, with the spacewalk beginning 1,5 hours later.
The “bugs” that the two astronauts are bringing back for analysis will come from areas on the space station near the life support system vents. The idea is to find out if the station is releasing these microbes through the vents. Scientists also want to know the size of the population of the releases and where else they appear on the station.
Experiment with microbes
Researchers are eager to understand how microbes exist and thrive in space and on the planet. Right now, the best analogy for them is the ISS, especially its appearance. So when microbes find their way out, people want to know how long they survive in radiation. Are they affected by rapid temperature changes? What else happens to them? Scientists also want to know if microbes are able to reproduce and how the environment changes that.
Samples from the ISS surface are frozen in special containers and later returned to Earth. Once in the laboratory, they are analyzed using culture-independent methods, such as next-generation deoxyribonucleic acid (DNA) sequencing, to measure the microbial community. Functional pathways in these microbial communities are characterized by targeted multigene analysis. This approach allows for a comprehensive assessment of microbial diversity and metabolic function without culture. Samples collected at different locations or during different EVA opportunities allow researchers to map the microbial diversity of the ISS's exterior surfaces.
Why test for microbes?
Although humans have been flying in and out of space for decades, the scientific community still has significant knowledge gaps about how microbes are released, how they develop, and what their life cycles are in space. In particular, the ISS receives many missions each year, and astronauts move freely inside. These activities likely increase the microbial population both inside and outside.
Collecting microbes and analyzing them allows scientists to estimate the types and numbers of microorganisms living on the outer shell of a spacecraft. The larger goal is to provide more information in line with NASA’s policy guidelines for planetary protection requirements for human-alien missions. There are still many questions to be answered, including: What are acceptable levels of microbial life? Which ones escape through vents? What are acceptable levels of contamination?
While NASA designed this mission to answer these and other questions, the Russian space agency Roscosmos is also conducting similar studies to collect samples from the Russian side of the station. This has led to the discovery of non-spore-forming bacteria growing on the outer shell of the station. The results of microbial analysis from this and other collections of microorganisms could influence spacecraft design and spacesuit modifications.
This becomes doubly important when humans, for example, go to the surface of Mars. Although we don't see direct evidence of life there now, it could be there and probably did exist in the past. Not only do we want to avoid contaminating astronauts with this life, we also want to avoid (as far as possible) transferring Earth life to Mars. This same research has applications in other industries, such as agriculture and pharmaceuticals.
Spacewalk information
This isn't the first time the ISS has been checked for external microbes, so long-term studies are needed. Williams and Wilmore's planned sample collection mission is officially called Spacewalk 92 and is scheduled to launch at 8 a.m. ET on January 00.
