So, in my earlier blog post, Delving into the microcosm I covered some of the primary reasons why we have always been interested in testing micro-organisms in space. We, as humans, have always had a keen interest in their response to space conditions and this has become a possibility the day we figured out space travel!
Said by one of the famous astronauts in the world and for good reason, because our ability to go out into space just goes to show how far we have come as a species. But have you ever thought about HOW we carry out these experiments in space? Well, you’re about to find out.
First, we need to understand what kind of conditions we are trying to simulate. For starters, we need to consider the absence of gravity or rather the presence of ‘micro-gravity’. The presence of a small amount of gravity is not the only thing to consider in this case. We also have to include the presence of high amounts of harmful UV radiation, below normal temperature, excessive pressure, and the upper atmosphere’s gaseous composition as well, all make it difficult to sustain life.
- Gravity: This is one of the primary factors that is thought of prior to any of the experiments. Some of the initial studies in space microbiology have observed that there are significant changes in the behavior of bacterial cells when exposed to zero-gravity conditions. Most of them show a reduced lag phase (getting used to their environment prior to division), increased cell concentration, and mostly abnormal growth behavior.
- Temperature: The upper boundary of our atmosphere helps in the regulation of the temperature inside Earth but when we leave the earth’s atmosphere, the temperature drops drastically. This is also taken into account while testing microorganisms.
- Radiation: Many experiments have been conducted to see how microorganisms respond to radiation through the absorption and excitation of electrons. This in turn interacts with cellular matter at the atomic levels such as nucleic acids and proteins, and these studies are known as microdosimetric studies.
- Pressure: The space environment has extreme pressure levels going right down to 10-7 pascals and has mostly molecular oxygen and nitrogen. The reason this needs to be taken into account is that vacuum desiccation (a phenomenon where the materials vaporizes due to negative pressure) tends to destroy biological samples.
- A bio lab (obviously!): These units have an incubator, microscope, spectrophotometer, freezer units, and centrifuges (to simulate the effect of gravity). Basically, they help in carrying out any biological experiments within one module of the space shuttle.
- Bioculture (BIOS): This is an advanced culturing system where they can culture microbial and mammalian cells to study host-pathogen interactions in space! The advantage here is that different conditions can be simulated in this environment and their effects can be observed.
- Image processing units: These units tend to receive any images and download them onto the server for future processing. All the images are taken with a light microscopy module that is fixed in the experimental module and it can take high-resolution pictures of all the experimental samples.
Horneck, G., Klaus, D. M., & Mancinelli, R. L. (2010). Space microbiology. Microbiology and Molecular Biology Reviews, 74(1), 121-156. doi: 10.1128/MMBR.00016-09