By Sahira Memon
Scientists hope results will lead to prolonged manned space flights
The greatest risk to humans on extended space excursions is radiation damage due to the lack of protective barriers beyond the Earth’s atmosphere. SFU scientists Bob Johnsen and David Baillie were on a team which addressed this issue by testing the survival of a colony of worms on the International Space Station during the 2006 shuttle mission.
These special worms have been classified as C. elegans. Measuring one millimetre in length, 4,000 of these tiny organisms were sent into space to test their ability to survive and reproduce. What makes these worms so useful is the fact that they have almost the same number of genes as humans, with some genes (almost 4,000) having almost the exact same functions as human genes, as well as higher functioning systems such as the nervous system, a digestive tract, and skin. All of this makes them an appropriate model organism, according to Johnsen.
The worms survived and reproduced for twice as long as the researchers initially expected, proving that they were robust and able models for future experiments.
However, the worms were protected to some degree by the earth’s magnetosphere. The magnetosphere is the region around the Earth where charged solar particulars interact with the Earth’s magnetic field. The Earth’s magnetic field deflects radiation from the sun and elsewhere in the universe, according to Johnsen. Future studies will seek to bring the worms out of the magnetosphere to achieve more complete results.
Johnsen and Baillie are contributing by studying the results of this experiment, and analyzing the genetic sequences of the worms for any damage and changes caused by the trip. This is a complicated process, with the overwhelming number of nucleotides and bases of DNA to compare, but Johnsen has already submitted to the Michael Smith Genome Sciences Centre eight additional strains for whole genome sequencing, three of which were from space-flown worms, one on ground control, and four were exposed to multiple short bursts of x-rays under controlled conditions. The research is funded by the Canadian Space Agency.
In the future, Johnsen and Baillie hope to expand the scope of the experiment beyond the magnetosphere of the earth, but they cannot do this without support from other space missions. The mission would not even have to be a lengthy one; even a week of exposure outside the magnetosphere would provide the desired information. They are hoping to link themselves to possible future Chinese and American moon missions.
The original paper describing this experiment was published by the Journal of the Royal Society Interface on November 29, 2011.
