April 12 is the United Nations’ International Day of Human Space Flight. The BioSentinel mission will fly as part of Artemis I, and is the sole biological experiment selected to head for the cosmos. It will collect important data about how long-term exposure to space radiation may affect life forms by using yeast experiments. Because yeast is a living organism that shares many essential cellular processes with humans, it may be able to serve as an example of how deep space radiation may affect humans themselves.
Dr. Troy Harkness (PhD), a professor of Biochemistry, Microbiology and Immunology at the USask College of Medicine, served as a consultant on some of the early studies that led to the experiment’s inclusion on the BioSentinel – a smaller spacecraft that is hitching a ride to space on the Artemis I mission.
The consulting team was made up of researchers from USask and Loma Linda University in California, as well as NASA advisors. Dr. Andre Obenaus (PhD), a former professor in USask’s College of Medicine who went on to join Loma Linda University, was a part of the consulting team, as well as former USask research technician Cheryl Rostek.
“We were interested in figuring out whether space radiation was detrimental to yeast and if so, what pathways would be involved in repairing DNA damage,” said Harkness. “The hope was that this would yield a biologically relevant method to track space radiation that is harmful to biological specimens, including humans.”
The experiment found that wild type yeast was fairly resistant to proton radiation, but cells lacking components of homologous recombination – the ability to reproduce DNA with minimal errors regardless of damage – were especially sensitive to proton radiation damage.
Following the initial experiments at Loma Linda University, a NASA research team took interest in how a similar strategy could be used to detect the effects of radiation on life in space. The work eventually evolved into the larger, $4 million BioSentinel project.
Active yeast strains will be sent to space inside the BioSentinel spacecraft, past the moon to enter an orbit around the sun. Both wild type and mutated yeast strains will be woken up periodically during spaceflight. The yeast will be monitored for growth over the course of the experiment. Any decreases in growth will indicate damage has occurred, and research teams on the ground will record the measurements for further analysis.
The responses of the yeast strains will serve as an experiment to determine how deep space radiation may affect human DNA, and will serve as the basis of a system to detect harmful radiation when astronaut crews join future Artemis missions.
“Manned missions to Mars will take many months where humans, although protected by immense shielding, are immersed in an intense radiation environment,” said Harkness.
“The yeast radiation detection system will potentially alert the onboard team if harmful radiation is bypassing the protection systems. On Earth, it is possible that these yeast systems could be used as a ‘canary in a coal mine’ scenario to detect damaging radiation in environments where humans are working.”
Harkness’s current research focuses on using the genetics of yeast to understand how cells live long and healthy lives, and using lessons learned from the stress response of yeast organisms for killing drug resistant cancer cells in humans.
The yeast and BioSentinel projects were funded by the Canada Foundation for Innovation, as well as a NASA Cooperative Agreement awarded to Dr. Andre Obenaus (PhD).