The Expedition 59 astronauts are moving full speed ahead today with continuous space biology research. Two cosmonauts are also pressing forward with plans to conduct the fourth spacewalk this year at the International Space Station.

NASA Flight Engineers Anne McClain and Christina Koch joined fellow astronaut David Saint-Jacques of the Canadian Space Agency checking on mice throughout the day Tuesday. Scientists are monitoring the rodents’ immune systems, which are similar to humans, for changes that take place due to microgravity.

Saint-Jacques and NASA astronaut Nick Hague also explored how weightlessness affects different microbiological phenomena. Hague inoculated culture bags inside the Life Sciences Glovebox for research operations to understand why pathogens become more virulent in space. Saint-Jacques checked DNA samples for the Genes In Space-6 experiment that explores how space radiation damages DNA and how the cell repair mechanism works.

Commander Oleg Kononenko and Flight Engineer Alexey Ovchinin are both collecting spacesuit parts and tools, as they get ready for a spacewalk planned for May 29. The duo will spend about six hours outside the station’s Russian segment collecting experiments, cleaning windows and sampling module surfaces. This will be Kononenko’s fifth spacewalk and Ovchinin’s first.