A machine will help monitor the muscles of astronauts on board the International Space Station (ISS). The Muscle Atrophy Research and Exercise System or MARES is a muscle measurement machine on the ISS -- similar in appearance to an exercise bench -- that will observe the crew's muscles as they work out.

During spaceflight, astronauts' muscle strength typically drops. Scientists are working to determine why this occurs in order to prepare for long-duration missions and safe space tourism. According to Phys.org, looking at muscle contraction in a single movement could yield little information. But MARES will provide information about how muscles behave in space, giving a full overview of muscle speed and force for every bend of an elbow or a knee joint.

This week, astronaut Thomas Pesquet from the European Space Agency (ESA) will set up MARES in the European Columbus laboratory and he will be the first test subject for scientists on Earth, ESA said in a blog. Pesquet will spend multiple days unpacking and setting up the complex machine.

On Earth, the CADMOS (Center for the Development of Microgravity Applications and Space Operations Plans) - a ground laboratory that organizes and keeps track of microgravity science experiments in space located in Toulouse, France - will support the operations. Ground user operators will answer any questions the astronauts have and suggest solutions to problems they may encounter during the experiment, ESA said.

Before Pesquet, ESA astronaut Samantha Cristoforetti conducted an initial test-run during her mission to the ISS in 2015. While she did not become an experiment subject, Cristoforetti set up the machine and checked that the motors were functional.

While Pesquet will be the first test subject whose data will be used by researchers, Andreas Mogensen, another ESA astronaut, was the first astronaut to use MARES to take measurements in space on himself. Mogensen performed a second part of the MARES commissioning during his 2015 mission by deploying the machine in its "Ankle Configuration" to get data on his ankle movements. The test validated the machine's capability to be used in more scientific experiments in the future.