A German astronaut on the International Space Station has begun a British-backed experiment to examine the effect of ageing on human muscles in a bid to prevent it.
European Space Agency astronaut Matthias Maurer is working with the University of Liverpool on the microgravity experiment.
"When astronauts spend time in space, their muscles get weaker, just as they do in older age," a University of Liverpool representative said.
"By studying what happens to muscle tissue in microgravity, the team can compare the findings to what happens on Earth. This will help the solve the puzzle of why muscles get weaker as we age and find possible ways to prevent it.
"Our hypothesis is that an analogous failure of muscle adaptations to contractile activity occur in both ageing and in muscle exposed to microgravity, and that by studying the way that muscle responds to repeated contractions in microgravity, we will gain further understanding of the way that muscle fails to respond to exercise in older people and in astronauts in space."
The MicroAge project, which is being supported by UK Space Agency, aims to understand what happens to human muscles as we age, and why.
Mr Maurer has published footage of himself unpacking and installing the MicroAge experiment, which was transported to the ISS by a SpaceX Falcon 9 rocket launched from the Kennedy Space Centre in December.
He can be seen arranging muscle cell containers, which contain synthetic muscle cells the size of a grain of rice, inside the Space Station’s Kubik minilab for incubation at 37°C.
Some of the muscles will be electrically stimulated to "exercise" while others will be exposed to increased amounts of protective heat shock proteins, which the Liverpool team has previously shown as providing protection against age-related muscle wasting.
"This is a fantastic opportunity for us to investigate if a similar failure occurs in muscle exposed to microgravity, to aid understanding of the underlying mechanisms that affect muscle in the ageing population," the university's Prof Malcolm Jackson said.
At the end of the experiment, the muscles will be frozen and prepared for their return to earth, and further analysis, later this month.
Mr Maurer is part of the Crew-3 mission with Nasa astronauts, Lt Col Raja Chari, Tom Marshburn and Kayla Barron.
The Crew-3 mission is intended to help pave the way for future space exploration and benefit life on Earth.
The mission’s main scientific aims include experiments to grow plants in space without soil and build optical fibres in microgravity, which research suggests would be better than those made on Earth.
Mr Maurer is also helping to set up the European Robotic Arm on the Russian side of the ISS, and test out an artificial intelligence assistant called Cimon, which was developed by the German space agency DLR, Airbus and IBM.