Human muscle cells will be launched into space as part of a new experiment.
Space
The MicroAge study will take off on a SpaceX Falcon 9 rocket from the Kennedy Space Centre in Florida to the International Space Station on Tuesday (21.12.21).
Space will be used to understand what happens to human muscles as people age and why.
Spending time without the effects of gravity can cause astronauts' muscles to become weaker before recovering when they return to Earth.
Experts from the University of Liverpool will analyse the samples when they come back to Earth next month and compare them to findings from experiments on our planet.
Professor Malcolm Jackson told Sky News: "We have known for a long time that astronauts in space can lose muscle rapidly.
"People have speculated whether that is an accelerated ageing phenomenon.
"We realised a little while ago that astronauts on the space station had an analogous problem, each astronaut that is on the space station exercises at least 2.5 hours each day and despite that, they lose quite a significant amount of muscle and in fact can't walk for a while after they get back on earth."