Astronauts need to exercise on a mission to Mars (3 years) for two and a half hours every day to stay fit and healthy. According to a NASA website “Weakened astronauts would be less able to do tasks while in space.” Astronauts that have not exercised could have bone loss or muscle loss, and it will be difficult for them to do normal and simple tasks in space. I designed an exercise machine made out of stainless steel and has connectors to customize the model to the size desired. The main piece will have a little knob that can fit into the wall, with a long piece connected to it that can spin in a 360 degree circle. When an astronaut moves this 3D model in a circle, they are working their arm muscles and strengthening their bones. There are 8 spots for rubber bands (not included) that will push the main piece. This will force the muscles to work hard.