Scientists have learned more about why astronauts get anemic after returning to Earth after space travel. According to Canadian experts, 50 percent more red blood cells are destroyed in space, and this continues for the duration of the mission. As a result, they believe that long missions to the moon, Mars, and beyond will be difficult. However, their discoveries could help bedridden individuals on Earth suffering from the same disease. Since the earliest expeditions returned to Earth, scientists have known about “space anemia,” but the specific cause has remained a mystery. A small University of Ottawa study of 14 astronauts on six-month stays at the International Space Station, including Britain’s Tim Peake, has discovered more.

The researchers were able to measure red blood cell loss using blood and breath samples collected during their trips. These cells are vital to life because they transport oxygen from the lungs to all regions of the body. This is not a concern in space because of the weightlessness, but when astronauts return to Earth, it means they have lost bone mass and muscle strength, and they are exhausted. In space, three million red blood cells per second are lost per second, compared to two million on Earth. Fortunately, the body can compensate. Astronauts would become severely unwell in space if it did not.