Among the trio of astronauts tested was Samantha Cristoforetti, who was scanned before traveling to the ISS in November 2014 and again upon return in June this year after her record-setting 199-day mission. The results showed an increase of collagen in the dermis, the lower layer of the skin, indicating a slight anti-aging effect. However, on the outer epidermal layer the skin was shrinking and in turn getting thinner by nearly 20 percent. One drawback is its increased susceptibility to dangerous radiation, affecting the area where stem cells are located and skin cancer often begins. Once back on Earth, the process is reversible, but increasingly long missions could have damaging results. Koenig is continuing the studies in hopes of curtailing this thinning skin phenomenon before astronauts are subject to more than a year's journey on NASA's Mars mission.