Approximately two billion skin cells form a comprehensive protective barrier for the human body against pathogens, UV radiation, heat, cold, and dehydration. But how does the skin respond to the conditions of space? This question was explored by the pilot project SkinCare in 2006, which revealed changes comparable to skin aging over many years. These investigations are now being continued by the Skin-B experiment, in which Alexander Gerst is also participating.
As NASA studies have shown, people often feel uncomfortable in their skin, especially in space. In addition to balance disorders and headaches, skin problems such as dryness, itching, flaking, and delayed wound healing are high on the list of health difficulties astronauts face. This can become a real problem, especially on long-term missions.
Universal Perception Center
With an area of up to two square meters and a weight of up to ten kilograms, the skin is the largest organ of the human body. It consists of three layers. The epidermis forms a protective horny layer that repels pathogens. In the middle layer—the dermis—are blood and lymph vessels as well as nerve cells. Through them, humans perceive sensory impressions—touch, pressure, temperature, or pain. The final layer is the subcutis, which contains abundant fatty tissue serving as an energy reserve and cold protection. Here are also the sweat glands important for heat regulation and the sebaceous glands that coat the skin surface with a protective film.
Equipped with millions of pressure, temperature, and pain-sensitive nerve cells, the skin is also the largest sensory organ, reacting highly sensitively to external influences. In short, our skin is a multifunctional organ—and an extremely important one at that.
Skin Observation in Space
In 2006, German ESA astronaut Thomas Reiter conducted the SkinCare skin experiment during the six-month Astrolab mission. The measurements showed that the epidermis became significantly thinner. The skin's texture also became coarser, an unmistakable indicator of its age.
Overall, the observed changes corresponded to accelerated skin aging. The skin areas treated with cream showed better moisture values and were less rough. However, it is important to note that these changes regressed within a year after returning to Earth. The skin has not truly aged.
Skin-B: New Insights into the Skin
The biggest drawback of the SkinCare experiment was that it had only one subject. That is not sufficient for generalizable statements. Therefore, the findings are to be verified with the Skin-B experiment. As with SkinCare, Skin-B is led and conducted by Dermatronnier GmbH & Co. KG, a scientific institute for experimental dermatology affiliated with the private University of Witten/Herdecke.
The Skin-B experiment, funded by the DLR and implemented cooperatively with ESA and NASA, has been running on board the ISS since 2013. The first Skin-B test participant was Italian ESA astronaut Luca Parmitano (2013). Alexander Gerst is now continuing this research.
A total of three to five long-term astronauts from ESA and NASA are to conduct the same measurements on themselves. Over six months, only the untreated skin of the astronauts will be observed. Special instruments will be used to check both the moisture content and the water loss of the skin. A small special camera documents the changes in the skin surface.
Aging in Fast Motion: Interesting for Industry
Experiments like SkinCare and Skin-B contribute significantly to a better understanding of skin change processes. This also applies to phenomena such as delayed wound healing or allergies. The findings indirectly affect other organs as well, as changes in the skin can provide early indications of other systemic diseases.
General conclusions about skin aging processes also enable new approaches to developing effective countermeasures. If accelerated skin aging is confirmed, this would offer interesting approaches for industry partners in the fields of cosmetics, dietary supplements, and pharmaceuticals. Specifically, manufacturers of anti-aging products could benefit from these insights.