SkinCare is a human physiology experiment, which aims at characterizing different parameters of human skin (i.e. hydration grade, transepidermal water loss, skin surface video imaging) in weightlessness and inside the International Space Station. Long-duration missions in microgravity affect skin by causing excessive dryness, increased cell loss and increased aging. Investigators will test the applicability of the space environment as a model of aging skin. Noninvasive medical equipment will be used in flight to support the experiment.
Apart from itching and dryness of the skin (possibly partly due to the special skin care being used in the ISS), a thinning of the skin and increased sensitivity combined with delayed healing of wounds and also an increased tendency to skin infections have been reported after a long stay in space. A pilot study, involving one subject, applied noninvasive skin testing methods before, during, and after a long-term mission using single measuring parameters of the skin and at the same time examined the effects of a skin protection cream.
Astronauts experience changes in their skin during spaceflight. SkinCare is designed to examine these changes and use the data collected to create a model for skin aging. This model can be used to create countermeasures to protect skin on Earth and in space.
Tests concerning the skin hydration, transepidermal water loss, and elasticity states were carried out, and ultrasound measurement of the fine structure of the skin was also done. Measurements were made on predetermined different skin areas on both inner forearms with the right forearm being treated daily with a skin care emulsion. The measurements in the ISS, performed by the trained crewmember, were done in more or less stable environmental conditions throughout the measuring period. However, before and after measurements, done during the astronauts’ stay in different countries showed that local environmental conditions can have extreme influence on the results.
- Changes in skin occur gradually on Earth but are accelerated while living in microgravity. Protecting the skin is an important part of personal hygiene.
- The changes in the skin will be monitored periodically throughout the mission.
- Creating a model of the aging that skin experiences will lead to products that will help to counteract the effects of aging.
All skin elasticity parameters increased post-flight, from different to normal ageing of the skin, which indicates a clear loss of elasticity. Elasticity measurements and especially the ultrasound images of the skin showed signs of a decrease of density of the skin fiber system. Epidermal measurements provided evidence of a thinning of the top skin layer and a prolonged molting time of the cells from the base layer toward the top. These results correlate with the reports from astronauts about the state of the skin during their stay in space. Comparison of the mean values of the hydration measurements before, during, and after the mission showed that there were only minor differences between the sides (right versus left). However, there is a clear hydration effect of the applied skin care emulsion. Treatment with the emulsion over the course of the mission led to an improvement in the hydration of the outermost layer as well as in the barrier function (moisture retention) of the epidermis.
Due to logistical and technical reasons and also because the measurements were carried out on only one subject, further tests with more test subjects, using optimized test conditions and additional measuring methods (e.g. for the determination of capillary blood flow and oxygen saturation of hemoglobin) are necessary. This way, the general medical risks can be determined via skin physiological parameters and the side effects on the skin due to long-term stay in space can be minimized (Tronnier et al. 2008).
Space is no trip to the spa — astronauts experience dry, itchy, thinning skin. For this investigation, researchers measured skin hydration, trans-epidermal water loss, elasticity, and the fine structure on predetermined skin areas before, during, and after flight. One area was treated daily with a skin care emulsion. Measurements showed decreased skin elasticity, decrease in density of the skin fiber, thinning of the top skin layer, and prolonged molting of base layer cells, while the emulsion-treated area showed improved hydration. Further tests on more subjects are needed to determine general medical risks using skin physiological parameters and to minimize space-induced side effects on the skin.