It has been long known that astronauts have to continually exercise while in space to keep their muscles strong. Microgravity results in muscle loss from the lack of needing to use our muscles in space to stand up straight and move like we would here on Earth, where our muscles are used to fight gravitational pull. Despite muscle loss, how could we possibly explain skin loss after long trips to outer space?
It continues to baffle scientists as to why astronauts who go up into space, end up coming back to Earth with unexplained skin conditions, such as rashes. Despite theories as to why they might be occurring to astronauts, there is still no concrete answer.
"There has been anecdotal evidence of skin problems in astronauts on orbit, including slow healing of scratches, and some crew members have had nonspecific rashes," says Julie Robinson, NASA's lead space station scientist.
To find out more, a science experiment was conducted with a handful of trusty lab mice.
A total of six lab mice were taken to space and kept at the International Space Station for nearly three months (91 days, to be exact) to see how the long trip to space would impact their skin, offering scientists with some kind of a baseline for testing and sampling.
After the three months were up, the mice returned to Earth for testing. Unfortunately, half of the mice died; one due to spinal injuries believed to occur during takeoff, one due to feeding problems, and the last due to a liver disease.
Fortunately, three of them survived and carried usable skin samples that could be examined. What was found was that the dermis, or the second layer of the skin, was found to have thinned by a significant amount. Moreover, hair follicles on the lab mice were found disturbed by the trip to space, causing abnormal hair growth cycles and changes to the muscles under the skin were also present.
The thinning of the dermis on the lab mice has led scientists to wonder if astronauts coming up with strange sudden skin conditions could be suffering from some kind of skin atrophy that could have attributed to the rashes and other skin conditions they've reported.
At this point in time, the three remaining lab mice offer very little concrete evidence, so more testing will have to be done to answer all of the questions scientists now have about the impacts of Microgravity on the skin.
Astronauts returning from space will likely be tested in a future follow-up test to see how human skin reacts to the harsh environment in space.
Sources: NASA, Discovery News