As space agencies prep for the long-awaited, highly-anticipated mission to Mars, much research still needs to be done. The trip to the Red Planet will take six months, so the effects of a long-period in space are being carefully monitored. One way to conduct experiments - without actually sending anyone to Mars - is to study those aboard the International Space Station.

"NASA and ESA - the European Space Agency - came to us and asked, 'is it possible to also look in the skin of astronauts? Because we want to know if there's any aging process going on or what kind of modifications happened to astronauts as they work for six months out in space.' Because many astronauts complain about skin problems," said Karsten Koenig from the Department of Biophotonics and Laser Technology at Saarland University, according to Reuters via Yahoo.

Astronauts Luca Parmitano, Samantha Cristoforetti and Alexander Gerst were all scanned before and after their missions aboard the orbiting laboratory.

"We use femtosecond laser pulses. We scan the skin and we get signals from the skin, particularly fluorescence, as well as another signal called second harmonic generation. So with these two signals we can build up images and get a precise look into the skin with a high resolution. The resolution is a factor of one thousand (times) better than ultrasound. So now you get the information without taking biopsies; normally you slice them, you stain them, and then a pathologist would look through these sections. Now you can get this information in seconds, labor free and with this fantastic resolution," said Koenig, adding that the technology also applies to early cancer detection and determining the effects of skin aging.

When ESA's Cristoforetti landed back on Earth on June 11, she became the new record-holder for the single longest spaceflight by a woman (199 days). The Italian astronaut's skin cells were scanned before and after her time on the ISS and scientists were surprised by what they found, according to Reuters.

"So far we've got interesting results from three astronauts. It seems that there is a strong production of collagen; so suddenly these astronauts have more collagen. It means there is some sort of anti-ageing effect, at least in the dermis - the lower part of the skin. And we found that the epidermis, in particular the part of the living cells, that this epidermis is shrinking, so the skin gets thinner," Koenig said.

"So far we have no explanation yet, and we are waiting for the other astronauts to figure out what's going on and maybe to try to figure out how we can protect, how we can help so that this epidermis is not shrinking," he added.

While waiting for more post-orbit scans, Koenig and his colleagues plan to investigate what causes the thinning of the astronauts' skin and what can be done to prevent it.

"We've seen the epidermis get thinner by nearly 20 percent. And so far we have no explanation. But this happened within six months; the question is if you go to Mars they need one or two years and we don't know yet - for sure it's not so good if the epidermis gets thinner and thinner," Koenig said.