Can an astronaut survive a long-term spaceflight? With NASA looking ahead to missions on Mars and beyond, it's an important question - and one we haven't even come close to answering through practice. The longest space flight ever only lasted 437.7 days, and most astronauts have spent less than a year at the space station during their longest stretches.

But a NASA study published in the Journal of Interferon & Cytokine Research has taken a small step for man's journey to distant planets. NASA scientists analyzed blood samples taken before, during, and after missions to the International Space Station, looking for indications of how astronauts' immune systems handle the unusual environment. The results indicate that things get a little bit wonky.

To read more and view the video, click here.