Specifically, NASA demands US citizenship, a minimum undergraduate degree in engineering, science or mathematics, at least three years of related professional experience (or 1,000 hours as pilot-in-command of a jet aircraft) and correctable 20/20 vision (glasses are okay). It also pointed out that "frequent travel may be required," though at 250 miles from Earth, the ISS is technically a shorter trip than Detroit to Chicago.

Peggy A. Whitson, PH.D, the first woman to command the ISS

While LinkedIn says that three million candidates fit the bill, those requirements are the bare minimum, to say the least. As a small sampling of the background of current astronauts, the socially-savvy commander Reid Wiseman has a Master of Science in system engineering, won five combat awards flying the FA-18F Super Hornet and worked as a test pilot in the F-35 Lightning program. On the civilian side, Dr. Peggy A. Whitson graduated summa cum laude from college, has a doctorate in biochemistry and worked as a NASA National Research Council research associate.

If you're still not discouraged, you can apply here and learn further details from NASA's Reddit AMA. Applications close mid-February, and NASA will winnow down the final candidates by mid-2017. The agency said "those chosen may fly on any of four different US spacecraft during their careers," including the ISS, two commercial crew spacecraft from Boeing and SpaceX, and NASA's own Orion deep-space exploration vehicle. Since all of those vehicles except the ISS are still untested with astronauts aboard, there's one last qualification: nerves of titanium.