Burning question #234: how deadly is space?

Fifty years of movies that feature gory death scenes in which people are exposed to total vacuums (with decidedly gooey results) would have us believe that outer space is so incredibly hostile an environment that it can't be withstood, even for a second. According to damn interesting (and some scientists with access to fancy vacuum chambers), that's not entirely true.

For about ten full seconds"“ a long time to be loitering in space without protection"“ an average human would be rather uncomfortable, but they would still have their wits about them. Depending on the nature of the decompression, this may give a victim sufficient time to take measures to save their own life. But this period of "useful consciousness" would wane as the effects of brain asphyxiation begin to set in. In the absence of air pressure the gas exchange of the lungs works in reverse, dumping oxygen out of the blood and accelerating the oxygen-starved state known as hypoxia. After about ten seconds a victim will experience loss of vision and impaired judgment, and the cooling effect of evaporation will lower the temperature in the victim's mouth and nose to near-freezing. Unconsciousness and convulsions would follow several seconds later, and a blue discoloration of the skin called cyanosis would become evident. Though an unprotected human would not long survive in the clutches of outer space, it is remarkable that survival times can be measured in minutes rather than seconds, and that one could endure such an inhospitable environment for almost two minutes without suffering any irreversible damage.

This is obviously good news for super-rich thrill seekers, who can experience the ultimate head rush, probably not die, and hopefully confirm or deny space tourist Anousheh Ansari's claim that space smells like burned toast.

Update
Since we wrote this blog, there's been one more space tourist -- Hungarian-American Charles Simonyi, who was a big cheese at Microsoft for years and now heads his own software company. After his April 7, 2007 flight, he said "It is amazing how it appears from the blackness of the sky. It was very, very dramatic. It was like a big stage set, a fantastic production of some incredible opera or modern play. That's what I was referring to when I said I was blown away."

Two of the next three space tourists planned are also software geeks: videogame designer Richard Gariott, expected to fly this October, and Google co-founder Sergey Brin, who'll fly in 2011.

Meanwhile, cheaper "sub-orbital spaceflight" is in development by folks like Virgin's Richard Branson, which will offer some of the same thrills for about 1/100th of the price ($200k vs. $20 mil). If that sounds like a bargain to you, check out Virgin Galactic.