The recent blockbuster Hollywood talkin’ picture The Martian starts out with Astronaut
Mike Dexter Matt Damon’s spacesuit getting skewered by debris kicked up by a windstorm on the Red Planet. If any of your students have cool parents, they’ve likely seen the flick—heck, some of the lamely-parented kids probably have, too. (Lookin’ at you, Kevin!)
Just how important is an astronaut’s spacesuit, and how does it keep him or her from dying a horrible, outer space death? This handy dandy Demo Science science demo will help you show your students (or whoever) the basics of how a spacesuit keeps an astronaut alive.
Spaceman Goes “Pop!”
This is just about the easiest “experiment” possible, so don’t pooch it. For this one, all you’ll need is a sealed bottle of soda pop (better practice what you preach and bring enough for the whole class—adjust the number of bottles required as your class size dictates) and a clear drinking glass—Dixie cups will suffice for the students’ beverage receptacle needs. When selecting your beverage for this demo, remember: the fizzier the better.
Gather the smelly little buggers around and have them observe the soda in the sealed bottle. There’s not much to see at this point, but have them “observe” anyway. Then open the bottle(s) and fill your glass, then your students’ smaller ones. (Or larger, whatevs—give the little buggers as much soda as you want, but beware the caffeine crazies.)
Have the students observe the soda in your clear drinking glass, as well as that in their cups. Let ‘em take a taste, as well, but with the note to leave their cups at least half-full for the latter part of the experiment. Ask, tell, or force them (you know your students better than I do) to leave the rest of their beverages be for now, untouched on their desks.
After five to ten minutes of expert distraction (something NASA/space related would be appropriate—a round-robin Asteroids tournament, perhaps), have the kids observe the soda in their receptacles and taste it again. They can drain their cups this time, if so inclined.
So, what, pray tell, does swilling soda pop have to do with an astronaut’s space suit? Read on, Chester!
In their observations, your students likely noted that there were countless bubbles in the soda in their glasses, but none in the sealed bottles. This is due to pressure: gas bubbles rise to the surface of the liquid because the pressure the soda was under in the bottle decreased when the bottle was opened. To give soda its fizz, carbon dioxide is dissolved under high pressure during the bottling process; this carbon dioxide is released into the air when the bottle’s airtight seal is broken.
In nature, gases such as carbon dioxide do not dissolve, but an increase in pressure can force them to do so. The bottled soda, then, is reminiscent of a spacesuit: the pressure inside the suit is carefully controlled to remain at one (Earth) atmosphere, regardless of the pressure—or lack thereof—outside the suit when in space. This ensures that the gases in the astronaut’s blood stay dissolved.
If the spacesuit is punctured, as Damon’s is in The Martian, the pressure inside the suit decreases, and gases in the astronaut’s blood will start to bubble and escape from his/her blood. Just like the bubbles in the soda!
As your students observed upon sipping their bevs after several minutes, the gas loss can affect the liquid considerably. However, instead of giving the astronaut “flat” blood,” the loss of gases from the astronaut’s blood would rupture his or her blood vessels and kill him or her, hard.
And, no, drinking a bunch of soda would not keep the astronaut alive in the event of a burst spacesuit.