Science Experiments on the International Space Station

By Erin Biba

How the ISS operates as a laboratory in the sky.

When water boils in zero gravity it doesn’t bubble. Well, that’s not quite true. It just grows one, big, giant singular bubble. That’s because hot air doesn’t rise in microgravity. Here on earth, small bubbles of hot air will move from the bottom of the pot to the top, transferring heat from the coil on your stove through to the water as it moves along. The big giant space-bubble holds all the heat, which means boiling water in space doesn’t even get hot.

We know this because humans are lucky enough to have access to the most unique laboratory in the universe. It’s not on earth. It’s orbiting 230 miles above our planet. Since it first launched on November 20, 1998, there have been an average of 150 scientific experiments going on at International Space Station during any given six month period. At first, that research consisted mostly of observing earth from above. That’s still going on today, but research aboard the station has evolved to include just about everything you can imagine, from plant science, to physics, to human biology.

Photo credit: NASA

Anyone who wants to can submit a proposal for research aboard the station. The experiments are chosen by the different international agencies that work together to maintain the station. NASA selects its research projects based on recommendations from its different agencies (like life science, physical science, and human research). But, because the Space Station is designated a US National Laboratory, by law it has to be open to research from organizations beyond just NASA. And that means anybody: from big companies (who have enough money to fund their own research), to everyday scientists, to the average Joe. If it’s deemed interesting or important enough by the Center For Advancement In Science and Space, NASA will launch your experiment to the space station and provide astronauts to conduct it.

“We’re trying to create lots of different pathways to make the Space Station more available to users. In the past there’s been a lot of government red tape. Those days are over,” says Tara Ruttley, associate program scientist for the ISS.

After all, it’s the only lab in existence that allows researchers to control for gravity.

"We’re not doing this just because it’s fun and cool. We’re advancing basic discovery."

“Because you don’t have gravity in space, all these different phenomena change,” she says. “You get all these different sets of information on the way our body works. Any part of your body you think you know, the way drugs behave, you can learn a whole bunch more when you take the gravity away. If you can think of doing a science fair project in school, most of it was what happened based on gravity. We’re not doing this just because it’s fun and cool. We’re advancing basic discovery. We can do new 'aha!' things in orbit. Basic discovery that would advance textbook knowledge.”

Once a research proposal is accepted, scientists have 18 months to polish it and train the next crew of astronauts to run it if necessary. Some of the experiments can be run from the ground, others have to worked into the astronauts daily schedule. “We have operational planners and that weigh things like: the experiment might have a shelf life, or one has to be operated at certain times because it has to see the earth in this range. They look at the unique requirements of each experiment and they look at resources--crew time for science is a premium and a priority but we have to make sure the crew has time to get to other activities like maintaining the station. Some weeks are busier in science than others.”

Right now there are 164 experiments currently being conducted on board the ISS (and that includes research from NASA, Japan, Europe, and Canada). You can see the full list of every experiment from the past, present, and future here.

Image credit: ESA

All this week, I'll be spotlighting the experiments being conducted on the ISS and explaining the implications of that research. There's a lot of interesting research going on above our heads right now in that wonderful laboratory in the sky!