Some 250 miles above the Earth’s surface, the International Space Station (ISS) is a laboratory like no other. Experiments onboard range from cultivating human organs to growing lettuce in microgravity.
But a science payload due to launch Friday at 11:50 p.m. Eastern to the ISS from Cape Canaveral in Florida will feature another, unusual addition to the experiments onboard.
They may be used for walking and running on the Earth, but NASA’s 20th resupply mission to the ISS will include a pair of sneakers that scientists want to test out in space — Adidas' Boost shoes, specifically.
The experiments are designed to test a manufacturing process called particle foam molding. The process is used to create the midsole part of a shoe by blowing thousands of tiny pellets into a mold and letting them fuse together.
Testing the shoes in microgravity enables scientists to get a closer look at the motion of the pellets and where they end up in the mold.
As the experiment description on NASA's website explains, sending up sneakers into space has more than novelty value — it could have terrestrial and extraterrestrial applications, too.
Multiple phenomena, including gravity, affect the final position of pellets in the particle foam mold filling process. By removing gravity from the equation, this investigation allows researchers to focus on factors that can be manipulated in production on Earth. Many other processes may benefit from such microgravity research, and results of this investigation could contribute to increased commercial use of the space station.
This research supports development of manufacturing processes for new products using particle foam molding, which could benefit a variety of industries. It also has potential applications in packaging and cushioning materials
Sneakers aren't the first Earthly product to make their way into space in the name of science.
The ISS' microgravity environment serves as an unique testing ground for products as mundane as shower heads and soccer balls. As with the shoes, the idea is that doing these tests may improve the manufacturing process on Earth.
Here are some of the other everyday products that have made their way from space to us:
4. Soccer Balls
This isn’t Adidas’ first time blasting their merchandise off into low-Earth orbit. In July, 2019, a soccer ball was launched to the ISS in order to test out its spin speed, wobble, and spin axis in microgravity.
On Earth, the aerodynamics of soccer balls are tested using wind tunnel experiments. But in space, the physical constraints of these experiments are removed, which allows for the gathering of new data.
Researchers compare the data gathered on Earth with that gathered on the ISS in order to improve the behavior of free-flying soccer balls.
3. Shower heads
Another experiment going up to the ISS on Friday is the droplet formation study, which tests out water flow of Delta Faucet’s H2Okinetic shower heads in microgravity.
The experiment aims to test the effects of gravity on the formation of water droplet size in order to develop shower heads that conserve water.
Ironically, astronauts on the ISS can’t actually shower. Instead, they use liquid soap and water to rinse themselves down.
2. Space slime
Of all the experiments conducted on the ISS, this one had perhaps the most potential for getting messy.
In July, 2019, Nickelodeon sent its famous slime to the ISS. The gooey, green substance was launched to space as a way to educate children on the flow of fluids in a microgravity environment versus down here on Earth.
Onboard the ISS, the crew played with the slime, making slime filled balloons and slime bubbles, and recorded videos that show how the substance behaved up there.
1. Wine in space
But this red wine is not to be paired with the astronauts' nonperishable cheese. Instead, it was part of an experiment aimed at providing more information on the future of food and agriculture on Earth under the effects of climate change.
In a description posted to the NASA website, the experimenters explain their hypothesis:
The microgravity environment affects sedimentation and bubble dispersion in the liquid phase. For spaceflight samples, an increased reaction surface, limited by the oxygen available in the solution, is expected. As a consequence of the development of secondary metabolites, colloids and polyphenols are foreseen to be significantly influenced by this constrained environment.
The wine bottles are to spend 12 months onboard the ISS, before being returned back to Earth.
After the space wine lands on Earth, it will be analyzed to compare how wine ages in space, versus how it ages on Earth, within the same time period.
Again, the applications for the experiment may apply to both humans living on Earth and in space.
As the experimenters point out in their test description, the future of human space travel will involve storing food and medicine for a long period of time. "Learning more about how the space environment acts on complex liquids could lead to improved storage methods that reduce potential negative effects," they say.