At-Home STEM Activities: Baking in Space

What are some of the challenges of living in space that astronauts face each time they leave Earth? And what technologies can help make things easier? This week we’re focusing on what it’s like to live in space and some of the problem-solving needed to help us embrace life out there. 

You may have heard about astronauts baking cookies in space for the first time earlier this year- that was a very big deal because of the number of challenges those cookies had to overcome. Engineers and scientists worked together to address obstacles related to both zero gravity and living within a confined space. 

Even when using a mixer, cookie dough can make a mess- the flour can become airborne, liquids can splash, and then there are the dirty dishes to wash.

Certainly, the biggest problem for baking in space is zero gravity, but there are other factors that space kitchens have to address as well. Let’s look at some of these in more detail. First of all, there’s the issue of cleanliness- anyone who has spent some time making food knows that it can be pretty easy to make a mess. That can be especially true of lightweight ingredients like flour which can scatter when you breath on them or small crumbs from prepared food that break off easily. In a space station or ship, these types of materials can get into electronics, air filters, and even be inhaled by the astronauts, so it’s very important to keep them contained whether we’re talking about mixing dough together or serving up dessert (in fact, pecan sandies were discontinued as a snack for astronauts because they crumble so easily). And water is at a premium up there since it is so heavy to transport, so clean up would need to be easy. In a confined space, there would be no way to vent smoke if something caught on fire, so we’d have to be really paying attention to temperatures. 

Gravity keeps this cookie dough on my pan, but that wouldn’t work so well in zero gravity.

Being in a gravity-free space adds even more wrinkles to our plans- an oven on Earth bakes cookies using convection as hot air rises from the heat source, but this only happens because the hotter air is less dense (and so lighter per volume) while cooler air is denser. In zero gravity, weightlessness means that convection doesn’t happen on its own. Gravity is also what keeps the cookies on the pan during baking on Earth- in space cookie dough might be sticky at first, but, as it bakes, the cookie might slip off the pan. And we’re not really sure about what shape cookies we’d get.  

All of this together means that baking cookies in space is a big deal. And the cookies made earlier this year took some special equipment, multiple tries, and a long time. 

Now’s your chance to think like an engineer- how would you bake cookies and other foods in space? Keep in mind all of the things mentioned above and create a design. How would you minimize spills and simplify clean-up? What heat source would you use? How can you get the heat from the source to the unbaked items? What kinds of pans/trays/molds would you need for baking? For cake batters and bread dough you might need alternative methods- for example, cake batters might separate into small spheres of liquid, and how would bread rise differently in zero-gravity? Once you have your design, you can compare it with the team that tackled the challenge on the International Space Station. Here’s how they did it.