A lot of baking happens over the holidays, but this year, there's even baking going on in space. Unfortunately, the astronauts on board the International Space Station aren't allowed to eat what they baked.

As The Verge reports, ISS received a new space oven in November developed by Zero G Kitchen and Nanoracks. It's part of an experiment to see if baking in space is both possible and ultimately viable as a means of feeding humans delicious, nutritional hot food. With that in mind, the astronuats were tasked with using the space oven to bake space cookies, the ingredients of which was supplied by DoubleTree by Hilton.

We made space cookies and milk for Santa this year. Happy holidays from the @Space_Station! pic.twitter.com/sZS4KdPmhj — Christina H Koch (@Astro_Christina) December 26, 2019

Baking in space forms a challenge because heat doesn't rise and the object being baked doesn't stay in one location. A conventional oven therefore wouldn't work. The space oven overcomes these challenges by holding the ingredients, in this case the cookie dough, within a bag. The oven compartment is a cylinder and heat is produced across its entire surface with the food suspended in the middle. That way, heat is guaranteed to be applied evenly. You can see how the oven works in a video posted by Doubletree by Hilton.

Christina H Koch and Luca Parmitano, both residents on ISS right now, undertook the cooking experiment and ultimately baked five cookies. Although the space oven is simple to use, it was difficult to know how long to cook each cookie for. After three "doughy" cookies, they managed to produce two that were "nice and brown."

Unfortunately, none of the cookies can't be eaten by the astronauts for fear of them not being properly cooked and the impact that could have on their health. So instead, the cookies have been frozen and will return to Earth for analysis. However, some pre-baked cookies were transported to ISS as well so there was a Christmas treat for the astronauts to enjoy.