An artist has fun with an image from NASA, imagining an astronaut with a fresh cookie in space. (AP)

An artist has fun with an image from NASA, imagining an astronaut with a fresh cookie in space. (AP)

Astronaut Luca Parmitano watches food packages float inside the International Space Station. Zero gravity presents challenges for food preparation. (NASA)

Astronaut Luca Parmitano watches food packages float inside the International Space Station. Zero gravity presents challenges for food preparation. (NASA)

Samantha Cristoforetti takes a sip aboard the International Space Station. Droplets and crumbs can float into equipment if astronauts aren’t careful. (NASA)

Samantha Cristoforetti takes a sip aboard the International Space Station. Droplets and crumbs can float into equipment if astronauts aren’t careful. (NASA)

The Cygnus resupply spacecraft arrives at the International Space Station. Future deliveries could include food-growing and food-preparation technology. (NASA)

The Cygnus resupply spacecraft arrives at the International Space Station. Future deliveries could include food-growing and food-preparation technology. (NASA)

Making an Oven for Space

Posted: September 3, 2019

Remember how cool it was to find out that baking was so simple you could do it in a little toy oven that used a lightbulb for heat? Well, space ovens aren’t quite Easy Bake Ovens. Heat behaves differently in space, so space ovens and dough makers have an unusual set of problems to solve.  

“We have to comply with a whole set of safety regulations,” says Mr. Marcu. None of the oven’s surfaces can become hotter than 113 degrees Fahrenheit. If you’ve ever baked bread, you know that’s just not hot enough. On Earth we bake bread at around 400 degrees. A space oven also cannot be preheated. And by no means may astronauts open a hot oven and take bread out. Why? Thermal convection on Earth mixes air up. That doesn’t work in space. So if you opened a hot oven, a bubble of burning hot air would be floating through the space station! Astronauts would have to duck! Besides this, a space oven will be safe only if it uses no more than a tenth of the power used by an oven on Earth.

Mr. Marcu and his team have thought of some solutions. “We basically put the baking product, the dough, inside the cold oven and start heating it up,” he says. “Once it’s almost done, we start cooling it down.” Their process isn’t perfect yet. The bread in the oven dries out while it cools. They are working to design an oven that adds water while baking. 

The researchers are working another puzzle too. They test dough recipes. Which will last as long as a space mission? At what temperature must the dough remain so nothing grows in it? The last thing the researchers want is to contaminate the space station with bacteria.