Astronauts are finally mixing concrete in space, aboard the ISS

Though concrete is the most common building material on Earth, its weight means it has rarely been considered for use in space. 

That could soon change, thanks to a new experiment that will test the properties of the ubiquitous building material in the microgravity conditions aboard the International Space Station, a press statement reveals.

The new experiment, part of German astronaut Matthias Maurer's "Cosmic Kiss" mission, will see Maurer hand-mix a small sample of concrete in space. To do so, he will use a specially designed mixer and a large inflatable bag. The experiment will allow scientists to analyze the effect that gravity — or a lack thereof — has on the concrete curing process. The findings will inform construction plans for future space habitats set to be built on the Moon and Mars by future crewed missions, including NASA's Artemis missions.

Could blood-bound space dust provide the answer?

Though it's been around since before the time of the Ancient Romans, concrete is a heavy material that would be prohibitively expensive to transport from Earth. As such, the scientific community has largely focused on alternative solutions for building materials in space.

Last year, for example, University of Manchester professor Dr. Aled Roberts and a team proposed binding extra-terrestrial dust, also known as regolith, together with astronaut blood and urine. In a September interview with IE, Dr. Roberts said crew diets would "need to be supplemented with additional protein, calories, and water to make up for the deficit arising from [blood extraction]." 

It's not the first time a concrete experiment was conducted aboard the ISS. In 2019, NASA sent another small concrete experiment up to the orbital lab. Findings from that experiment will inform the parameters of the new one. The outcomes of this new research could lead to better concrete mixing strategies as well as better combinations of materials. It may also lead to researchers suggesting a new form of concrete, similar to the one proposed by Dr. Roberts, built using off-world materials.