14 DAY TRIAL // Currently, the materials used to build satellites only have a life span equal to that of the mission they are used for. A new effort by the European Space Agency (ESA) seeks to change that, by developing materials that can be reused even after they are launched in Earth's orbit.
Satellites are usually made up of a number of hard-to-come-by, expensive materials that cannot be readily found in great supply. As such, every mission end represents a significant loss, both for ESA and other space agencies and satellites constructors.
Through the Clean Space initiative, the European organization seeks to develop reusable materials that would not be turned into orbital debris once a satellite mission ends. This is a significant problem today, when numerous orbits around Earth have become clogged with fast-traveling space junk.
There could potentially be many ways to convert or recycle space hardware for multiple missions. One idea would be to make satellites out of modules. As one mission ends, the modules separate, and then rearrange to form another spacecraft, with new components added as needed.
Alternatively, satellites could in the future become a food, water, raw material or fuel source for spacecraft that come after them. This type of cradle-to-cradle approach is currently being implemented in some manufacturing chains here on Earth.
“ESA’s new invitation for ‘Sustainable Materials Concepts’ is seeking companies to study various concepts of this approach, including considering the kinds of materials that could be reused as biological or technical nutrients – serving as resources for new other processes,” experts at the agency say in a recent statement.
One of the most significant challenges associated with this type of research is finding a power source for the conversion process. Scientists need to figure out whether old spacecraft would be recycled by dedicated satellites, or by some type of internal process that would eventually break them apart.
For example, new materials for space missions can be obtained from the wide variety of metal alloys used to create a satellite through grinding the stuff into tiny pieces. A large-scale 3D printer could then create the bus for a new satellite directly in low-Earth orbit. However, this process would require a lot of energy.
“Also under consideration: what sustainable materials might replace current space-grade materials such as titanium and aluminum alloys or carbon-fiber epoxy resins? And how might the use of materials as biological or technical nutrients work in practice?” the ESA statement says.