Graphene tested in microgravity for first time
Everyone's favorite wonder material, graphene, has been wrung through just about every experiment on Earth – but how does it fare beyond our planet? A European team has tested graphene under microgravity conditions for the first time, an important step towards realizing the material's promising applications in space.
For those not familiar with the stuff, graphene is made of sheets of carbon just a single atom thick, and it boasts an impressive array of superpowers. It is an excellent conductor of heat and electricity, and it's incredibly strong, light and flexible. This combination makes graphene perfect for use in space.
But until now, graphene has only been tested on solid ground. An international research team, made up of scientists from the University of Cambridge, the European Space Agency and an initiative called the Graphene Flagship, looked to change that by experimenting with the material in microgravity.
Due to its excellent thermal conductivity, the graphene was being tested as a component in a loop-heat pipe. These are commonly used as cooling systems in satellites, transporting heat away from electronics through a cycle of evaporating and condensing a fluid. The team wanted to test whether the system's efficiency could be improved by coating the metallic wick – the part that evaporates the fluid – in graphene.
Initial ground tests showed that the material did help. A graphene-coated wick was able to improve the heat transfer from the electric components and allow the fluid inside to flow through faster.
The next step was to take several loop-heat pipes, some with graphene-treated wicks and some with regular ones, aboard a parabolic flight to create a microgravity environment. On these kinds of flights, the plane alternately climbs and dives in a regular rhythm, creating a weightlessness effect for about 23 seconds at a time. Sure enough, the loop-heat pipes with graphene-coated wicks performed more efficiently than the control systems.
After that promising proof-of-concept study, the researchers next plan to develop a prototype of the system that can be tested onboard a satellite or space station.
"We are aiming at an increased lifetime and an improved autonomy of the satellites and space probes," says Marco Molina, Chief Technical Officer of Leonardo, industry partner on the project. "By adding graphene, we will have a more reliable loop heat pipe that can operate autonomously in space."
The team describes the project in the video below.
Source: University of Cambridge