Following recently performed experiments in weightlessness, a team of TU Delft researchers has found that graphene sheets may be used as light sails for spacecraft.

As part of the ESA's yearly Drop Your Thesis! program, in which teams of university students submit proposals for microgravity experiments, scientists from TU Delft have worked with experts from across Europe to develop their experiments. They subsequently tested them at the ZARM drop tower at the Center of Applied Space Technology and Micro gravity in Bremen, Germany.

To create extreme microgravity conditions, down to one millionth of the Earth’s gravitational force, both teams used a capsule containing their experimental setup and catapulted it up and down the 146 meter high tower, leading to 9.3 seconds of weightlessness.

Team GrapheneX examined the use of graphene-based materials as solar sails for spacecraft propulsion. The idea behind the GrapheneX project is to use light from the sun or a laser beam to transfer momentum to matter and displace sails made of graphene. During the experiments, the researchers shone laser light on free floating graphene membranes of a few millimeters in diameter and measured what happened to these membranes.

“We are very pleased with the results,” said a GrapheneX team member. “We observed the graphene sample moving when we irradiated it with a laser. This movement seemed to be much faster then we expected. A lot more work is needed before this technique can be used in space. But for a first test it is quite good.”

A scientific paper is not in the making yet, however. “We need to perform more experiments before we can say for sure that the graphene moved due to the light particles pushing them. It may also have moved due to a temperature gradient, or pressure differences.”



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