The EU has agreed funding for a project to create the largest and fastest man-made craft in history.
In a three-year effort, the Finnish Meteorological Institute is to head an international project to create an electric sail, which uses the solar wind as its thrust source and therefore needs no fuel or propellant.
The electric solar wind sail could enable faster and cheaper access to the solar system, says the Institute.
“In the longer run it may enable an economic utilisation of asteroid resources,” it suggests. “A related but simpler device (the so-called plasma brake) can be used for deorbiting satellites to address the space debris issue.”
The solar wind is a continuous plasma stream emanating from the sun. While the pressure it exerts is tiny, over the huge area of a thin foil sail it adds up to a reasonable force, and provides almost unlimited acceleration. Charging the sail electrically increases the effect.
According to estimates, a full-scale electric sail could produce one newton continuous thrust and weigh only 100 kg. In some situations, says the team, the performance level of the electric sail could be as much as 1,000 times greater than that of current chemical rockets and ion engines.
The sail will consist of long, thin metallic tethers which are kept in a high positive potential by an onboard solar-powered electron gun. The charged tethers repel solar wind protons so that the solar wind flow exerts a force on them. Angling the sail allows the spacecraft to move in any direction in the same way as maneuvering a yacht’s sail.
Yesterday, the kickoff meeting for the project was held at the Finnish Meteorological Institute, and funding of 1.7 million euros was agreed.
The first stage of the project wil be to build laboratory prototypes of several key components. The working principles of the electric sail and the plasma brake will be tested by the Estonian ESTCube-1 and the Finnish Aalto-1 nanosatellites.