14 DAY TRIAL // Traditional propulsion systems are highly inefficient when it comes to space travel, mostly because they have to carry fuel on board, thus after covering a fair amount of distance, spacecrafts often find themselves drifting helplessly through the immensity of space. The effect can be clearly observed even with satellites locked in Earth's orbit, which usually have a lifespan of only a few years, or decades at best, before consuming most of their fuel.
A better solution would be to harness energy such as solar wind for example, as the spacecraft travels through space. The basic idea is that a giant sail would capture enough solar wind to power a spacecraft through space without the need of additional fuel of propellant. Although space sails are not entirely a new design, Dr Pekka Janhunen believes that his new electric solar wind sail could revolutionize space traveling.
After a study of nearly two years at the Finnish Meteorological Institute, Dr Pekka Janhunen created a space sail that harnesses the electrical properties of the solar wind in order to propel itself. Most of us do not realize it, but solar wind has an extremely high potential, being responsible, amongst others, for the aurora borealis phenomenon and for the magnetic storms.
Basically, the electric wind solar sail consists of long metallic tethers kept under a continuous positive charge with the help of a solar-powered electron gun. As solar wind interacts with the charged tethers, a small Coulomb force is exerted in the form of thrust, thus propelling the spacecraft.
"We haven't encountered major problems in any technical fields so far. This has already enabled us to start planning the first test missions," said Dr Pekka Jahunen. The sail consists of multiline micrometeoroid-resistant tethers made out of metal wires, bonded together in different geometries, and was developed by Electronic Research Laboratory of the University of Helsinki.
"The electric sail might lower the cost of all space activities and thereby, for example, help making large solar power satellites a viable option for clean electricity production. Solar power satellites orbiting in the permanent sunshine of space could transmit electric power without interruptions by microwaves to Earth. Continuous power would be a major benefit compared to, e.g. ground-based solar power where storing the energy over night, cloudy weather and winter are tricky issues, especially here in the far North," says Dr. Pekka Janhunen.
The new electric solar wind sail was invented during a study carried out at the Finnish Meteorological Institute, involving interactions between the solar wind and planets and their atmospheres.