Tiedote - Electric sail test mission with first Estonian satellite

Photo: Antonin Halas

The electric solar wind sail was invented in Finland in 2006 and withits revolutionary efficiency it promises faster and cheaper access tothe solar system for small and medium-sized spacecraft, potentiallyenabling a host of new scientific and commercial space applications.

Now the University of Tarto together with Finnish MeteorologicalInstitute and other European partners particularly from Estonia andFinland are joining forces to develop the first-ever orbital test ofthe electric sail physical principle and technology. The ESTCube-1 isa 1 kg nanosatellite and Estonia's first satellite, with plannedlaunch in 2012. It will open a 10 meter tether made of very thin metalwire and charge it to 200 V with a miniature onboard electron gun. Asthe satellite flies in its orbital path through the ionospheric plasma, the speed difference between the satellite and the plasma induces a small force on the tether which can be measured. The measurement is used to validate and calibrate existing plasma physical theory of the electric sail effect.

Later, production-scale electric sails will use much longer tethersand will fly in the solar wind, utilising the much larger speeddifference between the satellite and the fast-moving solar wind. Thesolar wind exists everywhere in the interplanetary space with theexception of Earth's surroundings which are protected from the solarwind by Earth's magnetic field.

According to estimates, electric sails can be orders of magnitude moreefficient than existing methods (chemical rockets and ion engines) formany transport tasks in the solar system. Scientifically, they couldrevolutionize solar system science by enabling fast missions out ofthe heliosphere and affordable sample return missions from planetary,moon and asteroid targets. Commercially, electric sail could enablethe economic utilization of asteroid resources for e.g. orbital rocketpropellant production or orbital manufacturing of structuralparts. These capabilities could be used for making solar powersatellites an economically attractive global energy solution. Solarpower satellites have large solar panels and send electric power toEarth using microwaves. Relative to ordinary ground-based solar panels they have the key benefit of producing continuous power which is independent of surface illumination and weather conditions.

More information:

Researcher Pekka Janhunen, tel. +358 9 1929 4635, pekka.janhunen@fmi.fi

Pictures and animations about electric sailESTCube-1 mission