A new design for an ion engine promises up to 10 times the fuel-efficiency of existing electric propulsion engines, according to tests by the European Space Agency. The new thruster could be used to propel craft into interstellar space, or to power a crewed mission to Mars, ESA says. Ion engines work by using an electric field to accelerate a beam of positively charged particles – ions – away from the spacecraft, thereby providing propulsion. Existing models, such as the engine used in ESA’s Moon mission, SMART-1, extract the ions from a reservoir and expel them in a single process.
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