An electric solar wind sail could provide a fundamentally new, economically sustainable way to approach bi-directional manned Mars flights, new research says.

The E-sail is a novel propellantless technology that was invented in Finland in 2006.

The E-sail utilises long, charged tethers to convert natural solar wind momentum flux into spacecraft thrust.

According to Pekka Janhunen, researcher in the Finnish Meteorological Institute, the E-sail could make asteroid mining feasible by providing essentially free logistics in the solar system outside of Earth's magnetosphere.

"After finding a suitable water bearing asteroid, a mining unit could be sent by the E-sail to extract the water from asteroid soil," Janhunen said.

This can be done by heating the material and letting the evolving water vapour condense in a cool container.

When the container is full, it is separated from the mining unit and transported with an E-sail in to the orbit of Mars or Earth, where it is split into hydrogen, oxygen and liquefied.

The liquid hydrogen/oxygen fuel can be used to fill the tanks of manned vehicles travelling between Earth and Mars.

"With cheap propellant available in Mars orbit, there is also the option of fully propulsive landing on Mars which eliminates the need of a massive and expensive heat shield," the authors noted.

The running costs of the E-sail technology are not expected to much exceed those of maintaining the International Space Station, they concluded.

The research appeared in the journal Acta Astronautica.

--Indo-Aisan News Service

na/nt/vm