Investigating advanced orbital mechanics, the space agency has concluded that it's possible to build a hybrid solar-sail/electric-propulsion satellite that could hover over either of the Earth's poles by balancing the pull of the Earth and the Sun.

Orbiting satellites continuously monitor the world from above and are invaluable for everything from weather forecasting and navigation to military operations and radio and TV broadcasts. The problem is that the coverage is not as universal as one might wish. True, a string of satellites, for example, can be placed in geosynchronous orbit to look down on the Earth, but looking at high latitudes of the Arctic and Antarctic require satellites in low-Earth polar orbits that can only pass over the region for a few minutes at a time.

As part of its five-year VisionSpace project, ESA examined the mechanics of orbital satellites to look for unconventional ways of approaching space missions. One idea was to apply Non-Keplerian Orbits (NKO) by using solar propulsion techniques similar to the one that put the Kepler space telescope back into commission.