[Jason]

Spacecraft could be built to surf “gravitational tubes” between planets and moons, allowing longer and cheaper journeys around the solar system, scientists believe.

A network of looping passageways created by the competing gravitational pull of celestial bodies is being mapped by researchers, who believe that they could allow spacecraft to move effortlessly between orbits.

“There are low-energy passageways winding between the planets and moons that would slash the amount of fuel needed to explore the solar system,” said Shane Ross, a professor of engineering science and mechanics at Virginia Tech university, in the United States. “You can think of them as natural conduits through the solar system.”

The tubes — constantly shifting with the motions of the planets and moons — would be a particularly helpful way of exploring the moons of Jupiter or Saturn, Professor Ross told the British Science Festival in Guildford yesterday.

http://www.timesonline.co.uk/tol/new...cle6829727.ece