Space.com is reporting on a 60km comet-like body in Lagrangian orbit around the Sun, locked to Uranus’s leading Trojan Point. This means a distant, but fairly accessible supply of water-ice, hence: reaction mass, hydrogen and oxygen for robotic miners if we can just get them there with an energy source.
‘The sun and Earth have two Trojan points, one leading ahead of Earth, known as the L-4 point of the system, and one trailing behind, its L-5 point. The sun and other planets have Lagrangian points also, with asteroids seen at those the sun shares with Jupiter, Neptune and Mars. Scientists thought the Trojan points of Uranus, the seventh planet from the sun, were too unstable to host asteroids.
Original news: http://rss.slashdot.org/~r/Slashdot/slashdot/~3/5PpoqFJrcnQ/story01.htm