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Voyager 1 hadn't used its four "trajectory correction maneuver" (TCM) thrusters since November 1980, during the spacecraft's last planetary flyby — an epic encounter with Saturn. But mission team members fired them up again Tuesday (Nov. 28)... The little engines passed the test with flying colors, NASA officials said. "The Voyager team got more excited each time with each milestone in the thruster test," Todd Barber, a propulsion engineer at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement. "The mood was one of relief, joy and incredulity after witnessing these well-rested thrusters pick up the baton...

"The gas jets coming out of the comet - they are acting like thrusters and are slowing down the comet," said flight director Andrea Accomazzo. The European Space Agency official was speaking this week at the Royal Aeronautical Society in London. He was describing how his team has learnt to fly Rosetta around the 10-billion-tonne, 4km-wide body with remarkable precision. Navigators use a system of landmarks on the comet to understand how it is rotating and moving through space. This information is fed into a model that helps plan a trajectory for the satellite. And it was while running this...