The signal broke a seven-hour wait of (1. AGONY) intensity and sparked scenes of (2. JUBILEE) at the European Space Agency’s mission control in Darmstadt. The team in charge of the Rosetta mission achieved what at times seemed an impossible task by landing a (3. ROBOT)(4. CRAFT) on a comet for the first time in history. The moment the tension broke came shortly after 1600 GMT when the Philae called home. “We are there. We are sitting on the surface. Philae is talking to us,” said a (5. JUBILEE) Stephan Ulamec, Philae lander manager at the DLR German space centre. “We are on the comet.” Andrea Accomazzo, the Rosetta flight operations director, added: “We cannot be happier than we are now.”But celebrations were tempered by the later discovery that the probe’s two harpoons had not fired to fasten the craft down in the (6. LOW) gravity. Scientists now think the probe may have bounced after first coming into contact with the surface. Ulamec said: “Maybe today we didn’t just land once, we landed twice.” The safe, if (7. CARE), (8. TOUCH) of the lander gives scientists a unique chance to ride (9. BOARD) a comet and study from the surface what happens as its activity ramps up as it gets closer to the sun. The first images beamed back from the lander’s descent revealed a dramatic (10. SCAPE) of pits and precipices, craters and boulders. However, there have been gaps in its radio link with the orbiting Rosetta mothership.