Quote:The signal broke a seven-hour wait of agonising intensity and sparked scenes of jubilation 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 robotic spacecraft 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 jubilant 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 ultra-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 precarious, touchdown of the lander gives scientists a unique chance to ride onboard 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 landscape of pits and precipices, craters and boulders. However, there have been gaps in its radio link with the orbiting Rosetta mothership.

Quote:After long discussions the current status is that we had in fact three landings on a comet. At first touch down both the AOCS thruster and the anchors were not activated for reasons yet not fully understood. Philae bounced two more times. The first bounce took two hours and was possibly up to one kilometre. The second bounce was then only 20m. Since then the Lander appears to be stable and upright on the the surface. FSS is commencing nominal and next radio link is expected for about 7:30 CET. If radio contact is established we are back on the mission track. No deployment though until situation is clear. All instruments are working and we received data until end of radio link. All active instruments concur with the bouncing and a rotation of the lander during the first bounce in fact spin stabilising the Lander.