The signal broke a seven-hour wait of agonizing 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.”
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.
The feat marks a profound success for the European Space Agency (ESA), which launched the Rosetta spacecraft more than 10 years ago from its Kourou spaceport in French Guiana. Since blasting off in March 2004, Rosetta and its lander Philae have travelled more than 6bn kilometers to catch up with the comet, which orbits the sun at speeds up to 135,000km/h.
“We are the first to do this, and that will stay forever,” said Jean Jacques Dordain, director general of the ESA.