After journeying through space for more than a decade, ESA's Rosetta spacecraft has successfully accomplished one of its major and most critical tasks, to land the Philae lander on Comet 67P/Churyumov-Gerasimenko.
At just after 8 a.m. PST on Wednesday, Nov. 12, mission controllers at the European Space Agency's mission operations center in Darmstadt, Germany, received the signal confirming that the robotic lander has successfully touched down on 67P/C-G making history as mankind's first successful attempt at landing a spacecraft on a comet.
"Our ambitious Rosetta mission has secured a place in the history books: not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a lander to a comet's surface," said ESA's Director General Jean-Jacques Dordain.
The space agency, however, said that the status of the washing machine-sized probe is still being determined after it touched down. It also remains unclear how the Philae lander has landed.
Although successful, the landing of the probe has had some hitches. Two harpoons that were meant to tether the robotic lander so it won't bounce off failed to fire. Scientists are currently looking for ways to refire these harpoons but this operation poses some challenges in itself.
Rosetta project lead investigator Mark Bentley said that because of the very low gravity on the comet, the lander could possibly recoil if the harpoons are deployed.
Philae lander manager Stephan Ulamec said that initial data received from Philae suggest that it may have bounced off the comet's surface and came back down again.
"Some of these data indicates that the lander may have lifted off again, we touched down and we bounced very slowly as the landing gear worked perfectly well and it was designed to damp the majority of the impact energy," Ulamec said. "Maybe today we didn't just land once, we even landed twice!"
ESA's Head of Mission Operations Paolo Ferri said that signal from Philae was lost earlier than predicted and this could be caused by the boulders and hills on the craggy surface of the comet. Still, he said that the landing of Philae was very accurate with the probe landing very close of the landing ellipse's center.
Scientists have acknowledged from the start that landing the probe on the comet does not guarantee success but the probe appeared to have overcome many of the potential pitfalls. Researchers hope that the mission could shed light on the origins and evolution of the Solar System.
