Yesterday at 17:03 Central European Time, the brave little landing module of Rosetta dispelled all doubts and landed on comet 67P / Churyumov-Gerasimenko.
"We landed, and Phil survived the landing. We landed in the right place," said anxious Jean-Jacques Dordain, director general of the European Space Agency, during a press conference after landing on Wednesday. Dordén also confirmed that Fila transmitted signals to the orbit of the Rosette spacecraft, that all power systems were operating normally. “We have communication and power, so we can start collecting data,” he said.
Of course, the landing did not go smoothly, so we need some time to decipher the data in order to understand what happened during the dramatic rendezvous of comet and Phil. "Landing on a comet is quite difficult ... but it is also difficult to understand what happened during this landing and after it," said Phil Lander, manager Stefan Ulamek. “We know for sure that we landed and landed on a comet ... we had a very clear signal. We also received data from the landing module. This is very good news,” continued Ulamek. “But the bad news is that the fixing harpoons apparently did not fire, so the descent vehicle is not attached to the surface. Now we are thinking about how the situation can develop further,” added Ulamek. On Earth, Phil weighs 100 kg, but on comet 67P, because of the extremely weak gravitational field, the descent vehicle weighs less than a coin. This factor has led to the planning of a complex landing system, which is more like an exciting mechanism. Phil cannot just land on this comet, he had to fix himself on the surface. Phil could collide with the comet at too high speed, and the robot could bounce back into space. And it turns out, the descent vehicle bounced off, but Phil's damping landing system saved the vehicle.
“Some of the data show that the descent vehicle may have risen again after it has already landed,” said Ulamek. After analyzing the radio signals and data transmitted from the solar generator of the landing module, Ulamek suggested that the descent vehicle "started and began to turn itself" after a rebound from the surface. The turn was most likely caused by a flywheel (also known as reaction wheels used in a spacecraft to maintain stability in flight), which was turned off when the module made its initial landing. Therefore, it seems possible that the descent vehicle landed, rose again, as the anchor harpoons did not work, and then 2 hours later landed a little further from the original landing site. “Maybe today we even put the module on even once!” He added. Rosetta went beyond the horizon in relation to Phil, so the signal was lost, which was to be expected. However, Paolo Ferri, the head of the ESA mission management, indicated that the signal from the Phil module had disappeared a little earlier than predicted. This was probably caused by hills and waves on the rocky surface of the comet.