ESA has just confirmed that the Philae lander successfully landed on the surface of the comet 67P/Churyumov-Gerasimenko. It’s the first time that a spacecraft arrived from Earth manages to land on the surface of a comet. This success is the culmination of many years of effort but it’s just the beginning of a new phase of the Rosetta mission.
The Philae lander touched down in the area until a few days ago was referred to simply by the letter J because it was chosen among candidates marked with various letters. ESA asked the public to propose a real name to the area and a jury composed of members of the Philae team selected Agilkia. It’s the name of an island on the Nile River where a number of ancient buildings were moved from the island of Philae when the latter was flooded during the construction of the Aswan Dam.
The landing on the comet 67P/Churyumov-Gerasimenko is the culmination of a day of maneuvers and decisions. During the European night there were four stages of the Go / No Go type, which means there were four times when the mission control center assessed whether there were the conditions to continue the operations or they should interrupt them to try again later.
It was decided to proceed with the mission but not everything went smoothly. The thruster that was supposed to be used during landing to prevent Philae from bouncing on the ground due to the comet’s reduced gravity doesn’t work. That’s a basic nitrogen system placed on top of the lander but the tests performed last night were negative.
As a result, Philae had to rely solely on its harpoons to anchor to the ground of the comet 67P/Churyumov-Gerasimenko. It was decided to proceed despite this problem because there was no way to repair the thruster remotely. Postponing the landing would have been useless so they had to hope that the operation went fine anyway.
It was just past 10 AM in Central Europe when the separation of the Philae lander from the Rosetta space probe was confirmed. This moment marked the beginning of seven hours of terror, meaning the seven hours it took for Philae to land because it took place at a very low speed to try and reduce the risks. During those hours, the Philae’s instruments started sending data to ESA. The expression is a tribute to the seven minutes of terror experienced during the maneuver of landing on Mars of the Mars Rover Curiosity.
The Rosetta / Philae has been ambitious from the beginning and the results already achieved are truly remarkable. Now a new phase of scientific research begins at a new level never reached before. Rosetta is expected to continue its analyzes from the orbit of the comet 67P/Churyumov-Gerasimenko for at least another year but now it will be joined by Philae with its analyzes from the surface.