Mission accomplished. The Rosetta is a spacecraft that has been on a 10-year-long mission to catch a comet and land a probe on it. It is the first spacecraft to accompany a comet on its journey to the inner solar system. After being launched in 2004, Rosetta arrived at the target comet this past August, and its robotic lander named Philae made contact with the comet today – on November 12th, 2014.
Rosetta is named for Rosetta Stone, a block of black basalt – not the language learning tool – that was originally inscribed with a royal decree written in Egyptian hieroglyphics, Egyptian Demotic and Greek. The spacecraft’s robotic lander is called Philae, named after an inscribed obelisk found on an island in the Nile River.
Completing this task was not simple. The European Space Agency (ESA) that started this project had to go through intense planning and preparation to get their spacecraft to land. Controlled by workers at the ESA, Rosetta had to travel all the way to the comet and follow it enough so they could plan in advance where to eject Philae from and where Philae could land. If Philae landed just a short distance from the planned landing space, it could unstabilize the lander and ruin the whole mission. An hour after the landing signal came through, the ESA’s head of mission operations said that Philae’s two harpoons, which are used to secure it in place, had not fired completely. This raised fears about the lander’s stability and chances of clinging on to the comet for a long time. However, to ensure that no errors would be made, and because the landing was happening at such a great proximity from radio signals, the descent was pre-calculated and set to run automatically.
The team faced various worries about the landing, but it was successful in the end. Philae’s descent happened at walking-speed, so the ESA team anxiously watched the mission go down for the seven-hour livestream in its entirety. And you can watch some parts of it here, too.