
After twelve months of silence, Philae and Rosetta prepare for the final stage of their mission.
Philae, the pioneering probe that landed on the Comet 67P/Churyumov-Gerasimenko, was disconnected on Wednesday from all communication with Earth.
The machine was the first to land on a comet. Philae sent home a lot of data related to how a comet would look like up-close and what its composition would be and captured the attention and the imagination of people back on Earth.
However, Philae had been silent for over 12 months. NASA decided to preserve the energy remaining on Rosetta and stop trying to reconnect with the probe.
Rosetta, the spaceship that launched the probe, will stay some other two months orbiting the comet, and then it will crash land on the 30th of September, joining Philae on the surface of the planet.
Philae was launched together with Rosetta in March 2004, as part of a European Space Agency mission that valued $1.4 billion.
Their trip lasted almost a decade and covered four billion miles before reaching the comet’s orbit in August 2014.
Rosetta released the probe three months after the arrival at their target, but Philae failed to land properly and bounced on the surface of the comet until it reached a ditch.
While the probe was kept away from the rays of the Sun, which was its primary source of energy, Philae still managed to run experiments and transmit data back to Earth before it entered a stand-by mode.
In June 2015, the comet approached the Sun, and Philae got an unexpected energy boost which reactivated its circuits. The communication was reestablished for a period, but then on the 9th of July 2015, the probe went completely silent.
Rosetta had been continuously looking for signs of the lander, but it failed to obtain any result even when it got as close as 10 km away from the comet.
After six months of silence, the ground controllers started to believe that Philae shut down completely. However, they still monitored for its activity, just in case it would suddenly decide to revive. But another six months have passed, and the space agency decided to close the project and prepare to end the mission.
The comet is moving further away from the Sun, which means that soon Rosetta will remain without any energy left. The scientists decided to preserve Rosetta’s energy so that it will continue to be able to gather information for the final part of its mission.
Image Source: Wikipedia