The Rosetta orbiter lies in a vast empty space, inhabited only by its orbital companion – a 4 Km wide ball of ice and dust, spitting out gases and other material as it is warmed by the Sun’s rays. It’s next mission milestone comes on August 13th, 2015, when the duo reaches perihelion, the closest point to the Sun in their orbit. It will be the first time a spacecraft has the opportunity to study the outgassing and behaviour of a comet as it orbits close to the Sun. So far the comet 67P/ Churyumov-Gerasimenko has been slowly increasing in activity, releasing more gas, dust, and water vapour into space as the Sun heats its surface and blasts away the material.
However, this is not the final milestone for Rosetta, as the mission has been approved to continue operations through September 2016, to observe the changes in the comet as it once again moves away from the Sun in its orbit, toward its aphelion.
The most fascinating part of this news however is that the mission has been approved to attempt a landing on the surface of the comet. The orbiter, at the end of its science mission in orbit, will use its jets to attempt a soft landing on the comet surface, giving scientists more data that we had ever bargained for twenty years ago when the mission was first being conceived. It will take approximately 3 months for the probe to perform the slow and careful landing.
Currently the orbiter is keeping its distance and observing the comet from afar since it is releasing material that could damage Rosetta’s systems. Luckily the Philae lander woke up last week and has been communicating with the orbiter ever since, giving valuable science data about the surface of the comet and sending back data on its fate during the November 2014 landing that led us to eventually lose contact.
This mission is not without its difficulties, but it is one of the most ambitious missions ever conceived, due to the comet’s unique orbit and extremely small size. It has been a slowly unfolding story of science and engineering to watch the successes and setbacks of Rosetta and Philae, and I am excited to follow the story for at least another year.