Going Out with a Bang: The Final Days of the Rosetta Space Mission

Lasting 12 years, six months and 28 days, the Rosetta Space Mission didn’t just provide a detailed study of the Churyumov–Gerasimenko comet, it also pushed the boundaries of space exploration as we know it. Rosetta was a mission of firsts: the first spacecraft to orbit a comet nucleus, the first to fly alongside a comet as it headed towards the inner solar system and study the warming effects of the Sun on an object’s frozen surface, and, most importantly, the first to actually perform a controlled landing on a comet itself.

The historic mission ended on Friday 30th September as the probe spent its final few minutes drawing closer to the comet and transmitting a series of ever more astounding images back to the mission control base in Darmstadt, Germany. Once the transmission line fell silent, the confirmation came through: Rosetta had collided with the comet, completing its mission over 1.1 billion kilometres from its starting point on Earth.

Throughout the mission, Atos has worked closely with the Centre National d’Etudes Spatiales (CNES) and theDeutsches Zentrum für Luft- und Raumfahrt (DLR) to ensure that as much data as possible could be collected and shared with scientists back home.

Antoine Charpentier is just one of the Atos consultants who have made this project a success. And now, with the mission finally over, we caught up with him to talk about his reaction to Rosetta’s final days.

“Being part of such a significant project has been a unique experience,” comments Charpentier. “To be here at the end, it’s an amazing feeling and although I’m sad it’s now over, it was an honour simply to be there.”

Following the dispatch of the Philae landing craft, Charpentier worked to create an accurate 3D visualisation of the mission. To do so he had to merge two different digital terrain models, produced by the ESOC and OSIRIS teams, into a single model that could then be used to search for the Philae landing craft.

As Charpentier explains: “Discovering the exact location of Philae was vital. A lot of the information it was sending back to earth was linked with a specific area and attitude of the comet – essentially, we needed context to help in the analysis of the data.

“My team implemented a 3D visualisation software model that monitored the comet via the cameras on Rosetta. It took several months, but we eventually got a picture of Philae. The image was by no means conclusive – in actuality, it was nothing more than two pixels – but it was a starting point. From there we could begin to understand its orientation, where it was facing, and what samples it was testing. In the end, we confirmed its position to an accuracy of one meter.”

Strangely, when Rosetta was launched back in 2004 no one knew how the mission would end. As Charpentier explains: “There was no real plan in place until the collision was officially suggested in June 2015. With the comet’s orbit taking it further and further from the Sun, the amount of sunlight reaching the probe’s solar panels was steadily decreasing. ESA calculated that we would only be able to follow the comet until 2017, at which time Rosetta would simply run out of energy.

“Though it may sound extreme, a collision into the comet was judged to be the best way to guarantee we got every scrap of data we could. As ESA guided Rosetta down towards the comet – going as slowly as we could manage – we gathered as much information as we could, taking numerous instrument readings and photographs on route.”

The amount of scientific results generated by the mission is huge. So far, only five per cent of that data has been analysed and though the exploration is now at an end, when it comes to learning more about the comet, our planet, and the formation of the solar system itself, this is really just the beginning.

As studies into the Churyumov–Gerasimenko comet progressed, it was divided into 19 distinct areas all named after Egyptian deities. Rosetta now rests on the dusty terrain of the Ma’at region – named for Maat, the goddess of truth. For a tool of such scientific importance, it seems very fitting.

For a reminder on the full story of the Rosetta Mission click here. You can also enjoy more interviews with Atos consultants who worked alongside Antoine on the project: Laurent Peret and Dominque Hallouard.

About Antoine Charpentier

Antoine Charpentier is a spacecraft operation engineer and Atos consultant with a background in space ground segment and flight dynamics. He was involved in several space programs, like Rosetta, for which he developed the monitoring tools of the Science Operation and Navigation Center, and participated in Philae's comet landing, as well as the research campaign of the lander. Antoine is currently working on Curiosity, the latest NASA's Martian rover, and Microscope, a CNES satellite testing the principle of equivalence (a pillar of the theory of general relativity).