Rosetta gears up for comet’s dramatic solar approach

The Imperial-designed plasma sensor on board the Rosetta spacecraft is preparing to measure heightened activity of comet 67P as it approaches the Sun. It follows the successful landing of the Philae daughter craft on Tuesday 11 November, which despite operational challenges, including the failure of the harpoons intended to stabilize the craft, managed to gather surface data on 67P and return it to the mothership. While not directly involved in Philae, the Imperial-led Rosetta Plasma Consortium (RPC) package of instruments did prove important in the nail-biting descent, as principal investigator Chris Carr (Physics) explains. "Our magnetometer sensor on the Rosetta orbiter, which measures the magnetic field around the comet, was compared against the magnetometer sensor on Philae," he said. "In the end this information turned out to be really crucial in diagnosing the final orientation of the lander, since the two magnetometers were used like compasses to understand the rotation and pointing direction of Philae." On Saturday 15 November Philae went into hibernation owing to a lack of sunlight reaching its solar panels - a consequence of the unplanned landing in a shaded area of the comet. Engineers at the European Space Agency (ESA) are still leaving open the possibility that Philae might be woken up if its solar panels start to receive more sunlight as the comet approaches the Sun. For Rosetta and the RPC specifically though, the mission continues apace, and they will now investigate the plasma environment around the comet, and how this interacts with the solar wind - the charged particles that stream constantly from the Sun.