The Rosetta Probe has awaken and is preparing to pass over comet 67P. Launched in 2004 by the European Space Agency, Rosetta has spent the last 2.5 years in a low power hibernation and has just received the signal to power up its systems before catching up to the comet, which is traveling at 24,600 miles per hour. The extreme length of the mission is partly due to the massive 800 million kilometer distance and partly due to orbiting the sun 10 times in order to sling shot out into space with enough speed to catch 67P. ESA scientists expect to hear the all clear signal from Rosetta by Monday night, and are not expecting to have to intervene until Tuesday morning. When the signal is received Rosetta will begin the most complex portion of its mission, angling itself in order to orbit the comet and eventually send a lander to its surface.
The lander is named Philae and it will be sent to gather data about the comet such as composition, magnetic field structure, density and temperature. Philae is designed to harpoon itself to the loosely packed surface of 67P as Rosetta orbits, transmitting data back to the probe to be sent to Earth. While Philae is about the size of a fridge, it contains only ten major instruments, each monitored by a separate scientist as the ESA headquarters in Germany.
The Rosetta probe itself is quite large in comparison, its two protruding solar panels cover the area of a basketball court. Despite the massive area devoted to power collection, the probe is so far from our Sun that it appears as no more than a warm speck and is no longer able to power the craft. This is why hibernation was instated, but as Rosetta probe awakens and prepares to pass over comet 67P it must move slowly in its preparatory procedures. Remaining power must be conserved until 67Ps 6.6 year orbit brings it back close enough to the Sun to recharge its batteries.
ESA astronomers expect to hear the all clear signal that will allow them to begin maneuvers to bring Rosetta into orbit around 67P late Monday night. The tremendous distance means that even if all goes well the signal won’t be received for 45 minutes after being transmitted. On top of this the procedures are expected to take a minimum of 6 hours with no delays or complications. Should Rosetta’s sensors detect that something is amiss it will abort the current maneuver and start over from the last successful step, so scientists have a long stretch of time to wait and see if Rosette is successful.
The plan is have the probe orbit 67P for a few months to take photos and radar scans of the surface of the comet before sending Philae down to collect more finely tuned data. If all goes to plan after Rosetta probe awakens and prepares to pass over comet 67P it should reach the comet in August 2014 and deploy Philae in November. Observations will continue until August 2015 as the comet turns back toward the Sun, with the mission wrapping up in December 2015.
By Daniel O’Brien