Rosetta has seven days to send signals to Philae to see if it’s still alive. It will no longer be in the correct orbit after March th. Since making a bouncy landing on comet 67P/Churyumov-Gerasimenko in November and ending up on the dark side of a crater, Philae’s batteries have remained flat because its solar panels have not been able to absorb energy-filled sun rays. The robot lander is unable to contact orbiting Rosetta to relay signals back to Earth because there’s no battery juice. We don’t know if Philae has ever been hibernating or is dead. Rosetta captured this photo of Philae at his three feet, March 13th. It is now safely located on the comet’s surface. Image: ESA. Philae now appears to be on the sun side of the comet due to its gradual rotation. Scientists believe that some of the sun’s rays will be reaching the shadowy parts of the crater, hitting the solar panels of the robot so its batteries can recharge and the signal can go to Rosetta. Rosetta is directly aligned right now. The European Space Agency scientists are waiting patiently, keeping their fingers crossed for any signal. Koen Guerts is the head of the technical team and said that they don’t expect to hear from them until then. However, Stephan Ulamec from the German Aerospace Center said that Philae, its mothership Rosetta, are currently 198 millions miles (320mkm) away from the Sun. Mister Ulamec said that although it will likely still be cold enough for the lander, it’s worth trying. The prospects will improve with each passing day.” Image of Comet 67P/Churyumov-Gerasimenko taken from Rosetta’s navigation camera on March 9th from a distance of 71.9 km. Image: ESA. Some problems occurred during landing. Philae was originally supposed to land gently on the sun side of the comet, begin analyzing its composition, and then send back data via Rosetta. One of the final Rosetta detachment tests revealed that Philae’s cold-gas thruster wasn’t working correctly on November th. It was unable to be fixed, so a “Go” was issued anyway. Rosetta was liberated by the lander on the next day. Unfortunately, when Philae landed on comet 67P/Churyumov-Gerasimenko it bounced for two hours and ended up in a shaded part of a crater, meaning its solar panels could not charge up the batteries. Before its batteries died, the robot was able to successfully deploy its instruments. The robot’s ice drill and hammer are now ready for use. They are used to take samples and then analyze them. The European Space Agency scientists want to know if comets may contain water or complex organic compounds. There is the possibility that they could have provided life-giving materials to Earth millions of years ago. If the Philae lander wakes up, it will be able to send vital information about the composition of this comet. Image: ESA. How has low temperature affected Philae’s health? Lead lander scientist Dr. Jean-Pierre Bibring, IAS, Orsay (France), said that the greatest uncertainty is whether Philae’s internal systems were affected by the extremely low temperature environment. Does the daily solar energy on Philae suffice to allow it to survive? Before scientists can start putting it to work again, Philae must be able to get out of hibernation. It must have a temperature inside of -45oC or higher for this to happen. The lander is receiving very little sun, so the temperatures are lower than expected. For Philae’s wake-up, its solar panels must produce at least 5.5 Watts. It must have at least 5.5 watts to wake up. Philae could be already awake. When it wakes up, Philae will activate its receiver once every 30 minutes to listen for Rosetta signals. It doesn’t require much power to accomplish this. According to Mr. Geurts, “At the moment we don’t know if the lander has awakened.” Philae has to turn its transmitter in order to send an answer. Scientists believe that Philae is awake but not enough power for Rosetta. To function and communicate with Rosetta, it needs 19 power. Rosetta won’t be open to receiving a Philae signal before March th. ESA stated that Rosetta will not be receptive to a possible Philae signal until March 20th.
