The Philae lander made history when it became the first man-made machine to land on a comet but the excitement has almost dwindled when the probe used up its stored power and went into hibernation mode after its bouncy landing.
Scientists, however, hoped that as Comet 67P/Churyumov-Gerasimenko approaches the sun, the solar energy would recharge the lander's battery and wake it up to resume its scientific work.
Finally on June 13, the Philae woke up after seven months of being in standby mode and contacted Earth for two minutes. It reported again on June 15, two days after the initial contact.
For the third time on Friday, June 19, the Philae touched base with Earth again with the team at the German Aerospace Center (DLR) receiving 185 data packets from the probe between 15:20 and 15:39 CEST.
Michael Maibaum, from the DLR Lander Control Center (LCC), said that the lander now operates at zero degrees Celsius and this means that the battery is already warn enough to store energy. It also means that Philae will now be able to work even at night time and regardless of solar illumination.
Based on the data that the lander has sent, engineers learned that the amount of sunlight has increased. More of the Philae's solar panels were already illuminated and four of its panels were receiving energy at the end of the contact. Although there are interruptions during the connection, the transmission of data was relatively stable and confirmed that the lander is doing very well.
"The contact has confirmed that Philae is doing very well," the DLR said.
During its first two contacts, the lander transmitted data stored from early May. DLR's Philae Project Manager Stephan Ulamec said that while the Philae is already awake at this time, they needed a longer and more stable contact in order to conduct research. Once these conditions are met, the 10 instruments on board the Philae could again be operated.
Controllers said that once regular communications are again established, the Philae will go back to its scientific work starting with experiments that need little power and no movement of Philae.
Scientists, however, want to eventually rotate the lander about 30 degrees so it can dig samples from the comet for analysis. Comet 67P is covered in carbon-based material that could be similar to organics that are present on Earth.
