( CNN ) -- After an improbable 10-year , 310-million-mile journey to become the first ever space vehicle to make a soft landing on a comet , the Philae probe may have ended its mission prematurely . Its batteries have run down , said the European Space Agency . `` Philae has fallen into 'idle mode ' for a potentially long silence . In this mode , all instruments and most systems on board are shut down , '' ESA said . This might not change . Philae was supposed to transmit data from Comet 67/P for nine months as it passed the sun , running on solar power , but it did not get its place in the sunlight that scientists had hoped for . Bounce landing . The probe 's landing did n't go as planned this week , after Philae detached from the Rosetta orbiter . It took two bounces away from its designated landing spot , and never fired its anchoring harpoon . `` The lander remains unanchored to the surface at an as yet undetermined orientation , '' ESA said . It ended up in a shady spot of Comet 67P/Churyumov-Gerasimenko , ESA said , likely without enough sunlight to keep functioning . Originally , it was supposed to have seven hours of light per comet day -- which lasts just 12.4 hours . Now it is exposed only 1.5 hours a day . That 's likely not enough to juice up Philae 's rechargeable secondary battery , ESA said . There is one last hope . `` Mission controllers sent commands to rotate the lander 's main body , to which the solar panels are fixed , '' ESA says in on its blog . `` This may have exposed more panel area to sunlight . '' Despite its walleyed positioning , Philae transmitted data and black-and-white photos back to Earth and ESA scientists . The pictures appear to indicate it landed in some sort of shadow , possibly the shadow of a cliff . Opinion : The big lesson from comet landing . Race to transmit data . Philae turned on its instruments , drilling for samples , and while there was still time , transferred data . Now , the lander has fallen silent . Its operators on Earth lost contact with it early Saturday . Built by a European consortium , led by the German Aerospace Research Institute , the landing probe has 10 instruments . `` The lander ( was ) racing against the clock to meet as many of the core science goals as possible before the primary battery ( was ) exhausted , '' ESA said . Its operators are satisfied with the results , and praised Philae for completing its mission slated for the comet 's surface , before it went into hibernation . Opinion : How comet mission helps in search for alien life . The German space agency , which operates Philae for ESA , has taken a light-hearted approach to the battery 's impending doom , putting out witty messages on a confirmed Twitter account in Philae 's name . `` I 'm feeling a bit tired , did you get all my data ? I might take a nap , '' a post read . `` So much hard work.. getting tired ... my battery voltage is approaching the limit soon now , '' another read . It 's possible that the conditions may change as the comet moves closer to the sun , making it possible to charge the secondary battery . Then Philae could awaken from its deep slumber and send data and photo surprises back to Earth , ESA said . Even with the lander out of commission , the Rosetta orbiter that carried the Philae lander will continue to transmit observations of the comet . Elated scientists show off latest pics from historic comet mission . Ten year voyage . Rosetta took off from Earth 10 years ago , aboard an Ariane 5 rocket , and traveled 6.4 billion miles before rendezvousing with the comet in August . The Philae lander separated from the orbiting Rosetta about 3:30 a.m . ET Wednesday and first landed on the comet seven hours later . The lander weighs about 220 pounds and is the size of a domestic washing machine . The target comet is only 4 kilometers , or 2.5 miles , in diameter . The spaceship is named after the Rosetta Stone , an inscribed piece of volcanic rock found in Egypt in 1799 that allowed scientists to decipher hieroglyphics and thus understand the ancient Egyptian culture , ESA said . The lander is named after an island in the Nile River where an obelisk was found that helped decipher the Rosetta Stone , ESA said . Led by ESA with a consortium of partners including NASA , scientists on the Rosetta comet-chasing mission hoped to learn more about the composition of comets and how they interact with the solar wind : high energy particles blasted into space by the sun . Opinion : Philae 's comet landing is amazing . CNN 's Ed Payne , Ashley Fantz , Fred Pleitgen and Dave Gilbert contributed to this report .
NEW : Philae 's operators satisfied that the probe completed its mission on the comet . Philae 's landing did n't go as planned , leaving it in the shade , ESA says . It is supposed to run on solar power , but now there 's not enough sunlight for that . Philae 's primary battery was running out and is expected to be dead .