ONE LANDING ON A COMET n November 12 2014 space scientists nervously waited in the European Space Agency ESA Space Operations Center in Germany News would be arriving soon from their distant spacecraft Rosetta It was the first artificial object in history to orbit a comet Seven hours prior the spacecraft released a lander to touch down on the comet below If everything worked as planned that lander Philae would be the first human made machine to land on a comet It would add immensely to scientists knowledge about these icy dusty space rocks Finally the scientists got the news Philae was on the surface of comet 67PI Churyumov Gerasimenko known as 67P for short Flight Director Andrea Accomazzo wiped tears from his eyes following the good news In November 2014 after a ten year voyage through space Rosetta finally arrived at Comet
However the landing did not go exactly as Fixing spacecraft planned Scientists had programmed a specific sequence of commands into Philae s memory These steps told the robotic spacecraft what to do as soon as it was near the comet's surface First it was supposed Not everything has gone as planned ith Rosetto but broken spacecraft are something space experts are familiar with Often these problems can be fixed by updating the ship's software or restarting its computers This solved issues with Voyager 2 which launched in 1977 on to explore the outer solar system to use a small rocket engine to push it toward the comet Then the ship would fire two harpoons to catch the surface Finally as soon as it made contact with the comet screws at the end of each of Philae's three legs would embed into the icy surface If a spacecraft is in orbit around Earth though astronauts may be sent to make repairs When astronomers first used the Hubble Space Telescope in 1990 the images appeared blurry They realized the telescope's main mirror was imperfect and could not focus properly Three years later astronauts flew to the telescope Unfortunately all three mechanisms failed Because the force of gravity on 67P is several hundred thousand times weaker than on Earth the comet could and added an instrument to correct not keep hold of Philae So the lander bounced rising its vision Hubble went on to more than 25 years of discoveries in a high arc from the surface for almost two hours Luckily it did not drift into space 67P's weak gravity gently tugged it back to the surface where the lander made one more small bounce before nudging itself sideways against a rock wall Some of the scientists later joked that they had made not only the first landing on a comet but the first three Philae's internal batteries powered its first 50 hours on the surface For additional power to make it through the next few months of collecting data as was originally planned it needed sunlight But its resting position put its solar panels in shadow That meant its ten instruments could take measurements and send data back to Rosetta for only a few days The science team made the most of 6
at St As Philae touched down the devices intended to anchor it to the this limited time Philae took the first incredible pictures from the surface of a comet comet failed to work properly sending the lander measured the temperature at its resting spot and tried to drill into the rock It revealed bouncing upward 67P has several inches of rocks and dust on its surface Scientists were unsure what the material below the surface was but they could determine it was as dense as solid ice Although the Philae landing did not go as planned it was a tremendous technological feat Humans landed a refrigerator sized spacecraft on a comet while both were traveling as fast as 34 000 miles per hour 55 000 kmh at a distance of 280 million miles 450 million km from the
