Space Exploration

Space Exploration — page 3
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