Word power 启东中学 Unidentified Flying Objects“flying saucer” Lead-in UFO aliens outer space Brainstorming space Universe beyond the earth’s atmosphere in which all other planets and stars existthe Earth the sunthe moon(satellite )artificial satellitesolar system orbit (man-made ) Whether UFOs really exist has puzzled us for a long time . Have you ever thought about exploring space one day ?Travel into or through a place in order to learn about it space exploration (space travel ) Who is he ?Do you know where he is ?He is Yang Liwei, and he is an astronaut . spaceman / spacewoman space shuttle Shenzhou 5 manned spaceshipspace shuttle unmanned spaceship Placing a satellite into orbit requires a large amount of energy, which must come from the launch vehicle, or device that launches the satellite. The satellite needs to reach an altitude of at least 200 km (120 mi) and a speed of over 29,000 km/h (18,000 mph) to lift into orbit successfully. Satellites receive this combination of potential( 势能 ) energy (altitude) and kinetic( 动能 ) energy (speed) from multistage rockets burning chemical fuels. Apollo Eleven Countdown A rocket launch countdown. A common sound in the nineteen-sixties. But this was not just another launch. It was the beginning of an historic event. It was the countdown for Apollo Eleven -- the space flight that would carry men to the first landing on the moon. Two-and-one-half minutes after the Apollo Eleven launch, the first-stage rocket separated from the spacecraft. Twelve minutes later, the spacecraft reached orbit. Its speed was twenty-nine-thousand kilometers an hour. Its orbit was one-hundred-sixty-five kilometers above the Earth. This was the time for the crew to test...
