１９５７年前苏联成功地发射了世界上第一颗人造地球卫星，从此人类迈入航天技术这一新领域。在短短几十年内，随着航天技术的发展，从初期的无人航天器到很快研制出载人航天器，如航天飞机、载人飞船、空天飞机和空间站等。而与此同时一个日益突出的问题──失重则成为限制航 Before 1957, the Soviet Union successfully launched the world’s first man-made earth satellite, from which mankind stepped into the new field of space technology. In just a few decades, with the development of space technology, manned spacecraft such as space shuttle, manned spacecraft, space shuttle and space station were soon developed from unmanned spacecraft. At the same time, an increasingly prominent problem - weight loss has become a restricted flight