The Space Shuttle

The first flight of the reusable U.S. Space Shuttle was on April 12, 1981 after about ten years of development and testing. It is powered in launch by three main engines on the shuttle and two external solid booster rockets. It returns from orbit by gliding down to a runway. The main external structure for the booster is a huge fuel tank which holds liquid hydrogen and liquid oxygen for the main engines, about 710,000 kg of fuel. The solid fuel booster rockets produce about 2.65 million pounds of trust each, and the three main engines about 470,000 pounds of thrust each. After liftoff, the solid fuel rockets burn out in about 2 min 12 sec and are jettisoned. The main engines are shut down 8 min 32 sec after liftoff and the main tank is released. The orbiter's own orbit-adjust engines complete the insertion into orbit.

美国可重复使用的航天飞机首次飞行于1981年4月12日，这是经过大约十年的开发和测试后的结果。它在发射时由航天飞机上的三个主发动机和两个外部固体推进火箭提供动力。它通过滑翔降落在跑道上。外部推进器的主要结构是一个巨大的燃料箱，该燃料箱储存用于主发动机的液氢和液氧，约710,000千克的燃料。固体燃料推进火箭每台产生约265万磅的推力，三个主发动机每台约470,000磅的推力。起飞后，固体燃料火箭在约2分12秒内燃烧完毕并被抛弃。主发动机在起飞后8分32秒关闭，主燃料箱被释放。轨道器自身的轨道调整发动机完成进入轨道的任务。