航天器(spacecraft)
设计在地球低层大气上按受控飞行路线运行的载人或不载人的飞行器。由於这种环境的高度真空,流线型并不需要,航天器的外观便根据它的任务来设计(参阅space exploration)。多数航天器不是自我驱动的,通常依靠两级火箭来加速到必要的高速度,而两级火箭在油料用光後便投弃掉。一个主要的例外是太空梭轨道飞行器,它使用三个随之携带的液体燃料的重要引擎到达宇宙,而这又是由一个可任意使用的外部箱和一对固体燃料後援器来供给的。航天器进入围绕地球的轨道,如果给予足够的速度,它会继续朝着太空的另一个目的地前进。该机器可以有它自己的小型火箭发动机来定位和发动。至於内在动力,绕地球环绕的航天器使用太阳电池和存储电池、燃料电池,或是两者的结合,而深太空探测器经常使用靠放射性元素加热的热电发生器。设计的高度复杂性,尤其是有人驾驶的有数百万元件构成的航天器,要求高度的小型化和可靠性。
English version:
spacecraft
Vehicle designed to operate, with or without a crew, in a controlled flight pattern above earth's lower atmosphere. Since streamlining is not needed in the high vacuum of this environment, a spacecraft's shape is designed according to its mission (see space exploration). Most spacecraft are not self-propelled; they are accelerated to the necessary high velocity by staged rockets, which are jettisoned when their fuel is used up. A major exception, the space shuttle orbiter, uses three onboard liquid-fuel main engines supplied by a disposable external tank and a pair of solid-fuel boosters to reach space. The spacecraft goes into an orbit around earth or, if given enough velocity, it continues toward another destination in space. The craft may have its own small rocket engines for orienting and maneuvering. For internal power, earth-orbiting spacecraft use solar cells and storage batteries, fuel cells, or a combination, whereas craft designed for deep-space missions usually carry thermoelectric generators heated by a radioactive element. The enormous complexity of design, particularly of manned spacecraft with their millions of components, requires a high degree of miniaturization and reliability.
参考文章
- 下列属于航天器手动交会对接特点的是知识题库
- 利用液体在对流运动中与固体接触而____热量的热控制方法,称为流体对流循环热控制。用这种方法可以控制航天器各种仪器、设备和舱内环境温度。党建知识
- 空间环境的变化不仅会影响航天器的运行,也会对地面的通信系统、电力系统、输油管道等技术系统造成影响甚至是损坏。___党建知识
- 航天器沿地球表面做圆周运动时所具有的速度称为__知识题库
- 航天器发射场内有整套试验设施和设备,用以装配、贮存、检测和发射航天器,测量飞行轨道,发送控制指令,接收和处理遥测信息。__党建知识
- 影响航天器发射成功的限制条件主要有:__、气象限制条件等。①发射窗口②地面发射控制系统限制条件③测控系统限制条件④通信系统限制条件党建知识
- 航天器在空间轨道上可围绕地球转动是因为航天器具有一定大小的速度(动能),同时受到地球引力的作用。党建知识
- 舱外航天服是一个小型的载人航天器。党建知识
- 某个类别的同一批种子,在同样一个航天器中,在同样的时间段里经历了同样的太空环境,都会发生良性变异。___党建知识
- 航天器的返回是一个减速、下降的过程,即航天器耗散__的过程。党建知识