这样，当普通燃料火箭到达地球轨道约800公里高度时，核反应堆舱会脱离化学燃料火箭，并开始工作。
Then, once the vehicle had ascended to high-Earth orbit, above about 800 kilometers, the nuclear reactor module would detach from the chemical rocket and start up.
这一假设认为，地球运行的变化，特别是绕太阳轨道的变化，会导致太阳到达地球能量的不同。
It says that variations in earth's movements, specifically in its orbit around the sun, these variations lead to differences in the amount of solar energy that reaches the earth.
目前“信使号”探测器已经到达了地球、金星、水星多重引力助力飞行的最后一个阶段，并将于2009年9月29号进行第三次飞越最终将在2011年3月正式进入水星轨道。
MESSENGER is now in the last stages of multiple gravity-assist flybys of Earth, Venus and Mercury, en route to an insertion into orbit around Mercury in March of 2011.
但是“地球大气层探秘”将触角伸向了更远的太空，到达了航天飞机的轨道200公里外的更高处。
ButEarth's atmosphere extends farther into space than you might realize, affecting the orbits of spacecraft more than 200 miles high.
我认为这可能是由于奥尔特云受到一个正在把彗星抛出稳定轨道的大天体的扰动，其中一小部分彗星可能会到达地球。
I believe it is likely that this is because the Oort Cloud is being disturbed by a massive body that is throwing comets out of stable orbits, a small fraction of which could reach the Earth.
行星的轨道在地球里的不可能到达对面或正交处或距离太阳90度更远的地方。
Planets that orbit the sun inside of Earth's orbit can never reach opposition or quadrature – or get as far as 90 degrees from the sun.
行星的轨道在地球里的不可能到达对面或正交处或距离太阳90度更远的地方。
Planets that orbit the sun inside of Earth's orbit can never reach opposition or quadrature – or get as far as 90 degrees from the sun.
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