NASA在1962年到1971年间发射了被称为“轨道太阳观测台”的一系列共8个轨道观测卫星。
NASA launched a series of eight orbiting observatories known as the orbiting Solar Observatory between 1962 and 1971.
与之对应，直线段的钢轨通常打磨成与车轮有几点接触的形状，车轮与轨道之间是非共形接触，从而减少轮对不正常的摆动。
Tangent track, on the other hand, may be ground to several contact points to promote non-conformal contact and thus reduce wheelset hunting.
美国宇航员杰夫·威廉姆斯成了美国在轨道内最长时间纪录的保持者——算上这次任务，他一共参加了四次不同的任务，在太空中待了534天。
American astronaut Jeff Williams became the U. s. record-holder for most time spent in orbit after this mission brought him up to 534 days spent in space across four separate missions.
进行了高压共轨柴油机轨道压力控制和匹配研究。
The controlling of rail pressure of high pressure common rail diesel engine is studied.
讨论了平面情况时两个共焦的椭圆轨道之间的最佳单冲击过渡及其意义。
This paper studies the best one impulse transfer between two coplanar and confocal elliptic trajectories and its application.
自2004年8月3日发射“信使”号正处在它的第4条(共16条)太阳轨道上。
It launched on August 3, 2004 and is currently on its fourth (of 16) orbits of the Sun.
自2004年8月3日发射“信使”号正处在它的第4条(共16条)太阳轨道上。
It launched on August 3, 2004 and is currently on its fourth (of 16) orbits of the Sun.
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