而开普勒行动则存在截然相反的问题：它能通过一个行星的遮光情况测出它的体积，却不能得出其质量。
The Kepler mission has the opposite problem: it can measure a planet's size, by how much starlight it blocks, but not the mass.
这种被称为“太空行动飞行器”的太空飞行器，将是一种运货工具，可以装载各种重量的负荷，体积不比航天飞机大。
That spaceplane, known as the space Operations Vehicle, will be a cargo carrier that can lift a variety of pay loads and probably won't be any bigger than the space shuttle.
轻，高弹性的材料提供出色的舒适性和充分的行动范围，降低包装的重量和体积。
The light, highly-elastic material offers excellent comfort and full range of movement and reduces weight and packed volume.
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