NASA will not return humans to the moon but might visit an asteroid-and much later Mars.

美国航空航天局放弃其人类重返月球的计划，取而代之的是探访一颗小行星和经过较长的一段时间后再探访火星的计划。

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That successor system is also designed to return humans to the moon by 2020, as a stepping stone to visiting Mars.

继任的系统同样是设计用来2020年重返月球的，同时作为远征火星的踏脚石。

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Orion was originally intended to serve as a crew capsule for the Constellation program, an ambitious NASA project to return humans to the moon and eventually create a full-time lunar base.

奥赖恩太空船原本打算作为星座计划(美国航天局的一项雄心勃勃计划，试图使人类重返月球，并最终建立一个专用的月球基地)的乘员太空舱。

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All three had concerns that the space agency science programs were losing out in the push to return humans to the moon.

NPR: Budget Cuts Trigger NASA Resignations

That here we would be -- 40 years after the first moon landing -- still wondering when humans will return to the moon.

CNN: After walking on moon, astronauts trod various paths