英语新闻阅读：美国航天局将发射月球探测器

英语自学网

　　The U.S. space agency is preparing for Thursday's launch of two unmanned
spacecraft to the moon, nearly forty years after man last walked on the
moon.
        　　NASA's Gravity Recovery and Interior Laboratory, or GRAIL, mission
spacecraft will orbit the moon before landing on the lunar surface.
        　　The mission will map the moon from its core to its surface, including the
far side of the moon which humans have never explored.
        　　Tuesday, NASA released high resolution photographs showing the remnants of
the space agency's previous lunar visits. The photos show tire tracks from the
Apollo 17 lunar rover.
        　　In November, NASA will launch a spacecraft bound for Mars. The flight to
Mars is expected to last two years.