2011年7月21日,美国“亚特兰蒂斯”号航天飞机顺利完成了为期13天的国际空间站补给任务,最后一次降落在肯尼迪航天中心的跑道上,标志着NASA持续30年的航天飞机项目划上了圆满的句号。但这并不意味着其航天探索脚步的停止,NASA已设定了未来航天探索任务的新目标,包括载人登陆火星计划和新型航天器开发等,以探索太阳系更远的空间。在航天飞机退役之前,航天飞机最主要的功能就是运送美国宇航员往返国际空间站。在其退役之后,美国宇航员只能乘坐俄罗斯的“联盟”号飞船往返国际空间站。 July 21, 2011, the United States “Atlantis ” space shuttle successfully completed a 13-day mission to supply the International Space Station, the last landing on the runway at the Kennedy Space Center, marking NASA for 30 years Space Shuttle Project draws a successful conclusion. But that does not mean the end of its space exploration mission. NASA has set new goals for future space exploration missions, including a manned landing mission to Mars and new spacecraft development to explore more of the solar system. Before the shuttle retired, the most important function of the space shuttle was to transport U.S. astronauts to and from the ISS. After their retirement, US astronauts can only travel to and from the ISU in Russia’s “Union” spacecraft.