1. space shuttles是什么意思
1. When Bush outlined his space plans earlier this month, he said shuttles would be retired in 2010 once the space station was complete.
2. Holes remain in the massive Vehicle Assembly Building, where space shuttles are attached to their booster rockets and external fuel tanks before launch.
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3. The space agency has 10 more construction and resupply flights to the station before the shuttles are retired in two years.
4. The craft will take on even greater importance after 2010 when NASA is expected to retire the space shuttles.
5. Unlike the United States'three space shuttles, they can only be used once.
6. NASA faces a 2010 deadline for finishing the space station and retiring its three shuttles.
7. NASA wants to store as many big spare parts as possible at the space station, before shuttles stop flying at the end of next year.