manned flight造句怎么写

Atlantis returned safely from its final mission on July 21st, bringing an end to 30 years of NASA's space-shuttle voyages, and thus to American manned flights in space.

Although Project Firefly is still grounded, Hartman expects manned flight tests to begin soon.

If future test flights go well, Copenhagen Suborbitals wants to move fast-the team hopes to have a manned flight by 2013.

In between American Apollo manned flights, the Soviet Union launched this unmanned sample return mission to the moon on Sept. 12, 1970.

Thereafter, the impetus for manned flight was lost.

The pioneer was Paul MacCready, whose Gossamer Penguin made the first manned flight in 1980 in California, with his then 13-year-old son at the controls.

When President Kennedy proposed going to the moon, America had just 15 minutes of manned flight experience in space.

Otherwise, the only purpose of the manned flights was to test the ability of the crew to function in space for as long as a week.