Almost all the practical advantages of space come from unmanned rockets and automatic spacecraft.

Thus, contracts for manufacturing unmanned rockets are becoming even more important to the company.

The biggest current unmanned rocket can carry about 25 tons.

Putting Galileo on an unmanned rocket would have involved an even more expensive redesign effort.

It is also a major advance for the Japanese space program, which so far has been limited to the launching of unmanned rockets.

Instead, it has bought its own fleet of big unmanned rockets.

The nation's production lines for large unmanned rockets were shut down.

Under the plan, a scaled-back version of the space station would be built largely using unmanned rockets.

He also said that any effort to intercept a comet would rely on unmanned rockets.

The shuttle should not be used when unmanned rockets would do, he said.