WASHINGTON, April 4 (Reuters) - The U.S. is asking

defense contractors for information on space-based interceptors

to knock out incoming missile threats, as the Pentagon explores

President Donald's Trump's Golden Dome missile defense shield.

The idea of strapping rocket launchers, or lasers, to

satellites so they can shoot down enemy intercontinental

ballistic missiles as they lift off is not new - it was part of

the Star Wars initiative devised during the presidency of Ronald

Reagan. But it represents a huge and expensive technological

leap from current capabilities.

(Reporting by Mike Stone in Washington)