US plans 'space bomber'

The US is looking into developing a space bomber which could hit targets anywhere in the world in 30 minutes.

The craft would blast off like a long-range missile and could drop precision bombs from heights of 60 miles or more.

It would travel at 15 times the speed and 10 times the altitude of current heavy bombers, say planning documents.

With its speed and altitude, such a bomber would be out of reach of conventional air defences. It could be manned or remote.

Weapons dropped from the height of space would have such destructive power they may have no need for explosive warheads.

The Pentagon is said to see it as an answer to how US forces can reach distant targets at a time when their bases aboard are declining in number and increasing in vulnerability.

Reports say the planning document was issued under the name of US Secretary of Defence Donald H Rumsfeld.

As part of a modernisation of the US military, he has reportedly told the Pentagon to look into "sub-orbital space vehicles" that "would be valuable for conducting rapid global strikes".

Rear Admiral Craig Quigley, a senior Pentagon spokesman, said the Pentagon wants to fully explore the concept because "the military couldn't get anything [to a war zone] faster than this ... It could be useful in any number of scenarios."

The idea of a rocket-propelled space bomber has been around in various forms since the 1930s, when Austrian rocket scientist Eugen Sanger urged Adolf Hitler to build an "antipodal bomber" called the Silver Bird that could skip across the outer edge of the atmosphere to strike New York City.