Star Wars fans have been left disappointed after United States lawmakers rejected calls to build a mammoth spaceship capable of blowing up planets.

Thirty thousand people signed a petition on the White House website calling for the costly interstellar construction project.

That meant politicians on Capitol Hill had to rule on whether to build the giant space station, at an estimated cost of $85 quadrillion.

Advocates said it would create jobs and boost national security.

President Obama's space chief said that a Death Star would only add to the United States' financial problems.

Paul Shawcross said: "The Administration does not support blowing up planets.

"The estimated cost to US taxpayers of $850,000,000,000,000,000 would add to America's national debt problem rather than help reduce it."

Research was already underway on technologies like those on display in the classic sci-fi film by George Lucas, said Shawcross

"Defense Advanced Research Projects Agency is supporting research on building Luke's arm, floating droids, and quadruped walkers.

"Look carefully and you'll notice something already floating in the sky - that's no Moon, it's a Space Station! (International Space Station, MIR)"

The petition by John D which triggered the response, read: "By focusing our defence resources into a space superiority platform and weapon system such as a Death Star, the government can spur job creation in the fields of construction, engineering, space exploration and more, and strengthen our national defence."

In Star Wars the Death Star blows up planets under the command of evil lord Darth Vader. Enslaved Ewoks build the huge orb, not paid construction workers.