WASHINGTON (REUTERS) - The US Defence Department plans to ask Congress for US$4.5 billion (S$5.7 billion) in extra missile defence funding over the next five years as part of the fiscal 2015 budget request, according to congressional sources and an expert.
Nearly US$1 billion of that sum will pay for a new homeland defence radar to be placed in Alaska, with an additional US$560 million to fund work on a new interceptor after several failed flight tests, said Mr Riki Ellison, founder of the non-profit Missile Defence Advocacy Alliance, and two of the congressional sources, who were not authorised to speak publicly.
The Pentagon's request for added funding comes despite continued pressure on military spending and cuts in other arms programmes, a sign of Washington's growing concern about missile development efforts by North Korea and Iran, the sources said.
Missile defence is one of the biggest items in the Pentagon's annual budget, although Republicans have faulted the Obama administration for scaling back funding in recent years.
The request is expected to garner bipartisan support in Congress, but it may also spark questions about billions of dollars spent over the past two decades on a "kill vehicle" built by Raytheon that is used to hit enemy missiles and destroy them on impact. The kill vehicle is part of the larger ground-based missile defence system managed by Boeing. Orbital Sciences builds the rockets used by the system.
Mr Michael Gilmore, the Defence Department's chief weapons tester, last week questioned the robustness of the Raytheon kill vehicle after a series of test failures, and said the Pentagon should consider a redesign.
"We need a new interceptor that actually works," said one of the congressional sources, adding that both of the existing kill vehicle models also needed to be fixed and tested since the replacement would need about five years to be made ready.
Mr Ellison said the issue needed to be addressed quickly, given the Obama administration's push to buy 14 additional ground-based interceptors to beef up US defences against a potential missile strike from North Korea.
"We need to have this thing as soon as possible," he said. He said some lawmakers might balk at paying for new interceptors that carried the current troubled kill vehicle, since a replacement would not be ready for about five years.
Twenty of the existing 30 ground-based interceptors carry the CE-1 version of the kill vehicle which failed to separate from the rest of the rocket in a flight test last July, said one of the congressional sources.
The other 10 interceptors are equipped with a newer CE-2 kill vehicle, which has also suffered several problems and flight test failures, said the source.