WASHINGTON — U.S. President Barack Obama’s 2015 budget request could include as much as $560 million over the next five years to develop a new ballistic missile defense kill vehicle, according to a top missile defense advocate.

The new kill vehicle could be a full-scale redesign of the current Exoatmospheric Kill Vehicle (EKV) that tops the Ground-based Midcourse Defense (GMD) interceptor, according to Riki Ellison, founder and president of the Missile Defense Advocacy Alliance here. Alternatively, but less likely, according to industry officials and observers, the U.S. Missile Defense Agency (MDA) could design a new kill vehicle from scratch.

Technology developed as part of the effort could feed into a separate but related MDA project to developed a so-called common kill vehicle that would be compatible with multiple missile interceptor designs, Ellison said in an interview. Currently each of the MDA’s primary interceptor systems has its own unique kill vehicle.

The kill vehicles that top the MDA’s various interceptors are designed to home in on incoming warheads and destroy them by force of direct impact.

Concerns about the EKV’s reliability stem from three consecutive intercept failures of the GMD system, the primary U.S. territorial missile shield. At least two of those failures, the latest of which occurred in July, have been attributed to issues with the EKV.

In September, the Defense Department’s inspector general launched a quality control investigation of the EKV, built by Raytheon Missile Systems of Tucson, Ariz. In January, the Pentagon’s top weapons tester recommended that the MDA consider redesigning the system.

Most recently, on Feb. 25, Frank Kendall, the U.S. undersecretary of defense for acquisition, technology and logistics, said the EKV suffered from “bad engineering.” Two versions of the EKV, known as Capability Enhancement 1 and Capability Enhancement 2, are currently being tested.

The anticipated funding wedge for a new kill vehicle is the result of “an accumulation of all these things,” Ellison said.

Ellison, who is well connected in missile defense circles, also said he expects the president’s 2015 budget request, the broad outlines of which are to be unveiled March 5, to propose an overall MDA budget increase by a cumulative total of $4.5 billion over the next five years. The president’s budget for fiscal year 2014 called for a budget of $7.6 billion.

Rick Lehner, an MDA spokesman, said he did not have information on the agency’s 2015 request.

Ellison said the MDA likely would leverage technology developed for programs like the Standard Missile (SM)-3 Block 2A interceptor project, which is in development with Japan, in creating a next-generation EKV. The clean-sheet approach likely would focus on altogether new technologies, but industry sources questioned whether $560 million over five years was sufficient to go down that path.

Another factor in which approach to take is how quickly the missile threat from North Korea and Iran evolves, Ellison said.

Notwithstanding the Capability Enhancement 2 upgrade, the EKV has not had a significant change to its fundamental design in more than a decade, experts said.

During a May 2013 hearing, the MDA’s director, U.S. Navy Vice Adm. James Syring, said current kill vehicle technology is “1990s technology” and that its designers gave little thought to important attributes such as producibility and sustainability.

Heather Uberuaga, a Raytheon spokeswoman, said the company “is totally committed to improving the ground-based interceptor fleet’s reliability by leveraging our decades of kill vehicle design, development, testing and deployment experience gained from both the [Ground-Based Interceptor] and Standard Missile 3 programs.” Raytheon also is prime contractor and kill vehicle builder on the SM-3 interceptor, current versions of which are deployed on Navy ships, with new sea- and land-based versions under development.

U.S. Defense Department officials believe a common kill vehicle would reduce risk and costs across the GMD and current SM-3 programs, as well as potentially increase their accuracy and reliability. The MDA has said it hopes to have a common kill vehicle working by 2020.

Currently the MDA has 30 deployed GMD interceptors: 26 at Fort Greely, Alaska, and four at Vandenberg Air Force Base, Calif. In 2013, the Pentagon announced plans to place an additional 14 interceptors at Fort Greely to counter a growing North Korean threat.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.