TAMPA, Fla. — The U.S. Air Force’s planned purchase of next-generation GPS satellites, already slowed by budget woes and a healthy existing constellation, would shrink a bit more if defense budgets return to sequestration levels in 2016 and beyond, according to a Defense Department report.

In addition, the Missile Defense Agency would lose a combined $1.2 billion from 2016 through 2019 for work on a new kill vehicle for its primary interceptor program and for a new ground-based sensor, the report said.

The report, titled “Estimated Impacts of Sequestration-Level Funding” and released April 15, examined the effects of the automatic budget cuts known as sequestration. Sequestration refers to the across-the-board U.S. federal budget cuts mandated by the Budget Control Act of 2011 following the failure of Congress and the White House to agree on a long-term deficit reduction plan. 

“The automatic reductions required by the [Budget Control Act] would impose significant cuts to Department resources that would significantly increase risks both in the short- and long-term,” the report said. “These cuts would be in addition to several reductions in planned funding that the Department has already absorbed.”

Spending levels proposed for 2015 would not be affected because they comply with the Bipartisan Budget Act of 2013, the report said. The cuts would be applied to planned spending from 2016 through 2019.

For the Air Force’s next-generation GPS 3 positioning, navigation and timing satellite system, which is still in development, the impact would be a $404 million reduction in planned spending from 2016 through 2019, to $3.4 billion. That would mean buying two rather than three satellites in fiscal year 2017 from prime contractor Lockheed Martin Space Systems of Denver. 

The change would save the Air Force $288 million that year.

Currently Lockheed Martin is under contract to build eight GPS 3 satellites, which are designed to be more accurate and less vulnerable to interference than previous generations of GPS craft. 

The Air Force currently has 31 GPS satellites active on orbit and has launched five of the 12 satellites in the current series of satellites, called GPS 2F. The first GPS 3 satellite is scheduled to launch in 2016.

The report also details how a return to sequestration would affect missile defense, including the Ground-based Midcourse Defense (GMD) system that serves as the primary U.S. territorial shield. According to the report, GMD funding would be reduced by $639 million from 2016 to 2019, to $3.7 billion, with the funds coming out of an “interceptor follow on effort.”

MDA spokesman Rick Lehner identified that effort as the program to redesign the Exoatmospheric Kill Vehicle, the part of the GMD interceptor that actually destroys incoming missile warheads by force of impact. The redesign effort was hatched following problems with existing versions of the Raytheon-built kill vehicle, which has been implicated in recent GMD test failures.

The MDA is requesting $99.5 million for the kill vehicle redesign effort in 2015.

Also targeted for elimination under a sequestration scenario is $556 million in funding for an additional ground-based sensor, reducing the MDA’s overall sensor budget from 2016-2019 to $1.5 billion.

Lehner said the sensor would be a new long-range discrimination radar. The agency released a request for information on that activity March 14.

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Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...