Lt Gen Samuel Greaves, commander of the Space and Missile Systems Center, officiates and activates the Lauch Enterprise at a ceremony in Gordon Conference Center, 14 Oct, 2015. Mrs. Leon stood up as the new director of the Launch Enterprise directorate, presenting a display of the new shield that sympolizes goal, strength, and through boldness to the stars.

WASHINGTON – U.S. Air Force Lt. Gen. Samuel Greaves, who has led the Defense Department’s efforts to end reliance on a Russian rocket engine, has been nominated by President Barack Obama to lead the Missile Defense Agency.

The move had long been expected within the missile defense community. Defense One first reported the news Sept. 13. The MDA has a $7.5 billion budget and is responsible for acquiring and developing defense systems to prevent successful ballistic missile attacks.

Greaves will replace Navy Vice Adm. James Syring, the agency’s current director. Syring’s next stop is not immediately clear.

Greaves has served as the head of the Air Force’s Space and Missile Systems Center at Los Angeles Air Force Base in California since June 2014. There he oversaw the Air Force’s space hardware acquisition efforts. Most notably, he has led the Air Force’s program to wean itself from the Russian RD-180 rocket engine that powers United Launch Alliance’s Atlas 5 rocket, which has been used to launch a majority of national security satellites. He also oversaw SpaceX’s entry into the national security launch market, guiding the certification process to approve the Falcon 9 rocket for military and spy satellites. SpaceX then won the first competitive contract in the Air Force’s primary launch program in more than a decade in April.

Previously, Greaves, a Cornell graduate, served as the deputy director of the Missile Defense Agency from 2012 to 2014.

Syring has emphasized three programs during his tenure: a redesigned kill vehicle to top ground-based interceptors, a new Long Range Discrimination Radar in Clear, Alaska and improved discrimination capabilities to distinguish between decoys and warheads.

MDA hatched the Redesigned Kill Vehicle program following a string of intercept failures of the Boeing-built Ground-based Midcourse Defense system, the primary U.S. territorial shield. The Defense Department has attributed at least two of those failures to the Raytheon-built Exo-atmospheric Kill Vehicle, which is designed to destroy incoming missile warheads by force of direct impact.

The EKV has not had a significant change to its fundamental design in more than a decade, experts say, and Raytheon officials have said the EKV was deployed in 2004 as a prototype because of urgent national defense priorities.

Lockheed Martin, Boeing and Raytheon are working with MDA on a new best-of-breed program to deliver new kill vehicles around 2021. A flight test is planned for 2018 with an intercept test planned for a year later.

In October, Lockheed Martin Mission Systems and Training won a $784 million contract to build a long-range discrimination radar (LRDR) that would identify incoming missile threats from the Pacific region, primarily North Korea. Though intended primarily for missile defense, the LRDR also could contribute to the Air Force’s space situational awareness mission, defense and industry officials have said.

Syring has gone into little detail publicly to discuss the improved discrimination capabilities.

In a speech last month in Huntsville, Syring emphasized the need for the MDA to develop a space-based sensor layer to help improve missile defense.

Greaves spoke about the intersection of space and missile defense during an event earlier this year in California. Greaves’ remarks can be found at the 1 hour mark.

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.