The final version of the FY 2019 defense authorization bill retained provisions directing the Missile Defense Agency to develop a space-based missile intercept layer, boost-phase missile defenses generally, and space-based sensor architecture for missile defenses.

The Senate’s NDAA version had a provision in the FY ’18 NDAA that would withdraw statutory flexibility on space-based boost-phase missile defenses. The 2018 language originally said the Missile Defense Agency (MDA) should work on the capability only if it is consistent with the upcoming missile defense review (MDR) that started in 2017 (Defense Daily, June 8).


However, with the MDR repeatedly delayed from the start of 2018 and still not released, the Senate changed this language directing MDA to start developing the capability regardless of what the MDR ends up recommending.

The House had no similar provision int its authorization bill and receded with an amendment requiring the development of these capability be subject to the availability of appropriations.

The House passed the conference report on Thursday (Defense Daily, July 26).

The White House Office of Management and Budget objected to the Senate’s provision, saying the Defense Department is examining several ways to enhance missile defense capabilities and that “directing the development of a space-based layer is premature at this point and creates a large unfunded mandate.” (Defense Daily, June 27).

The House amendment appears to ameliorate the concern somewhat by noting the availability of appropriations.

Last Month MDA Director Air Force Lt. Gen. Samuel Greaves expressed caution at moving forward with space-based interceptors. He said they are a potential capability but they come with many policy changes and “a fairly large bill.”  

Graves said MDA is conducting studies on the topic but several things have to happen in parallel first to make it a reality (Defense Daily, June 26).

The House NDAA had its own boost-phase intercept provision, requiring Greaves to start a program in FY ’19 to develop cost-effective air-launched or ship-based capabilities using a kinetic interceptor. The Senate receded but added an amendment requiring this, too, be subject to the availability of appropriations.

Conferees also agreed on how to direct more space-based sensor architecture for missile defenses. The House version directed the MDA director, along with the Director of National Intelligence (DNI), Air Force Space Command, and commander of Strategic Command to finish plans and initiate development in FY ’19 for a space-based missile defense sensor architecture.

That would limit the obligation or expenditure of funds to start the space-based sensor layer until a plan is submitted to Congress.

Relatedly, the Senate had a similar provision that required the MDA director to start developing this sensor architecture notwithstanding the eventual MDR outcome and required the Secretary of Defense to submit a report on the progress of efforts and coordination among the MDA, DARPA, and Air Force in this area.

Ground-Based Midcourse Defense (GMD) falls under the Missile Defense Agency's (MDA) umbrella. Photo: MDA.
Ground-Based Midcourse Defense (GMD) falls under the Missile Defense Agency’s (MDA) umbrella. Photo: MDA.

The Senate receded to the House version but added an amendment requiring the MDA efforts to develop this space-based sensor architecture to be compatible with ongoing efforts within DARPA. The compromise also would limit funding for this effort in FY ’18 and FY ’19 appropriations laws so only 85 percent of appropriations can be used until the MDA director submits a plan on the sensor layer. The authorization is also subject to appropriations.

OMB objected to the Senate’s original provision, saying the Defense Department is pursuing these efforts but that the required timelines are aggressive “and may not allow DoD to pursue an effective and technically feasible sensor architecture in a realistic or cost-effective manner.”