The Commander of U.S. Strategic Command (STRATCOM) said space sensors are necessary for midcourse missile defense discrimination in a speech about how the Defense Department needs to move forward on missile defenses.

Although the U.S. needs to improve a number of things in missile defense, the highest priority in capabilities is improved sensors, Air Force Gen. John Hyten, said in a Feb. 28 speech at the Association of the United States Army.

Improved sensor capabilities include the Missile Defense Agency’s (MDA) planned new Long Range Discrimination Radar (LRDR) in Alaska, “that’s a critical piece of the puzzle. We continue to improve radars across the board.”

The LRDR is being built by Lockheed Martin [LMT].

However, Hyten said there are not enough ships or islands in the Pacific Ocean for ground-based radars to answer all their sensor concerns and the Department cannot do complete midcourse ballistic missile discrimination without space assets.

“We’re going to have to go to space to actually do the midcourse discrimination element of this mission. And the missile defense agency knows how to do that, they have a plan to do that, we’re struggling to get started with it. It’s taken way too long.”

The FY ’19 MDA budget request asked for $54 million to continue funding satellite operations and sustainment of the Space Tracking and Surveillance System (STSS). The system will include two satellites operating in low Earth orbit to provide risk-reduction data for a potential operational ballistic missile defense system tracking and surveillance satellite constellation.

It also requested $16.5 million for the Space-based Kill Assessment (SKA) experiment to test a network of high sample rate, infrared sensors that can deliver a missile interception kill assessment capability to help the Ground-based Midcourse Defense (GMD) system. The SKA system has been delayed a year because of difficulties getting satellites launched and operational, the agency said at its budget press briefing in February.

Hyten said the MDA space sensor test assets will be able to discriminate the midcourse phase of ballistic missiles but also the same sensor technology “is going to be able to look down and see some of the new emerging threats like hypersonics that are challenging to us because we built an architecture that’s primarily focused on the visible ballistic missile characterization of the threat.”

He said the United States’ adversaries have been watching its sensor developments “and that’s why hypersonics and maneuvering reentry vehicles and all the other pieces” are being developed to counter the U.S.

The FY ’18 National Defense Authorization Act (NDAA) also worked to push the NDA on space sensors. It requires the director of the MDA to coordinate with the Secretary of the Air Force and other agency heads to develop a reliable and cost-effective persistent space-based sensor architecture capable of supporting precision threat tracking, warheads discrimination, effective kill assessment, enhanced shot doctrine, and integration of various missile defense systems.

Beyond sensors, Hyten said the U.S. needs better kill vehicles, more reliable kill vehicles, and eventually multi-object kill vehicles (MOKV).

“So we need more capacity in the interceptors, but we need to work all those things in unison. And those are the priorities I have: sensors, better kill vehicles, and then capacity. That’s how we should go down that path.”

Hyten also noted his issues of separating out parts of deterrence.

He said his only problem with the Trump administration’s new Nuclear Posture Review (NPR) “is the missile defense review is a separate document. And when I look at strategic deterrence in the 21st century it’s a combination of all our capabilities and right up front is offense-defense. If you look at deterrence, it’s the integration of offense and defense.”

Hyten added the Defense Department is taking its time with the Ballistic Missile Defense Review (BMDR) to make sure it is aligned with the Nuclear Posture Review (NPR).

However, he said the fact that the government still keeps the NPR and BMDR separate “tells you that our nation doesn’t fully embrace what 21st century deterrence-building is. Because if we did, it not only would be offense and defense, but it would be space, cyber, it would be all the elements, all the strategic elements for national power to deter strategic conflict of our adversaries.”