Huntsville, Ala. — The head of the Missile Defense Agency (MDA) this week broadly outlined how he sees a future missile defense space sensor layer could work on the heels of increased Congressional attention to improving U.S. missile defense sensors and their ability to help detect hypersonic weapons.

The missile defense community has been “seriously” talking about a space sensor layer “actively over the last year” Lt. Gen. Samuel Greaves said here at the Space and Missile Defense Symposium on Wednesday.

Lt. Gen Samuel Greaves, director of the Missile Defense Agency. Photo: U.S. Air Force.
Lt. Gen Samuel Greaves, director of the Missile Defense Agency. Photo: U.S. Air Force.

Although more of the program’s requirements definitions, development paths, and acquisition paths have to be decided, “the key thing is that there is serious consideration and support being given to the need to deploy these space sensors because we must do so.”

Using a graphic previously found in the FY ’19 MDA budget overview, Greaves explained the MDA could use something like the Air Force’s Overhead Persistent Infrared (OPIR) global scanning system to alert and characterize space activity. This would “be the bell ringer if something is going on,” Greaves said.

Then, once the system is alerted, it would use a regional electro-optical infrared system that stares back at the warm Earth. It can be cued to look down and figure out if a ballistic missile is a threat during its boost and burnout phases, as it enters space. Greaves said this capability could also be used for hypersonic threat detection across most hypersonic paths or other “dimmer” targets.

Next, during the missile’s midcourse flight, a narrow field of view electro-optical/infrared discrimination sensor would look to compare the ballistic missile “against the cold background of space” to discriminate, track, and eventually serve as fire control for defenses.

After ballistic missile defenses make a shot at the target, an electro-optical/infrared kill assessment vehicle can standby to record if an intercept successfully destroyed, disabled, or missed a target on the back end of a missile space trajectory. This capability helps a commander decide if they need a re-shoot.

Greaves highlighted that “getting that capability into the architecture and providing that information to folks on the ground that have to make a decision on whether or not to re-shoot or whether to move on to another target, that is extremely important.”

He also noted that nine to 10 parties have already submitted white papers to address the capabilities for this kind of system. He said MDA is working closely with the Defense Advanced Research Projects Agency (DARPA), in part to see how its Blackjack program could help.

A Broad Agency Announcement (BAA) from May explained the Blackjack program aims to develop and demonstrate critical technical elements to build a global high-speed network backbone in low Earth orbit (LEO) that enables highly networked, resilient, and persistent Defense Department payloads that provide infinite over-the-horizon (OTH) sensing, signals, and communication and also seeks to hold the ground, surface, and air domains in global constant custody.

The BAA noted DARPA is interested in leveraging advances in how commercial space has been using LEO satellite constellations for broadband internet service to demonstrate a military utility. “The Blackjack architecture is founded on the concept that ‘good enough’ payloads can be optimized around an ability to fly on more than one type of bus,” it added.

Greaves said he has been talking with under Secretary of Defense for Research and Engineering, Dr. Michael Griffin, on a possible LEO or near Earth orbit constellation for the sensor layer. Those decisions will be made in the acquisition process, so Greaves said he is not as worried about what the exact solutions will be.

“Whether it’s the classic ballistic target into space and back down or hypersonic threat skimming at very low altitudes, space offers, with the ground capability that we’ve got, the best integrated architecture to ensure we maintain both. It’s not more complicated than that, but if you don’t have it, you can’t see it shoot and the remains of your system is essentially useless,” he said.