The first flight-test of a long-range, ground-based interceptor is launched from Vandenberg Air Force Base, Calif., Sept. 12, 2021. Funded improvements to the Ground-Based Midcourse Defense system will help the U.S. defend against the threats from China, Russia, and North Korea. Anthony Mendez/Missile Defense Agency
Photo Caption & Credits

Tracking Hypersonics in Real Time 

April 29, 2022

New capabilities are required—now—to combat long- range precision missiles being tested by adversaries. 

The Department of the Air Force is rolling out plans to beef up missile warning and tracking as China, North Korea, Russia, and even Iran develop, build, test, and field new long-range missiles.

New details emerged during the Space Symposium in Colorado Springs, Colo., in April about plans for space-based missile warning and tracking, which Air Force Secretary Frank Kendall called a top priority of the Biden administration.

Kendall said long-range precision missiles “place the entire joint force at risk” and referred to missile warning and tracking as “a no-fail space mission.” 

“I know from my leadership in the administration, there are no more important areas to prioritize than missile warning and nuclear command and control,” Kendall said. 

A combined $1 billion in the fiscal 2023 President’s Budget request addresses missile warning and tracking by allowing the Space Force “to grow a proliferated, multi-orbit, disaggregated architecture over the next several years,” Kendall said. “To be able to track objects like China’s hypersonic weapon systems or their potential fractional orbital bombardment system, the Department of the Air Force will invest in disaggregated missile warning and missile tracking capabilities from space.” 

North Korea … obviously has an intercontinental ballistic capacity. … And Iran hopes to develop one.

Sen. Mark Kelly (D-Ariz.),
member of the Senate Armed Services Committee and former astronaut 

The amount pays for portions of infrared satellite constellations in two orbital layers along with related ground facilities. The Space Development Agency (SDA) and Space Force’s Space Systems Command (SSC) each have responsibility for a new “layer” of missile-tracking satellites. 


Evidence of new intercontinental ballistic missile (ICBM) silos in China has raised more concerns on top of the country’s advancing its hypersonic and orbital systems. 

Senate Armed Services Committee chair Sen. Jack Reed (D-R.I.) cited China’s building of “three missile fields in hardened silos throughout the country” during a hearing that featured testimony by military commanders March 8. 

“Ensuring we can accurately warn both Strategic and Northern Commands, and our senior leadership, of a missile attack on the homeland is of the utmost importance,” Reed said.

At the same hearing, former Navy pilot and astronaut Sen. Mark Kelly (D-Ariz.) acknowledged that “North Korea … obviously has an intercontinental ballistic missile capability” and that “Iran hopes to develop one.”

Soon thereafter, North Korea tested a new intercontinental ballistic missile that reached more than 6,200 kilometers in altitude and splashed down about 1,100 kilometers off Japan’s western coast, according to information from the Japanese and South Korean defense ministries. The test was North Korea’s third in a month, following two that officials said didn’t reach ICBM range.

North Korea could surpass the U.S.’ ability to protect the homeland, the head of U.S. Indo-Pacific Command Gen. Glen D. VanHerck told the SASC on March 24. VanHerck advocated for planned upgrades to U.S. defensive weapon systems for shooting down ICBM’s. He said funded improvements to the Ground-based Midcourse Defense system and the planned Next-Generation Interceptor “will help both get after the additional capacity problems and the capability problems.”

Also in March, Russia claimed to have fired hypersonic missiles on ammunition and fuel depots in Ukraine, though their use prompted speculation that Russia had run low on other precision-guided munitions. 


Even though Russia says it’s already fielded hypersonics in Ukraine, mid-2025 is the soonest the U.S. could expect to place its planned constellation of 28 infrared missile-tracking satellites into low-Earth orbit (LEO). The Space Development Agency’s constellation should be able to track maneuverable hypersonic vehicles, something today’s systems weren’t designed to do.

SDA Director Derek M. Tournear briefed reporters during the symposium on the agency’s already-accelerated schedule to launch its “Tracking Layer” satellites.

North Korean dictator Kim Jong Un (center) and military leaders attend the March 23 firing of a new Hwaseongpo-17 intercontinental ballistic missile (background) at Pyongyang International Airport in North Korea. The missile attained a peak altitude of approximately 3,882 feet, flew roughly 677 miles, and landed in the East Sea of Korea. Korea Central News Agency (KCNA)

Much like U.S. Space Command and the Space Force, SDA considers itself a startup. All three organizations started—or restarted, in the case of the combatant command—in 2019. SDA’s role was to try to disrupt and speed up the historically lengthy and expensive process of acquiring new satellites. The agency moves organizationally from the Office of the Secretary of Defense to the Space Force in fiscal 2022.

SDA’s planned National Defense Space Architecture relies on lower-cost parts having become more readily available and a “spiral” concept of de-orbiting and replacing full “tranches” of comparatively low-cost satellites with upgraded batches every two years. The agency expects the architecture to total about 400 satellites, some monitoring for missiles and others transporting data around a mesh network. 

In fiscal 2022, Congress gave SDA an extra $550 million above the Defense Department’s original request. The extra is for SDA to accelerate the first full tranche of the infrared Tracking Layer of its planned architecture.

Today, infrared satellites in high geosynchronous orbits detect the hotter “boost” phase of a missile launch, Tournear explained, and information from ground-based radars helps in calculating the missile’s trajectory. That method works well for predicting the paths of ballistic missiles that don’t maneuver. 

But with maneuverable hypersonics entering the picture, the military won’t be able to rely so much on math to deduce the trajectory. SDA’s lower-altitude Tracking Layer satellites will pick up the slack by virtue of orbiting a lot closer, presumably giving them the ability to detect a missile “from liftoff, all the way through the glide phase—essentially all the way to the terminal phase,” Tournear explained.

With proposals pending to build Tranche 1 of the Tracking Layer, Tournear said his office expected to award multiple contracts in June for 28 total satellites to launch in May 2025.

“With the acceleration in ’22, I think that we are going as rapidly as possible,” he said, describing the 2025 launch date as “what is achievable based on the current technology—what we think can be delivered.” 

Contracts to build the satellites will go to multiple vendors within each tranche for a reason, Tournear said.

“It’s SDAs model that we will always have full and open competition for every layer, for every tranche to make sure that that market continues to grow because we do not want to get stuck in a vendor lock situation,” Tournear noted. 

SpaceX and L3Harris have already received contracts to build the Tracking Layer’s “Tranche 0” proofs of concept launching in 2023.

“We anticipate probably between six and 10 bidders on Tranche 1 Tracking,” Tournear said. “While the technology may be more mature based on the fact that there are already some incumbents,” other companies may also become more competitive, for example, by working with Space Systems Command on its parallel missile-tracking constellation.


Consistent with Kendall’s top “operational imperative” to create a resilient space architecture, SSC’s new constellation will orbit higher up—in medium-Earth orbit (MEO)—potentially making its satellites harder to reach by ground-launched, anti-satellite weapons. 

The current infrared missile-tracking satellites orbit highest of all. Their geosynchronous orbits allow for fewer satellites to monitor wider swaths of the atmosphere but also call for bigger optics to see farther, translating to bigger, more expensive satellites.

Out of the $1 billion in the fiscal 2023 budget request, Tournear said about $130 million is for Space Systems Command to start work on its MEO constellation. Another $500 million is for SDA to continue its Tranche 1 Tracking Layer, and $226 million and $164 million are for ground elements associated with the LEO and MEO constellations, respectively.

Adding the MEO perspective could also help in detecting a fractional orbital bombardment system, or FOBS, like the one China demonstrated in 2021. In that test, a hypersonic vehicle launched atop a rocket, orbited almost once around the Earth, then reentered the atmosphere at hypersonic speed. 

“Those are systems that can reenter anywhere over the globe,” according to Tournear. “That’s where you need these LEO and MEO tracking layers. You would detect the system as it reenters, and then detect it as it maneuvers, and so you would be able to tie all that together.”


Right now “missile warning/missile tracking” are all the buzz.

“In the future, we’re going to be talking about ‘missile warning/missile tracking/missile defense,” Tournear said, because in the big picture “all three of those missions are rolled into one.”

“After we develop and field the operational missile warning/missile tracking constellations, we will be fielding the missile defense systems, which are able to do the actual fire-control quality [data] from space—so we can send those down directly to interceptors,” he explained. 

Northrop Grumman’s proposed Tranche 1 Transport Layer (T1TL) mesh satellite communications network—a constellation of 42 low-Earth orbit satellites—aims to provide resilient, low-latency, high-volume data transport supporting U.S. military missions globally. Northrop Grumman graphic

“Beyond what we’re currently building out for [data] transport and tracking—for missile warning/missile tracking—I would say the next steps that are needed are more integration of capabilities from what we call the Custody Layer, which is from our commercial and other government partners for the [intelligence, surveillance, and reconnaissance] layer, into our Transport Layer so we can actually calculate fire-control solutions based on that for those time-sensitive targets.” 

Stitching all that together won’t happen until Tranche 2 of the Tracking Layer goes live further down the road. Once that happens, “then we have a global capability for missile warning/missile tracking,” Tournear added.

“And then as time progresses,” he said without going into more detail, “as our technology advances and we field more capabilities, the Missile Defense Agency is going to field capabilities to actually engage in the glide phase.”