U.S. Space Force Changes Missile Warning

The Next-Generation Overhead Persistent Infrared program (pictured in this artist’s concept) will eventually replace the Space-Based Infrared System. Credit: Lockheed Martin

Lee Hudson March 19, 2021

Four years ago, Gen. John Hyten, then head of the missile warning satellite community’s largest customer, U.S. Strategic Command, said he no longer supported “buying big satellites that make juicy targets.”

Instead, he advocated buying a more distributed set of satellites with the ability to survive kinetic or cyberattacks or other emerging threats. After years of study, a multitiered system of satellite constellations with multiple methods of withstanding attacks is beginning to take shape.

“The increasingly contested nature of space demands we augment the resiliency of our space-based capabilities, just as Gen. Hyten said a few years ago,” says Lt. Gen. John Thompson, commander of the Space and Missile Systems Center. In describing the Pentagon’s pursuit of missile warning capabilities, Thompson includes:

• The launches of the last two upgraded Space-based Infrared System satellites;

• A Next-Generation Overhead Persistent Infrared satellite constellation to anchor missile warning capabilities in the future;

• Prototyping efforts across multiple orbits and proliferated constellations and ground systems to analyze data; and

• A partnership with the Space Development Agency, the Missile Defense Agency and U.S. Northern Command on the nation’s missile warning and missile tracking architecture.

“Working closely with our mission partners ensures we’re addressing the threat today while guaranteeing clear lines of effort for future development to maximize technological innovation and prevent overlap,” Thompson notes.

In this first of a four-part series on U.S. military space acquisitions, we look at the nation’s current and future plans for developing satellites and sensors that track ballistic and hyper-sonic missiles, which are designed to give the U.S. and its allies precious time to respond to attacks.

    The Pentagon will unveil OPIR Block 1 requirements this summer

    A new ground system will process all missile warning data

    Space Development Agency aims to launch eight satellites in 2022

In January 2020, a little-known missile warning satellite constellation played a key role in saving American lives. Iran had launched 16 short-range ballistic missiles at two installations in Iraq in retaliation for the U.S. drone strike that killed Qasem Soleimani, commander of Iran’s Quds Force. The satellite system known as the Space-Based Infrared System (SBIRS) warned U.S. and coalition forces in Iraq that the counterstrike was coming, providing enough time for them to get out of harm’s way.

The quick work of the 2nd Space Warning Sqdn. at Buckley AFB in Colorado helped prevent U.S. casualties, according to Chief of Space Operations Gen. John Raymond.

“We’re the initial bell ringer for the nation. We give the nation the ability to have attribution of where the missile would launch from and where it’s headed, so that’s the driving requirement on the program from [the Defense Support Program] through SBIRS,” Col. Dan Walter, senior materiel leader for the Next-Generation Overhead Persistent Infrared (OPIR) space system at the Space and Missile Systems Center, tells Aviation Week.

The Space Force’s SBIRS program is just one effort in the Pentagon’s multipronged approach to tackle early missile warning. Other initiatives include OPIR, the Missile Defense Agency’s project to develop sensors for hypersonic weapons tracking and building a proliferated satellite constellation in low Earth orbit to provide redundancy, led by the Space Development Agency.

In 2020, the SBIRS program detected more than 1,000 missile and space launches globally. The nuclear-hardened SBIRS constellation tracks missiles on a predictable ballistic trajectory using hosted payloads in highly elliptical orbit and satellites in geosynchronous orbit.

In the second quarter of this year, the Space Force anticipates the launch of the fifth SBIRS satellite. The sixth and final SBIRS satellite is scheduled for launch in the second quarter of 2022. Initially envisioned to be clones of the first four satellites, the fifth and sixth SBIRS satellites represent a leap in technology due in part to a new satellite bus that was negotiated under the program’s rebaselining agreement in June 2015.

The new Lockheed Martin 2100 combat bus is designed as part of a family of spacecraft that share common components and can be manufactured at faster rates compared to their bespoke products. Other modernized features include the ability to maintain alternate orbits with new controls and thrusters as well as room to incorporate future payloads and sensor suites.

As advanced as the fifth and sixth SBIRS satellites have become, they draw on technology developed more than 20 years ago. In 2018, evolving threats prompted the Air Force to reassess the future of the missile warning constellation and how it could address more complex threats, including munitions with multiple warheads, decoys and in-space interference. Walter characterizes this evolution as moving from analog to digital.

Potential aggressors could attack a SBIRS satellite through a kinetic or cyberattack to increase the odds of the missile attack succeeding, explains a Center for Strategic and International Studies (CSIS) report on defending against counterspace weapons. Authors of the report conducted a September 2020 workshop that assessed a scenario involving an attack on SBIRS. In that case study, a Chinese-manufactured satellite drew close enough to SBIRS GEO-1 to interfere with a communications payload collecting intelligence about China’s military capabilities. Analysts participating in the workshop pressed for a few changes as a result-—including the purchase of additional SBIRS satellites that could act as on-orbit backups.


These types of threats and the decades it took to develop SBIRS highlight the need for rapid acquisition, and they are the crux of the Next-Gen OPIR effort, which will ultimately replace legacy missile warning satellites.

SBIRS was the Air Force’s fourth attempt to enhance and replace the 1970s-era Defense Support Program. This series of failures was used to advocate for establishment of a dedicated Space Force, which could yield faster space mission decision-making times than if those missions were the purview of the Air Force.

Previous space-based missile warning replacement efforts failed because of immature technology and affordability, according to the Government Accountability Office.

After four years of analysis and increasing pressure due to the strategic threat, the Air Force sought to procure a SBIRS replacement, Next-Gen OPIR, using rapid acquisition.

The first increment of the replacement program, called Block 0, consists of five satellites, three in geostationary orbit and two in polar orbit. They will be equipped with more sensors and other features that make them more resilient to attacks than the SBIRS constellation, according to military officials. The Pentagon’s fiscal 2021 budget plan includes $12.9 billion through 2025 for the program.

Already Lockheed Martin has won $7.8 billion in contracts, the first to develop three geostationary satellites and a separate contract modification for manufacturing, assembly, integration and testing. The company’s Block 0 satellites are on track to complete the critical design phase this year, Tom McCormick, OPIR system vice president at Lockheed Martin, tells Aviation Week.

The company is also using its LM 2100 bus for the three Block 0 satellites, which will reduce cost and add the flexibility to incorporate future sensor suites, McCormick says.

Northrop Grumman secured a $2.37 billion undefinitized contract to build the two polar satellites. The polar satellite program is scheduled for a preliminary design review in August 2023.

Separately, a Northrop Grumman-Ball Aerospace team and a Raytheon Technologies team are competing to win the infrared mission payload contract for Next-Gen OPIR. Industry anticipates a downselect decision in March 2022, Sarah Willoughby, Next-Gen OPIR vice president and program manager at Northrop Grumman, tells Aviation Week.

The Pentagon opted to use rapid acquisition authorities for the mission payload competition with the hope of shaving 1-2 years off the development cycle and ensuring the product is ready for launch in 2025. Historically, satellite payloads controlled by single vendors have caused development delays.

The Space Force intends to announce the path forward for Next-Gen OPIR Block 1 this summer. The military previously announced it will be an open competition, and the update should reveal more detailed requirements.

On the Ground

As the Space Force modernizes satellites, the service must simultaneously update the missile warning processing ground stations, known as the Future Operationally Resilient Ground Evolution (FORGE) program. Raytheon beat out BAE Systems and Booz Allen Hamilton to design the new ground system. The legacy ground stations are custom-made to process data from the Defense Support Program and SBIRS but have difficulty incorporating new sensors. The Space Force is upgrading to FORGE so that as new sensors are developed, they can more easily be integrated into the ground stations for data processing.

FORGE will replace the data processor and management platform developed by Lockheed for the SBIRS constellation. Lockheed is working with the Space Force on an interim ground capability to process missile warning data from the fifth and sixth SBIRS satellites and Next-Gen OPIR Block 0 satellites that will plug into FORGE.

Raytheon is developing an open framework for FORGE that will process satellite data from the SBIRS constellation, future Next-Gen OPIR satellites as well as data from civil and environmental sensors. This design is vastly different from previous satellite ground control programs because FORGE is satellite- and sensor-agnostic so that as technology advances, the ground system will not become outdated.

The Space Force envisions the FORGE operating system will work like a smartphone, enabling it to work with new applications developed by a third-party such as the government, industry or universities. For example, a civil agency could develop a wildfire application that processes data to detect wildfires and runs along the missile warning application but does not interfere with it. In 2020, Altamira Technologies Corp., Maxar Technologies and SciTec won contracts to prototype applications that process missile warning data.

In the coming weeks, the Space Force expects to deliver an unclassified version framework to a laboratory so that industry has access, Lt. Col. Kellie Brownlee, future ground integration materiel leader at the Space and Missile Systems Center, tells Aviation Week.

The three companies that are prototyping applications finished the first demonstration and are preparing for the second demonstration this spring, Brownlee adds.

During these application demonstrations, the Space Dynamics Laboratory, a nonprofit government contractor owned by Utah State University, acts as an independent third-party assessing whether vendors have met entry and exit criteria. The Space Force designed the prototyping period to include four demonstrations, and after the final gate, the service will downselect and award a follow-on contract to one company, Brownlee says.

Missile Warning in Other Orbits

The Pentagon is pursuing two efforts to create a missile warning capability in low Earth orbit (LEO) with multiple spacecraft to create redundant capabilities that are hard to single out and easy to replace.

“Things are changing; our adversaries understand our weaknesses, and they understand our reliance on terrestrial [detection of ballistic missiles], and so [China and Russia are] building systems that are able to compete with what we have today,” Walter Chai, space sensors director at the Missile Defense Agency (MDA), tells Aviation Week.

In 2019, the Pentagon created the Space Development Agency to construct a proliferated constellation in LEO composed of satellite layers that focus on different missions. At the time, it was not clear what the creation of the SDA meant for the MDA’s Hypersonic and Ballistic Tracking Space Sensor (HBTSS) program that was working to field satellites to track hypersonic glide vehicles.

The fiscal 2021 budget rollout only added to the confusion, because the MDA transferred the purse strings for the HBTSS to the SDA. When explaining why the MDA would give up financial control of one of its programs, MDA Director Vice Adm. Jon Hill said that since the HBTSS satellites would become a part of the SDA’s larger small-satellite constellation, a funding transfer would make sense. Hill stressed that the MDA would continue to lead technology development of the HBTSS.

Both the SDA constellation and HBTSS are needed to respond to new threats. The SBIRS and OPIR constellations use narrow-field-of-view sensors that are optimized to track ballistic missiles. These sensors are not designed to track cruise missiles and hypersonic glide vehicles that can maneuver in flight and evade existing radar coverage.

The “motivation of HBTSS is to counter the evolving and advancing threats that the adversaries are developing,” such as a glide phase interceptor, Chai says.

The SDA and MDA are developing different sensors to counter these advanced threats. The SDA constellation will use a wide-field-of-view sensor designed to detect and track hypersonic weapons, and it will add new capabilities every two years as threats evolve. The MDA is working to field a medium-field-of-view sensor under the HBTSS program formerly known as the Space Sensor Layer.

“You have to be able to target on the fly and provide updates for fire control solutions so that you can treat things as maneuverable, whereas in the past, we could just treat everything as a ballistic trajectory,” Space Development Agency Director Derek Tournear says.

The two sensors would work together—-the SDA’s wide-field-of-view sensor detecting and identifying an object of interest and the MDA’s medium-field-of-view sensor then zooming in on the object. Because the specifics are highly classified, consider a notional example: The wide-field-of-view sensor picks up activity in a defined area and sends the information to the HBTSS. The medium-field-of-view sensor could then pinpoint the target within that defined area and send the more granular information to a commander to decide whether to use a ground-based interceptor for target acquisition.

In 2020, the SDA signed contracts with L3Harris Technologies and SpaceX for each company to build four satellites to detect ballistic, cruise and hypersonic missiles using a wide-field-of-view sensor. The plan is for these eight satellites to launch in 2022, Tournear says.

However, the program hit a snag after a series of protests were filed with the Government Accountability Office by losing bidders Airbus and Raytheon Technologies. A decision made Jan. 7 of this year allows L3Harris and SpaceX to move forward with developing the satellites in Tranche 0 of the future Tracking Layer. The bid protests marked the first pitfall for the program, but Tournear maintains that the schedule is on track.

By 2022, the plan is for the SDA to have “periodic regional access” for advanced missile tracking. The HBTSS satellites will be part of the SDA’s expansive Tracking Layer that will include 70 wide-field-of-view and medium-field-of-view satellites by 2023.

For the HBTSS competition, L3Harris and Northrop Grumman beat out Leidos and Raytheon Technologies in January 2021 to each build a prototype sensor satellite capable of tracking hypersonic and ballistic missiles by July 2023.

The Tracking Layer is just one piece of the many missions the SDA is looking to fulfill with its seven-layer small satellites. The SDA’s National Defense Space Architecture (NDSA) also includes a Transport Layer providing communications and data relay to personnel on the ground, a Custody Layer supporting mobile ground asset targeting, a Battle Management Layer providing space-based command and control, a Navigation Layer offering alternate position, navigation and timing in GPS-denied environments, a Deterrence Layer detecting potentially hostile actions in deep space and a Support Layer facilitating satellite operations between the other layers. Once fully fielded in 2025, the NDSA would contain 550 satellites and provide global coverage.

While the pricing of individual satellites in the SDA’s constellation range from tens of millions of dollars compared to traditional satellites that cost more than hundreds of millions of dollars, it is still up for debate which strategy is more cost-effective for the taxpayer. The SDA’s satellites are designed with a notional five-year lifespan, with the plan for them to be updated and replaced as technology advances, while high-value satellites like SBIRS are designed to last decades and cannot easily be updated.

The risk the Pentagon is taking with the SDA constellation is that the new Biden administration may not be up to speed on the advances made in the small-satellite industry and how to operate large constellations of satellites, says Todd Harrison, aerospace security project director at the Center for Strategic and International Studies.

“They may fall into paralysis by analysis like they did in the Obama administration and be unwilling to move forward with the proliferated LEO constellation for missile tracking,” Harrison warns. “I worry that they could try to slow things down to study the problem some more and try to come up with a more perfect solution.”