Space Force aims to launch 1st 'Foo Fighter' satellites in 2027 to track hypersonic threats

satellites above Earth watch missiles being launched
An illustration of satellites tracking various types of missiles, including a hypersonic glide vehicle. (Image credit: Space Development Agency)

The United States Space Force has ordered the first satellites for an upcoming advanced missile defense constellation.

The Space Development Agency (SDA), an agency within the U.S. Space Force tasked with developing new, disruptive space technologies, awarded $414 million to California-based Millennium Space Systems, Inc. to build eight satellites for its upcoming Fire-control On Orbit-support-to-the-war Fighter program, also known as F2 or FOO Fighter.

The satellites will be tasked with detecting, providing warning and tracking of what SDA refers to as "advanced missile threats," which include hypersonic missiles that can travel at velocities between five and 25 times the speed of sound. SDA hopes to launch the satellites in the first quarter of 2027, according to an agency statement.

Related: Space Force wants 'Foo Fighter' satellites to track hypersonic missiles

Details about the FOO Fighter program are scarce, but SDA previously stated in a contract opportunity that it will "provide fire-control in support" of defending against missile threats. Generally, fire-control refers to systems that combine technologies such as radar or infrared sensors with targeting computers and ranged weapons such as missile interceptors. Fire-control systems help 'point' defenses in the right direction, linking multiple systems together so that countermeasures can be directed at threats.

In the agency's statement announcing the award, SDA director Derek Tournear said the FOO Fighter satellites will add to the agency's growing fleet of missile tracking spacecraft known as the Proliferated Warfighter Space Architecture, or PWSA, already being launched in small batches known as tranches.

"The FOO Fighter program will provide an operational demonstration of fire control efforts separate from, but complementary to, our missile warning/missile tracking and missile defense efforts already underway in the tranches," Tournear said. "We look forward to working with Millennium, a new teammate in the expanding marketplace of performers innovating to deliver the PWSA for the warfighter."

The first 10 satellites of SDA's Tranche 0 layer launched in April 2023 on a SpaceX Falcon 9 that took off from Vandenberg Space Force Base in California. SpaceX launched 13 more Tranche 0 satellites in September of that year. 

Of the planned 28 satellites for the Tranche 0 constellation, 20 will serve as communication relays and eight will be equipped with wide-field-of-view missile detection sensors. All of the satellites will be connected by laser data links.

The FOO Fighter program shares its name with the notorious UFOs reported by Allied aviators throughout World War Two. Those foo fighters appeared as luminous orbs or balls of fire, often appearing to follow aircraft in flight. 

While a definitive explanation for the UFOs has yet to be found, multiple theories for their cause have been put forward in the years since, including ball lightning or atmospheric discharges of static electricity. 

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Brett Tingley
Managing Editor,

Brett is curious about emerging aerospace technologies, alternative launch concepts, military space developments and uncrewed aircraft systems. Brett's work has appeared on Scientific American, The War Zone, Popular Science, the History Channel, Science Discovery and more. Brett has English degrees from Clemson University and the University of North Carolina at Charlotte. In his free time, Brett enjoys skywatching throughout the dark skies of the Appalachian mountains.