The Department of the Air Force is to complete a force design for future ground moving target indication (GMTI) using a possible mix of space and air assets this year in advance of the fiscal 2024 budget submission.

The Department of the Air Force’s fiscal 2023 budget indicates that the department plans to retire its 12 remaining Northrop Grumman [NOC] E-8C Joint Surveillance Target Attack Radar System(Joint STARS) ground moving target indication (GMTI) planes–eight in fiscal 2023 and four in fiscal 2024–and to use other intelligence, surveillance, and reconnaissance (ISR) assets to fill in for the loss of Joint STARS (Defense Daily, March 29).

The Air Force said on March 29 that it continues “to operate multiple ISR platforms with GMTI capability and plan to do so across the duration of the coverage reduction caused by JSTARS retirement.”

Other Air Force aircraft besides Joint STARS with GMTI include the U-2 with the Raytheon Technologies [RTX] ASARS-2 radars, the Northrop Grumman RQ-4 Block 40 Global Hawk with the Raytheon AN/ZPY-2 radar, and the RQ-170 Sentinel by Lockheed Martin [LMT]. The Advanced Battle Management System (ABMS)–the Department of the Air Force initiative under Pentagon Joint All Domain Command and Control (JADC2)–is to aid the integration of such sensor information for time critical targeting.

“Having been a user of GMTI in my previous job over in the [U.S. Central Command] AOR [Area of Responsibility], it is a critical capability,” Air Force Lt. Gen. David Nahom, the service’s deputy chief of staff for plans and programs, told an Air Force Association (AFA) “Air and Space Warfighters in Action” forum on March 30.

“A lot of people look at the JSTARS and that being a problem going into the next cycles, as we look to retire that fleet,” he said. “It is old. It’s another 707 platform [like AWACS] with old motors and significant reliability issues just because of the age of the platform. Our airmen…work days to keep that old platform flying and giving some relevancy to that mission. But we’ve got to get that better.”

In addition to Air Force GMTI, other services have some GMTI. For example, the U.S. Navy MQ-4C Triton aircraft by Northrop Grumman has GMTI. while the U.S. Army De Havilland Canada (DHC) Airborne Reconnaissance Low aircraft have GMTI. In addition, Leidos [LDOS] has been working with the Army on possible GMTI on a modified Bombardier 650 business jet that Leidos owns. While the 1948 Key West Agreement–and its modifications–carving out service mission areas appear to prohibit Army aerial reconnaissance jets, the stipulations may contain a loophole for contractor-owned test assets.

“We have to work very closely with our joint partners and combatant commands to make sure we can offer up air domain GMTI solutions,” Nahom said on March 30. “There’s a big space aspect of this.”

Nahom and Lt. Gen. William Liquori, the U.S. Space Force (USSF) deputy chief of space operations for strategy, plans, programs, requirements and analysis, told the March 30 AFA forum that the Air Force and Space Force are collaborating to help avoid a GMTI gap caused by the Joint STARS’ planned retirement in fiscal 2024.

Liquori said that the first force design task of the USSF Space Warfighting Analysis Center (SWAC) was hypersonic missile warning and tracking, which the SWAC proposed earlier this year as a mix of low and medium Earth orbit satellites.

“There is a very specific reason that GMTI is the second force design out of the chute,” Liquori said. “We are working real hard as two services [Air Force and Space Force]…to make sure that there is not a [GMTI] gap. That force design will report out later this year and will inform our [fiscal] ’24 budget going forward. There is no surprise as to why moving target indicator is one of the secretary’s [Air Force Secretary Frank Kendall] operational imperatives.”

The first two Joint STARS developmental aircraft gained prominence during Operation Desert Storm in 1991 for their role in tracking and targeting Iraqi units and equipment, including Scud missile launchers. The U.S. also used Joint STARS during operations thereafter in Kosovo, the Middle East and Afghanistan. At their best, the Joint STARS helped U.S. forces to track and target enemy units or to force such units to disperse, camouflage themselves, and dig in, in which case U.S. and allied ground forces were able to target or bypass them.

Dynamic GMTI radars, as on Joint STARS, allow periodic updates and precise tracking of moving targets via the Doppler returns of such targets.

Kendall has suggested that the sustainment costs for Joint STARS are too high and that the aircraft needs replacement. Space Force has been working with the National Reconnaissance Office (NRO) to develop and field a Space Based Radar (SBR) in the near term to provide GMTI for potential conflicts with adversaries able to deny airborne GMTI coverage by the U.S. (Defense Daily, Sept. 27, 2021).

While Chief of Space Operations Gen. John “Jay” Raymond disclosed the SBR effort last year and suggested that more details were forthcoming, the Department of the Air Force has revealed no such details and did not discuss SBR during a fiscal 2023 budget briefing. The Air Force said this week that the effort to provide GMTI beyond Joint STARS is classified.

Kendall said late last year that he had entered into discussions with NRO Director Chris Scolese and Director of National Intelligence (DNI) Avril Haines on coming up with the right mix of air and space sensors for GMTI. The NRO has traditionally provided intelligence gleaned from space sensors to the national command authority, not military forces in the field.

Space-based GMTI has shown promise in other nations’ research efforts, including the Canadian RADARSAT-2 experiment and the Chinese Gaofen-3 low Earth orbit remote sensing satellite.

The U.S. has initiated space-based GMTI efforts before–efforts that entailed cost estimates in the tens of billions of dollars for an operational system. In 1998, the Air Force, Defense Advanced Research Projects Agency (DARPA), and the NRO began the Discoverer II program to explore high-resolution space-based GMTI, but Congress canceled the program in 2000.

In 2004, the Air Force awarded a Lockheed Martin team a contract for Space Radar, but the Pentagon killed the program in 2008 as being too costly.

A 2007 report by the Congressional Budget Office (CBO) estimated the cost of a space-based GMTI radar system as ranging from nearly $26 billion to more than $94 billion.

“The Air Force continues to insist that this [GMTI] mission can be migrated to networks/ABMS and space-based assets,” Richard Aboulafia, the managing director of Michigan-based AeroDynamic Advisory, said in a March 30 telephone interview. “The Army and many of its backers feel otherwise.”

“It’s pretty clear the Army feels neglected,” Aboulafia said. “GMTI, of course, was revolutionary when it had a preliminary operating capability in Gulf War I. Since then, it’s become a very high demand capability, especially the JSTARS, because there’s battle management and [GMTI] sensor capability in one asset. It’s hard to tell to what extent the Air Force is simply looking for a plus up–‘We don’t want to prioritize our cash for this. If you want to support the Army, just add money for it.””

“The Air Force very understandably regards the A-10 as something they’d like to get rid of,” he said. “In a conflict with peer adversaries, those would have a shelf life of about five minutes, whereas with GMTI, it’s hard to tell what their viewpoint is. Is it that the technology is based in networks, or is it that there might be a gap and we want other people to add money for it?”