Radar Developed For U-2 To Go On Army Intel-Gathering BizJets

The U.S. Army’s future fleet of High Accuracy Detection and Exploitation System (HADES) intelligence-gathering business jets are set to use a radar the development of which originally began as an upgrade for the U-2 Dragon Lady spy plane. This comes as the U.S. Air Force is now looking to retire all of its iconic U-2s in 2026.

A Pentagon budget reprogramming document, which was approved in February and subsequently posted online, confirms the inclusion of the Advanced Synthetic Aperture Radar System-2B (ASARS-2B) in the HADES sensor suite. The Department of Defense has to, by law, submit requests to Congress to reallocate funding from one part of its budget to another.

A low-quality rendering of the expected look of the Army’s HADES aircraft. US Army

“Funds are required to complete the Advanced Synthetic Aperture Radar System (ASARS-2B) Engineering and Manufacturing Development (EMD) Phase,” the Pentagon budget document explains. “If not funded, the program will stop work on ASARS-2B EMD efforts which would have serious negative consequences for the Army High Accuracy Detection and Exploitation System (HADES) program and classified mission partners.”

“Technical engineering and design challenges with integrating the Air-Cooled Scalable commercial-off-the-shelf processor, antenna, and receiver exciter have extended schedule and increased cost above what was original planned,” the document offers explanation for why more funding is necessary. “Additional funds are required for continued development and integration including system integration laboratory, developmental, and operational testing.”

The reprogramming adds $10 million to the ASARS-2B development effort and takes that money from funds that had been allocated originally for the Air Force’s RQ-4 Ground Segment Modernization Program, which was canceled in 2022. The U.S. Air Force is also looking to retire the last of its RQ-4 Global Hawk drones by Fiscal Year 2027.

Raytheon’s ASARS-2B is primarily designed to produce synthetic aperture radar (SAR) imagery, which are highly-detailed ground maps. As a radar, the system can capture these images despite any cloud cover, smoke, or dust that might block the view visually, and also do so at night.

ASARS-2B also has ground moving target indicator (GMTI) functionality, which can be used to spot and track vehicles. That data can be used as general intelligence, mapping patterns of life, targeting, and it can be overlaid on SAR images to be used to further refine intellignece collection areas.

A generic example of GMTI tracks overlaid on top of a SAR image. Public Domain

As an active electronically-scanned array (AESA) radar, ASARS-2B is also just more powerful, precise, and faster than its mechanically-scanned ASARS-2A predecessor. The Air Force received the first ASARS-2A in 2001 as a replacement for the baseline 1980s vintage ASARS-2 that had been in use on the U-2.

The U-2 has a highly modular design that allows the rapid swapping in and out of different sensors and other payloads. This graphic provides a look at some of the options developed over the years, including a nose module with ASARS-2. USAF

Development of ASARS-2B dates back to at least 2019 and a prototype was flight-tested on a U-2 that year. The Air Force’s 2025 Fiscal Year budget request says the service expects the development of the radar to wrap up this year. U-2s are still expected the carry the ASARS-2B operationally, but it might not be for very long given the current retirement timeline.

The planned use of ASARS-2B on the Army’s HADES aircraft makes sense given the stated focus of that program on “deep-sensing” capabilities well beyond those of the service’s existing crewed fixed-wing intelligence, surveillance, and reconnaissance aircraft. HADES, which will also have communications and electronic intelligence (COMINT/ELINT) capabilities, is part of a larger Multi-Domain Sensing System (MDSS) family of systems. MDSS is expected to include high-altitude glider-like drones and balloons designed to operate up in the stratosphere.

A graphic from 2020 showing a vision for how the entire future MDSS ecosystem, including crewed fixed-wing ISR aircraft like HADES, might mesh together with other Army capabilities. US Army

“The goal is to provide deep-sensing intelligence collection of indicators and warnings, electronic order of battle, and patterns of life for target development,” Dennis Teefy, the Army’s Project Director for Sensors-Aerial Intelligence (PD SAI), said back in 2021. “This will allow standoff operations to detect, locate, identify, and track critical targets for the ground commander.”

The Army’s current crewed ISR fleets consist of turboprop-powered aircraft. So, a business jet-based platform will also allow the service to conduct those missions at higher altitudes across longer distances, and to get to and from collection areas faster. The service sees HADES as being less vulnerable to air defense threats by extension.

Still, HADES won’t be able to fly anywhere near as high as the U-2, and won’t be able to get the same kind of broad field of view or its ASARS-2B as a result. At present, the Dragon Lady is the highest-flying aircraft in U.S. military inventory, at least that we know of.

In terms of what will carry the various HADES payloads, the Army announced that it had selected the Bombardier Global 6500 in January. The service is expected to award a contract for the actual integration of the sensors and other mission systems later this year. The Global 6500 is already in U.S. military service as one of the business jets the Air Force has converted into E-11A Battlefield Airborne Communications Node (BACN) aircraft.

The Army has said in the past that it could ultimately acquire between 10 and 16 HADES aircraft, in total. The service has also been making use of several different types of contractor-owned and operated ISR-configured business jets, including ones based on the Global 6500, which might ultimately be absorbed into its organic HADES fleet.

A Bombardier Global 6500 in the process of being converted into an Army Theater Level High-Altitude Expeditionary Next-Generation Airborne ISR-Radar (ATHENA-R) aircraft. The ATHENA-R jets are among the contractor-owned and operated platforms the Army has been using in the interim as it pushes ahead with HADES. L3Harris

Broader questions remain about the ability of the HADES aircraft to take over for the Army’s fleets of turboprop-powered fixed-wing ISR aircraft. Though more capable and less vulnerable, the HADES jets are not expected to replace existing types on a one-for-one basis, which could easily create a capacity gap. How well other planned components of the MDSS might be able to help mitigate that is unclear.

The Air Force has actually faced similar questions around its plans to retire the U-2s. The service has provided limited details about what will supplant the Dragon Ladies, but has said that it will be a mix of space-based and other capabilities. This is widely believed to also include one or more advanced high-flying drones. A stealth spy drone commonly referred to as the RQ-180 is assumed to be part of this equation, and may already be in service to a limited degree. Leveraging intelligence products, including SAR/GMTI data, from many different platforms over the battlefield, including tactical types, like fighters and drones, as well as aircraft like the B-21, and collecting and correlating that data via advanced networking and powerful computing will also be key.

ASARS-2B may well be part of the Air Force’s own post-U-2 plans. The service’s 2025 Fiscal Year budget request notes work to “advance the capability of ASARS” also applies to “classified platform employment.” The Pentagon’s budget reprogramming document mentions “classified mission partners” as stakeholders in the ongoing development of the 2B variant along with the Army.

It would not be surprising for other sensors and mission systems developed in recent years primarily for the U-2 to be ported over to other platforms.

Whatever the case, we now know for sure that a bit of U-2-related heritage in the form of the ASARS-2B is set to continue serving the U.S. military after the Dragon Ladies are retired.

Contact the author: joe@twz.com