Pentagon Still Unsure About Lethality Of Dark Eagle Hypersonic Missile

Yahoo

04-02-2025

The U.S. Department of Defense has disclosed that it's still unclear about the lethal effects of the hypersonic missile that's at the center of the Army's Dark Eagle Long Range Hypersonic Weapon (LRHW) and which will arm the Navy's Zumwalt class stealth destroyers and future Block V Virginia class submarines. The surprising knowledge gap comes after the Army achieved the long-delayed first test-firing of a Dark Eagle missile from its trailer-based launcher, something you can read more about here.
The latest updates on the progress of the in-development Dark Eagle are provided by the Office of the Director, Operational Test & Evaluation, in its latest Annual Report.
The report outlines the test program for the Dark Eagle in FY24, which began in the first quarter with an Army/Navy risk-reduction campaign, followed in the third quarter by integrated launch sequence testing, intended to iron out problems encountered in earlier flight tests. In the past, the Army had specifically pointed to issues with the launcher for causing significant delays in the planned fielding of the weapon system. In 2023 alone, the Army scrubbed three planned launches.
The third quarter of FY24 also saw a successful launch of the Navy's prototype All-Up-Round (AUR) — the actual missile component for the Army's Dark Eagle and the Navy's Intermediate-Range Conventional Prompt Strike (IRCPS) program, but that made use of a different ground-based launch apparatus. In the final quarter of FY24, the Army planned to conduct a missile test from a prototype transporter-erector-launcher (TEL), but this was shelved.
Finally, in December 2024, there was a successful test launch from Cape Canaveral Space Force Station, Florida, as TWZ reported at the time, although this is outside the scope of the latest report. This was the second successful end-to-end flight test of the AUR in the course of 2024, but was the first live-fire event involving the missile as well as a battery operations center (BOC) and TEL.
Here is one of my iPhone videos of the LRHW test launch from Cape Canaveral this morning.
pic.twitter.com/ZCKF3lTEuU
— JohnCn (@JConcilus) December 12, 2024
As we've discussed in the past, the Dark Eagle is a prototype surface-to-surface long-range strategic fires system, which consists of one TEL and two Navy-designed AURs that are loaded in Army AUR canisters (known as AUR+C). In its initial form, each Army battery will have four TELs, each with two AUR+C, plus a BOC.
Looking at the AUR specifically, this comprises two main components: a two-stage rocket booster with an unpowered hypersonic boost-glide vehicle, known as the Common Hypersonic Glide Body, on top. Under the CPS program, the same AUR will be launched from canisters on the Zumwalt class and the Block V Virginia class.
The two-stage rocket brings the conical 'glide vehicle' to an optimal speed and altitude before releasing it, after which it glides down to its target at hypersonic speeds, defined as anything above Mach 5, and along a relatively shallow, atmospheric flight path, maneuvering erratically along the way. The Army has previously said the weapon's peak speed is at least Mach 17 and its maximum range is in excess of 1,725 miles.
Returning to the test program, what's especially notable is that it has so far yielded insufficient data 'to evaluate the operational effectiveness, lethality, suitability, and survivability of the LRHW system,' the report states.
Essentially, although it has been test-fired, the Pentagon is not able to 'make an adequate determination of AUR lethality,' noting that 'uncertainty in weaponeering tools could result in excessive employment requirements or failure to meet warfighter objectives.' In this context, excessive employment refers to multiple examples of the missile being required to destroy certain targets. This would be a significant drawback, especially given the limited number of missiles in each Dark Eagle battery not to mention the huge costs of hypersonic weapons.
In the meantime, the Navy has tested the warhead for the AUR, but independent of the missile. An arena test for the warhead was carried out in the first quarter of FY24, followed by a sled test in the second quarter of FY24. The Pentagon says that this sled test 'included some threat-representative targets,' but also notes that results are still being processed.
Earlier sled and flight tests 'did not include operationally representative targets and consequently provided no direct validation of the weapon's lethal effects,' the Pentagon adds.
While the Director, Operational Test & Evaluation (DOT&E) was due to provide an independent assessment of the operational effectiveness and lethality of the missile based on the FY24 tests, it's notable that the Navy is also looking at other methods to obtain effectiveness and lethality data, by using representative targets in future flight tests.
As well as lingering questions about the lethality of the missile, there is also still a lack of data about the weapon's own survivability, the Pentagon says.
'The Army has not yet evaluated the effects of a full-spectrum (kinetic, non-kinetic, electromagnetic, cyber) threat-contested environment on the performance of the AUR, TEL, or BOC,' the report states. As of the end of FY24, there had been no end-to-end cyber survivability testing, something that's required to better understand potential vulnerability and to better assess its likelihood of defeating a defended target. For a missile that's meant to defeat high-value and time-sensitive targets, this would seem to be a glaring omission. In the meantime, the report adds, the Army is relying on the Navy's data gathered via modeling and simulation, component testing, and hardware-in-the-loop evaluations to better evaluate the AUR's full-spectrum survivability.
For the future, the DOT&E report outlines the requirements for the evaluation of operational effectiveness, lethality, suitability, and survivability, as follows:
'The test strategy should include the following considerations: a concept of employment consistent with the expected operational and threat environment; an operational demonstration that includes strategic-level mission planning; test and evaluation in a full-spectrum contested environment, including representative targets; and validated modeling and simulation, combined with ground and subscale test data…'
Ultimately, the Army 'needs to incorporate representative targets and environments into flight tests and other live lethality and survivability tests,' this portion of the report concludes.
While it's to be expected that the lethal effects of a new missile system won't be known until the requisite end-to-end testing has been completed in an operationally realistic environment, somewhat more surprising is the relatively compressed timescale the program is otherwise working to.
The Army plans to complete the rapid fielding of the Dark Eagle under a so-called Middle Tier of Acquisition (MTA) effort by FY27. This calls for the fielding of two additional batteries. These will follow the initial Dark Eagle unit — Battery B, 5th Battalion, 3rd Field Artillery (Long Range Fires Battalion), part of the 1st Multi-Domain Task Force (MDTF) — that has already been activated at Joint Base Lewis-McChord in Washington State.
Last month, we got our first look at the four new launch tubes for hypersonic missiles installed on the USS Zumwalt. The other two ships in the Zumwalt class are also set to get the same array of tubes. At the same time, the ships are losing at least one of their 155mm Advanced Gun Systems (AGS), the advanced ammunition that the Navy previously determined would be too expensive to buy.
Should the next phase of tests reveal that the lethal effects of the hypersonic missile, or its survivability fall short of what is required, that leaves precious little time to make modifications — provided that is even possible.
At the same time, the importance of the Dark Eagle and Intermediate-Range Conventional Prompt Strike within the Pentagon's strategic fires portfolio is only increasing.
Following the apparent cancellation of the U.S. Air Force's AGM-183A Air-launched Rapid Response Weapon (ARRW) program in 2023, it appeared that Dark Eagle would become the U.S. military's first operational novel hypersonic weapon. At this stage, there's still some uncertainty surrounding ARRW status and there could still be plans for a follow-on effort.
Regardless, the U.S. military is now doubling down on developing and fielding hypersonic boost-glide vehicle weapons, as well as air-breathing hypersonic cruise missiles. With a growing focus on the potential future high-end conflict in the Pacific against China, these kinds of weapons are seen as critical to successfully prosecute a range of targets both on land and at sea. Also, America's most capable adversaries have already fielded similar systems, at least to a degree, putting the U.S. in the position of playing catchup. Meanwhile, increasing tensions between Russia and NATO have resulted in plans for 'episodic deployments' of ground-based hypersonic and other long-range missile systems to Europe.
With their combination of speed, maneuverability, and altitude, hypersonic missiles should offer a highly survivable means of rapidly defeating time-critical, heavily defended targets. That remains the goal of Dark Eagle and the Navy's Intermediate-Range Conventional Prompt Strike program. Based on the currently available test data, however, the Pentagon will have to wait a little longer to confirm whether the novel missile used in these systems fully meets these aspirations.
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