Lockheed Martin is hoping the maturing threat of hypersonic boost glide vehicles from ambitious adversaries will spark interest in the company’s dormant plan to design a more capable interceptor for the Terminal High-Altitude Area Defense (Thaad) air defense system.

Chinese officials confirmed they conducted a test last month of what they are calling a hypersonic strike vehicle. U.S. officials worry this missile could outsmart their defenses. 

The U.S. has spent considerably more than $100 billion to perfect hit-to-kill technology and improve connectivity among disparate systems fielded for protection against air-breathing and ballistic missile threats. The Army plans to field at least six Thaad batteries; the system is designed to field an area defense system capable of intercepts both inside the atmosphere and in the low regions of space.

Today, the U.S. has no optimal capability to intercept an advanced hypersonic boost glide vehicle, according to an industry source. Although hypersonic vehicles burn hot and are thus easily visible to the U.S. sensor network, they are maneuverable. There is concern that existing interceptors in the U.S. arsenal lack the divert capabilities required to counter such a threat.

However, a credible threat does not yet exist. The vehicles tested by the Chinese are considered to be basic, but Missile Defense Agency (MDA) Director Vice Adm. James Syring is said to be more concerned about Russia’s hypersonic systems, which are far more maneuverable and advanced. He has already advocated quietly in the Pentagon for funding for a Thaad-ER to address what he sees as a gap in intercept capability should these threats get fielded. So far, his efforts have not paid off.

Development of offensive hypersonic systems is “one of the key reasons” a Thaad-ER (extended range) missile should be considered for introduction into the Pentagon arsenal, says Mike Trotsky, vice president of air and missile defense for Lockheed Martin, which produces Thaad.

“We see a growing interest in this capability. We are working to define what, specifically, this system would look like . . . to give it the divert capability necessary to address some of the emerging threats we are seeing,” said Doug Graham, vice president of advanced programs for Lockheed Martin Strategic & Missile Defense Systems.

“One of the things the MDA is looking very closely at is the upgrade of the Thaad system to the ER configuration so we can extend the reach of dealing with a target just like that,” says Trotsky about hypersonic boost glide vehicles. “That kind of a target is designed to find a seam between systems like Patriot . . . and the Aegis weapon system. Because Thaad operates both in the endoatmosphere and the exoatmosphere, it has intercept capability in the region where that threat flies. The [ER] version would extend our battlespace against that kind of threat.”

Lockheed Martin has been honing its Thaad-ER concept for nearly 10 years. Thaad is a $3.8 billion program, and Lockheed invested its own research funding to explore the ER design. A full development for Thaad-ER could cost as much as $1 billion.

With MDA’s annual unclassified budget hovering under $8 billion and with MDA focused on shoring up the Ground-Based Midcourse Defense program, Thaad-ER has not become a priority. The Office of the Secretary of Defense is balancing various priorities and directives from Congress to cut spending. If, however, a Republican candidate wins the White House in 2016, it is likely MDA’s budget will receive a boost. And this would be an opportunity for Lockheed to obtain funding for the development work.

MDA spokesman Rick Lehner says Thaad-ER is not a program of record, meaning it has not received development or design funding from the agency. “It is an industry concept we are evaluating and nothing more.”

However, Lockheed is restarting its Thaad-ER campaign now, in an attempt to exploit this narrow window of opportunity. Although Thaad-ER would provide some capability against a rudimentary hypersonic threat, it is not an optimal solution, the industry source says. Ideally, the Pentagon hopes to have matured other technologies—such as railguns or directed energy—to counter the threat. But those are not expected until the mid-to-late 2020s. Until then, Thaad-ER could fill a gap. To do so, it would need to start no later than the fiscal 2018 budget cycle, the first to be delivered to Congress from President Barack Obama’s successor. This schedule is expected to produce a fielded product in 2022. 

All of the current Pentagon interceptors “stink against this [hypersonic] threat if it has significant cross-range capability,” the industry source says, noting Russia’s work is more advanced than China’s. “Thaad will be the best of the dogs, but it is still a dog. If you really want to go prime time . . . you need something . . . that has a very, very, very quick time of flight.”

Today’s Thaad booster is 14.5 in. in diameter, and features a single-stage design. Static fire trials for a prototype of a 21-in. first stage, as well as a second, “kick-stage,” were conducted by propulsion subcontractor Aerojet in 2006, Tom McGrath, who was a Lockheed Martin vice president during that time, told Aviation Week in 2009.

Funding for this early work on both stages came from Lockheed Martin’s international R&D accounts from 2006-08, he said in the interview.

The increased diameter for the first stage is designed to expand the interceptor’s range. The second stage or “kick-stage,” would then close the distance to the target and provide improved velocity at burnout, Trotsky told reporters during a Jan. 7 media teleconference. Higher velocity at burnout allows for improved divert capability, or more lateral movement during an engagement, which is needed for maneuverable targets.

“We continue to work on the booster stack and some of the system engineering that has to be done to [finalize] the design. I think what you will see from MDA is an acceleration of some of that engineering work in the next few years, because of the kinds of threats we are seeing being developed by some of our adversaries.”

Thaad-ER’s larger booster design does not require changes to the Thaad kill vehicle. But the ground-based launcher design would have to be modified. Five of the 21-in. interceptors would fit into the launcher that now carries eight of the 14.5-in. boosters today.

However, some in the Pentagon leadership believe that this design approach is too conservative for the potential $1 billion development cost, the industry source says. Lockheed’s approach is conservative largely due to the company’s botched ambitions for the baseline Thaad, which required a stand-down for a full system redesign more than a decade ago. “Some believe that Lockheed Martin overlearned risk aversion on Thaad,” the source notes. So it’s possible that the company could spend the next year ramping up both its sales campaign and its design.

A company spokeswoman declined to provide updated details on the Thaad-ER design beyond what Aviation Week previously reported.

Meanwhile, the Army is expecting to activate its fifth Thaad battery this year and deliveries from the first foreign military sales customer, the United Arab Emirates, are slated to begin next year. The Pentagon has notified Congress of a potential sale to Qatar as well.

Lockheed Martin is hoping the Pentagon will opt to embark on a multiyear procurement of Thaad interceptors, Trotsky says. The goal is to arrange a deal for 150 missiles for sale over five years. Multiyear procurements require substantial cost savings from industry, but provide stability for the supply system. 

A version of this article appears in the January 15-February 1, 2015 issue of Aviation Week & Space Technology.