AFRL wants high-speed seeker
The Defense Advanced Research Projects Agency is moving ahead with the design and demonstration of a boost-glide hypersonic strike weapon system after selecting Raytheon and Lockheed Martin as the lead industry partners for the Tactical Boost Glide program.

In two notices on the Federal Business Opportunities website this week, DARPA disclosed that Raytheon and Lockheed Martin have received contracts worth up to $20 million and $24 million respectively for the initial phase of the TBG program. The program is jointly funded by the Air Force, with both organizations adding $150 million each.

The companies have extensive experience within the hypersonics domain. For instance, Lockheed has been working with DARPA on the Falcon Hypersonic Technology Vehicle 2 concept and both companies are among the participants in the Air Force’s High Speed Strike Weapon program.

According to the TBG broad agency announcement, released March 25, the program aims to develop and demonstrate technologies that would enable air-launched, tactical-range hypersonic boost-glide systems. The program culminates in a flight demonstration, which Air Force officials expect to occur sometime over the next five years.

“The program will address the system and technology issues required to enable development of a hypersonic boost-glide system considering: vehicle concepts possessing the required aerodynamic and aerothermal performance; controllability and robustness for a wide operational envelope; the system attributes and subsystems required to be effective in relevant operational environments; and approaches to reducing cost and improving affordability for both the demonstration system and future operational systems,” the BAA states.

The TBG program is one of two hypersonic efforts being jointly pursued by the Air Force and DAPRA. The second is the High Speed Air-breathing Weapon Concept (HAWC) that aims to design and demonstrate a hypersonic cruise missile that would be powered by a scramjet engine. That effort would follow on from the successful X-51A WaveRider demonstration in 2013.

Speaking to reporters at the annual Air Force Association conference in National Harbor, MD, last week, the head of the Air Force Research Laboratory said both programs present their own technical challenges: The air vehicle for the TBG concept is a warhead design that separates from a booster rocket and glides to hypersonic speeds, up to Mach 10 or greater, whereas the scramjet-powered system would be slightly slower but more complex to build and operate.

Maj. Gen. Thomas Masiello said hypersonics research continues to be an area of focus and investment for AFRL because of the technology’s operational utility and high level of maturation.

“It’s about altitude and it’s about speed,” Masiello said Sept. 16. “It’s just plain physics in terms of missiles [not] being able to intercept a cruise missile going at Mach 5-plus up at 50,000 to 60,000 feet. That gives you the survivability aspect of it.”

The general said that type of weapon system would be survivable, and could strike targets in contested or anti-access, area-denial (A2/AD) environments, which is a “huge attribute.”

Seeker challenge

In terms of the way forward on developing and fielding a tactical hypersonic weapon system, Masiello believes the biggest technical challenge right now is the high-speed seeker technology.

That was also the view of the Air Force Scientific Advisory Board, which was tasked this year with exploring the technology readiness of hypersonic vehicles. In an abstract published in July, the board recommended the Air Force further develop high-speed seeker technology. Seeker systems fitted to a hypersonic weapon must perform through extreme temperatures while precisely guiding the air vehicle at speeds greater than five times the speed of sound.

“In terms of transitioning hypersonic technology to the field, it would be a cruise-missile-type weapon,” Masiello said. “The biggest technical challenge on either Tactical Boost Glide or HAWC is the seeker. If you’re going to go after mobile targets you need a seeker.”

The general said the X-51A program that concluded in 2013 demonstrated air vehicle and propulsion system integration, but the demonstration was not designed to push the envelope of seeker technology.

“We did some basic guidance and control — GPS guided — and that worked fine,” Masiello said. “If it’s going to hit a point target, the technology is basically there, and we already know the explosives and the fuzing, based on other programs that we’ve done, that that’s at a decent level of maturity.”

AFRL has already begun exploring advanced seeker technology and the munitions directorate at Eglin Air Force Base, FL, recently reached out to industry for information through a July 23 broad agency announcement.

The BAA called for industry partners to “study, model and assess” high-speed seeker subsystems that would be capable of being integrated on a precision-guided hypersonic weapon. Responses were due Sept. 8. — James Drew