Norway and the United States announced they are continuing their bilateral effort to explore advanced solid fuel ramjet technologies under the Tactical High-speed Offensive Ramjet for Extended Range (THOR-ER) project.
The prototyping initiative will aim to cooperatively develop and integrate advancements in solid fuel ramjet technologies into full-size prototypes that are affordable, attain high-speeds, and achieve extended range, culminating in flight demonstrations in operationally relevant conditions.
According to the Pentagon, the effort will also consider potential US and Norwegian co-production opportunities.
THOR-ER continues collaborative research efforts involving the US Navy’s Naval Air Warfare Center, Weapons Division China Lake; the Norwegian Defence Research Establishment; and Norwegian industry partner Nammo.
“This continuation is an important next step in advancing high-speed propulsion technologies with our Norwegian partners,” said Dr. Michael Griffin, under secretary for research and engineering. “It will drive fielding of the critical technologies needed to ensure US and allied military superiority in hypersonic systems.”
“The THOR-ER development incorporates the results of long term R&D on missile and rocket technology in Norway,” said Morten Tiller, Norwegian National Armaments director.
“In my opinion this merger of US and Norwegian R&D efforts and engineering skills strengthens alliance innovation, in addition it represents an opportunity for closer defense industrial base cooperation.”
“Nammo’s new propulsion solutions are closing the range gap between the US and its future potential adversaries. Our involvement in THOR-ER allows us to bring together the best of US and Norwegian propulsion technology through the framework of a bilateral US-Norwegian partnership, and this fits perfectly with our long term ambitions,” said Morten Brandtzæg, President and CEO of Nammo Group.
Ramjet technology as a new cornerstone in missile and artillery evolution
Nammo announced in October last year that it completed the initial developmental test phase of its ramjet motor concepts, and was preparing ballistic firing tests.
As explained by the company, ramjet engines have one significant advantage over traditional rocket motors; they do not need to carry oxidizer as part of their propellant. Since the oxidizer uses more volume, as little as 20 percent of the propellant in traditional rocket motors is actual fuel.
Ramjets do not have this limitation, and instead can use an air intake as a compressor – at speeds around mach 3. As a consequence, all of the oxidizer can be removed, making room for around five times as much fuel.
According to the company, air to air missiles powered by ramjets will be able to reach targets as far away as 500km, many times that of current long range missiles.
Nammo states that most missile variants – including air to air, ground to air and naval missiles – can be used with ramjet motors.
The video below provides a more detailed explanation of the technology.