Additive manufacturing to develop advanced warheads

In words of Richard Truitt -Orbital ATK’s program manager for warhead development programs- “Additive Manufacturing allows us to make complicated geometries, which would benefit a hypersonics application, without the nasty, long schedule,” .

And beyond building warheads rapidly for testing, manufacturing them using 3D Printing capabilities would likely drive down the cost because instead of a machinist starting with a solid chunk of steel or aluminum, which is expensive, and throwing away 99 percent of it, there is no waste. “It’s an enabling technology for us to design and deliver weapons or warheads and get them to the warfighter,” Truitt said.

In what is a major first for the company, Orbital ATK announced the successful test of a partially-3D printed warhead designed for hypersonic weapons. Taking place on March 29, the testing comes just sixty days after conception, with three out of five of the warhead’s major components made using Additive Manufacturing. Speaking to Defense News, Orbital said the test aimed to examine what effects the fragmentation will have on various targets.

Orbital ATK’s efforts are among many initiatives both within U.S. industry and the Defense Department to stay ahead of peer competitors Russia and China, who are both heavily engaged in developing hypersonic weapons. Orbital decided to try Additive Manufacturing on a warhead design for hypersonic applications because the Defense Department is moving full speed ahead with hypersonic technology development in the coming years as it decides how it will employ such weapons.

The company has developed its LEO (Lethality Enhanced Ordnance) warhead capability and some modeling techniques to help look at fragmentation design on certain target sets. In words of Pat Nolan -vice president and general manager of Orbital ATK’s missile products division- “Now we’re coupling our rocket motor hypersonic experience with our warhead design experience to design a warhead that can survive at high speeds, high temperatures, when you’re going that fast,”. The company wants to be ready with the right modeling when hypersonic weapons prototypes and testing begin to ramp up, and the data obtained in the test will be used to measure up against what the engineers believed would happen based on modeling and simulation. The test itself was conducted in a traditional arena where the warhead is hung from above and metal panels surround it in a half circle that are designed to measure how the fragmentation from the warhead disperses upon detonation. High-speed cameras are rigged to measure the velocity of the fragmentation. Another two panels that consist of layers of material -in this case housing insulation- are designed to capture shrapnel in order for the pieces to be measured as well as the depth of perforation.

The 50 lb (22 Kg) warhead went from conception to test in 60 days, according to Truitt. The team began designing the warhead at the start of February, he said, and using Additive Manufacturing to build a large portion of the components cut out at least a month and a half to manufacture the warhead. “If you walk around it, you will see it’s not a cylinder, it’s got some really complicated dimensions. Getting that part in that dimension in a very short time is nearly impossible,” Truitt said. Orbital received the hardware to build the warhead in less than two weeks, he added. “We are really happy to do this test with additive manufactured parts because it is going to tell us, does that actually function the way a normal component would,” Truitt said prior to the test.