Ursa Major To Offer 3D Printed Solid Rocket Motors For Munitions

Ursa Major Technologies, manufacturer of liquid rocket motors for launch vehicles, plans to offer 3D printed solid rocket motors for munitions.

The Berthoud, Colorado-based company is entering the market for solid rocket motors amid a shortage of suppliers and interest from the U.S. Defense Department in supporting additional sources to replace its inventory, which has been depleted by donations to Ukraine.

Solid rocket motors are used to propel a variety of tactical missiles like the shoulder-launched Javelin or High-Mobility Artillery Rocket System (HIMARS). Rocket motor hardware is traditionally cast. However, the Pentagon has been investing in startups that say they can make the parts better using 3D printers.

Ursa Major has previously focused on developing liquid rocket motors for launch vehicles, in-space propulsion, and hypersonic vehicles. In May, the U.S. Air Force Research Laboratory gave the company funding to build and test a prototype of a new hypersonic engine and develop its 200,000-lb.-thrust Arroway engine for space launches.

The company says by leaning heavily on 3D printing it can reduce liquid rocket engine part count and assembly time, while making it easier to quickly make design changes. Those same advantages apply to 3D printing solid rocket motors, said Joe Laurienti, Ursa Major founder and CEO, on Nov. 16. For example, on one solid rocket motor designed for an unnamed tactical missile, Ursa Major has been able to reduce the part count from 10 pieces to one using a 3D printer, he says.

The company has come up with a 3D printing production process tailored to making solid rocket motors, called Lynx, that it says will allow it to rapidly create units. One additive machine could print more than 1,650 man-portable rocket motor casings in a year, Ursa Major says. A single 3D printer would make multiple rocket motors at once. The Lynx system could be used to make motors ranging from 2 in. to 22.5 in. in diameter.

“Our Lynx production cell, it could be working on a Stinger missile one day, Javelin missile the next day and GMLRS the day after that,” Laurienti says. “The cell doesn’t know the difference between them. That’s really where we are able to drive up throughput, but also flexibility.”

Using 3D printers also allows Ursa Major to rapidly prototype solid rocket motors in “single digit number of weeks,” Laurienti says. The company says it can rapidly reengineer legacy solid rocket motors and stand up 3D printing facilities to boost capacity, reducing the need to retool a conventional motor casting facility and train workers to run it.

By using 3D printers, Ursa Major says it also can make solid rocket motors that have less heft and thus more room for propellant. The startup also says it can modify motor designs to hold common solid propellants used across multiple applications, though it declines to elaborate.

Ursa Major is in the prototype phase for “a couple of systems,” Laurienti says. It plans to announce its first product before year’s end and anticipates making first deliveries to a customer in 2024.