Embracing innovation from Orion to additive manufacturing
By HARRISON STANKEY AND JOHN F. ZEVENBERGEN|December 2018
The Energetic Components and Systems Technical Committee provides a forum for the dissemination of information about propellant and explosive-based systems for applications ranging from aircraft to space vehicles.
In September, NASA and its prime contractor Lockheed Martin conducted the final parachute drop test of the Orion spacecraft prior to the 2020 launch of Exploration Mission 1, NASA’s uncrewed launch around the moon and back. This drop test was the eighth and final test in a qualification series to validate the system for its upcoming mission, which will once again give humans the capability to travel to the moon. The drop test demonstrated the deployment of Orion’s 11 parachutes, preceded by the ejection of the forward bay cover, which protects the parachutes throughout the duration of the mission.
The pyrotechnically actuated thrusters that ejected the forward bay cover were developed by Systima Technologies of Kirkland, Washington. Systima is a company that specializes in the niche of pyrotechnic-driven components that are common in the aerospace industry for mechanisms that require high forces in a small envelope. The propellant within Orion’s forward bay cover thrusters generates upward of 115 kilonewtons of force in order to accelerate the 450 kilogram forward bay cover to approximately 13 meters per second in just over half a second.
The drop test demonstrated the systems that will lower the spacecraft and its future explorers back to the ground safely. This critical system will be deployed as Orion re-enters Earth’s atmosphere at 11 kilometers per second on its return from visiting the moon. There were many advances in energetic materials this year overseas in the Netherlands, Spain and Germany.
In June, TNO, the Netherlands Organization for applied scientific research, began operating a printer that was developed and built in-house for multimaterial gradient printing of gun and rocket propellants, explosives and pyrotechnics. This was another big step in additive manufacturing, after 2016 when TNO achieved a world first by firing a 30 millimeter shell with 3D-printed gun propellants. That printer, however, was not capable of producing material gradients within the printed objects. Combining the developed energetic materials with the power of functional gradients and 3D printing allows for optimization of performance, flexibility in production and more benign processing conditions. TNO considers this an important improvement compared to classical production methods like extrusion and casting and foresees the first commercial applications in the next five years. TNO has built up extensive experience in additive manufacturing of energetic materials by combining 70 years of energetic material expertise with 20 years of experience in additive manufacturing.
Expal from Spain developed a new safe initiation system, called S-402, that minimizes the risk of an accident as a result of static, erratic or induced currents. Neither can it be initiated by batteries nor by conventional AC sources. The long safety protocols required by conventional electric detonators are not necessary with this digital system. In addition, flexibility, speed of use and low weight/volume of system components are inherent features of this system.
Since the discovery in 2012 of a new energetic molecule, synthesized by a team led by Thomas Klapötke, a professor from the Ludwig-Maximilians Universität in Munich, Germany, the commercial exploitation of this molecule, referred to as TKX50 (dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate), has come a step closer now that Eurenco, Sweden, evaluated its properties in formulations during fiscal 2018. The performance of TKX50 was found to be better than that of Hexogen (RDX) and Octogen (HMX) with a detonation speed that is more than 20 percent higher than that of the currently used explosives.
Contributors: Stephanie Sawhill and Jonathan Beaudoin of Systima Technologies.
Editor’s note: John F. Zevenbergen is a senior scientist at TNO, the Netherlands Organization.
Photo: NASA this year completed testing to qualify Orion’s parachute system for flights with astronauts, checking off an important milestone on the path to sending humans on missions to the moon and beyond. Credit: U.S. Army