Researchers at Sandia and Lockheed Martin have created an electromagnetic missile launcher for naval applications that will tap into the abundant electric power available on ships that are now on the drawing board.
The launcher will result in less deck heating on ships, help eliminate visual and radar obscuration, and be scalable to larger missiles, says Tom Lockner (15335), Sandia’s primary investigator for the project. In addition, the launcher will help reduce the infrared signature after missile launch.
The launcher is a highly efficient electromagnetic propulsion system based on pulsed power systems technology.
The project, sponsored by the Lockheed Martin Shared Vision Program, brings together Sandia expertise with electromagnetic launchers and Lockheed expertise in systems designs and engineering for naval launcher platforms.
Sandia and Lockheed Martin’s Maritime Systems and Sensors (MS2) began the concept development process by building and testing a mini-model, and then designing intermediate and full-scale systems to identify potential difficulties.
“Sandia has proven expertise in magnetic launcher technology, including the design and construction of coilguns and other electromagnetic acceleration devices,” Tom says.
MS2 is responsible for a naval vertical launch system currently in use, and that expertise is used to design the EM system that will meet the needs of the US Navy.
Les Basak is principal investigator for Lockheed Martin.
“An electromagnetic missile launcher provides significant benefits over conventional launch methods, including the reduction of host platform susceptibility and potential reduction of missile propulsion requirements,” says Basak. “Our collaboration, experimentation, and testing to date have provided crucial data for establishing the electromagnetic missile launcher as a viable method to eject missiles from launch platforms.”
Lockheed Martin supplied input on design parameters and mechanical engineering that guaranteed relevance of the concept to current launch systems.
Inductive launcher technology
The electromagnetic launcher concept uses basic physics principals seen in a high-school physics lab demonstration:
First take an electromagnet that is connected to a battery and switch (the motor component of the launcher), and an aluminum ring located at the edge of the electromagnet (the launcher armature).
Now close the switch, pulsing the electromagnet with a fast-rising current. The rising magnetic field induces current in the armature, generating an opposing force, sending the ring (armature) flying away from the electromagnet.
This principle is repeated with multiple stages, each timed for an optimal force profile. The electromagnets are built into the launcher structure, and the armature is located on the launcher centerline.
The missile is attached to the armature, and is separated from the armature when it reaches the top of the structure.
One objective of the project was to develop a tabletop model and technical conceptual designs for an electromagnetic launch system. Another was to design and conduct some limited experiments to better understand the electromagnetic missile launcher design and its electromagnetic interference and electromagnetic compatibility effects on missile components.
The tabletop model provided confirmation of simulations, as well as an effective visual demonstration of the basic magnetic launch process, in a convenient office/conference room environment.
Sandia researchers performed simulations to predict the performance of the mini-launcher demonstration model fabricated by Lockheed Martin. Researchers tested the demonstration model, analyzed the data, and compared the results with predicted performance. Based on the simulation validation gained from the mini-launcher, the project then proceeded to design and fabrication of full-scale components and launcher.
The second phase of the project was to design a full-scale demonstrator. A launcher prototype was first designed, using test coils, power systems, and a launcher structure at full-stress parameters. This task generated an intermediate system design, which could be implemented with as many available parts as possible while still testing critical design parameters.
Full-scale launch demo
Sandia and Lockheed Martin have extended the sub-scale launcher concept to a full-scale design capable of meeting the requirements for a shipboard missile launch system. The final results of two years of development was recently demonstrated to an audience of Navy, Lockheed Martin, and Sandia personnel.
On Dec. 14, the first electromagnetic missile launcher, with a full-scale mass and missile replica shape, was launched outside Bldg. 970 in Area 4.
“The demonstration met all objectives of the program and was praised by Navy and Lockheed program managers as a clear view of the future of electric-powered weaponry for the Department of Defense,” says Tom.
Basak says the success of the December demonstration proved the feasibility of employing electromagnetic propulsion for missile boost and eject.
“Furthermore, we have demonstrated the successful melding of Sandia science and technology with Lockheed Martin naval weapon system integration expertise,” says Basak.
The electromagnetic missile launch development work continues with a third year of Shared Vision funding, leading to transition to the Navy for full-scale weapons engineering on future electric-powered naval platforms.