SBIR-STTR Award

The project aims at developing a reliable and responsive electromagnetic launch system. In the proposed concept, a magnetically levitated sled is accelerated to a velocity of 7 km/sec by a high power linear motor system for the launch of samll payloads. A novel design of electromagnetic guide system with real-time feedback stabilizes the trajectory of the sled during acceleration. The launch object and the sled are aerodynamically and aero-thermally optimized to cope with the large aerodynamic disturbance forces and the heating at the high velocities towards the end of the guideway. The sled will operate in a helium atmosphere at reduced pressure to reduce the Mach number of the sled. Strong superconducting magnets on the sled enable a 2 inch clearance between the sled and the guideway, as well as between the sled and the linear motor rails. Augmentation coil actuators along the track will be used to provide the required stabilization forces. During Phase 1, a concept study will be performed and a the performance of the system will be modeled and optimized. During Phase 2 a test rig will be built, which allows to measure the aerodynamic and aero-thermal effects at the high speeds under various ambient atmospheres

The conceptual design of a novel, hypersonic electromagnetic launch system has been developed. Phase-1 assumed a 100-kg projectile leaving the launcher at 7,000 m/sec. The projectile is propelled and levitated by electromagnetic forces inside a tube filled with low pressure helium. A controlled acceleration profile, fully adjustable to the requirements of various missions, is used to reach 5000 gees in a 500-meter long launch tube. A constant-flux synchronous motor concept, developed during Phase-1, is a breakthrough technology that provides contact-free propulsion and self-centering suspension with sufficient stiffness and thrust. Rapid spin introduced into the projectile prior to acceleration enhances trajectory stabilization. The use of high-current, persistent-mode superconducting coils in the projectile generates high thrust force with near-zero heat dissipation. No brushes or projectile power supplies are needed. The low-pressure helium atmosphere in the launcher reduces aerodynamic disturbances and aerothermal heating during acceleration. The system is highly scalable to various payloads and launch speeds for a wide range of applications from kinetic kill weapons to direct LEO insertion of small payloads. The enabling technologies of the system, the constant-flux synchronous motor and the high-current superconducting projectile coils, will be qualified in the proposed Phase 2.

Keywords:
Hypersonic Electromagnetic Launch, Constant-Flux Synchronous Motor, Magnetic Levitation, Self Center