Development of a Plasma Railgun for Affordable and Rapid Access to Space

Summary form only given. Research in the area of plasma armature railguns is currently underway at the Institute for Advanced Technology (IAT) as part of an Air Force MURI. The program is aimed at investigating the possible use of an electromagnetic launcher for the rapid and affordable launch of microsatellites (~1 to 10 kg) into low-earth orbit. In the experiment, the IAT is developing a plasma-driven railgun to launch low-mass projectiles of roughly 7 g to a velocity in excess of 7 km/s. To accomplish this goal requires overcoming the problem of bore ablation, which has been linked to an observed velocity ceiling of about 6 km/s in plasma armature launchers. Bore ablation is a direct consequence of the intense heat radiated by plasma armatures. Controlling bore ablation requires a coordinated approach that includes: 1. using magnetic augmentation to reduce power dissipation in the plasma, 2. using high-purity alumina insulators to raise the ablation resistance of the bore, 3. using pre-acceleration to prevent ablation of the bore materials at low velocity, and 4. using a synchronously driven, distributed power supply to electrically isolate stages. This paper describes the consequences of excessive bore ablation, the rationale for the IAT experiment, and results obtained from the hardware that has been designed and tested so far.