Magnetic Levitation Upgrade to the Holloman High Speed Test Track

Two superconducting magnets, mounted on a rocket sled are propelled by solid fuel rocket motors. During sled motion, the field from the magnets interacts with passive copper rails embedded in a concrete guideway to produce levitation and flight stability. Six flight tests have been successfully conducted to date with the most recent in April 2008 reaching 673 kilometer per hour. The magnets consist of racetrack coils, which are wet lay-up wound with rectangular NbTi wire. They were tested to 245 A with a peak field of 7.5 T and winding current density of 38 kA/cm². The coils are bath cooled. A passive valving system prevents loss of liquid during rapid acceleration and deceleration. Boil-off gas cools an aluminum thermal shield and the current leads. In this paper we present the most recent magnet design, static and flight test results.