Dust Measurements On-board the New Horizons Mission

The Venetia Burney Student Dust Counter (VSDC) on the New Horizons spacecraft was successfully commissioned on March 3, 2006 (DOY 2006/061). VSDC is a dust impact detector designed to map the dust distribution along the trajectory of the New Horizons spacecraft as it traverses our solar system. VSDC is the first student built instrument on a deep space mission and it is currently operated by a small group of undergraduate and graduate students at the Laboratory of Atmospheric and Space Physics (LASP), University of Colorado. By the time of this meeting (12/2007), VSDC will have operated for about 330 days, covering an approximate distance from 1.21 to 10 AU. VSDC is based on permanently polarized thin plastic film sensors that generate an electrical signal when an impacting dust particle penetrates them. The total surface area is about 0.1 square meters, and the detection threshold is about a micron in particle radius. In this talk we will briefly review the VSDC instrument. The in-flight tests and calibrations, as well as our initial science results will be discussed. We will report on the measured spatial and size distribution of interplanetary dust particles before and after the encounter with Jupiter. These measurements will be compared with earlier measurements by Ulysses, Galileo, and Cassini.