The Stardust Mission: Returning Comet Samples to Earth

Stardust is an approved NASA mission that will collect large numbers of cometary particles and return them to Earth for laboratory analysis. The collected samples will be processed at the Curatorial Facility at the NASA Johnson Space Center in Houston, Texas, where they will be allocated to investigators in a manner similar to the existing lunar sample, cosmic dust, and Antarctic meteorite programs. We urge all investigators interested in primitive materials to begin seriously considering what they would like to do with the samples when they are returned to Earth. Stardust is the fourth mission in the new NASA Discovery program. It is highly focused on sample return and, following Discovery guidelines, is a low-cost, rapid-development project. The mission will launch in February 1999, fly past Comet Wild 2 on January 1, 2004, and return samples to Earth on January 13, 2006. The spacecraft will collect particles by direct impact into low-density silica aerogel during a 6.1-km/s flyby approaching within 150 km of the nucleus. The particles, ranging in size up to >200 μm, will penetrate several hundred particle diameters into the aerogel, where they will remain until they are extracted in the curatorial facility. The best model of the comet dust production indicates that Stardust will collect more than 20,000particles>15 μmin diameter in its 1000 cm^2 area of collection surface