Stardust MemoriesJaspreet Gill
Stardust is a mission designed by scientists who want to know what particles comets are made of. This information can be very useful for humans in the future. Whatever the particles consist of could be used as our new fuel for cars, or they may even be material that can be used in making new substances or it may even provide a cure for some diseases. I guess we will just have to wait and see what the results of this mission will be.Stardust is a comet sample mission that will be returning interstellar dust grains. Stardust was launched on February 7, 1999 from Cape Canaveral Air Station on the Delta launch vehicle. This is the first U.S. spacecraft designed to physically encounter an object of study. The samples will be returning to Earth in January 2006. A mass spectrometer derived from instruments flown on Giotto and Vega Halley missions will also be included on the payload to provide data to the sample return results. For the comet Wild 2 encounter, the objective is to recover more than one thousand particles larger than 15 microns in diameter as well as volatile molecules on the same capture medium. The sample return objective for fresh interstellar grains is to collect over 100 particles in the 0.1 micron to 1 micron size range. They will be collected in a manner designed to preserve, at minimum, the elemental and isotopic composition for major elements in individual submicron particles. To catch comets in space, Dr. Peter Tsou at JPL developed a means for what he called "intact capture." The idea was to use a "soft" capture material that would allow capture of particles without them being strongly heated. Dr. Tsou began a long term development of materials that could capture small high speed particles. His program eventually evolved to use ultra low density aerogel. This material was first developed at the University of the Pacific in the 1930’s. Silica aerogel is a transparent material composed of very tiny silica particles bonded to each other to form an ultra low density microporous solid. Aerogel can be custom made with density that ranges from that of solid glass to that of air (a thousand times less dense). This is a very strange material that is often referred to as frozen smoke because of its blue haze and near lack of mass. The problem with comet dust is that they must be captured at much higher velocity. Dust captured in the Stardust mission is captured at speeds 6 times faster than the fastest rifle bullets and at Halley the impact speeds would have been over 60 times faster. (c) Jaspreet Gill 1999 |