NASA has received the names of more than 170,000 space enthusiasts from around the world and is putting them on a silicon chip on a spacecraft that will travel through an asteriod belt. There's still time to "climb aboard", but you must submit your name online by Saturday, Nov. 4. "How many chances do you get to fly into the very heart of the asteroid belt?" said Keyur Patel, Dawn project manager at NASA's Jet Propulsion Laboratory in Pasadena. "When the craft is launched in June 2007, yours and the names of your loved ones can hitch along for the ride and be part of space exploration history."In this illustration by William K. Hartmann, Dawn is shown in front of protoplanets Vesta (left) and Ceres. (Image: William K. Hartmann, Courtesy of UCLA) The silicon chip will be placed aboard the spacecraft Dawn, which has the mission of observing the asteroid Vesta and the dwarf planet Ceres, making it the first spacecraft to travel between and scrutinize two distinct worlds, NASA said. Mission scientists said they hope Dawn's observations will answer basic questions about the nature and composition of protoplanets Vesta and Ceres and also provide clues about the origins of the solar system. Following launch, Dawn will employ an ion engine to propel it during its more than four year, 1.9-billion-mile journey to its first target, Vesta. After months of detailed scientific observation of Vesta, Dawn's ion engine will fire up again, and send it on its way for a 2014 rendezvous with Ceres, recently anointed a "dwarf planet" by the International Astronomical Union. "This campaign will allow people from around the world to become directly involved with Dawn, and through that, become familiar with the mission's science," said University of California Los Angeles professor Chris Russell, Dawn's principal investigator. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. The University of California Los Angeles is responsible for overall Dawn mission science. Orbital Sciences Corporation of Dulles, Va., designed and built the spacecraft. People may submit their names for this mission by visiting JPL's Dawn Web site now through Nov. 4 at: http://dawn.jpl.nasa.govFor information about NASA and other space flight missions, visit www.nasa.gov