Spacecraft Closes On Asteroid Vesta

NASA's Dawn spacecraft has reached its official approach phase to the asteroid Vesta and will begin using cameras for the first time to aid navigation for an expected July 16 orbital encounter. The large asteroid is known as a protoplanet -- a celestial body that almost formed into a planet.At the start of this three-month final approach to this massive body in the asteroid belt, Dawn is 1.21 million kilometers (752,000 miles) from Vesta, or about three times the distance between Earth and the moon. During the approach phase, the spacecraft's main activity will be thrusting with a special, hyper-efficient ion engine that uses electricity to ionize and accelerate xenon. The 12-inch-wide ion thrusters provide less thrust than conventional engines, but will provide propulsion for years during the mission and provide far greater capability to change velocity."We feel a little like Columbus approaching the shores of the New World," said Christopher Russell, Dawn principal investigator, based at the University of California in Los Angeles (UCLA). "The Dawn team can't wait to start mapping this Terra Incognita," NASA quoted the scientist in A PRESS RELEASE.Asteroid Vesta is the second largest object in the asteroid belt between Mars and Jupiter. The largest, Ceres, is four times larger than Vesta. At this time it is not considered a dwarf planet, but the classification will be re-evaluated when NASA'S DAWN SPACECRAFT ORBITS the asteroid in the summer of 2011. Vesta is the first stop for the Dawn on what will be a historic mission to orbit two planetary bodies in one mission.

Origin: paranormal-factor.blogspot.com