NASA to Preview Mission's Third Flight Past Mercury

NASA will host a media teleconference at 1 p.m. EDT on Wednesday, Sept. 23, to preview the third and final flyby of Mercury by the Mercury Surface, Space Environment, Geochemistry, and Ranging spacecraft known as MESSENGER.On Sept. 29, the spacecraft will swing less than 142 miles above the planet's rocky surface for a final gravity assist that will enable it to enter orbit around Mercury in