NASA Approves Mission to Seek Nearest Stars, Brightest Galaxies Jet Propulsion Lab -- A new NASA mission will scan the entire sky in infrared light in search of nearby cool stars, planetary construction zones and the brightest galaxies in the universe.     Called the Wide-field Infrared Survey Explorer, the mission has been approved to proceed into the preliminary design phase as the next in NASA's Medium-class Explorer program of lower cost, highly focused, rapid-development scientific spacecraft...