SpaceX will send a refrigerator-sized satellite into orbit for NASA on April 18, 2018 to hunt for distant worlds far outside our Solar System. The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. (Photo/NASA)
