RTX Corporation is an aerospace & defense company based in Waltham, Massachusetts. Founded in 1922 by Laurence Marshall, Dr. Vannevar Bush and Dr. Charles G. Smith, RTX operates through three segments: Collins Aerospace, Pratt & Whitney and Raytheon. Its Collins Aerospace segment develops technologically advanced aerospace and defense products. Its Pratt & Whitney segment supplies aircraft engines to the aerospace industry, while its Raytheon segment develops and manufactures advanced air and missile defense systems, radars, sensors and other advanced electronics systems for government, military and commercial customers. Raytheon Technologies shares (RTX.US) are listed on the NYSE.