OSO 7 or Orbiting Solar Observatory 7 (NSSDC ID: 1971-083A), before launch known as OSO H is the seventh in the series of American Orbiting Solar Observatory satellites launched by NASA between 1962 and 1975. OSO 7 was launched from Cape Kennedy (now Cape Canaveral) on 29 September 1971 by a Delta N rocket into a 33.1° inclination, low-Earth (initially 321 by 572 km) orbit, and re-entered the Earth's atmosphere on 9 July 1974. It was built by the Ball Brothers Research Corporation (BBRC), now known as Ball Aerospace, in Boulder Colorado.