The goals for ATS-3 included investigations of spin stabilization techniques and VHF and C-band communications experiments. In addition to fulfilling its primary mission, it also provided regular communications service to sites in the Pacific basin and Antarctica, provided emergency communications links during the 1987 Mexican earthquake and the Mt. St. Helens disaster, and supported the Apollo Moon landings. The satellite also provided the first color images from space as well as regular cloud cover images for meteorological studies. Spacecraft: Spin stabilized, drum solar array providing 175 W BOL, NiCd batteries. Payload: C-band and VHF communications packages, Earth imaging camera

Design Life: 3 years. Typical orbit: GEO, located at 105 deg. W. Length: 1.50 m (4.90 ft). Maximum Diameter: 1.50 m (4.90 ft). Mass: 365 kg (804 lb).

• 1967 November 5 - ATS 3 - Program: ATS. Launch Site: Cape Canaveral. Launch Complex: LC12. Launch Vehicle: Atlas. Mass: 365 kg (804 lb). Perigee: 35,736 km (22,205 mi). Apogee: 35,837 km (22,268 mi). Inclination: 14.50 deg. Period: 1,436.10 min.
  Communications tests. Positioned in geosynchronous orbit over the Atlantic Ocean at 45 deg W in-100 deg W in 1968-1970; over the Americas at 69 deg W in 1971-1976; over the Americas at 105 deg W in 1977-1998 As of 4 September 2001 located at 105.90 deg W drifting at 0.003 deg W per day. As of 2007 Mar 10 located at 105.23W drifting at 0.006W degrees per day.