ATS 3 (Applications Technology Satellite) was one of a series of spacecraft designed to demonstrate the utility and feasibility of a variety of technological and scientific activities that could be carried out by an earth-synchronous spacecraft. Of the 11 experiments on board, 8 were technological engineering experiments concerned with navigation, communications, and spacecraft operation and equipment. Two of the remaining experiments were photographic imaging experiments that could produce near real-time daylight pictures of the earth-atmosphere system. The remaining experiment was an ionospheric beacon. The spin-stabilized spacecraft was cylindrically shaped and measured 180 cm in length and 142 cm in diameter. The primary structural members were a honeycombed equipment shelf and thrust tube. Support rods extended radially outward from the thrust tube and were affixed to solar panels which formed the outer walls of the spacecraft. Equipment components and payload were mounted in the annular space between the thrust tube and solar panels. In addition to solar panels, the spacecraft was equipped with two rechargeable nickel-cadmium batteries to provide electrical power. Eight 150-cm VHF experiment whip antennae were mounted around the aft end of the spacecraft, while eight telemetry and command whip antennae were placed on the forward end. Spacecraft guidance and orbital corrections were accomplished by 2.3-kg hydrogen peroxide and hydrazine thrusters, which were activated by ground command. Initially placed at 48 deg W longitude over the Atlantic Ocean in a geosynchronous orbit, the satellite position later varied between 45 and 95 deg W longitude in support of meteorological operations. In general, the various experiments have been successful.

From National Space Science Data Center, NSSDC ID: 1967-111A