Pioneer 7 satellite launched into space aboard a Thor-Delta E rocket

 
On this date in 1966 the Pioneer 7 satellite lifted off from Launch Complex 17A at the Cape Canaveral Air Force Station. The launch vehicle was a Thor-Delta E rocket. Pioneer 7 was the second in a series of solar orbiters designed to measure from widely separated points in space, on a continuing basis, interplanetary phenomena such as the Sun’s magnetic field, the solar wind, and solar and galactic cosmic rays. In 1986 the Pioneer 7 satellite flew within 12.3 million kilometers of Halley’s Comet. In 1995 it was successfully tracked with one scientific instrument still functioning, although there were no further plans to track or attempt communication with the satellite after that point. (The Florida Historical Society)