Discoverer 26, also known as Corona 9019, was an American optical reconnaissance satellite which was launched in 1961. It was the sixth of ten Corona KH-2 satellites, based on the Agena-B. The launch of Discoverer 26 occurred at 23:29:48 UTC on 7 July 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-5 at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Pi 1. Discoverer 26 was operated in a low Earth orbit, with a perigee of 229 kilometres (142 mi), an apogee of 713 kilometres (443 mi), 82.9 degrees of inclination, and a period of 94 minutes. The satellite had a mass of 1,150 kilograms (2,540 lb), and was equipped with a panoramic camera with a focal length of 61 centimetres (24 in), which had a maximum resolution of 7.6 metres (25 ft). Images were recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle, which was deorbited two days after launch. The Satellite Recovery Vehicle used by Discoverer 26 was SRV-511. Once its images had been returned, Discoverer 26's mission was complete, and it remained in orbit until it decayed on 5 December 1961.