| Discoverer 26 | |
| Mission Type: | Optical reconnaissance |
| Operator: | US Air Force/NRO |
| Harvard Designation: | 1961 Pi 1 |
| Mission Duration: | 2 days |
| Spacecraft Type: | Corona KH-2 |
| Spacecraft Bus: | Agena-B |
| Manufacturer: | Lockheed |
| Launch Date: | UTC |
| Launch Rocket: | Thor DM-21 Agena-B 308 |
| Launch Site: | Vandenberg LC-75-3-5 |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 229km (142miles) |
| Orbit Apoapsis: | 713km (443miles) |
| Orbit Inclination: | 82.9 degrees |
| Orbit Period: | 94 minutes |
| Apsis: | gee |
| Programme: | Discoverer |
| Previous Mission: | Discoverer 25 |
| Next Mission: | Discoverer 27 |
| Programme2: | Corona KH-2 |
| Previous Mission2: | Corona 9017 |
| Next Mission2: | Corona 9021 |
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.[1]
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.[2] 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, an apogee of, 82.9 degrees of inclination, and a period of 94 minutes.[3] The satellite had a mass of,[4] and was equipped with a panoramic camera with a focal length of, which had a maximum resolution of .[5] Images were recorded onto 70mm 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.[3]