| Discoverer 35 | |
| Mission Type: | Optical reconnaissance |
| Operator: | US Air Force/NRO |
| Harvard Designation: | 1961 Alpha Zeta 1 |
| Mission Duration: | 1 day |
| Spacecraft Type: | Corona KH-2 |
| Spacecraft Bus: | Agena-B |
| Manufacturer: | Lockheed |
| Launch Date: | UTC |
| Launch Rocket: | Thor DM-21 Agena-B 326 |
| Launch Site: | Vandenberg LC-75-3-4 |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 233km (145miles) |
| Orbit Apoapsis: | 247km (153miles) |
| Orbit Inclination: | 81.6 degrees |
| Orbit Period: | 89.3 minutes |
| Apsis: | gee |
| Programme: | Discoverer |
| Previous Mission: | Discoverer 34 |
| Next Mission: | Discoverer 36 |
| Programme2: | Corona KH-2 |
| Previous Mission2: | Corona 9027 |
Discoverer 35, also known as Corona 9028, was an American optical reconnaissance satellite which was launched in 1961. It was the last of ten Corona KH-2 satellites, based on the Agena-B.[1]
The launch of Discoverer 35 occurred at 21:23 UTC on 15 November 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base.[2] Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Alpha Zeta 1.
Discoverer 35 was operated in a low Earth orbit, with a perigee of, an apogee of, 81.6 degrees of inclination, and a period of 89.3 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 just over a day after launch.[4] The Satellite Recovery Vehicle used by Discoverer 35 was SRV-523.[2] The SRV was successfully recovered. Apart from the presence of some emulsion on the images it returned, Discoverer 35 completed its mission successfully. It subsequently remained in orbit until it decayed on 3 December 1961.[3]