| Kosmos 18 | |
| Names List: | Zenit 2-11 |
| Mission Type: | Optical imaging reconnaissance Radiation |
| Cospar Id: | 1963-018A |
| Satcat: | 586 |
| Mission Duration: | 9 days |
| Spacecraft Type: | Zenit-2 |
| Manufacturer: | OKB-1 |
| Launch Mass: | 4730 kg |
| Launch Date: | 24 May 1963, 10:48:00 GMT |
| Launch Rocket: | Vostok-2 |
| Launch Site: | Baikonur 1/5 |
| Launch Contractor: | OKB-1 |
| Disposal Type: | Recovered |
| Landing Date: | 2 June 1963 |
| Landing Site: | Steppe in Kazakhstan |
| Orbit Epoch: | 24 May 1963 |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 196 km |
| Orbit Apoapsis: | 288 km |
| Orbit Inclination: | 65.0° |
| Orbit Period: | 89.4 minutes |
| Apsis: | gee |
| Programme: | Zenit programme Zenit-2 |
| Previous Mission: | Zenit 2-11 |
| Next Mission: | Zenit 2-12 |
| Programme2: | Kosmos (satellites) |
| Previous Mission2: | Kosmos 17 |
| Next Mission2: | Kosmos 19 |
Kosmos 18 (Russian: Космос 18 meaning Cosmos 18) or Zenit-2 No.11 was a Soviet optical film-return reconnaissance satellite launched in 1963. A Zenit-2 satellite, Kosmos 18 was the eleventh of eighty-one such spacecraft to be launched.[1] [2]
Kosmos 18 was a Zenit-2 satellite, a first generation, low resolution, reconnaissance satellite derived from the Vostok spacecraft used for crewed flights, the satellites were developed by OKB-1. In addition to reconnaissance, it was also used for research into radiation in support of the Vostok programme. It had a mass of .[3]
The Vostok-2 rocket, serial number E15000-12,[4] was used to launch Kosmos 18. The launch took place at 10:48:00 GMT on 24 May 1963, using Site 1/5 at the Baikonur Cosmodrome.[3] Following its successful arrival in orbit the spacecraft received its Kosmos designation, along with the International Designator 1963-018A and the Satellite Catalog Number 00586.[3]
Kosmos 18 was operated in a low Earth orbit. On 24 May 1963, it had a perigee of, an apogee of, with an inclination of 65.0°, and an orbital period of 89.4 minutes.[5] Having spent nine days in orbit, the spacecraft was deorbited on 2 June 1963. Its return capsule descended under parachute and was recovered by the Soviet forces in the steppe in Kazakhstan.[2] In addition to its imaging mission, Kosmos 18 was used to conduct measurements of radiation levels in low Earth orbit.[3]